MĂDĂLINA POŞTARU, CORINA CHEPTEA,
GLADIOLA ANDRUSEAC, DAN CAŞCAVAL, ANCA-IRINA GALACTION
pages 9 - 21
Abstract
Methylbenzylamine is
a chiral amine used as an intermediate for pharmaceuticals,
especially for antidepressants and also as an emulsifying agent.
There are two general strategies to
obtain the target chiral amine: either direct asymmetric synthesis or
kinetic resolution of a racemic amine. Methylbenzylamine was successfully
obtained by asymmetric synthesis using pro-chiral ketones with
ω-transaminase (ω-TA) from Vibrio fluvialis,
recombinant
Escherichia coli, and recombinant
Pichia pastoris.
The resolution of α-MBA was
studied in a biphasic reaction system using (S)-specific
ω-transaminase
from B. thuringiensis JS64 strain,
in a two-liquid-phase system with ω-transaminase
from Bacillus thuringiensis, and
in a solvent-bridge reaction system. Keywords:
methylbenzylamine; direct asymmetric
synthesis;
kinetic resolution.
Removal of inorganic pollutants from
waste water by adsorption
CLAUDIA AVASILOAEI, MIHAELA VIZITIU
pages 23 - 38
Abstract
Adsorption is a process that can be applied in order to remove inorganic
pollutants from water, using an adsorbent which is relatively inexpensive
and does not require pre-treatment before use. This technique is superior to
other methods because it has a simple design, low price and a high capacity
of removal various types of pollutants. In this paper, some adsorbent
materials suitable for removing inorganic pollutants such as: Ni (II), Cu
(II), Cd (II), Zn (II), Pb(II), As (III), Cr (III), Cr (VI), Ag (I), Th
(IV), Ur (VI), Eu (III) are presented.
Keywords: inorganic pollutants; adsorptions; adsorbents.
Management possibilities of plants
used for phytoremediation of soils polluted with heavy metals
IULIA SIMONA BĂDESCU, OFELIA AXINTE,
LAURA BULGARIU
pages 39 - 50
Abstract
Spatial expansion
of socio-economic systems related to economic progress led to increasing
pressure on systems under natural and semi-natural conditions and to
depletion of available natural resource including soil. Because of the
impact on the environment and large areas occupied by them, the contaminated
sites must be restored. The use of conventional techniques for
decontamination of soils polluted with heavy metals is expensive and can
have a negative impact on environment. The phytoremediation is a viable
alternative for the removal of heavy metals from polluted soils, but after
application of this method are obtained significant quantities of plants
contaminated with heavy metals that must be managed. Recent studies have
shown that the plants contaminated with heavy metals can be successfully
used in the installations for to produce electrical energy from biomass, and
thus are solved three problems: managing the plants contaminated with heavy
metals, reduce the agricultural areas that are used for the production of
biomass which is used for this purpose and also
contribute to the energy supply and can play an important role in achieving
the targets for use of renewable energy sources (RES).
In this study are presented the main management possibilities of plants used
for phytoremediation of soils polluted with heavy metals. The main
advantages and limitations are pointed out for each technique. Basis of the
results obtained from cost-benefits analysis, the most adequate management
possibility of plants contaminated with heavy metals obtained after
phytoremediation of polluted soils is presented and discussed. Keywords:
heavy metals; phytoremediation; contaminated crop management;
pyrolysis.
Synthesis and characterization of
aluminum complex dyes with Alizaringelb R as ligand
DOINA SIBIESCU, MIHAELA VIZITIU
pages 51 - 57
Abstract
This
paper reports the synthesis and the study of the complexes with Al(III) and
azo dye Alizaringelb R, (Mordant Orange I). The study of the new compounds
was performed in aqueous solution and in solid state.
The molar ratio
was found by spectroscopy, pH measurements and electric conductivity
measurements using the continuous variation methods.
There were synthesised two complexes, at the molar
ratio 1:1 and 1:2, metal: ligand. In order to determine the structure of the
new compounds, the following analyses were performed: elemental analysis,
UV-VIS spectroscopy, IR and XRD spectroscopy, and the thermal stability.
From the experimental data one observes that the both new compounds have a
thermal stability to about 100ºC. The experimental results were used to
propose the structural formulae of these compounds. So, the proposed
structures indicate that Alizaringelb R dye is a bidentate ligand.
Keywords: Alizaringelb R dye; ligand;
complex compounds; Al(III).
Vitamins as food supplements for
health care
ANCA MIHAELA MOCANU, GABRIELA
CIOBANU, CONSTANTIN LUCA
pages 59 - 66
Abstract
This paper presents a review on the vitamins contained in the food
supplements. Many vitamins function as such or after biotransformation,
forming coenzymes of specific enzymes (all the vitamins A, B and K). Some
vitamins act on similar pathways like hormones (vitamins A and D) and other
(vitamins C and E) functions as antioxidant systems against harmful
peroxides. The vitamin supplementation is widespread, food supplements being
indicated in the diet as concentrated sources of nutrients or other
substances with a nutritional or physiological effect. Keywords:
food supplements; vitamins; health
care.
Acetophenone applications,
production and separation
LENUŢA KLOETZER, ALEXANDRA CRISTINA
BLAGA, ALEXANDRA TUCALIUC, ANCA-IRINA GALACTION, DAN CAŞCAVAL
pages 67 - 79
Abstract
This paper presents a literature survey regarding the applications,
production, and separation methods for acetophenone. Acetophenone is used as
component in pharmaceuticals, cosmetics, food flavoring agents and is even
used as an additive in cigarettes, adhesive, paint and household cleaning
agents. It can be obtained by chemical synthesis, by microbial and enzymatic
processes. Regardless of the method used for acetophenone production, its
separation is usually the limiting step. Due to large area of applications
the acetophenone is a product raising a keen interest for developing new
methods for production and separations.
Keywords:
acetophenone; enzymatic processes;
separation.
Hydrophobic and transparent silica
hybrid sol-gel coatings for polycarbonate substrate
Abstract
Hydrophobic and transparent silica hybrid films, deposited on
polycarbonate (PC) substrate, were prepared by sol-gel process at room
temperature (25°C), using two coating routes. The first route consists in
covering the PC substrate by dipping it into acidic solutions, containing
tetraethylorthosilicate (TEOS) and different surface modifying
co-precursors:
octyltriethoxysilane (OTES), phenyltriethoxysilane (PhTES), and
diethoxydimethylsilane (DEDMS), when monolayer-coatings were obtained. By
the second route, the wettability properties of polycarbonate were modified
by preparing bilayer-coatings. Thus, the PC substrates were firstly dipped
in acidic solutions, resulting the first layer, which was let to dry at room
temperature for 5 days before being covered with
perfluoroalchyltriethoxysilane
(perfluorooctyltriethoxysilane or perfluorodecyl triethoxysilane). The water
contact angle values of the PC surface samples covered with bilayer-coatings
are higher compared with both, the references and the monolayer-coatings.
Keywords: silica hybrid film; hydrophobic coating; polycarbonate
automotive applications.
2015,
Volume LXI (LXV), Issue 2*
The natural and artificial drying
process of grapes. Comparative studies
CLAUDIA COBZARU, GENOVEVA BORDEIANU,
ADRIANA MARINOIU, NICOLAE APOSTOLESCU, RAMONA ELENA TATARU FARMUS, CORINA
CERNĂTESCU
Abstract Grapes
have been dried by two methods: natural – by sun exposure, and
artificial – using laboratory drying oven. Naturally the grapes are dried
for 190 h and artificially for 30 h. It has been proved that by natural
drying the products do not modify their colour comparing to those
artificially dried. Sun drying method is more economical then the artificial
one because the last one requires higher energy consumption, but it has the
disadvantage of requiring longer time. Keywords: natural drying process; artificial drying process; grapes.
Effect of water quality parameter on
fish culture in lake with reference to statistical approach
Abstract Water samples were
collected from different locations around Lakha Banzara Lake. These water
samples from 9 sampling points during three seasons were analyzed for their
physicochemical characteristics, viz. pH, Colour, Odour, Hardness, Chloride,
Alkalinity, TDS, COD, Metal ion content etc. to investigate the effect of
physico-chemical parameters on fish production. A Systematic study of
correlation between water quality parameters has been done with the
objective of minimizing the complexity and dimensionality of large set of
data. An attempt has been made to find the seasonal quality of water in
Lakha Banzara Lake, in order to establish relationship between
physico-chemical characteristics and fish production of the lake and
generate a statistical model for examine water quality. Keywords:
water quality; fish culture;
statistical model.
New complexes of Sm(III), Eu(III),
Tb(III), Ho(III), Dy(III), AND Tm(III) with N-hydroxyphtalimide
CORNELIU SERGIU STAN, MARCEL POPA,
CRISTINA ALBU, MARIUS SEBASTIAN SECULA, PETRONELA HORLESCU
Abstract The present work
describes the synthesis and characterization of several lanthanide complexes
with N-hydroxyphtalimide (HL). The main objectives of the present study
aimed at finding the mechanisms of radiative transition taking place in the
luminescence centers consisting in the trivalent cations of the considered
lanthanides; establishing the combination ratios between lanthanide cations,
such as Sm(III), Eu(III), Tb(III), Dy(III), Ho(III), Tm(III), and
N-hydroxyphtalimide ligand; physical-chemical characterization of the
obtained complexes; establishing the molecular structure of the obtained
complexes; investigation of photoluminescence properties of the prepared
complexes. The obtained lanthanide complexes were characterized by elemental
chemical analysis, FTIR, TGA, EDX, SEM and fluorescence spectroscopy. Data
show the formation of lanthanide complexes with N-hydroxyphtalimide ligand
in 1:3 ratio. Keywords: lanthanide complexes; N-hydroxyphtalimide ligand;
luminescence.
Catalytic hydrogenation of carbon
dioxide over Pd base catalyst
Abstract The performances of the
commercial catalysts with various content of Pd in the hydrogenation process
of carbon dioxide to methane have been analyzed. Catalytic test for carbon
dioxide hydrogenation was conducted in mild reaction conditions (temperature
up to 320°C and atmospheric pressure). Optimizing the main parameters such
as, reaction temperature, H2/CO2 molar ratio, high CO2
conversion and total methane selectivity were obtained up to 300°C. Also,
the performances of these catalysts in the hydrogenation process of carbon
dioxide to methane in the conversion and selectivity terms have been
highlighted by a mathematical model developed by means of the Table Curve 3D
software. The mathematical model corresponding to the characteristic
equation provides a good arrangement of the experimental points on the
responding surface, simplicity of the characteristic equation and a good
determination coefficient that is near unity. Keywords: hydrogenation
process; Pd base catalyst;
mathematical model.
Synthesis, spectral
characterization, thermal studies and structure of bidentate azo dye Cr(III)
complexes
DOINA SIBIESCU, MIHAELA VIZITIU,
ANDRA MANUELA CRUDU
Abstract In this paper a two new
complexes of Cr(III) and Acid red 44 azo dye were synthesized and
characterized. The structures of these metal complexes of Cr(III) were
confirmed by elemental analysis, spectroscopic UV-Vis, IR, conductivity and
pH-metric measurements. Also was investigates the thermostability by
thermogravimetric analyses (TG-DTG). The X-ray powder diffraction reflects
that azo dye complexes with Cr(III) are amorphous. The octahedral geometry
of the metal complexes of Cr(III) structures was confirmed by experimental
data. The ligand coordinates through the azo dye nitrogen atom and hydroxyl
oxygen atom after deprotonation, so the
proposed structures indicates that Acid red 44 dye is a bidentate ligand.
Keywords: Dye Acid red 44; ligand; complex compounds, Cr(III).
Removal of Cu(II) ions from aqueous
solution by biosorption on marine algae biomass
IULIA SIMONA BĂDESCU, LĂCRĂMIOARA
NEGRILĂ, GABRIELA NACU, LAURA BULGARIU
Abstract In this study, the
marine algae biomass was used as biosorbent for the removal of Cu(II) ions
from aqueous solution. The biosorption process was studied in batch systems
at room temperature (19°C) as a
function of initial Cu(II) concentration and contact time. The experimental
results were analyzed using Langmuir and Freundlich models for isotherm
modeling, and pseudo-first order and pseudo-second order models, for
kinetics modeling. The Langmuir model best describe the biosorption isotherm
of Cu(II) ions onto marine algae biomass, and the maximum biosorption
capacity calculated in this case is 64.4445 mg·g-1. The kinetics data are
well fitted by pseudo-second model, which means that in the biosorption
mechanism the rate limiting step is the chemical interaction between metal
ions from aqueous solution and superficial functional groups of biomass. The
results included in this study indicate that the marine algae biomass can be
considered a viable biosorbent for the removal of Cu(II) ions from aqueous
solution. Keywords: Cu(II) ions; marine algae biomass; biosorption;
isotherm; kinetics.
2015,
Volume LXI (LXV), Issue 3-4
Comparative study of water softening
with new zeolite and ion exchange resins
Abstract This paper presents a
comparative study on the behaviour of different ion exchange materials used
for food water softening
based on new zeolite delivered in the form of natrium-aluminosilicate
crystals (Crystal-RightTM
CR100) and strong acid
cation resins in natrium form (Purolite
C100E) and in hydrogen form (Pure Resin
PC002). The sorption
capacity of the calcium cations from different synthetic solutions or
groundwater samples as a measure of the three ion exchange materials
performance has comparable values in the given experimental conditions. For
the dose used of 8 g/L at 298 K and 24 h, the experimental results (q,
mg/g; R, %) reporting to the
materials dry state on the performance in the softening of the natural hard
water samples, according to the following order:
Purolite C100E (15.74 mg/g; 85.55%) >
Pure Resin PC002 (12.45 mg/g; 66.69%) > Crystal-Right TM
CR100 (11.94 mg/g; 63.98%).
Purolite C100E resin has the best performances in the given experimental
conditions, thus confirming its choice as a benchmark material for the
comparisons. In the same given conditions the sorption capacity of
Crystal-Right TM CR100 zeolite is around 25 % less than
that of the resins, and of the benchmark can be positively influenced by
increasing the temperature by approx. 10 degrees to the ambient temperature.
Keywords: Crystal-RightTM CR100,
Purolite C100E, Pure Resin PC002.
Road inspection system prototype
using mobile data acquisition
BOGDAN CRAMARIUC, LUCIA RUSU
pages 21 - 34
Abstract Current techniques for
pavement management and monitoring
systems use satellite solution or specialized dedicated vehicles. We
have analyzed several vehicles like Roadware–ARAN, Fugro Consultants LP and
RoadCrack as specialized pavement
monitoring vehicles for automated digital pavement distress surveying
systems. For image processing and analysis we have studied WiseCrax, an
analysis and classification system developed by Roadware, Swedish PAVUE
system analysis and uniANALYZE, an automated crack detection. Our paper
presents an original solution for road inspection system using mobile data
aquisition as an image and/or movie, indispensible in pavement management
and monitoring systems. The novelty brought by the present prototype is
justified by the absence at international level of an automated, portable
visual road inspection/monitoring system operable at traffic speeds which,
given its integration and cost efficiency, can be made available in large
numbers and mounted on non-dedicated vehicles.
Keywords: pavement
management and monitoring systems; road inspection systems; camera; sensors;
GPS.
Case study regarding the estimation
of CO2 emissions generated by minibuses
MARIUS KOVACS, ARTUR GEORGE GĂMAN,
EMILIAN GHICIOI, ANGELICA CĂLĂMAR, DANIEL PUPĂZAN
pages 35 - 46
Abstract Transport in general
represents an indispensable part of our life and society and road transport
is an important pillar of it. It is well known that road traffic
significantly contributes to emissions of air pollutants (gases) which
generate climate changes.
The paper highlights improvement of air
quality in urban/rural areas by purchasing new and cleaner school buses,
which contribute to reducing greenhouse gases emissions, using the CORINAIR
method. In order to reduce emissions generated by school transport, car
fleet renewal activities were developed across the country, new school buses
(type 16 + 1 seats) equipped with EURO V that have reduced CO2
emissions and hence little impact on the environment, were purchased. In
2014, the staff within INCD INSEMEX - Petroşani conducted a comparative
study on estimating CO2 emissions generated by school buses
belonging to the old car fleet and the new one. Thus, emission estimation
was carried out with the use of a calculation algorithm, according to level
3 of CORINAIR method, emissions of dust, CO, CO2, NOx and VOC
being calculated for buses belonging to both old and new car fleet.
Assessment of CO2 emissions from old (existing) and new
(purchased) school buses was performed by the CORINAIR method, considering
the following elements: number of vehicles per vehicle category; fuel
consumption per fuel type; vehicles capacity utilization rates. Final CO2
emissions are estimated based only on fuel consumption, assuming that all of
the fuel’s carbon content is completely oxidized to CO2. Given
the impact on environment caused by vehicular transport pollutants, the
paper presents synthesis data obtained for pollutant emissions resulting
from new school buses having Euro V technology and pollutant emissions
resulting from old school buses, having Non Euro technology. Keywords:
environment; CO2 emissions; air quality; pollutant.
Humprod model for avoiding romanian
agricultural collapse, generated by the destruction of humus as a natural
resource
MIHAI BERCA, VALENTINA-OFELIA
ROBESCU, ROXANA HOROIAŞ, GABRIEL CROITORU
pages 47 - 61
Abstract Romanian society is in a
mediocre position as regards the phenomenon of development. Since it was
never a part of the developed societies and the current social
stratification and social parameters show that it is on a downward curve, we
proposed a statistical model to position the current state of Romanian
agriculture and to predict to what extent it is moving or not towards
collapse. Unlike the HANDY Model, we used as assessment parameters the ones
resulting from the natural state of resources. There have been used, for
this purpose, soil humus content and soil biological activity or ecological
activity index (biological). Methodologically, we have tried to obtain a
probabilistic model. Size and dynamics of the two indicators are correlated
with crop production, and therefore, with the evolution of life. The HumProd
Model consists of two equations and shows a massive loss of humus and
biological activity, which in the year 2050, the last year of the model’s
forecast, is dangerously close to a collapse of the country. The model,
which assesses the amount of any kind of energy in agriculture, shows that
there also can be optimistic variants, which can lead to restoration of soil
and to the postponement of collapse, unless other factors intervene and
disturb the system. Keywords: HANDY Model; HumProd; humus; agricultural
collapse.
Pollution prognosis in the area of
the industrial waste
MIHAIL LUCA, RĂZVAN-PAUL BĂLAN, ILIE
GELU, CRISTIAN-FLORIN SCRIPCARIU
pages 63 - 73
Abstract The paper presents the
monitoring and the prognosis of the pollution phenomenon of underground
water in the industrial waste area. Industrial waste causes pronounced
underground water pollution in the operation phase, but also in the
conservation phase. The pollution monitoring is carried out on all
environmental components: air, soil and underground water. Pollution
phenomenon is analyzed in time by using a tracking and data reception
characteristic control section. By using simulation model (FEFLOW program
package) provides a forecast of the pollution in different periods of time.
We successively treated a flow problem in four scenarios and two flow and
transport problems (therefore, in total, 6 calculation variations). The
simulation model is applicable to the operating period taking into account
the change in quantities and concentrations of pollutants. This paper
presents remediation measures appropriate to the type of industrial landfill
analyzed. The results obtained allow modeling of environmental protection
measures and especially the subsoil and groundwater. Keywords:
industrial waste deposits; pollution flow modeling; pollution phenomenon;
protection.
Impact of tillage operations for
autumn wheat crop set up over some soil properties
IOAN ȚENU, RADU ROSCA, PETRU
CÂRLESCU, CONSTANTIN LIVIU BUTNARU
pages 75 - 84
Abstract Soil has an important
role in sustaining life on earth and represents the support for the practice
of agriculture, which provides the population’s food security and safety.
Preserving the land’s production potential and ensuring a durable
development is a key factor in the present times. In this context the
researches presented in the paper analyze the effects of soil compaction and
of the type of tillage machinery over some soil properties for autumn wheat
crop set up. In order study the effects of the tillage machinery system and
of the soil compaction twelve experimental variants were considered, based
on two influencing factors: factor A = soil compaction, with 3 variants;
factor B = tillage machinery system, with 4 variants. In order evaluate the
effects of tillage machinery system and soil compaction the following
indices were taken into account for each experimental variant: apparent
volumetric mass, penetration resistance and stability of the soil’s
structural elements, expressed by the means of two indices: weighted average
diameter and water stability of the aggregates. The results of the
experiments regarding the effect of soil compaction and tillage machinery
system led to the conclusion that the technological variants that create
favorable conservation conditions were the ones leading to minimum soil
compaction, obtained through direct seeding into the stubble and no plowing.
Keywords: soil compaction; tillage machinery system; autumn wheat crop.
Study on competitive advantage
through innovation and creativity in private universities (study on the Alma
Mater University Sibiu, România)
LEILA BARDAŞUC, JOSÉ LUIS MARTÍNEZ
RUBIO, MONICA DELIA DOMNICA, NICUŞOR MARCEL UDREA
pages 85 - 98
Abstract In this article we
started from the need to analyse the system of private higher education, to
see what advantages this system can offer to its students. As a growing
number of graduates from Romania choose to follow programs of study abroad
in order to find a better paying job and specialize themselves, universities
in Romania and especially private ones have difficulties in designing
strategies to attract students. This analysis was conducted through a
questionnaire administered to students that choose to follow educational
programs at Alma Mater University of Sibiu Romania, a private university of
Economic and Social Studies situated in the centre of the country and with
an activity of 10 years on the educational market. The results obtained led
to the discovery of some of the features that can enhance the interests of
students, characteristics such as greater flexibility, increased use of
innovative and practical programs. The importance of this work consists in
the possibility to determine the views of students on the private university
analysed, on the characteristics that they search for in an educational
program and try to turn all of these into sources of competitive advantage.
Keywords: competitive advantage; innovation; educational systems;
creativity; flexibility.
2014,
Volume LX (LXIV), Issue 1
A new approach for optimizing the
main components for PEM fuel cell
Abstract The aim of this work is
to study the manufacture a PEM fuel cell stack which can be used for
portable applications. The originality of this work is a new coating
technique called "ultrasonic spray coating technique" developed for membrane
electrode assembly (MEA) manufacturing. Also this issue present new metal
and graphite bipolar plates designed and manufactured by computer numerical
control (CNC) technique. A fuel cell controller hardware is developed for
fuel supply and system control. These are some of the main components of the
fuel cell studied and manufactured by us in order to develop new efficient
and reliable devices as PEM fuel Cell and PEM Fuel Cell Stack. Keywords:
PEM fuel cell, stack, bipolar plates.
Study about the development of a
portable fuel cell system containing an integrated hydrogen generator
ADRIANA MARINOIU, CLAUDIA COBZARU,
SIMONA MOSTEANU, IRINA PETREANU, MIRCEA RACEANU, CĂTĂLIN CAPRIS, IOAN
IORDACHE
pages 17 - 28
Abstract The aim of this work is
to study the manufacture a PEM fuel cell stack containing a hydrogen
generator, which can be used for portable applications, namely the
developing hydrogen storage/generating system using NaBH4 ‘fuel’.
The effective use of fuel cells in the military field requires a high energy
density to sustain long missions (more than 24 h), safe, transportable, high
purity and a reliable source of hydrogen. A particularly attractive hydrogen
delivery system is sodium borohydride (NaBH4) as a stable and
inexpensive material, one of the highest hydrogen containing materials,
which could provide hydrogen for a required period, at a required rate and
at a required quantity, through the hydrolysis reaction, on the low-cost
catalyst. Keywords: fuel
cell, hydrogen generator, sodium borohydride.
Training of salespersons for a
careers in the health care and food supplements industry
GABRIELA CIOBANU, MARIA HARJA,
OCTAVIAN CIOBANU
pages 29 - 34
Abstract The paper presents the
main objectives and the methodology an international educational project
funded through the Lifelong Learning Programme and the European Community.
The Lifelong Learning Programme promotes innovative and transnational
initiatives for the development of skills and competences for the inclusion
of unemployed or low paid people in the European job market. The project
called "Launching of Sector Skills Alliance for Training & Apprenticeship of
Health Care and Food Supplements Salespersons" (H-CARE) uses advanced
e-learning technologies to provide a platform-independent prototype for
training and apprenticeship in the area of health care and food supplements.
The project in which the "Gheorghe Asachi" Technical University of Iaşi is
partner offers training courses in the area of health care and food
supplements. Using the training courses discussed in this paper, the
companies from the Food supplements and Health sectors may save their time
and resources in order to improve the qualification of recently hired
salespersons. Keywords: project, training, health care, food supplements.
Water monitoring of the commune
Holboca
GABRIELA GAVRILUŢĂ, LAURA BULGARIU
pages 35 - 41
Abstract The Greek philosopher,
Thales of Milet, said that universal principle of all things is water. We
consume lifelong about 50 tons of water - more than any other product. For
this reason, the health of all, depends on the quality of water consumed.
The inhabitants of the Holboca village complained of kidney pain,
gallbladder because of stones. Calcium deposits also occur on appliances
resistances. The determinations of calcium, magnesium, chlorides and total
hardness of the water samples from the fountains of the population, were
performed using the titrimetric method.
NO3-
ions were determined spectrophotometrically at 412 nm with chromotropic acid
in concentrated sulfuric acid medium. The study showed a weak basic
character of water in the area, indicating the absence of bicarbonate ions to give a high temporary
hardness. The water from the fountains in the Holboca village are
very tough (DT > 30ºG), and water from neighboring villages are tough (DT =
20-30ºG). High hardness is a general feature of water from Moldova; the
springs are formed on a layer of limestone. The content of the ions
determined values are within in the quality standards for surface waters,
making possible safe household consumption of water by the inhabitants. The
water in the area can be a source of mineral water, without requiring a
preliminary treatment. Keywords:
turbidity, electrical conductivity, pH,
chemical
parameters.
Columnar zinc oxide synthesized
under solvothermal conditions
GABRIELA APOSTOLESCU, RAMONA-ELENA
TATARU-FĂRMUŞ, NICOLAE APOSTOLESCU, CORINA CERNĂTESCU
pages 43 - 48
Abstract This paper reports the
synthesis and characterization of nanocrystalline zinc oxide powder obtained
by a simple method using zinc acetate dihydrate and sodium hydroxide,
followed by the thermal treatment. The morphological properties and
crystalline state of the powder obtained after calcination were studied and
SEM analysis showed that the ZnO powder consists of larges spherical
aggregates with a diameter of about 1 µm, made up from columnar particles
around 500-700 nm length and 40-50 nm in diameter. Keywords: ZnO,
columnar habitus, solvothermal synthesis.
Determination of the degree of
pollution of Bistriţa River on the Piatra-Neamţ sector
EUGENIA PÂRLEA, MĂDĂLINA ZĂBAVĂ
pages 49 - 58
Abstract In addition to the air
and the soil, water, a constituent element of the biosphere is also known as
an environmental factor. Water, in all its forms has been and remains a key
component of living matter and at the same time represents a valuable factor
for human activity. This paper presents some general concepts of water
(source and uses, water classification, description of water quality
indicators), contamination of natural waters with pollutants (pollution
source, natural water sources protection, water self-purification) and
results obtained from experimental measurements (determination oxygen
dissolved in water, the oxygen demand, the biochemical oxygen demand (BOD5),
oxidizable substances in water (CCOMn) qualitative determination of ammonia
as ammonium ion by colorimetric method and determination of nitrite on
Bistiţa River. It can be said that now, because of reduced industrial
activity in the area Piatra - Neamţ, Bistriţa River has a low pollution, due
to the discharge of sewage and storm water. Keywords: Ground/Tap water,
physico-chemical parameters, water quality index.
Methods used for heavy metals
removal from wastewater
ANA MARIA BARGAN, GABRIELA CIOBANU,
CONSTANTIN LUCA
pages 59 - 68
Abstract This paper presents a
review of methods used from heavy metals removing on industrial wastewater.
High degree of wastewater contamination with heavy metals as Cd, Cr, Cu, Ni,
As, Pb, Zn, with the harmful effects on human health, demands the using of
the effective methods that can improve the quality of waters. Chemical
precipitation, ion exchanges, adsorption, membrane filtration,
electrodialysis and photocatalysis are using methods in water
decontamination. The study aims mainly adsorption and ion exchange methods
applied to remove heavy metal ions from wastewater using new adsorbent
materials based on phosphates. Also, this work presents some of the
advantages and disadvantages of removing heavy metals methods from
wastewater. Keywords: adsorption, ion exchange, heavy metals, apatite
materials.
2014,
Volume LX (LXIV) , Issue 2
Graphene-based materials for fuel
cell applications
ADRIANA MARINOIU, CONSTANTIN
TEODORESCU, DANIELA MARINESCU, MIHAI VARLAM, CLAUDIA COBZARU, AMALIA SOARE,
CRISTINA IONESCU
pages 9 – 18
Abstract
In consideration of their high surface area, high
conductivity, unique graphitized basal plane structure and potential low
manufacturing cost, graphene nanosheets have been investigated as a support
for low-temperature fuel cell catalysts. Graphene nanocomposites were
synthesized as a simple chemical route by chemical oxidation and graphite
oxide exfoliation and confirmed by characteristic analysis. The structure,
morphology and properties were characterized using X-ray diffraction (XRD)
and Scanning Electron Microscopy (SEM). Keywords:
grapheme; fuel cell; X-ray diffraction; Scanning Electron Microscopy.
Modified nanotextured carbon
materials for volatile organic compounds adsorption
ETELKA DAVID, IOAN MĂMĂLIGĂ
pages 19 – 43
Abstract
The purpose of this research was to investigate the
adsorptive potential of carbonaceous nanotextured materials for removing
volatile organic compounds (VOCs), considered major pollutants of the
environment. Adsorption of VOCs was carried out from gaseous stream using
different precursors and under varying operating conditions. The adsorbent
materials were characterized in term of macro structure and internal
porosity. Examples of industrial developments were presented showing the
nowadays technologies used for the removal of VOCs such as benzene, toluene,
formaldehyde, acetone, phenols, alone and in a complex mixture. Keywords: activated carbon; adsorption; volatile
organic compound; carbon nanotube; graphite; fullerene
Analysis methods of chloride ions
with industrial applications
LOREDANA FLUERARU, GABRIELA RĂUL,
MĂDĂLINA TĂTARU, LAURA BULGARIU
pages 45 – 56
Abstract Chloride ions
concentration is an important parameter in many industrial processes and
from this reason it must be determined with high accuracy. The Romanian
standard recommends the analysis of chloride ions from various industrial
samples by Mohr method. Unfortunately, the Mohr method cannot be always
utilized for this purpose. In this study we have comparatively examined
three different methods that can be used for chloride ions determination
from industrial aqueous samples, in order to establish the applicability
limits in each case. All these methods, namely: Mohr method, conductometric
titration and turbidimetric method, are based on the reaction between
chloride ions and AgNO3 standardized solution. The analytical
parameters (such as: utilizable concentration range, detection limit,
precision, etc.) were calculated from experimental results. The
interferences caused by several common ions and heavy metals, that can be
present in industrial samples were identified. The experimental results show
that these three methods complement each other and allow the analysis of
chloride ions from a much wider range samples. Keywords: chloride
ions; analysis methods; industrial applications.
Abstract A series of four
hydroxyazomethines have been synthetised using ortho-aminophenol and
para-aminophenol as raw matherials and coupling them with benzaldehyde,
anisladehyde and salicylaldehyde, respectively. The azomethines were
purified, and analysed using FTIR, UV-Vis and NMR spectroscopy. Keywords:
Schiff bases; hydroxyl azomethines; transitional metals complexes.
Synthesis and characterization of
H-ZSM-5 zeolite
SUSANA SOLANO ARANA, GABRIELA
CIOBANU
pages 67 – 74
Abstract The paper deals with the
review of the synthesis and characterization techniques of the H-ZSM-5
zeolite. ZSM-5 zeolites are commonly prepared by the hydrothermal method of
the gel containing precursors of silica, alumina, nonbridging metal cations,
and organic template as structure directing agents (SDAs). The main
characterization techniques used for H-ZSM-5 are explained. The most
important applications of these zeolites are presented. Keywords:
H-ZSM-5; zeolite; characterization; synthesis.
The effect of the biofertilizer
based on potassium humates and galactomannans extracted from seeds of
Gleditsia Triacanthos used in
extraroot plant fertilization
Abstract The study is based on
the effect of a fertilizer based on potassium humates mixed with the
galactomannans extracted from seeds of Gleditsia triacanthos, boron,
calcium and zinc applied on tomato culture. The test of the biofertilizer
was carried out on a culture of tomatoes consisting of a tomato variety
named Precos. It was foliculary applied in a concentration of 10 mL/L at 4
weeks after planting in four stages at an interval of 10 days. The effect of
the biofertilizer on tomato crops has been studied by measurements made on
leaves (chlorophyll a and b, total Carotene, plasmatic
membrane permeability, total content of free ions and permeability Index)
and on fruits (antioxidant activity in hydrophilic and lipophilic phase).
Two sets of samples were used: a control sample (blank) and a sample treated
with the fertilizer obtained from potassium humates 0.1%, calcium chloride
1%, zinc sulfate 1% and galactomannan extracted from seeds of Gleditsia
triacanthos 1%. The chlorophyll a content increased by 53.4% as
compared to the control sample, chlorophyll b by 75% and total
chlorophyll content by 60.3%. Carotenoid pigments content from the leaves
varied between 10.75 mg·100 g-1 FW for the blank and 21.10 mg·100
g-1 FW for the fertilized sample, and the ratio between
chlorophyll and carotenoid pigments ranged from 15.14 in the control sample
(blank) to 12.36 in the fertilized sample. The permeability of the plasmatic
membranes of tomato leaves had a value of 98 μSg-1 for the blank
and 47 μSg-1 for the fertilized sample. The total content of free
ions was between the value of 168 μSg-1 (blank) and 85 μSg-1
(fertilized sample) and the permeability index values was between 1.67 for
the blank and 1.8 for the fertilized sample. The permeability of the
plasmatic membranes of the tomato leaves had a value of 98 μSg-1
(blank) and 47 μSg-1 for the fertilized sample. The inhibition
percent of free radicals in the lipophilic phase had a growth from 20.2% for
unfertilized tomatoes to 33.5% for fertilized tomatoes and in the acetonic
phase from 1.07% unfertilized tomatoes to 1.51% for fertilized tomatoes.
Keywords: humic acids; Gleditsia triacanthos; galactomannan;
tomatoes.
2014,
Volume LX (LXIV), Issue 3-4
Infant methemoglobinemia incidence
in Iaşi County between 2010 and 2014 with reference to the drinking water
supply system
RALUCA MITROI, VALENTIN BOBOC,
LOREDANA POPOIU, DANIEL LEPĂDATU
pages 9 - 22
Abstract Acute nitrate poisoning,
registered mostly in children aged 0-1 years, is a medical emergency
identified as a public health problem with relevance in assessing the health
quality of the population in relation to environmental factors. Purpose:
Knowledge of the incidence of acute methemoglobinemia recorded in Iaşi
county between 2010 and 2014 and the evaluation of the causes favoring the
occurrence of acute nitrate poisoning. Material and method: data regarding
acute nitrate poisoning in all communes from Iaşi county was analyzed since
2010 until 2014, with reference to the provided water resources: centralized
public systems of water supply or individual sources: wells. Acute
methemoglobinemia incidence was analyzed in infants in five cases recorded
between 2010 and 2014 compared with the situation in five other communes, in
which there were no acute nitrate poisoning cases, having similar
statistical background: general population, number of villages, 0-1 year old
population, number of households, but different access to a water supply.
Results: in communes where drinking water coming from centralized systems,
with corresponding chemical and bacteriological indicators, was used for
infant feeding there were no diagnosed cases of acute nitrate poisoning. In
comparison, in communes where the population has access only to wells, the
drinking water presents a major risk due to high content of nitrates and
bacteriological inconsistency. Conclusions: The occurrence of new cases of
acute nitrate poisoning imposes a need for continuous health promoting
activities informing mothers on the risks they expose infants to and the
sensitization of local authorities in order to find solutions for quality
drinking water supply. Keywords: methemoglobinemia; nitrate poisoning;
water supply system.
Abstract The hemp is one of the
most important plants being cultivated for many years both in Romania and in
other countries. Because it contains a small amount of tetrahydrocannabinol,
hemp was associated with cannabis and it is listed as prohibited plants.
However, due to the chemical composition rich in essential amino acids,
Omega 3, Omega 6 and fiber, it was found that the plant can supply the most
basic needs of man, namely: food, shelter, clothing and fuel. In literature
there are many studies on nutritional value and uses of hemp and their
analysis are the subject of this paper. Keywords: hemp; miracle plant;
uses; chemical composition.
Integrated design and control of
1,1-diethoxy butane production process
Abstract Acetals are additives
which improve various fuels properties, such as cetane number, lubricity,
biodegradability, flash point. Acetals can be obtained by reacting an
alcohol with a suitable aldehyde, in the presence of an acid catalyst. The
production of several acetals has been studied at laboratory scale, using
conventional reactors, membrane reactors and reactive distillation. However,
few studies are concerned with the design, control and economic evaluation
of an entire plant. In this article we consider a process for production of
1,1-diethoxy butane by reaction of ethanol with butanal, catalyzed by
Amberlyst 47. A simplified model of the Reaction – Separation – Recycle
process is used to analyze the feasibility of different control structures.
Irrespective of the reactor type (CSTR or PFR), the plant exhibits multiple
steady states and a limited range of feasible production rates. The maximum
production rate increases if more catalyst is used and the reaction is
carried on at higher ethanol/butanal ratio. The complete plant design was
achieved using Aspen Plus. A rigorous dynamic model was developed using
Aspen Dynamics and used to prove the controllability of the entire plant.
Keywords: process design;
process control; nonlinear behavior; acetal.
Synthesis and in vitro studies of
new chitosan scaffolds
ALINA GABRIELA RUSU, MARCEL IONEL
POPA, MARIA CELINA ALEXANDRICA, MARIA BUTNARU, LILIANA VERESTIUC
pages 49 - 56
Abstract In this study, the
in vitro degradation and
cytotoxicity of hydrogels based on maleoyl-chitosan/citraconyl-chitosan and
poly(acrylic acid) were studied for potential applications as wound
dressings. The functionalization of chitosan and the presence of the two
polymeric components in the hydrogels were confirmed by Fourier Transform
Infrared Spectroscopy with Attenuated Total Reflectance (FTIR-ATR). Scanning
electron microscopy (SEM) was used to observe the morphology of newly
synthesized hydrogels. SEM data showed an interconnected macroporous
structure for prepared scaffolds with different pore size based on
preparation conditions. The degradation behavior was evaluated by measuring
the concentration in reducing units using spectrophotometrycally method and
the results demonstrated that hydrogels based on maleoyl-chitosan are
slightly degraded compared to those based on citraconyl- chitosan. The
cytotoxicity tests indicated that the hydrogels based on citraconyl-chitosan
and poly(acrylic acid) are more suitable for using as wound dressings.
Keywords: hydrogels; polymeric networks; morphology; degradation;
cytotoxicity.
Testing of rheological properties of
quaternized polysulfones/polyvinyl alcohol blends for upgrading biomembranes
ANCA FILIMON, RALUCA MARINICA ALBU,
ECATERINA AVRAM
pages 57 - 67
Abstract In this research has
been investigated the rheological response of blends based on the modified
polysulfones as against structural peculiarity of polymers from the blend,
composition of polymer mixtures, as well as the types of interactions.
Rheological behavior of complex systems, described by the nonlinear flow
curves, indicates the impact of polyvinil alcohol content to polysulfone
solutions, in order to facilitate the subsequently preparation of bioactive
membranes. Thus, for blends with a higher amount of polyvinyl alcohol,
namely over 0.5 weight fraction, appear a shear thinning behavior at low
shear rates. Instead, chloromethylated polysulfones, polyvinyl alcohol, and
blend with high content of polysulfones (i.e.,
0.75 weight fraction), exhibit a Newtonian behavior over the entire shear
rate domain. Additionally, increasing of the polyvinyl alcohol content
favors polymer (1)-polymer (2) interactions and increases the ability to
form association phenomena through hydrogen-bondings, leading to increases
of the activation energy. The results allow us to conclude that these blends
are optimum and may lead to specific properties that make them suitable for
future investigations concerning membranes with controlled porosity used in
biomedical applications. Keywords: modified polysulfones; blends;
shear-thinning; thermodynamic parameters.
Transport phenomena of polymer
mixtures solution based on quaternized polysulfones
ADINA-MARIA DOBOS, ANCA FILIMON,
ECATERINA AVRAM
pages 69 - 79
Abstract
Electrostatic
interactions between polyions and counterions are, to a large extent,
responsible for the behavior of polyelectrolytes in solution. From this
reason, in this paper the effect of charge density
on the transport properties of quaternized polysulfone/polyvinyl
alcohol/N-methyl-2-pyrrolidone and quaternized polysulfone/cellulose acetate
phthalate/N-methyl-2-pyrrolidone thernary system were investigated by
conductometric measurments. The obtained results, analyzed in terms of the
Manning’s counterion condensation, were presented as a function of polymer
solution concentration, polymer mixture composition, charge density and
polarity of the solvent. It was found that, the values are affected by the
charged groups from quaternized polysulfone, by the content of the neutral
polymer from the mixtures and, also by the nature of the solvent. Also, low
polarity of the medium results in the decrease of the number of free ions
and, consequently, of the equivalent conductivity values. Keywords:
polysulfones; polymer mixtures; specific interactions; transport properties.
Evaluation of Solid Waste Management
Scenarios using Analytic Hierarchy Process (AHP) Technique
CRISTINA GHINEA, DIANA ELENA
COMANITA, PETRONELA COZMA, HANS Th. A. BRESSERS, MARIA GAVRILESCU
pages 81 - 89
Abstract Four different waste
management scenarios were evaluated
in this paper with Analytical Hierarchy Process (AHP) method based on
environmental, economic and technical criteria. Municipal solid waste
management (MSWM) system existent in Iaşi, Romania in 2008 (scenario 1, S1 –
which included as treatment/elimination method of waste only landfilling)
was the basis for development of scenarios. The actual municipal solid waste
management system with the following processes: sorting, composting,
landfilling represents scenario 2 (S2). Scenarios S3 including sorting,
composting, anaerobic digestion, landfilling of municipal solid waste and S4
with sorting, composting, incineration as treatment methods are two possible
alternatives to the present system. Since almost 40% from the amount of
waste generated is represented by biodegradable waste, methods such as
composting and/or anaerobic digestion must be taken into consideration for
treatment of this type of waste. The Expert Choice software (built
especially around the AHP) was applied to calculate the criteria weights and
the final rank of alternatives scenarios. Performance sensitivity analysis
was used to represent the variation of alternative ranking to changes in
each criterion and illustrate the ratio of each alternatives weight
percentage to criteria weights. The results show that the alternative S4 is
ranked with the highest grade, while the alternative S1 is ranked with the
lowest score. Overall the
alternative S4 has an average of priority weights of 0.353 and is followed
by S3 and S2 with 0.235 and respectively 0.208, while S1 alternative
represents the last choice with priority weights of 0.204. Results showed
that scenario 1 which includes only landfilling of solid waste is the worst
scenario due to the negative environmental impacts. Even if Scenario 4 has
high costs, it was found favourable since it proved to be the most suitable
alternative from environmental and technical points of view. Software such
as Expert Choice facilitates the sensitivity analysis. Keywords:
Analytical Hierarchy Process, economic, environment, solid waste.
2013,
Volume LIX (LXIII), Issue 1
Recent advanced in Micro → Nano
porous CeO2 synthesis and characterizations
GABRIELA ANTOANETA APOSTOLESCU,
NICOLAE APOSTOLESCU
pages 9 - 19
Abstract The purpose of this
paper is to provide an overview of the current state of the literature
concerning micro to nano-porous material based on cerium(IV) oxide. The
paper presents the main synthesis methods, the most representative
characterization techniques and various applications of this versatile
material, as good catalyst for different reactions, in ceramics,
photosensitive glass, infrared filters and UV protection or personal care
products, replacing similar compounds based on zinc or titanium.
Keywords: ceria (CeO2), redox property, nanoporous materials,
morphology-controlled synthesis.
Analysis of the wastewater quality
of the city of Roman
Abstract The influence of the
wastewaters on the environment depends on the composition and concentration
of the pollutants contained in these wastewaters. The pollutants can be
mineral, organic, bacteriological and biological substances. These can be
found in higher or lower concentrations depending on the origin of the
wastewaters. In comparison with other industrial branches, the food industry
is the main supplier of wastewaters which originate from numerous physical,
chemical and biochemical processes. Based on these considerations we
analysed the wastewaters originating from the Technical College with
specialisation Food Chemistry from the city of Roman. Keywords:
wastewater, food industry, pollutants.
Aspects of medical wastes management
in Iaşi. Case study: a dental surgery
CARMEN ZAHARIA, MIHAELA ONOFREI
pages 35 - 46
Abstract The paper presents some
aspects of proper management of medical wastes in Iasi county area. Some
data of qualitative and quantitative characteristics of individual medical
wastes (i.e. estimated quantities
and types of medical waste as anatomical-pathological wastes,
pricking-cutting wastes, infectious wastes, non-dangerous wastes, etc.),
collection system, treatment procedures (e.g., sterilizing, neutralization, disinfection using thermal,
physical-chemical, ionizing-irradiative methods), elimination procedures (e.g.,
incineration), and final controlled storage of treated medical wastes (e.g., controlled storage of ashes, etc.) are discussed. The
application of a management system of medical wastes in a dental surgery is
presented together with a general solid wasted mass balance, specific
production and collection data, indicating the companies implicated in the
waste management system, quantities and procedures of treatment and final
storage. Keywords: dental surgery, medical waste, management, waste
collection, treatment, elimination, final storage.
Solid-liquid extraction – an old but
still future promising method
MARCELA POPA, EUGENIA TEODORA
IACOB-TUDOSE, IOAN MĂMĂLIGĂ
pages 47 - 60
Abstract This paper presents a
literature study on solid-liquid extraction, a separation method extensively
used in chemical industry, food industry, metallurgical industry,
environmental protection etc. Reference is made to the basic principles of
operation, the influence factors, the major equipment and applications.
Keywords: solid-liquid extraction, extraction equipment.
Aspects concerning the integrated
management of solid urban wastes in Botoşani county
CARMEN ZAHARIA, LILIANA MUTU
pages 61 - 73
Abstract The paper presents some
basic aspects concerning the integrated management of solid urban wastes in
Botoşani county area. Some qualitative and quantitative data of individual
types of solid wastes (i.e. estimated quantities and types of municipal or
production wastes assimilated as municipal ones from industrial,
agricultural, commercial units, institutes, education schools, other
specialized units, wastes from clearing of streets, parks, gardens, wastes
from constructions and demolishment), collection system, treatment
procedures (e.g., reuse, recycling or recovery of useful constituents for
their use as raw materials or energetic use - 3R treatment of wastes),
elimination procedures (e.g., incineration), and final controlled
landfilling of stabilized solid municipal wastes (e.g., controlled storage
of solid wastes in ecological landfill) are summarized. The application
status of this integrated management system of solid urban wastes in the
Botoşani county area is described together with the specialized sanitation
services and companies implicated in the solid waste management system.
Keywords: selective collection, final landfilling, integrated management,
solid municipal and urban waste, construction wastes, 3R treatment.
Removal of Pb(II) ions from aqueous
solution by adsorption on lignin obtained from rape wastes
LAURA BULGARIU, TEODOR MĂLUŢAN,
DUMITRU BULGARIU
pages 75 - 85
Abstract In this study, the
lignin obtained from rape wastes was used as sorbent for removal of Pb(II)
ions from aqueous solution. Batch adsorption experiments were carried out as
a function of initial solution pH, sorbent dosage and initial Pb(II)
concentration, at room temperature (20±0.5°C).
The higher value of adsorption capacity was obtained at pH 6.0 (acetate
buffer) and 5 g×L-1 sorbent dose. The value
of 53.67 mg×g-1
obtained under these experimental conditions indicate that the lignin
obtained from rape wastes has a good capacity for Pb(II) ions adsorption,
and can be considered a potential sorbent for effluents treatment processes.
The Langmuir and Freundlich isotherm models were used to describe the
equilibrium data and the isotherm parameters were calculated for each case.
The experimental adsorption data were fitted to the Langmuir isotherm model
and the maximum adsorption capacity was 175.44 mg×g-1,
at studied temperature. Keywords: Pb(II) ions, adsorption, lignin, rape
wastes.
Carbon dioxide absorption into new
amines aqueous solutions
RAMONA-ELENA TATARU-FARMUŞ, ILIE
SIMINICEANU
pages 87 - 98
Abstract The absorption of CO2
into aqueous solutions of amines has been studied at three temperature (298,
313, 333 K) in a Lewis type absorber with a constant gas-liquid interface
area of (15.34 ± 0.05) x 10-4 m2. The experimental
results have been interpreted using the equations derived from the two film
model with the assumption that the absorption occurred in the fast pseudo-
first- order kinetic regime. The results confirmed the validity of this
assumption for the experimental conditions: the enhancement factor was
always greater than 3. The rate constant derived from the experimental data
(kov, s-1) was correlated through the Arrhenius plot
(ln kov = A-B/T), and the optimal values of the constants A and B
were obtained by the linear regression. The absorption of CO2
from flue gas into binary mixtures of ethylenediamine + water and
triethylenetetramine + water solutions is a promising process for practical
application at least from the kinetic point of view. Keywords:
acid gas absorption, ethylenediamine, triethylenetetramine, Lewis
cell absorber, enhancement factor, rate constant.
2013,
Volume LIX (LXIII), Issue 2*
Effect of the metal loading degree
and the impregnation method on the structural, textural and catalytic
properties of CuNi/SBA-15 materials
CONSTANTIN RUDOLF, ALEXANDRU
CHIRIEAC, BRÎNDUŞA DRĂGOI, ADRIAN UNGUREANU, EMIL DUMITRIU
Abstract CuNi/SBA-15 catalysts
with different metal loadings (1, 2, 5 and 10 wt.%) and constant Cu:Ni
weight ratio of 1:1 were prepared by wet impregnation (WI) and incipient
wetness impregnation (IWI) of the SBA-15 silica support with the
corresponding aqueous solutions of the metallic nitrate precursors.
Structural, textural and catalytic properties of these samples are reported
in the present study. According to the low-angle XRD patterns and nitrogen
physisorption isotherms, all the CuNi/SBA-15 catalysts have highly ordered
2D hexagonal mesostructure while XRD at high angles revealed the formation
of the specific phases of NiO and CuO with crystallites size slightly larger
for the samples prepared by WI that those prepared by IWI. Liquid phase
hydrogenation of trans-cinnamaldehyde was used to evaluate the catalytic
properties of the bimetallic supported catalysts. Depending on the
preparation method, differences between the catalytic behaviors of the two
series of catalysts at the same metal loading degree were noticed,
especially at low metal loadings. Improvements of the catalytic activity
with the increasing of the metal loading from 1 to 5 wt.% were observed.
Further increasing of the metal loading up to 10 wt.% did not considerably
change the catalytic behavior of the materials. Therefore, a loading degree
of 5 wt.% in metals was found to be optimum value in relation to the
dispersion of metal nanoparticles (NPs) as well as the activity and
selectivity of the catalysts. Keywords: CuNi/SBA-15, impregnation,
trans-cinnamaldehyde, hydrogenation.
Characterization of granulated and
powdered solids
CRISTIAN ANDREI HOROBA, IOAN
MĂMĂLIGĂ, LILIANA HOROBA
Abstract The objective of this
study is to investigate the physical properties of urea, granules and
powder, for characterizing the material behavior during storage, handling
and processing. The particle size distribution, bulk density, Carr’s Index,
Hausner ratio, porosity and specific surface area of the bed, angle of
repose and flow rate were determined for granular and powdered urea. Also,
the influence of the particle size on the physical and flowing properties
was investigated. Experimental results are in good concordance with those of
the literature. Keywords: particle size distribution, bulk density, angle
of repose, bed porosity.
Solid waste recycling for
remanufacturing and bioremediation
CRISTINA GHINEA, ISABELA MARIA
SIMION, MARIA GAVRILESCU
Abstract Economic growth and
increased urban agglomerations lead to rapid increase in volume and types of
waste. Ideal situation according to the cradle-to-cradle principle is a
world without waste, but this it is not yet achievable. The manners in which
the growing amount of solid waste are managed influence the human health and
the environment and could contribute significantly to resources
conservations. In recent years the attention was focused on the fact that
solid waste should be managed according to the hierarchy of waste which
comprises the most and less favorable options for waste management. Methods
like recycling, reuse, remanufacturing, bioremediation were applied to
diminish the amount of waste, pollution of the environment, as well as to
reduce the amounts of virgin raw materials used for different product
manufacturing so as to obtain economic and social benefits. Recycling
materials can offer valuable products for industry in the process of
remanufacturing. Also, some of these materials possess a high potential to
be applied in environmental bioremediation, in particular as sorbents. This
paper discusses the situation of solid waste in Europe and the real chances
to reduce the waste quantities by remanufacturing and/or valorize them as
sustainable tools in bioremediation. Keywords: bioremediation,
recycling, remanufacturing, waste management.
A new way for V2O5
/Fe2O3 separation and recovery from spent catalysts
DANIEL SUTIMAN, GABRIELA ANTOANETA
APOSTOLESCU, NICOLAE FOCA, DANIEL MARECI, ADRIAN CĂILEAN
Abstract The paper presents data
on the study of V2O5 and Fe2O3
spent catalysts used in the sulphuric acid obtaining process. During
oxidation of SO2 to SO3 the spent catalysts undergoes
a series of physical and chemical transformations, the most important is the
reduction of V5+ and Fe3+ ions in contact with sulphur
dioxide. Thus, V5+ is reduced to V4+ and V3+
resulting VO2, VOSO4 and V2(SO4)3
and Fe3+ ions are reduced and passing at FeSO4.
Resulting sulphates are soluble in water and can be separated by filtering
support (mass of) insoluble. Vanadium oxides VO2 and V2O3
or V2O5 surface retain some quantities of SO2
and SO3. Due to these processes, novel compounds are resulting
that can hydrolyse in contact with water, and creating acidic solutions -
corrosive agents which are environmental pollutants. Also, the separating
process of vanadium (V4+ and V3+) from spent catalysts
as V2O5 and Fe3+ and Fe2+ in the
form of Fe2O3 is presented. The resulting V2O5
and Fe2O3 oxides are insoluble and can be separated
from initial solutions and reused. Keywords: spent catalysts, divanadium
pentoxide, sodium hypochlorite, sodium acid phosphate, ion exchange,
precipitation, separation, neutralization.
Characterisation of chitosan
modified by carboxymethilation
DOINA ASANDEI, ANCA MOISE, GABRIELA
LISĂ, ELENA BOBU
Abstract Modified chitosan was
obtained by the reaction of chitosan and monochloroacetic acid. The
characterization of the obtained reaction product was achieved by FT-IR
spectroscopy, polarized light microscopy and thermogravimetric analysis.
FT-IR spectroscopy confirmed the transformation of chitosan in
carboxymethylchitosan by the appearance of specific functional group
absorption bands. The results of the thermal degradation of
carboxymethylchitosan are consistent with the literature. Polarized light
optical microscopy shows that, compared to the chitosan, melting was
evidenced for the synthesised carboxymethylchitosan, probably due to the
introduction of large lateral group on the hydrocarbon chain. After
functionalizing, the melting temperature of chitosan fell slightly below the
degradation temperature, which demonstrates its successful derivatization.
Modified chitosan has better features for use in cosmetics. Keywords:
chitosan, FT-IR, polarized light microscopy, thermogravimetric analysis.
Direct determination of menthol
using a simple spectrophotometric method
ANDA ANASTASIA-SANDU, SERGIU BÎRZU,
IRINA DIŢU, LAURA BULGARIU
Abstract A simple, selective and
accurate spectrophotometric method is proposed for rapid and direct
determination of menthol and the optimal experimental conditions along with
other analytical parameters have been evaluated. This method is based on the
reaction between menthol and salicylaldehyde, in concentrated sulphuric acid
media (96-98%), when a red-orange coloured product is obtained. The visible
spectra of this reaction product, recorded against a blank solution, show a
maximum at 510 nm, and the absorbance remains stable for at least 12 h. The
method allows the menthol determination over the range 1.33 – 13.33 μg·mL-1,
with a molar absortivity of 1.1533·104 L·mol-1·cm-1
and a detection limit of 0.17 ppm. The interferences caused by several
organic compounds (acetic acid, citric acid and ascorbic acid) which can be
present along menthol in various samples were also determined. The
validation of the spectrophotometric method was done by recovery test of
menthol from green tea. The results show that the proposed method can be
successfully used for direct determination of menthol and the main advantage
is that the coloured reaction product appears immediately after mixing the
reagents. Keywords: menthol determination, salicylaldehyde,
spectrophotometric method.
Influence of different calcium and
phosphorus sources in the synthesis of nanohydroxyapatite powder
ANA-MARIA BARGAN, SIMONA ILISEI,
GABRIELA CIOBANU, CONSTANTIN LUCA
Abstract Due to the high
similarity to the inorganic material of bone and tooth, also due to its
excellent biocompatibility and bioactivity, hydroxyapatite (HA) is one of
the most investigated materials for biomedical applications as bone
substitute and implants. The main purpose of the research in this study is
to compare two type of stoichiometric hydroxyapatite performed by chemical
precipitation method using different source of calcium and phosphorus. The
synthesized samples were characterized by X-ray diffraction (XRD) and
scanning electron microscopy (SEM) techniques. Keywords: hydroxyapatite,
chemical precipitation method.
Pretreatment of vegetal materials by
ionic liquid dissolution
ADINA ELENA PÂNZARIU, TEODOR
MĂLUŢAN, IONEL MANGALAGIU
Abstract In this work
investigates effects of dissolving vegetal materials in the ionic liquids
1-ethyl-3-methylimidazolium acetate, 1-butyl-3-methylimidazolium chloride,
1-ethyl-2,3-dimethylimidazolium chloride,
3-(2-methoxy-2-oxoethyl)-1-(3-methoxy-3-oxopropyl) imidazolium bromide. Good
solvent for cellulose is 1-butyl-3-methylimidazolium chloride, whereas for
vegetal material the best solvents is
3-(2-methoxy-2-oxoethyl)-1-(3-methoxy-3-oxopropyl) imidazolium bromide. A
total reducing sugar (TRS) yield of 39.75% was obtained in ionic liquid
1-butyl-3-methylimidazolium chloride at 105ºC in 300 min reaction time.
Keywords: ionic liquid, vegetal materials, TRS, crystallinity index.
2013,
Volume LIX (LXIII), Issue 3
Pertraction equipments
ALEXANDRA CRISTINA BLAGA, ALEXANDRA
CÂRLESCU, ANCA IRINA GALACTION, DAN CAŞCAVAL
pages 9 - 23
Abstract Among the different
separation methods, membrane operations have the potential to replace
conventional energy-intensive techniques. Pertraction is a new and promising
membrane-based extraction process, which allows organic and inorganic
compounds to be removed from dilute streams. This review presents and
evaluates the complex equipments used for pertraction. Many types of
pertractors were used over time, of real importance being which one offers
better constructive possibilities, in order to make the correct choice of
membrane. Keywords: pertraction, liquid membrane, pertractors,
extraction.
Biocomposites from renewable
resources – a review on current trends and challenges in building energy
savings
PETRONELA NECHITA, ŞTEFANIA MIŢA
IONESCU
pages 25 - 35
Abstract
Lately many types of composites have
been developed, mostly by combination of
bio-fibers such as kenaf, hemp, flax, jute, pineapple leaf fiber with
synthetic polymer matrices. Natural fiber–reinforced polypropylene
composites have attained commercial attraction in automotive industries.
But
in the field of
new buildings construction and
especially in the
renovation and thermal
insulation of
old buildings,
natural fiber−polypropylene or natural fiber−polyester
composites are not sufficiently eco-friendly because of the petroleum-based
source and the non-biodegradable nature of the polymer matrix. Using natural
fibers with polymers based on renewable resources will allow many
environmental issues to be solved. The bio-composites are emerging products
as a viable alternative to glass fiber reinforced composites especially in
automotive and building product applications. The aim of this paper is to
cover the recent developments and key challenges for introduction of
renewable materials in the building composites production. Keywords:
bio-composites, lignocelluloses fibres, polymer matrix, building
isolation.
Synthesis methods of II-VI quantum
dots
CORNELIU SERGIU STAN, MARIUS
SEBASTIAN SECULA, MARCEL POPA
pages 37 - 57
Abstract Research on
semiconductor nanocrystals (NCs), also known as quantum dots (QDs), has
increased rapidly in the past few decades. Extensive studies have been
performed on the influence of quantum confinement on the electronic and
optical properties of nanocrystalline semiconductors. The size dependence of
their electronic and optical properties is one of the unique features of
semiconductor NCs, turning them into promising materials for a wide range of
applications in optoelectronics and medical imaging techniques. Recent
advances in synthesis methods of quantum dots with very high quantum yields
could stand at the basis of large scale production of high quality QD for
the mentioned applications. The present
review is focused on the preparation of II–VI semiconductor NCs due to their
various applications in optoelectronics, especially for solid state
lightning, which is one of the most promising solutions for
environmentally-friendly energy saving lightning devices. Some of the
reviewed synthesis methods may not be scalable at mass production due to the
using of expensive or health hazardous reactants but remain of great
interest for laboratory scale synthesis. Some practical laboratory scale
synthesis and separation and purification methods are also included.
Keywords: semiconductor nanocrystals, quantum dots, QD synthesis,
colloidal synthesis.
Mixed oxides derived from chromium
substituted hydrotalcites like anionic clays: studies of the structural
properties
SOFRONIA BOUARIU, MAGDA PUSCASU,
GABRIELA CARJA
pages 59 - 67
Abstract The aim of this paper is
to study comparatively the structural features of two types of mixed oxides
derived from chromium substituted hydrotalcite-like clay. For this purpose
CrLDH clays were prepared previously, using inorganic salts of chromium as
trivalent ion source and inorganic salts of magnesium/nickel as divalent ion
source. This step was followed by the controlled thermal treatment of the
clays up to 750°C, this giving rise to the derived mixed oxides. The
chromium substituted hydrotalcites like clays were obtained by the
coprecipitation method. The specific structural properties of the described
mixed oxides were investigated by X-ray diffraction (XRD) and UV-VIS
spectroscopy. Keywords: CrLDH, mixed oxides, structural features, XRD,
UV-VIS.
Grapes: chemical composition,
extraction and application
Abstract Archaeological evidences
found along the time attest the existence of grape vine long before
apparition of the human being. Although a long period of time the grapes
were consumed only as fresh products regarded as a valuable gift of nature,
the application of wine processing operations resulted in the development of
grape vine cultures used on this purpose. The numerous studies performed
along the years on the chemical composition of the grapes made evident their
potential using in various industries. Many studies are to be found in
scientific literature on the chemical composition of the grapes, extraction
of the active compounds and their use, these topics being discussed in the
present paper. Keywords: grape vine, grapes, extraction,
characterization, uses.
Effect of the catalytic ink
preparation method on the performance of membrane electrode assemblies
MIRCEA RACEANU, ADRIANA MARINOIU,
CLAUDIA COBZARU, ELENA CARCADEA, MIHAI VARLAM, DORIN SCHITEA
pages 81 - 88
Abstract The deposition of the
right catalyst content on the electrodes by a simple method is desirable in
the effective production of MEA. In this study a precursor ink composition
is developed to produce high performance catalyst layers. Utilized
dispersion solvents are water, methanol, iso-propanol and glycerin. The
effect of dispersion solvents in catalyst ink on performance of structural
catalyst layer is studied. The control of the surface tension of the
catalyst ink is fundamental to allow the catalyst layer deposition by
spraying technique and an optimal ink composition was studied. Different
catalyst inks with various solvents were prepared and the effect of
dispersion solvent was discussed. The prepared CCM (catalyzed coated
membrane) were observed under scanning electron microscope (SEM) to examine
its morphology: the thickness and uniformity of the catalyst layer.
Keywords: Proton exchange membrane, catalyst layer, membrane electrode
assembly.
Theoretical description by molecular
modelling of micellar aggregates of functionalized azo-polysiloxanes
ELENA-LUIZA EPURE
pages 89 - 96
Abstract In aqueous solution the
amphiphilic molecules self-assemble into various aggregates. The aim of the
article is a theoretical description of the aggregates generated by
amphiphilic systems of ammonium functionalized azo-polysiloxanes.
Complementarity of the hydrophobic and hydrophilic segments of the synthetic
polymers determines their aggregation into micellar structures. As a
function of the chemical structure of the ammonium group more or less
compacted aggregates were obtained. Due to the particular polymers
architecture some difficulties concerning the molecular simulation was
encountered. As a consequence, the selection of a correct force field was
crucial in the simulation procedure. The obtained structures were validated
by the experimental data. Keywords: amphiphilic azo-polysiloxanes,
self-assembling process, molecular dynamic.
Biomass in environmental remediation
– a review
MARIANA DIACONU, CAMELIA SMARANDA,
RALUCA MARIA HLIHOR, MARIA GAVRILESCU
pages 97 - 113
Abstract Environmental
contamination with heavy metals and other pollutants hardly biodegradable,
that threaten the ecosystems and human health, require increasing standards
of pollutants detection and treatment. A number of methods have been
developed for the removal of pollutants, especially heavy metals and dyes.
Besides physical and chemical methods of treatment, biological methods have
received growing interest, because of their efficiency, simplicity, and
availability of biomass. Lots of bioremediation technologies which include
biosorption processes used to decontaminate the polluted sites. Biosorption
is specific to both living and dead biomass being a promising tool for
pollutant removal and/or recovery. During biosorption, various kinds of
biomass (bacterial, fungal, algal and from plants) are used which helps to
trap heavy metals. In parallel, bioaccumulation is described as involving
living biomass. The paper analyses various categories of biomass, such as
bacterial and fungal dead and living biomass, algae and plants as potential
biosorbents and/or bioaccumulators for environmental contaminants, in
particular heavy metals. The study focuses on their availability, mechanisms
and capacities for heavy metals removal. Keywords: biosorption,
biosorbent, bioaccumulation, bacteria, fungi, algae, plants.
2013,
Volume LIX (LXIII), Issue 4
Aloe Vera (Aloe Barbadensis Miller)
Characterization And Application
Abstract In recent decades the
medical investigations have confirmed and extended the range of the curative
properties attributable to the "biter substance" in the plant Aloe Vera.
Although it is not the only species with curative effects Aloe Vera gives
the best results as settled by the most recent investigations in the field.
The most valuable component of the plant is the gel containing more than 75
nutrient substances, 200 active components, 20 minerals, 18 amino acids and
12 vitamins. Due to its complex composition, the Aloe Vera gel could to be
found in the composition of many cosmetics for its hydrating, emollient,
anti-inflammatory effects with no irritating action on the skin. A large
number of studies on the chemical composition of the plant and the uses in
medicine and cosmetic fields are reported in literature and their analysis
is the aim of the present paper. Keywords:
Aloe Vera, chemical composition, extraction, applications.
Sulfonated Aromatic Polymers As
Approach To Achieve Proton Exchange Membrane For PEM Fuel Cell
IRINA PETREANU, ADRIANA MARINOIU,
CLAUDIA COBZARU, AMALIA SOARE, ELENA CARCADEA, CĂTĂLIN CAPRIS, VASILE
TANISLAV, MIRCEA SAVA TEODORESCU
pages 19 - 29
Abstract Commercial
Poly(-2,6-dimethyl-1,4-phenylene oxide) (PPO) was chosen to synthesize a
polymer electrolyte for Proton Exchange Membrane Fuel Cell (PEMFC). The PPO
is an aromatic, high performance plastic, cheap and easy to modify by
polymer analogous reaction. By sulfonation with several amounts of
cholorosulfonic acid was produced an ionomer with proton exchange behaviour
and different sulfonation degrees. Membrane films have occurred by recasting
from solution of sulfonated product in N,N’-dimethylformamide (DMF). The
sulfonated polyphenylene oxide (sPPO) was analyzed by Fourier Transform
Infrared Spectroscopy (FTIR), was characterised by titration to determine
Ion Exchange Capacity (IEC) and Sulfonation Degree (SD) and the morphology
was studied by Scanning Electron Microscopy (SEM). The results are in behalf
of using the sulfonated polyphenylene oxide as proton exchange membrane for
PEMFC. Keywords: aromatic polymers, polymer electrolyte, fuel cell,
proton exchange membrane.
Theoretical Study Of
Aggregation/Disaggregation Process Of Triethylamine Modified
Azo-Polysiloxanes
ELENA-LUIZA EPURE
pages 31 - 38
Abstract
Molecular dynamic
simulations were performed on amphiphilic azopolymers systems (polysiloxanes
modified with 32% azophenol and 35% triethylamine). Theoretical studies were
been carried out in order to investigate the self-assembling process of the
polymers and the disaggregation as a consequence of the UV irradiation. The
simulations started from a detailed molecular model with a clear
representation of the polymer and water molecules. This study predicts a
highly dense structure corresponding to the trans configuration of the
pending azo group, correlated with experimental data. A less compact
structure was obtained for solvated cis azo- polysiloxanes. Keywords:
micellar aggregate, molecular dynamics, non-bonded interactions, potential
energy.
Pneumatic Bioreactors With
Immobilized Biocatalysts: An Overview
RAMONA-MIHAELA MATRAN, ANCA-IRINA
GALACTION, DAN CAŞCAVAL
pages 39 - 47
Abstract The air-lift
bioreactors, which are the most attractive type of pneumatic bioreactors,
have been widely used in the last decades, due to their numerous advantages
compared to the stirred ones: low energy consumption, simple design and
exploitation, easily maintaining of the medium sterility due to the lack of
the moving elements, superior values of heat and mass transfer rates, and,
especially, the possibility of growing microorganisms sensitive to high
shear stress. At the same time, the use of immobilized biocatalysts in
chemical bioprocesses became a prevalent working-method, owing to the higher
thermal and mechanical stability of biocatalysts, easier recovery of the
immobilized microorganisms, high specificity of the biochemical reaction,
and low overall cost of the biochemical technology. This work reviews the
main applications of the pneumatic bioreactors with immobilized
biocatalysts, as well as the characteristics and performances of
bioprocesses carried out in air-lift bioreactors catalyzed by biocatalysts
entrapped on various supports by different immobilization techniques.
Keywords: air-lift bioreactor, immobilized biocatalysts, hydrodynamics,
oxygen mass transfer.
Abstract
or
common nettle, "Urtica dioica",
is a herbaceous perennial flowering plant, native to
Europe,
Asia, northern
Africa, and
North America, and is the best-known member of the
nettle genus Urtica. The
plant has many hollow stinging hairs called
trichomes on its leaves and stems, which act like hypodermic
needles that inject
histamine and other chemicals that produce a stinging sensation
when contacted by humans and other animals. The general aspects, taxometry,
cultivation, harvest, conditioning are also described in this paper. The
plant has a long history of use in medicine and cosmetic and as a food
source. Keywords:
urtica dioica,
stinging nettle, acetylcholine,
histamine,
serotonin.
Inorganic Pigments: Synthesis And
Luminescent Properties
NICOLAE APOSTOLESCU, GABRIELA
ANTOANETA APOSTOLESCU
pages 59 - 72
Abstract Inorganic pigments,
particularly those with special properties such as the luminescent have seen
an appreciable development in recent years due to the major advantages that
they present, compared to the natural organic materials: synthesis simple
and easy operation, low production costs, easy maintenance, good weathering
resistance. Luminescent pigments are used in various applications such as
X-ray and computer tomography technology, cathode ray tubes, lighting,
safety and accident prevention (inorganic pigments phosphorescent brightness
over a long time) encoding products, detect infrared radiation or
thermoluminescent dosimeters. Based on information from the literature, this
paper provides an overview of the main applications of luminescent pigments,
as well as their characteristics and performance. Keywords: inorganic
pigments, luminescent pigments, optical property, activated halides.
Nickel Substituted Hydrotalcite Like
Clays: Studies On Their Structural Evolution To Mixed Oxides
SOFRONIA BOUARIU, LIVIA BIBIRE,
GABRIELA CARJA
pages 73 - 81
Abstract The influence of the
nature of the trivalent ion from the hydrotalcite like network on the
structural evolution of NiLDHs to mixed oxides was studied as a function of
nickel content of the clay. The substituted hydrotalcite - like clays
studied in present work are described by a different composition of the
layers regarding the nature of trivalent ion. Aluminum and respectively iron
salts were used as source of trivalent ion in this study. The structural
evolution of NiLDHs-like anionic clays to mixed oxides and their structural
features were investigated by means of specific characterization techniques:
X-ray diffraction (XRD), thermal analysis (TG-DTG-DTA) and IR spectroscopy
(FTIR). Keywords: NiLDH, mixed oxides, structural evolution, XRD,
TG-DTA, FTIR.
Decoloration Study Of Remazol
Arancio 3R Azo Dye From Aqueous Solutions By Homogeneous Fenton-Like
Oxidative Processes
CARMEN ZAHARIA, CRISTINA MĂDĂLINA
LUCA, ANDREEA ROMAŞCANU
pages 83 - 93
Abstract Some laboratory scale
set-up results of homogenous oxidative processes with hydrogen peroxide (i.e.
advanced Fenton-like oxidation process with ferrous-based catalyst)
applied for textile Remazol Arancio 3R azo dye solutions were summarized.
The different influences of few operating parameters of this advanced
oxidative process (i.e. pH, H2O2
concentration, homogenous catalystconcentration, dye
concentration, temperature, oxidation time and stirring regime) were studied
to perform the adequate or corresponding values for the highest performance
of decoloration or/and dye removal. The highest decolouration efficiency
(total decolouration) in the case of a 50 mg-Remazol Arancio 3R
dye-containing solution was performed at pH (2.34), with 88.64 mM H2O2,
0.09 mM FeSO4, temperature of 19-20°C, continuous stirring regime
(30 rpm), after only 30 min of homogenous advanced oxidation. Some very good
results (decoloration of 94.779% after 90 min with a little decreasing at
92.05% after 120 min) were performed also working at pH (7.28), with 88.46
mM H2O2, 0.18 mM FeSO4, continuous stirring
regime, after only 10 min. These data are encouraging and useful in
preparation of future experiments, and also of industrial applications and
process optimization. Keywords: decolouration, Remazol Arancio 3R azo
dye, advanced homogenous oxidation, Fenton reagent, aqueous system,
treatment performance.
New Configurations Of Immobilized
Biocatalysts Beds - Bioethanol Production In Basket Bioreactors
DAN CAŞCAVAL, ANCA-IRINA GALACTION,
RAMONA MIHAELA MATRAN
pages 95 - 112
Abstract The basket bioreactors
represent a new generation of equipments which offer the possibility to
reach high mass and heat transfer rates inside the broths, as well as
superior rates of substrates consumption and products biosynthesis. These
advantages are due to the complex hydrodynamics around and inside the basket
bed (a combination between the perfect mixing and plug-flow) and to the
diminishing of the influence of inhibitory effects.
In this context, the review presents the studies on the optimization of
broths circulation and the applications of the bioreactor with basket bed of
immobilized yeast cells for bioethanol production. Keywords: basket
bioreactors, immobilized biocatalysts,
alcoholic fermentation.
BOOK REVIEW: Coloring the
Cosmetic World. Using Pigment in Decorative Cosmetic Formulations. Edwin B.
Faulkner, Allured Books, 2012, ISBN: 978-1-932633-97-9
review by CORINA CERNĂTESCU
pages 113 - 114
2012,
Volume LVIII (LXII), Issue 1
Preliminary Study of Decolourization
by Sorption Onto Sawdust of a Real Textile Effluent
CARMEN ZAHARIA, DANIELA ŞUTEU
pages
9 - 18
Abstract The paper presents a
preliminary laboratory study of adsorption onto wood sawdust applied to
decolorize a real textile effluent. The main factors tested for high
efficiency of decolorization were pH, sorbent dose, temperature, and contact
time. The highest treatment performance was obtained at high acidic pH
(1-2), with sawdust dose of 12-40 g/L, temperature of 20-25°C,
initial intermittent agitation, continuous sorption operating regime, a
minimum contact time of 900 min, and was of 41.379-76.47%.
Other treatment steps into the
technological treatment process of tested textile wastewater can be used for
increasing of treatment degrees (i.e.
chemical oxidation/reduction, membrane processes, ultrafiltration, etc.).
Keywords: adsorption, decolourization, industrial textile effluent,
sawdust, treatment efficiency.
Experimental Researches Regarding The Stability With Zinc Oxide Applied Onto
Synthetic Textile Materials
Abstract The garments with
special destination, such as police uniform, should fulfill a series of
requirements specific to utilizing domain. One of this requirement is
related to the increasing of the inssurance concerning the exploitation and
life time enhancement of the special clothing. For this reason an optimal
solution for increasing the functional attribute of garments is mandatory.
The present paper reveals the research results concerning the stability
treatment consisting of ZnO powder, having as binder an acrylic copolymer,
applied on 100% PES fabric, by padding method. The treatment has been
performed to optimize the antimicrobial capacity providing by the police
uniform during the wearing. The stability of these treatments has been
tested by Zeta potential measurement. The researches target the following
work proceedures: 100% PES fabric – non-treated; 100% PES fabric treated
only with binder (for comparison); 100% PES fabric treated with different
concentrations (1%, 3%, 5%, 7%) zinc oxide and binder; 100% PES fabric
treated with binder + 1%, 3%, 5% 7% zinc oxide + methanol; 100% PES fabric
treated with binder + 1%, 3%, 5%, 7% zinc oxide + methanol after 48 h
consequently to treatment. Keywords: polyester fibres, Zeta potential,
zinc oxide, police uniform.
Performances of Natural
Polyelectrolytes Based on Starch in Aggregation and Stabilization of Aqueous
Coal-Containing Systems
CARMEN ZAHARIA
pages
29 - 39
Abstract The paper presents some
preliminary aggregation-stabilization studies of some coal-containing
colloidal systems (un-oxidated and oxidated coal with H2O2)
as a result of starch action as flocculation agent or coagulation aid. There
were used coal dispersion samples of different turbidity, at different pH
values, with or without coagulant (aluminium sulphate, 10-1-10-4
M) or flocculant (starch solution, 5-35 mg/L) doses. In these experiments
were determined the relative absorbance progress of aqueous systems, but
also the critical values of pH and coagulant/starch concentration for
initiating aggregation of aqueous colloidal systems
(coagulation/flocculation), and also those corresponding to stabilization of
colloidal systems (action of starch as stabilization agent or solid
protection agent). Keywords: aggregation, colloidal coal-containing
aqueous suspension, flocculation, natural polyelectrolyte, stabilization,
starch.
Adsorption of Cobalt(II) from
Aqueous Solution Using Marine Green Algae –
Ulva Lactuca
sp.
MARIUS LUPEA, LAURA BULGARIU, MATEI MACOVEANU
pages
41 - 47
Abstract The removal of
cobalt(II) from aqueous solution by adsorption on marine green algae
Ulva lactuca sp. was studied as a
function of several experimental parameters (initial solution pH, adsorbent
dose and initial metal ion concentration) at room temperature (23
±
0.5°C).
The batch system experiments carried out showed that this biosorbent was
effective in removing of cobalt(II). The higher value of adsorption capacity
was obtained at pH 5.0 and at 8 g×L-1
adsorbent dose. The value of 11.69 mg×g-1
obtained under these experimental conditions indicate that
Ulva lactuca sp. has a good
capacity of cobalt(II) adsorption, and can be effectively used as adsorbent
for effluents treatment process. Keywords: cobalt(II) ions, adsorption,
Ulva lactuca sp. marine algae.
Extraction and Identification of
Bioactive Compounds Using Non-Destructive Separation Techniques
ROXANA-ELENA GHIŢESCU,
IOANA IGNAT, IRINA VOLF, VALENTIN I.
POPA
pages 49 - 56
Abstract Black currant is one of
the raw materials used to obtain phenolic compounds, especially being
recognized as a rich source of natural antioxidants, which can be used in
various fields such as pharmaceutical, food, cosmetic and agrochemical. This
study was carried out using two mild conditions to recover natural compounds
with biological activity, using ultrasound and supercritical fluid assisted
extraction. Extracts were obtained varying the temperature in isobaric
conditions for the supercritical method, while in the ultrasound method the
temperature’s and extraction time’s influence was studied. The qualitative
and quantitative analysis of the polyphenolic compounds existing in the
extracts was performed by high performance liquid chromatography. The
obtained results showed a much higher efficiency in supercritical
extraction, ensuring higher concentrations than those obtained thru
ultrasonic extraction. Also the concentrations of the investigated compounds
increased along with the pressure and contact time, fact which underlines
these variables’ influence in the extractive process. The application of
high performance liquid chromatography provides information regarding
phenolic acids’ and flavonoids’ concentration. Hence it derives that both
the flavonoids’ and the phenolic acids’ content in the extracts obtained is
higher when using supercritical fluids, in contrast with the ultrasound
method, the main influencing factor performance wise in the latter case
being the extraction time. Keywords: polyphenols, supercritical fluids,
ultrasound, HPLC.
Use of Sustainable Indicators in
Solid Waste Management – a review
ISABELA MARIA SIMION, MARIA EMILIANA
FORTUNA, MARIA GAVRILESCU
pages 57 - 71
Abstract This paper is a short
analyze of indicators that are powerful instruments for identifying and
evaluating optimal courses of action and supporting structured and coherent
decision-making.
The development of sustainable indicators sets is characterized by clarity
and transparency. An indicator must be understandable, and reliable. Some
characteristics that indicators have in common:
relevancy; they show
something about the system that you need to know;
understandable, easy to
understand even by people who are not experts;
reliability, the information
that the indicator is providing are real. Lastly, indicators are based on
accessible data; the information is available or can be gathered while there
is still time to act. Indicators can be powerful tools in project management
systems for monitoring and evaluating project, or product outcomes and
impacts. Solid waste management represents one of the major environmental
problems, because these types of waste are growing in the same time with
population growth and their different way of life. In scientific literature
the problem of different type of waste is studied, but to
manage
the solid waste is needed firstly to carry
out an
analysis of existing problems, and to
identify indicators that help to realize the management.
Keywords: environmental, indicators, solid waste.
Biogas Upgrading Using Water
Scrubbing Technology
PETRONELA COZMA, WALTER WUKOVITS, ANTON FRIEDL, MARIA GAVRILESCU
pages 73 - 84
Abstract Biogas is an environment
friendly, clean, cheap and versatile fuel, and has a great potential for
wide applications. Depending on the end of use, the quality of biogas must
be upgraded to meet de desired conditions for proper applications. Various
technologies have been developed to improve the quality of biogas by removal
of the contaminants through upgrading. Among these methods, the absorption
with water or water scrubbing is the most common technique applied in an
upgrading biogas plant due to the lower capital and operational cost
implied. The principle of the pressurized water wash process is based on the
fact that hydrogen sulphide and carbon dioxide are more soluble in water
that methane, since these substances are physically dissolved in water under
pressure. From this reason, the water scrubbing is considered an efficient
method to remove CO2 and H2S, and to enrich the gas
with methane. This paper reviews the efforts made to improve the quality of
biogas using this technology and the results obtained. Even though biogas is
increasingly upgraded for different uses, such as vehicle use, there is no
much literature available on upgrading of biogas using this process,
although it is a proven technology and is implemented at small and large
scale. Keywords: biogas quality standards, biogas upgrading, water
scrubbing, solubility.
An Water Quality Index Mathematical
Modeling of Water Samples of Rajghat, Water Supply Reservoir Sagar (M.P.)
With Respect to Total Dissolved Solids: A Regression Analysis
HEMANT PATHAK, DEEPAK PATHAK, S.N.
LIMAYE
pages 85 - 104
Abstract
Rajghat dam
(source - Bebus River) is the one of the major resource of the water for
domestic used, supplied by Municipal Corporation of Sagar city (M.P.). In
the present study quality of the Rajghat dam water reaching for the domestic
supply is taken for under investigations on 15 physico-chemical parameters
were carried out during different seasons of the 2009–2010. The correlation
and multiple regression analysis applied to the datasets indicated their
interrelationships, for evaluating water quality during the pre-monsoon,
monsoon, and post monsoon seasons.
The present work is aimed at assessing the water quality index (WQI) model
for the Rajghat reservoir water of Sagar city. This has been determined by
collecting water samples from selected 20 locations covered entire reservoir
and subjecting the samples to a most important physico-chemical analysis for
create a water quality index (WQI) model. The
objective of the present work is to create a model based on computed water
quality index values to assess the suitability of water for human
consumption. It thus becomes an important tool for the assessment and
management of water body. It has to summarize large amounts of water quality
data into simple terms for reporting to management and the public in a
consistent manner. Keywords:
physico-chemical parameters, water quality index, regression analysis,
seasons.
Environmental Comparison of Solid
Waste Management Systems: A Case Study of The Cities of Iaşi, România and
Enschede, Netherlands
CRISTINA GHINEA, MĂDĂLINA PETRARU, HANS BRESSERS, MARIA GAVRILESCU
pages 105 - 116
Abstract
Sustainable approach to solid waste
management in any region can be achieved by integrated waste management
systems. The waste management systems differ in developed and developing
countries. The Netherlands has a unique waste management system, the Dutch
approach to waste consist in "avoid waste as much as possible, recover the
valuable raw materials from any waste that is created, try to generate
energy by incinerating the residual waste, and only then dump what is left".
Netherlands is today among the leading countries in terms of waste
management and especially in recycling solid waste. Compared with the waste
situation from Netherlands the waste management in România is far behind.
Landfilling of municipal solid waste is still the most used method to
disposal of waste in Romania. The solid waste management sector in România
is expected to develop in the coming years. In this paper environmental
impact evaluation of these two different systems was realized with GaBi4
software. Keywords: environmental impact, life cycle assessment,
municipal solid waste.
Comparative Study About Biomimetic Methods Used in Hydroxyapatite Crystals
Growth on the Polymeric Surface
SIMONA ILISEI, GABRIELA CIOBANU,
CONSTANTIN LUCA
pages
117 -
125
Abstract The aims of this
research are to obtain hydroxyapatite thin layers on porous polyurethane
substrates using two biomimetic methods and to make comparisons between
results. To produce bone-like apatite coatings on polyurethane surface, two
types of solutions, such as a supersaturated calcification solution (SCS)
and modified synthetic Simulated Body Fluid (SBF) solution were used. The
images obtained by scanning electron microscopy (SEM) coupled with energy
dispersive X-ray analysis (EDX) show that on porous polyurethane support is
deposited a thin layer of hydroxyapatite. The crystals of hydroxyapatite
grow under the action of SBF or SCS solutions. But, based on the results
obtained, it is found that the formation of hydroxyapatite layer on a
polymer substrate is more favored by the presence of SCS solution. In biomimmetic treatment with SCS solution, compared with
treatment with SBF solution, it saw that apatite layer is formed on
polyurethane scaffolds in less time and is more uniform and homogeneous.
Keywords: hydroxyapatite, porous polyurethane substrate, biomimmetic
treatment.
The Electrochemical Behaviour in
Fusayama Saliva of Five Non-Precious Ni-Based Dental Alloys With Different
Composition
SORIN CLAUDIU IACOB STRUGARU
pages 127 - 136
Abstract
In this study five non-precious alloys
NiCr based were utilized. From the industrial processes practice it is known
that a correlation between the amount of the elements Cr and Mo and the
corrosion characterization exists and is given by the indicative pitting
resistance equivalent number (PREN). Based on the cyclic curves in case of
the five commercial alloys maintained in Fusayama saliva, one established
the type and the intensity of the corrosion process by means of the
corrosion currents value. The passivation of all the samples occurred
spontaneously at the open circuit potential. Scanning electron microscopy
(SEM) observations were made following the cyclic potentiodynamic
polarization tests. The NiCr alloys with chromium (14-18%)
contents were susceptible to localized
corrosion. The NiCrMo alloy with
chromium (≈ 13%) content and molybdenum (9%) content presents a dangerous
breakdown but have a sufficiently negative
zero corrosion potential
that the difference between them
is around 650 mV. The NiCrMo alloys with higher chromium (22-25%) and
molybdenum (9-11%) contents had a much larger passive range in the
polarization curve and were immune to pitting corrosion. Pitting resistance
equivalent (PRE) of about ≈ 54 could provide the Ni-based alloy with a good
pitting corrosion resistance. Keywords: corrosion current,
potentiodynamic cyclic curves, scanning electronic microscopy, pitting
resistance equivalent number.
Recent Advances in the Field of
Enzimatic Hydrolyses of Penicillin G Using Penicillin Acylase
ANCA-MARCELA LUPĂŞTEANU
pages 137 - 148
Abstract The development of the
semi-synthetic antibiotic field has led to extensive research regarding the
production of 6-aminopenicilanic acid (6-APA), the main product resulting
from the split of penicillins, compound used to obtain semi-synthetic
antibiotic by subsequent condensation reactions with acil donors. The use of
penicillin acylase as a biocatalyst determined "the taming" of the necessary
reaction conditions to break the amidic bonds in the penicillin structure
and, in addition, the reduction of side products and reaction waste.
Keywords: 6-aminopenicilanic acid, penicillin acylase, enzymatyc hydrolysis,
semi-synthetic antibiotic.
Total Phenolic Index Methods Used in
the Present Scientific Literature
IOANA PETRONELA TĂRĂBUŢĂ, IRINA
VOLF, VALENTIN I. POPA
pages 149 - 156
Abstract
Phenolic compounds
are the most important class of secondary metabolites in the plant kingdom.
Until present day the method most used is based on the reduction of the
Folin-Ciocâlteu
reagent in the presence of disodium carbonate. Unfortunately, although the
kinetic reaction is the same, the methods used differ in terms of reagent
concentrations, sample dilution, temperature, reagent to sample ratio and
the adding order of the reagents. Another variation is the standard phenolic
compound and the wavelength used. The aim of the present study is to
recommend one of the methods encountered which is better suited for total
phenolic index determination in concentrated samples. Also increasing the
efficiency in the use of reagents would make the entire process more cost
effective. Keywords: Folin-Ciocâlteu
reagent, phenol, method, TPI.
Distribution of Mixing Intensity of
Olive Oil Dispersions in Aerated
Saccharomyces cerevisiae Broths for Stirred Bioreactors
ELENA FOLESCU
pages 157 - 170
Abstract The circulation of
aerated broths inside a stirred bioreactor is more complex than in the case
of anaerated medium, due to the cumulated pneumatic and mechanical
agitation. Therefore, it is very important to analyze the distribution of
mixing in such systems. Furthermore, the addition of olive oil as an
oxygen-vector complicates even more the hydrodynamics of these types of
fermentation broths. The addition of the organic phase determine an
enhancement of mixing intensity, especially for higher concentrations of
biomass and for higher volumetric fraction of olive oil compared to aerated
fermentation broths which doesn’t contain oxygen-vectors. The analyze of
mixing distribution for olive oil dispersions in aerated
Saccharomyces cerevisiae broths in
a stirred bioreactor with a double Rushton impeller indicated an
inhomogeneous distribution of mixing intensity into the medium, although,
for certain conditions (i.e. at
200 rpm and Da between 150-450 L/h for Cx=150g/L d.w.)
a relatively homogenous medium can be achieved.
Keywords: aerated broths, mixing distribution,
Saccharomyces cerevisiae, olive oil, oxygen-vector.
Study Concerning Treatment of Birch Veneer With
Hydroxymethylated-Epoxidated Lignin Derivatives
ADINA-MIRELA CĂPRARU, IULIAN-ANDREI GÎLCĂ, ELENA UNGUREANU,LUCIA
CARMEN TRINCĂ,TEODOR MĂLUŢAN, VALENTIN I. POPA
pages 171 - 176
Abstract
The paper presents the results
obtained in a study concerning the obtaining and characterization of
hydroxymethyl- epoxy lignin derivatives which were tested in terms of their
biocides properties in birch veneer protection. There used three types of commercial lignin’s (Protobind 1000, 2000, 3000) offered by the company Granit (Switzerland). By
applying suitable conditions of synthesis, it was possible to obtain lignin
derivatives using the reaction of hydroxymethylation followed by
epoxydation. The resulted products were applied in the treatment of birch
veneer samples. These were successively immersed in solutions containing
copper ions and unmodified and modified lignins with concentration of 5%
dissolved in furfuryl alcohol. The biostability of veneer samples thus
treated were appreciated through their burial in soil for six months and
characterized by mass losses, contact angle against water and its
modification during the measurement. The obtained results show that the
treatment of birch veneer with complexes of hydroxymethyl-epoxy lignin
derivatives with copper offers a high stability of the substrate timber
products in comparison with unmodified products. Keywords:
lignin, hydroxymethylation,
epoxydation, biostability, birch veneer.
Development and Validation of an
HPLC-DAD Method for Determination of Diosmin and Hesperidin
ANDREIA CORCIOVĂ, LAURIAN VLASE,
CONSTANTIN CIOBANU, MARIUS TURNEA
pages 177 - 185
Abstract Diosmin and hesperidin
are glycosylated flavonoids with health related properties. These compounds
are involved in complex biological processes at cellular level and they are
found in various pharmaceutical products. The aim of this study was to
develop a fast and sensitive HPLC-DAD method for the determination of
diosmin and hesperidin content in pharmaceutical tablets. An Agilent 1100
HPLC Series with a diode-array detector system was used throughout the
analysis. The system is equipped with a Zorbax SB-C18 100 mm x 3.0 mm i.d.,
3.5 µm column and as a mobile phase a
mixture of acetic acid 0.1%/methanol (60:40, v/v) was used. At the
same time, a validation study was conducted for the proposed method, in
accordance with the bioanalytical method validation guidelines. The studied
validation characteristics showed that the proposed method can be
successfully applied to drug tablets analysis.
Keywords: HPLC-DAD, diosmin, hesperidin, flavonoids.
Electrochemical Studies on CoCrMo
Alloys in Artificial Saliva and Aspirin
MANUELA ROMAŞ, DANIEL MARECI,ANNA IGUAL MUNOZ, DANIEL MIRCEA
SUTIMAN
pages 187 - 194
Abstract CoCrMo alloys, used as
dental materials, were subject of electrochemical studies in order to obtain
information about electrochemical behaviour of alloys in presence of
artificial saliva and aspirin. The following electrochemical methods were
used: open circuit potential (OCP), potentiodynamic polarization and
electrochemical impedance spectroscopy (EIS) in solutions at pH value 3 and
37ºC. Due to electrochemical data it were studied electrochemical properties
of corrosion and EIS data helped to modelate an equivalent circuit (EC) for
studying the nature of pasive film formed on CoCrMo alloys. Keywords:
CoCrMo alloy, aspirin, potentiodynamic polarization, electrochemical
impedance spectroscopy, corrosion.
Kinetic Characterization of Some
Phenoloxidases from Mushrooms
LUMINIŢA ANCA GEORGESCU,
DANA IULIA MORARU, VERONICA STELUŢA MINCIOR
pages 195 - 206
Abstract Amongst the
phenoloxidases found in mushrooms, laccase and tyrosinase are two important
copper enzymes, which participate to oxidative browning. Even so, they are
useful as food additives, as quantitative measurement reagents and they have
an interesting potential in wastewater bioremediation. The purpose of this
study is to enlighten the enzymatic activity of some aqueous extracts made
of Pleurotus ostreatus and
Agaricus bisporus and to analyze
the kinetic parameters resulting from the activity of laccase and tyrosinaze
over certain substrates. As specific substrates for tyrosinase were used
L-tyrosine, L-DOPA and catechol,
respectively syringaldazine and guaiacol for laccase. The data
obtained by using mushroom extracts were compared with those that were
found by
using commercial purified enzymes. It was
discovered that laccase prefers syringaldazyne as substrate and that
tyrosinase oxidizes L-DOPA faster than
catechol, although the kinetic parameters did not
show a high affinity, but a moderate one. This fact leads us to the
hypothesis that the mushrooms we have
tested were treated with inhibitors in order to be commercialized.
Keywords: phenoloxidases, mushrooms, laccase, tyrosinase, enzymatic
activity, kinetic parameters.
Swelling Behavior Of Some
Semi-Interpenetrating Polymer Networks Based on Polyacrylamide and Starch or
Modified Starch
DIANA FELICIA APOPEI, ECATERINA
STELA DRĂGAN
pages 207 - 216
Abstract Preparation of novel
semi-interpenetrating composite hydrogels based on poly(acrylamide) as a
matrix and either native potatoes starch (PS) or a polyanion, obtained by
the hydrolysis of PS-g-PAN, as
entrapped polymer has been studied in the paper. The composite hydrogels
have been characterized by swelling behavior as a function of the
cross-linking ratio and medium pH, water retention capacity, and by the
retention capacity of Methylene Blue. Keywords: potatoes starch,
poly(acrylamide), semi-interpenetrating composite hydrogels, Methylene Blue.
Characterization of Several Aromatic
Copolyethers with Flexible Methylene Spacer Using Thermal Methods
GABRIELA LISĂ, NICOLAE HURDUC,
SILVIA ALĂZĂROAIE, NATALIA HURDUC
pages 217 - 227
Abstract
The purpose of this paper is to collect
information on the thermal behavior in dynamic temperature conditions of
several aromatic copolyethers synthesized by interphasic transfer catalysis
in liquid system. Thus, we analyzed the influence of the molar
copolymerization ratio, comonomer type and rate of heating. Thermal methods
such as thermogravimetric analysis, derived thermogravimetry or differential
analysis were employed as investigation methods. Copolyethers enjoy good
thermal stability, which is influenced by the comonomer type and molar
copolymerization ratio. The degradation mechanism is radicalic and includes
successive reactions. Keywords: thermal behavior, aromatic
copolyethers, degradation mechanism.
Synthesis and Characterization of
Nanohydroxyapatite Powders
SIMONA ILISEI, ANA MARIA BARGAN,
GABRIELA CIOBANU, CONSTANTIN LUCA
pages
229 - 234
Abstract This paper investigates
the possibility to obtain nanocrystalline hydroxyapatite by precipitation
method. The morphology and crystallization of the prepared samples were
described by scanning electron microscopy (SEM) and X-ray diffraction (XRD)
methods. Based on the method applied under certain conditions of synthesis
nanocrystals of hydroxyapatite were obtained. For samples obtained at pH ≥
10, the crystallite mean sizes varied from 40 to 70 nm.
Keywords: hydroxyapatite, nanoparticles, precipitation.
Applications of Thermogravimetric
Analysis on the Study of Composition of Polyester-Wool Fabrics
LUCIA ODOCHIAN, ANCA MIHAELA
MOCANU, LORELA IANCU, ADRIANA BĂICEANU, CRISTINA MARIA PĂIUŞ
pages 235 - 243
Abstract Due to the many
characteristics shown by the polyester fabrics when processed as mixtures
with wool these fabrics were studied from several points of view. The
composition of the polyester-wool material is determinative for the fabric
properties and hence for the purpose to be used so that this feature is of a
great significance. By taking these considerations into account the present
paper is aimed to present a method for determining the composition of the
polyester-wool textile material and that can be applied to any bi-component
material consisting of a strongly hydrophilic component along with a
hydrophobic or slightly hydrophilic one. Keywords: fabrics: wool (W),
polyester (PS), wool (W) + polyester (PS); thermogravimetric analysis (TG);
derivative thermo-gravimetric analysis (DTG).
CAMELUŢA BELDIE in memoriam
by GHEORGHE NEMŢOI
pages 245 – 246
2012,
Volume LVIII (LXII), Issue 2
CuCo Nanosized bimetallic particles
hosted by pure and phenyl modified mesoporous MCF silicas for cinnamaldehyde
hydrogenation
BRÎNDUŞA DRĂGOI, ALEXANDRU CHIRIEAC,
ALINA MOSCU-CORCODEL, ADRIAN UNGUREANU, EMIL DUMITRIU
pages 9 - 24
Abstract This work is focused on
the preparation of copper and cobalt containing catalysts supported on MCF
(mesocellular foams) silica and phenyl-MCF hybrid materials and their
applications in the hydrogenation of cinnamaldehyde. Silica MCF was prepared
by "oil-in-water microemulsion" templating while the incorporation of the
phenyl groups in the silica MCF was performed by direct-synthesis. Cu and Co
containing catalysts were prepared by co-precipitation on the calcined
supports. Catalysts with 5 wt % in metals and Cu:Co weight ratio = 4:1 were
used in this study. The high quality of the supports and catalysts in
relation to their structure, texture, size and dispersion of the metal
oxides was proved by XRD and N2 physisorption. The surface chemistry of
samples (i.e. the identification of the organic functions, as well as the
metallic cations environments) was analysed by thermogravimetry and
DR-UV-Vis-NIR. The catalytic performances were evaluated in the
hydrogenation of cinnamaldehyde in liquid phase. All catalysts were very
active and highly selective to the unsaturated alcohols. Further improvement
in the catalytic performances was achieved for the materials containing
phenyl groups. Keywords: copper, cobalt, MCF, phenyl, hydrogenation,
cinnamaldehyde.
Romanian environmental ergonomics
standards
OCTAVIAN CIOBANU, GABRIELA CIOBANU
pages 25 - 32
Abstract Environmental Ergonomics
approaches the issues of design and evaluation of human comfort, activity
and health in indoor and outdoor environments. Environmental factors include
thermal environments, lighting level, noise, vibration, atmospheric pressure
and air quality. Paper deals with the state of art of Environmental
Ergonomics in Romania approaching and making a comparative study between
Romanian standards and standards of the European Committee for
Standardization and of the International Standards Organization.
Keywords: comparison, Environmental Ergonomics, Romanian standards.
Advanced electrochemical oxidation
process for removal of refractory contaminants from wastewater
CARMEN IONELA BRÎNZILĂ (ALEXANDRU),
ROMEO CRISTIAN CIOBANU
pages 33 - 43
Abstract This paper aims to
develop a brief overview of Advanced Electrochemical Oxidation Processes
(AEOPs) that will be applied to the degradation/mineralization of refractory
and toxic contaminants in aqueous solution. AEOPs are based on the
generation of hydroxyl radical •OH, a powerful oxidizing agent,
non-selective, which reacts with organic contaminants to their complete
mineralization (conversion to CO2 and inorganic ions). Anode
material is a very important factor influencing the efficiency of
electrochemical processes used for degradation of contaminants. Boron doped
diamond (BDD) thin film anode has attracted great attention due to his
important characteristics: wide potential windows, inert surface with low
adsorption properties and a high corrosion stability. Adding that the
concentration of hydroxyl radical generated at BDD surface is much higher
than conventional anodes, with a higher total organic carbon (TOC) removal
rate, makes AEOPs with BDD to be a suitable procedure for complete
mineralization of organics in aqueous medium. Keywords: wastewater,
boron-doped diamond, electrochemical treatment, hydroxyl radical.
Investigation of the thermal
degradation products of high density polyethylene and polypropylene using
analytical techniques
MIUŢA RAFILA FILIP, TIBERIU RUSU
pages 45 - 57
Abstract High density
polyethylene (HDPE) and polypropylene (PP) are part of the most common
plastics extensively used in different fields due to their low cost and
various applications: packing, toys, containers, house wares, gas pipes,
automotive parts, electrical components. The thermal degradation by
pyrolysis is the most suitable method for converting of these plastic
polymers into fuel. In this paper the HDPE and PP were thermal degradated at
350°C. The obtained products were a mixture of hydrocarbons which contains a
gas fraction, a liquid fraction and a solid residue. Yields of liquid
products were 83.14% and 89.90% for thermal degradation products of HDPE and
PP, respectively. The gas chromatography couplet with mass spectrometry
(GC-MS) and Fourier transform infrared spectroscopy (FT-IR) techniques were
used for the investigation of the thermal degradation products. The liquid
fractions were analyzed through GC-MS technique. The GC-MS results show that
the liquid fractions obtained contain a mixture of hydrocarbons with
straight-chain and branched-chain
of range C7…C31. All of the thermal degradation
products were investigated by FT-IR technique. The FT-IR spectra indicate
the specific bands of the
vibration functional groups
which belong to the
components of all the thermal degradation products. The investigation
of thermal degradation liquid products of HDPE and PP are useful because it
is possible to be used as fuels. Keywords:
thermal degradation; polymer; hydrocarbons; GC-MS; FT-IR.
Lignocellulosic agro-industrial
wastes as sorbents for dyes removal from aqueous media
DANIELA ŞUTEU, CARMEN ZAHARIA,
MARINELA BĂDEANU
pages 59 - 67
Abstract The article presents our
results into the evaluation of adsorptive potential of some materials from
the agricultural wastes, using the well-known procedure, into the optimal
proposed and tested operational conditions for retaining of textile dyes of
industrial effluents. The accent is pointed on the valorization of an
important category of by-products and/or agro-industrial wastes together
with wastewater treatment generated by the textile chemical finishing, the
industry of chemical synthesis of dyes, the industry of leather processing,
industry of material printing etc. Keywords: sorption, dyes, wastewaters,
lignocellulosic adsorbent.
Control and analysis of some water
quality indicators of Bahlui river in Iaşi county area (spring season)
CARMEN ZAHARIA, ISABELA MARIA
TESLARU
pages 69 - 79
Abstract Some important quality
indicators (i.e. pH, color,
suspended solids, turbidity, fixed residues, dissolved oxygen, COD, BOD5,
total hardness, nitrites, nitrates, phosphates, phenolic derivates,
extractible substances in organic solvents – petroleum ether, etc.) were
analysed during the spring season (i.e.
March-May months, 2009) in four control sections of Bahlui River – Iaşi
County area (i.e. sections with
known potential polluting sources around: 1- Antibiotice zone, 2- Tudor
Vladimirescu zone, 3- upstream and 4- downstream Dancu urban wastewater
plant). The performed results permitted the establishment of water quality
classes for each analysed quality indicators, and estimation of pollution
level, but also further actions for this natural water resource protection
and conservation. Keywords: analysis, Bahlui River, conservation,
control section, pollution level, quality indicator, water resource.
Charmomille old issues, new
approaches
MIHAELA BUDUR, CORINA CERNĂTESCU
pages 81 - 87
Abstract Chamomile (Matricaria
Chamomilla - Fam. Asteraceae) is one of the oldest and most used herbs. It
grows everywhere, on roadsides, fields, besides houses. In some regions of
the country, are plains with chamomile. Flowers - Flores Chamomille -
contain a volatile oil, blue, which due to a compound called azulene and the
nature of glycoside flavones (apigenin) exhibit antispasmodic properties,
anesthetics, disinfectants and anti-inflammatory. This article will review,
briefly, cultivation techniques, harvesting and storage and the main
constituents and organoleptic properties. Detailed in this article are its
medicinal uses and methods of administration. Keywords: matricaria
chamomilla, chamazulene, chamomila flos, medical uses, essential oil.
Deuterium depleted water and spruce
bark extract - bioregulators for maize and rape plants
CORNELIU TĂNASE,
IRINA VOLF, VALENTIN I. POPA
pages 89 - 98
Abstract The aim of this study
was to evaluate the influence of deuterium depleted water (DDW) in
combination with spruce bark aqueous extract on maize and rape seedlings
growth and development. Taking this into account, germination tests were
carried out in the presence of distilled water (DW-control), DDW, spruce
bark extract, and polyphenolic extract in combination with DW and DDW
respectively. The characteristic effects of each tested treatment was
assessed after ten days from the beginning of the experiment through
biometrics analysis and quantitative determinations of plant biomass and by
setting the total content of assimilatory pigments. The obtained results
have shown that in the presence of DDW a stimulatory effect was evidenced on
accumulated biomass and photoassimilatory pigments synthesis for both plants
species. It was observed that the combination of polyphenolic extract with
DDW stimulates germination energy and capacity for both plants being
accompanied by biomass accumulation in the primary leaves with 45% over the
control sample value and also, stimulating photoassimilatory pigments
synthesis. Keywords: deuterium depleted water (DDW), maize, rape, spruce
bark, polyphenolic compounds.
Gas drying using "selective water
sorbents" based on alumina
OANA-ROXANA HAUTĂ, MARIUS-SEBASTIAN
SECULA, IOAN SOLOMON, IOAN MĂMĂLIGĂ
pages 99 - 104
Abstract The present paper
examines the adsorption of water vapors by mesoporous alumina containing
various amounts of hygroscopic salt impregnated in his pores. The mesoporous
structure of alumina was studied by BET technique. The water adsorption was
studied under classical industrial conditions (a temperature of 30ºC and
relative humidities of 40% and 60%). Keywords: composite adsorbent,
alumina, water vapors adsorption.
Ni–Ti–Nb tapes obtained by rapid
solidification technique
GYÖRGY THALMAIER, N. JUMATE, I.
VIDA-SIMITI, L. BUKKOSI
pages 105 - 111
Abstract Nickel–titanium–niobium
alloys are known as promising hydrogen-selective membrane materials. They
can potentially be combined with a suitable water–gas shift catalyst to form
a catalytic membrane reactors, which can produce high-purity H2
and CO2 streams from coal-derived syngas at elevated
temperatures. The possibilities of obtaining thin tapes by rapid
solidification technique from the Nb–Ti–Ni alloy have been examined. The
master alloy was prepared by arc melting using high purity Nb, Ti and Ni in
a Ti-gettered argon atmosphere. The alloys were melted several times in
order to improve homogeneity. The alloy ingot was induction-melted under a
high-purity argon atmosphere in a quartz tube and graphite crucible injected
through a nozzle onto a Cu wheel to produce rapidly solidified amorphous
ribbons. Investigations were made regarding thermal stability and mechanical
behavior of the obtained tapes using scanning electron microscopy, X-ray
diffraction and tensile tests. Keywords:
nickel–titanium–niobium alloys; rapid solidification; amorphous
tapes.
Synthesis and characterisation of a
new class of bent-core type compounds
DRAGOŞ-FLORIN IUGANU, GHEORGHE
SIMION, DAN SCUTARU
pages 113 - 118
Abstract The synthesis and
structural characterization of some new symmetric bent-core compounds which
have as central core 1,3-bis-(4`-hydroxyphenylazo)benzene are reported.
Compounds were prepared by esterification of the central core with a series
of aliphatic carboxylic acids. 1H-NMR, 13C-NMR, IR and
mass spectroscopy were used for structural characterization of these
compounds. Keywords: symmetric bent-core compounds,
1,3-bis-(4`-hydroxyphenylazo)benzene.
Ground and tap water quality
assessment of Sagar city especially in terms of saturation index
HEMANT PATHAK, DEEPAK PATHAK, S.N.
LIMAYE
pages 119 - 126
Abstract The present research is
aimed at assessing the saturation index for the ground/tap water of Sagar
city to assess the suitability of water for human consumption. This has been
determined by collecting water samples from selected 24 locations covered
entire city, and subjecting the samples to a necessary chemical analysis in
3 seasons from PreMonsoon 2008 to Post Monsoon 2010 was carried out to
assess suitability of ground/tap water. The results of chemical analysis
have been used to determining water quality. The results obtained from
Langelier Saturation index (LSI) and Ryznar saturation index (RSI) revealed
that the water quality of the Sagar city needs some degree of treatment
before consumption, and it also needs to become imperative to regularly
monitoring the quality of water to protect it. The mean positive LSI value
for the samples was 1.556, indicates over saturated and it can precipitate
calcium carbonate and mean RSI value 4.546 for all the samples
i.e. less than 6 it means water is
scale forming. Thus it becomes necessary for the assessment and management
the scale formation and corrosiveness in reference to sampling places.
Keywords: Ground/Tap water, Langelier saturation index, Ryznar saturation
index.
Formation mechanism of polymer films
NICOLETA BUNDUC, MARIA-ANDREEA
LUNGAN, CIPRIAN NEGOESCU, IOAN MĂMĂLIGĂ
pages 127 - 143
Abstract Understanding the
mechanism of formation for polymer films is fundamental to the success of
many industrially products such as paints, coatings, adhesives, medical
devices etc. In the last decades, the environmental concerns due to emission
of large amounts of volatile organic compound (VOC) have forced the coating
industry to move away from traditional organic based formulations towards
water based dispersions. Hence a series of new and innovating methods for
film formation were developed. This review of polymer film tries to provide
a general overview of the trends taken into consideration when a coating
material is developed, but without providing any specific values of
variables or quantities which may be a function of a polymer’s composition,
molecular weight or functionality. Keywords:
film formation, latex, dispersions,
deformation of particles.
New catalysts for chemoselective
hydrogenation of cinnamaldehyde based on Co and Cu incorporation in MgAl LDH
matrix
BRÎNDUŞA DRĂGOI, ADRIAN UNGUREANU,
ALEXANDRU CHIRIEAC, EMIL DUMITRIU
pages 145 - 155
Abstract
A series of Mg/Co/Cu/Al
layered double hydroxides (LDHs) with variable Co/Cu ratios but constant
Mg/Al, as well as M2+/M3+ ratios, was synthesized by
co-precipitation under low supersaturation with CO32–
as compensating anion. The aim of the study was to investigate the influence
of the catalysts composition, especially Co/Cu ratio, on the catalytic
properties of the as-synthesized materials. According to XRD results, all
the samples are well crystallized and contain only pure LDH phases while the
spectroscopic techniques (FT-IR and DR UV-Vis) indicated that both Co and Cu
species are substituted in the brucite-like layers. The shape of the
nitrogen physisorption isotherms obtained at –196°C indicates a
predominantly mesoporous texture of materials. The chemoselectivity of the
as-made materials were evaluated in the liquid phase hydrogenation of
trans-cinnamaldehyde. Keywords: LDH,
MgCoCuAl,
co-precipitation,
cinnamaldehyde, hydrogenation.
Acetylacetone used as a complexing
agent in ZnO precursor solution
MIHAELA POPA
pages 157 - 161
Abstract ZnO precursor solution
was prepared by using zinc acetate, ethanol and acetylacetone, as a
complexing agent. The stability in time of the solution was observed.
Increasing the metal concentration in the precursor solution from 0.2 to 0.4
M, a decrease of the solution stability was observed. The FTIR analysis
indicated the formation of zinc acetylacetonate,
prior to the precipitation of the ZnO precursor solution.
Keywords: ZnO; acetylacetone;
solution stability.
Experimental study of active carbon
drying in a batch fluidized bed
MIRCEA TEODOR NECHITA,
STELIAN PETRESCU
pages 163 - 172
Abstract This paper presents a
study on the batch fluidized bed drying of active carbon granules with high
content of moisture, using air as drying agent. The effects of the initial
moisture content (80, 90, and 95%), of the drying agent flow (14, 18, 40 and
78 m3·h-1) and temperature (40, 50 and 60ºC) have been
studied. The rate-determining step was established based on the
shrinking-core model. It was found that not one, but two elementary steps
are simultaneously rate limiting for the drying process. Keywords: drying
kinetics, evaporation, film diffusion, pore diffusion, shrinking-core model.
Analysis of the cellolignins
obtained from hydrolytical conversion of vegetal materials
ADINA - ELENA PÂNZARIU, TEODOR MĂLUŢAN
pages 173 - 181
Abstract The paper presents
chemical composition of the vegetal materials obtained during the various
treatment with hot demineralized water in a flowthrough mode, batch mode,
under pressure (200÷400 atm), in the temperature range of 150°C÷190°C. The
Fourier transform infrared spectroscopy (FTIR) method has good potential to
determine the structural characteristics and distribution of chemical
components in vegetal materials. Using FTIR technologies, it was found a
correlation between FTIR data and chemical composition of vegetal material,
the ratio of peak areas of polysaccharides (Pz) to lignin (L) in cellolignin
increased from 0.45 (140°C) to 0.64 (150°C) for the hydrolysis under
pressure, while if the hydrolysis without pressure decreased (0.21).
Keywords: infrared spectroscopy, vegetal materials, cellolignin, hot water.
Lavender oil. Origins. Properties.
Applications
ANDREIA TOPALESCU, CORINA CERNĂTESCU
pages 183 - 188
Abstract Lavandula is a plant
that undergrowth to a height of up to 50 cm with thin and woody stems, small
leaves of green-gray, lilac-red and the lignified roots 2-3 cm thick.
Volatile oil, distilled from fresh inflorescences of lavender and Lavandin
is the main product of this plant and is widely used in perfumes and
cosmetics industry. Lavender oil has a soothing and calming effect, relieves
tension and otherwise helps the digestive system. Lavender oil is one of the
few essential oils that can be used for all types of skin problems such as
abscesses, acne, oily skin, sunburn, wounds, lice, insect bites, and stings,
and is especially useful when treating a minor burn, wound. Keywords:
Lavandula, Lavander oil, therapeutic properties, lavender uses.
Kinetic modelling of the cathodic
hydrogen release process in acid environments
LILIANA LAZĂR, NICOLAE APOSTOLESCU,
FLORIN BANDRABUR
pages 189 - 199
Abstract Metal materials
corrosion in strong acid environments takes place according to the anodic
oxidation process of the metal compensated by the cathodic process of
hydrogen release. This paper treats the kinetic modelling of the cathodic
process of hydrogen release in the Zn-OL37 bimetallic systems corrosion
process in aggressive environments based on sulphuric and formic acid
respectively. The kinetic mechanism of the process involves elementary
processes of hydrogen ions transfer through the liquid phase and surface
transformation. The plate model was employed as model for the metal and
electrolyte contact to describe the mathematic relation considering that the
corrosion takes place uniformly on the entire surface. Keywords:
corrosion, hydrogen transfer, kinetic mechanism, modelling.
BOOK REVIEW: Hair Care Formulation for All Hair
Types. Edited by Cosmetics & Toiletries Allured Books, 2011, ISBN:
978-1-932633-86-3.
review by CORINA CERNĂTESCU
pages 201 - 204
STELIAN PETRESCU in memoriam
by IOAN MĂMĂLIGĂ
pages 205 - 206
2012,
Volume LVIII (LXII), Issue 3
Optimization of Several Process
Parameters for Indigo Carmine Adsorption by Activated Carbon Using Central
Composite Design
MARIUS SEBASTIAN SECULA
pages 9 - 18
Abstract The response surface
methodology was applied for modeling and optimization of the adsorption
process of an acid indigoid dye from aqueous solutions on granular activated
carbon (GAC). The considered independent variables were the initial pH,
ranged between 3.64 and 10.36, GAC dose, ranged from 0.16 to 1.84 g·L-1,
and initial dye concentration, ranged from 33 to 117 mg·L-1. A
rotatable central composite design was employed in order to develop two
second order polynomial models as functional relationships between
adsorption capacity and color removal efficiency respectively and the
independent variables. Keywords: response surface modeling,
optimization, adsorption, granular activated carbon, indigo carmine.
Influence of pH and Redox Potential
on Electrochemical Treatment Efficiency in Case of Soil Pollution with
Petroleum Products
IRINA ISTRATE, DIANA MARIANA
COCÂRŢĂ, ADRIAN BADEA, TALIDA CÎRLIORU
pages 19 - 27
Abstract
The present paper presents the main results obtained during the
developing of two different research approaches. One has been developed
during a project co-funded by the European Regional Development Funds, while
the second one, during a post PhD research. Both experimental researches
involved the application of electrochemical treatment on petroleum product
polluted soil. For the first case, artificially soil contamination with
total hydrocarbons was used. In the second case, the pollution was natural
and resulted during the extraction and processing of different petroleum
products. The paper illustrates the correlation between the pH and ORP
changes and the treatment efficiencies of the performed tests. The main
conclusion of the present research is the fact that, if we have a much
higher initial hydrocarbons concentration in soil, the necessary treatment
time must be increased. The artificially contamination had an initial
concentration of 8.33 mg/kgdw, while the natural one was 33.20
g/kgdw. Keywords: pH, redox potential, hydrocarbons,
electrochemical remediation.
Producers and Distributors Survey on
Green Products in Romania
VASSILIS INGLEZAKIS, VALENTIN
NEDEFF, MIRELA PANAINTE, IULIANA CARAMAN, CARMEN MURARU, MIHAI DRAM, LAURA
FOCARIU, CHRISTOS VENETIS, PHILIPOS COUTSIKOS
pages 29 - 40
Abstract
The green products market in Romania is just in the beginning of
its development and the concept of eco-products is quite new for Romanians
with the exception of the food sector. It is also true that
producers/distributors of products are not informed on the business
opportunities relevant to green products. In order to raise awareness
-regarding green products, the project LIFE+08/INF/RO/000507
"Promoting Green Products",
financed by the European Commission through the LIFE+ program was developed
and is under implementation (2010-2013). In the framework of the project, a
questionnaire has been created targeting producers/distributors. The main
aim of this questionnaire was to capture the feedback of
producers/distributors on green products. The questionnaire was sent by the
Bacău Chamber of Commerce (partner in GREEN PRO project) to all its members
and in total 155 questionnaires with useful data was collected. From the
above data analysis it can be concluded that the producers/distributors are
not very interested to respond to questions about green products and many of
them have no a clear idea about green products and eco-labeling. The change
of customers’ demand/needs and feedback was identified as the significant
factor that could influence the eco-material/component/product’s development
while the majority of participants to the survey expressed their desire to
participate in events at home and abroad to promote eco products. Finally,
the most suitable fiscal measure to promote green products is a combination
between lower taxes for environmentally friendly products and increase taxes
for products that harm the environment. Keywords: green products, green
labels, eco-labeling, LIFE+, Romania, market research.
Combined Chemical/Cold Plasma
Treatment for Functionalization of Some Polymeric Films
CONSTANTIN LUCA, ANA-MARIA GRIGORIU,
EMIL GHIOCEL IOANID, DORINA-EMILIA RUSU
pages 41 - 53
Abstract
Aiming at applying some ecological technologies for the polymeric
films for food package materials, the present paper suggests the involvement
of plasma treatment as a distinct stage in the support activation for the
improvement of the chemical treatment effects. The functionalization agent,
monochlorotriazinyl-β-cyclodextrin (MCT), bearing as guests different
substances (ferulic acid, allantoin, Michler ketone) with antimicrobial or
anti-UV properties, has been investigated. This study also includes a number
of physical surface -sensitive methods revealing the efficiency of the high
frequency cold plasma treatment, such as: scanning electron microscopy and
energy-dispersive X-ray microanalysis (SEM-EDX), atomic force microscopy
(AFM), Fourier Transform Infrared Attenuated Total Reflexion (FT-IR ATR) and
Ultraviolet (UV) techniques, wetting angle. Keywords: chemical
treatment, cold plasma treatment, polymeric films,
monochlorotriazinyl-β-cyclodextrin.
Determination of Activated Corrosion
Products Concentration in Spent Resins from Nuclear Power Plants
RUXANDRA TOMA, ILIE PRISECARU
pages 55 - 63
Abstract
This paper presents the mathematical model for the determination of
activated corrosion products concentration in spent ion exchange resins from
the primary heat transport purification system in a CANDU 6 nuclear power
plant. Spent ion exchange resins from a nuclear power plant represent a very
important issue as they need to be properly characterized for disposal in
the final repository. Keywords: CANDU 6, nuclear, radioactive waste,
spent resins.
Impact Assessment of PAHs and Heavy
Metals from Industrial Pollution Sources in a Central Romania Area
Abstract
The present paper illustrates the impact of heavy metals and PAHs
pollution in a Central Romania metallurgical industrial area, where
authorities are trying for many years to reduce or to maintain below allowed
limits heavy metals concentrations in soil. In order to develop an
integrated methodology for human health risk concerning the organic
pollution, also PAHs were identified. Existing contamination level was
pointed out through soil samples laboratory analyses from 0 -0.2 and 0.2
-0.4 m soil layers depth. Some heavy metals concentrations exceeded the
intervention thresholds for sensitive use related to the national
regulation. As an unexpected result, also PAHs background contamination was
identified, even that not as significant as for heavy metals: PAHs
concentration in soil between 1 - 56 µg·kg-1d.w for surface soil layer and 1 - 330
µg·kg-1d.w
for depth soil layer. Considering the synergism of both types of persistent
pollutants, the potential risk for the human health and living organisms,
became a concern and an important issue in this area. Keywords: heavy
metals, PAHs, pollution, intervention thresholds, sensitive use, exposure.
Fuel Consumption and CO2 Management
in Petroleum Refinery
MIHAELA NEAGU, DANIELA LUMINIŢA
MOVILEANU, ION ONUŢU, PAUL ROŞCA
pages 79 - 90
Abstract
The present study investigated the fuel consumption, energy
distribution and CO2 emissions in a typical Romanian petroleum
refinery. A way to reduce these emissions is CO2 post-combustion
capture and storage (CCS) from refineries flue gases. The opportunities of
CO2 capture are evaluated based on the sources’ intensity and
their distribution around the site. The study is structured in five
sections. Section 1 provides an overview of the product quality impact and
demand evolution on the EU oil refining industry in terms of energy
consumption and CO2 emissions. Section 2 describes the profile of
a typical Romanian oil refinery and stationary combustions source placements
in the refinery block diagram. The fossil fuels type used in the refinery
and their contribution to every heating process are also discussed. Section
3 estimates the CO2 emissions according to the IPCC methodology
based on the amount of each type of fuel and the default emission factors.
In order to perform a suitable classification of CO2 sources,
calculations of CO2 concentration in flue gases in the main
combustion processes are shown in section 3. Section 4 explores the options
for CO2 capture based on sources distribution, intensity and CO2
concentration in flue gases. In terms of source intensity, the CHP (Combined
Heat and Power) plant is feasible for CO2 capture. The FCC (Fluid
Catalytic Cracking) is a point source with CO2 high
concentration, which is an advantage in terms of CO2 capture. The
opportunity to combine a number of close smaller sources (such as catalytic
reforming and hydro-treating processes) and route all these emission sources
to a single CO2 capture plant seems to be a valuable option. The
final conclusions reported in Section 5 showed that CCS in a Romanian
petroleum refinery is technically feasible to be applied. Keywords:
fuel, refinery, CO2 management.
The Influence of Some Essential Oils
of Aromatic Plants on Cell Division
VERONICA STELUŢA MINCIOR, VASILICA
BARBU
pages 91 - 99
Abstract
Essential oils are mainly obtained by steam distillation of some
aromatic plants in special installations. Because of their antibacterian and
antifungal properties, they represent a viable option to replace chemical
food additives such as preservatives or flavoring agents. The purpose of
this study is to evaluate the citotoxicity and genotoxicity of basil (Ocimum basilicum), thyme (Thymus
vulgaris) and oregano (Origanum
majorana) essential oils on some meristematic plant cells. All these
measurements were accomplished in order to identify some oil concentrations
low enough not to induce significant mitosis abnormalities to the tested
plant tissue. In the first stage of the cytogenetic assay, the plant tissue
was preserved in water up to the point when the root tips started to
develop. Consequently, the meristems were immersed for 3 respectively 6 h in
a micro emulsion, essential oil based and obtained through a previous
ultrasonic treatment. Following the completion of exposure time, the roots
were detached and fixed with Carnoy solution for 24 h. The coloring method
involved aceto-carmine staining and simultaneous hydrolysis of the plant
cells’ walls using HCl 1N at 60°C for 10 min. The root tips containing
meristems were squeezed in carmin stain and analyzed with an optic
microscope (Olympus CKN41 SF model). An important decrease of the mitotic
index was shown, despite the fact that only a few cell division
abnormalities were noticed at low concentrations. The results were
statistically processed with the SPSS 13.0 software for Windows and the
ANOVA test showed to be significant for P < 0.05. Keywords: essential
oils, meristems, cell division, abnormalities, Ocimum basilicum, Origanum
majorana, Thymus vulgaris.
Study Concerning the Extraction of
Photosynthetic Pigments from Spinach
RAMONA MIHAELA COJOCARU, IONEL
MARCEL POPA, GHEORGHE SURPǍŢEANU, ANA MARIA ROŞU, NECULAI DORU MIRON, ILEANA
DENISA NISTOR
pages 101 - 109
Abstract
This study was aimed to asses the feasibility of extracting
photosynthetic pigments and compares the content of chlorophylls and
carotenoids obtained through different extraction methods. Changes in the
levels of these compounds were also determined in the course of
technological process of freezing and drying. Pigments were separated by
solvent extraction using acetone, diethyl ether, ethanol and
dimethylformamide. The isolation procedures investigated in this study
included the method of single step extraction, Soxhlet extraction and ultra
sound assisted extraction. Ultraviolet-visible spectroscopy was used to
evaluate the efficiency of the extraction methods and it was also used to
quantitatively analyze the extracted chlorophylls and carotenoids. The
optimum extraction method was established depending on the processing method
applied to the raw material. Keywords: chlorophyll, total carotene,
spinach, extraction.
Environmental Assessment of
Pyrolysis as Ex-Situ Thermal Treatment Applied to PAHs Contaminated Soils
Abstract
In the last years, decontamination of the soil polluted with PAHs
gained an increasing interest in the environmental field (EEA, 2007). With
this aim, the present paper describes laboratory experiments focused on
pyrolysis efficiency concerning PAHs removal from crude oil-contaminated
soil. Additionally, emissions from the thermal treatment were analysed in
order to assess the environmental impact. Experiments were conducted for
temperature ranged from 350ºC to 600ºC, using a small scale bench reactor.
Tests were performed for two different types of polluted soil samples: in
the first case it was about anthropogenic contamination (oil spills), while
in the second case it was done artificially pollution with crude oil. The
experimental results showed a significant pyrolysis process efficiency
concerning PAHs removal from contaminated soils. ΣPAHs removal efficiency
over 99% was gained applying the pyrolysis treatment only for temperatures ≥
than 600°C and 30 min retention time. Keywords: decontamination,
emissions, PAHs, pyrolysis, soil.
Steam Reforming of Bio-Ethanol Over
Pt/SBA-15 Catalyst
DĂNUŢA GHIŢĂ, PAUL ROŞCA, DORIN
STĂNICĂ EZEANU
pages 123 - 130
Abstract
Bio-ethanol reforming process to produce hydrogen was performed
using Pt catalyst supported on mesoporous SBA-15 prepared by impregnation
method. The catalyst was tested in a fixed bed reactor at atmospheric
pressure over a temperature range of 300ºC to 500ºC. Bio-ethanol from
renewable sources (alcohol 10%) was used as raw material for the experiment.
The catalyst was prepared and characterized by N2
adsorption/desorption, XRD (SAXRD and WAXRD), XPS and TGA techniques. The
results confirmed that the as obtained mesoporous support SBA-15 shows a
well-ordered hexagonal array structure. On the other hand the nitrogen
adsorption/desorption are type IV exhibiting a H1 hysteresis loop
characteristic of large pore mesoporous materials with narrow pore size
distribution. The results obtained from ethanol steam reforming process have
shown that the main reaction is staged by a number of secondary reactions.
The gaseous products resulting from the reaction were analysed on-line using
a gas chromatograph Varian CP-3800. Previous to reaction, catalyst was
reduced under flowing hydrogen at 550ºC for 6 h. The catalytic results
indicate that Pt/SBA-15 mesoporous material can be used as catalyst for
steam reforming bio-ethanol reaction. Keywords: steam reforming,
ethanol, Pt, SBA-15.
Study Concerning the Utilization of
Cellulose Derivates as Development Support for Microorganisms
ANDREA-ELIZA FARKAS, DAN SCUTARU,
DORU NECULAI MIRON, ANA-MARIA ROŞU, CARMEN ELENA ŢEBRENCU, ILEANA DENISA
NISTOR
pages 131 - 140
Abstract
Cellulose is considered as a nearly inexhaustible raw material with
fascinating structures and properties for the remarkable demand for
environmentally friendly and biocompatible products. Each rest C6H10O5
of cellulose molecule, originated from glucose, contains three alcoholic
groups OH. This is derived from the fact that cellulose can turn in
triacetyl-derivates, trimethyl-derivates and in other esters and ethers. The
main changes made to these polysaccharides are realized in order to obtain
esters and ethers. Utilization of cellulose derivates is various. Derivates
obtained through etherification such as methylcellulose is used in the
preparation of construction materials and cosmetic paints; ethylcellulose is
used to fabricate adhesives, paints and films; carboxymethyl cellulose is
used in the preparation of detergents, food, pharmaceutical and textiles
products, and the benzylcellulose is used to fabricate varnishes. Derivates
resulting from esterification are used in the preparation of explosives,
fuels, paper, adhesives (cellulose nitrate), textiles, cigarette filters and
ultrafiltration membranes (cellulose acetate) and to obtain detergents and
cosmetics (cellulose sulfate). In addition, they can be used in the
preparation of fireproof materials (deoxycellulose phosphorus). The aim of
this study was to obtain cellulose acetate (Cabiac
et al.) and carboxymethyl
cellulose (CMC). CMC was obtained by replacing a hydroxyl proton with a
carboxymethyl group. The reaction occurred between cellulose and
chloroacetic acid in basic medium. CA was obtained from the reaction of
cellulose and a mixture of acids (H2SO4 + CH3COOH).
Both products were analyzed using
Fourier Transformed InfraRed spectroscopy (FTIR) and determining the
degree of substitution for their characterization. FTIR analysis showed the
success of reactions and the synthesis, by chemical modification, of CA and
CMC. The objective pursued was to create a chemically modified macromolecule
tolerable by microorganisms, in view of industrially application. Tests were
performed on some microorganisms (sp.
Penicillium and
sp. Cladosporium) to observe their development using as substrate
cellulose and cellulose derivates. Results obtained shows that the
modification of the initial cellulose structure allows its use as substrate
favoring the development of microorganisms. Keywords: cellulose
derivates, microorganisms, degree of substitution.
Permanent Hard Water Softening Using
Different Cation Exchange Resins
BOGDAN BANDRABUR, LILIANA LAZĂR,
RAMONA-ELENA TATARU-FĂRMUŞ, LAURA BULGARIU, GHEORGHE GUTT
pages 141 - 150
Abstract
This paper presents a comparative study on the behaviour of two
synthetic ion-exchanger used for food water softening based on different
functional groups: Purolite C100E
and Pure PC200FD. Investigations
on the practical sorption capacity in the softening process on calcium and
magnesium binary chloride solution and natural ground water were conducted
in batch mode as function of the ion exchange process’ specific experimental
factors. FTIR spectra for cationic exchange resins samples before and after
retention of Ca2+ and Mg2+ ions were used to show
conclusive evidence for ion exchange process. Keywords: food grade water
softening, ion exchange, SAC, WAC, resins.
Grape Phenolic Evolution Study of
Cabernet Sauvignon During the Maturation Period in Iaşi Vineyard
ŞTEFAN TUDOSE-SANDU-VILLE, VALERIU
V. COTEA, MARIUS NICULAUA, CINTIA COLIBABA
pages 151 - 159
Abstract
Red grapes contain a high quantity of phenolic compounds in skins,
which are being transferred partially in wine during the maceration
procedure. These are being accumulated during the maturation period and
reach maximum concentrations at phenolic maturity. The present study follows
the phenolic maturation evolution for the Cabernet Sauvignon grape variety
in Iaşi-Copou vineyard during 2009 harvest. From the mean grape samples,
harvested once every five days, from start of ripening to harvest, phenolic
compounds from skins have been completely extracted using methanol and
hydrochloric acid; specific analysis methods to phenolic compounds have been
applied to the extracts, most important being the anthocyan profile by using
a HPLC method of analysis, in order to point out the optimum harvest moment
and grape proficiency in future wine processing in regard to total phenolic
concentration. The HPLC analysis determined and quantified the relative
proportions of the following anthocyans: delphinidin-3-monoglicoside (Dp),
cyanidin-3-monoglicoside (Ci), petunidin-3-monoglicoside (Pt),
peonidin-3-monoglicoside (Po), malvidin-3-monoglicoside (Mv),
peonidin-3-monoglicoide-acetilate (Po-a), malvidin-3-monoglicoide-acetilate
(Mv-a), peonidin-3-monoglicoide-cumarilate (Po-c) and
malvidin-3-monoglicoide-cumarilate (Mv-c). The obtained data was correlated
with the climatic parameters variation registered during the maturation
period. Keywords: polyphenol, grapes, maturation, anthocyans.
2012,
Volume LVIII (LXII), Issue 4
Ultrasound and microwave assisted
extraction – sustainability through efficiency
ANI ALUPULUI, IOAN CĂLINESCU, VASILE
LAVRIC
pages 9 - 17
Abstract The aim of the paper is
to assess the sustainability of ultrasound (UAE) and microwave (MAE)
assisted extraction through an economic analysis.
Our results show that the usage of these modern
intensification techniques (UAE and MAE) leads to the minimization of the
production costs, the maximization of the extraction efficiency yields,
while significantly reduces the processing time.
Microwave and
ultrasonic fields were used separately to extract bioactive constituents
from Stevia rebaudiana Bert. leaves
(SR), Cynara scolymus leaves (CS)
and Arctium lappa roots (AL). UAE
and MAE need special equipment to be functional, translated into higher
investment costs, and electricity to produce the ultrasonic and microwaves
fields, which means rather high operating costs, as compared to the
classical techniques. But, due to the significantly shorter operating times,
the productivity of the former outscores the productivity of the latter
methods. Both intensive extraction techniques seem to be economically
promising, simple and efficient. Keywords:
ultrasound-assisted extraction (MAE), microwave-assisted extraction
(MAE), flavonoids, phenolic acids, stevioside.
Direct extraction of butanol from
fermentation broth
ALEXANDRA CÂRLESCU, LENUŢA KLOETZER,
ANCA-IRINA GALACTION, DAN CAŞCAVAL
pages 19 - 33
Abstract The production of
butanol by fermentation, also known as the "acetone–butanol–ethanol (ABE)
fermentation", is one of the oldest fermentation processes used for the
commercial production of a chemical. Recently, there has been a great
interest in "green" butanol fermentation (biobutanol) both as a potential
fuel and as a chemical feedstock. Biobutanol is not economically competitive
when produced using traditional batch fermentation because of product
inhibition which generates low productivities and low product concentration.
In order to deal with this issue, several methods have been developed for
removing the butanol from fermentation broth beyond the constraints of
normal batch fermentation. Among them, liquid-liquid extraction represents
an advantageous method for butanol recovery from fermentation broth, mainly
due to high extraction capacity of the solvent and the high selectivity of
the alcohol/water separation. Keywords: butanol, liquid-liquid
extraction, fermentation broth.
Glucose analysis in extracts of some
fruits and vegetables with a high sweet degree
CLAUDIA COBZARU, CORINA CERNĂTESCU
pages 35 - 39
Abstract We identified and
calculate the glucose content in three extracts from: apples, grapes and
carrots, raw materials considered to have a high sweet degree. After FTIR
analysis and coresponding calculus it has been showen that the glucose
amounts are low in all samples, but slighly higher for apples compairing to
other two. Keywords: extract, glucose, apples, grapes, carrots.
Aroma compounds from tămâioasă
românească wines obtained through cryomaceration
CINTIA COLIBABA, VALERIU V. COTEA,
MARIA CODREANU, MARIUS NICULAUA, ŞTEFAN TUDOSE-SANDU-VILLE
pages 41 - 46
Abstract The study has analysed
wines produced from Tămâioasă românească grapes from Cotnari vineyard. The
wines were obtained by using cryomaceration technology (freezing the grapes
at −20ºC and their processing in this phase). The obtained wines were
analysed after the second racking, through gas-chromatography coupled with
MS. The extracts were obtained by using SPEs, LiChrolut EN/RP-18 cartridges.
The aroma compounds were determined using the NIST 08, Wiley 08 and SZTERP
spectrum library. The results showed the presence of high quantities of
linalool and hotrienol, and also other compounds with a sensorial profile in
cryomacerated wines. Keywords: Tămâioasă românească, aroma compounds,
cryomaceration, gas-chromatography.
Poly (ε-caprolactone) nanocapsules
immobilized into chitosan microgels for controlled release of active
principles
Abstract There have prepared
chitosan based microgels containing PCL nanocapsules for controlled release
of indomethacin. Microgels were obtained by ionic crosslinking of
polysaccharide in W/O emulsion and polyester based nanosuspension by
nanoprecipitation. Nanocapsules stability, size and zeta potential as well
as particles morphology were evaluated. The incorporation of indomethacin
into PCL nanocapsules proved to retard and sustain the in vitro release, as
compared to incorporation into chitosan microgels. Keywords:
poly(ε-caprolactone), nanocapsules, chitosan, microgels, controlled release.
Integrated rural tourism in regional
marketing
ISTVÁN RÁDULY, LENKE RÁDULY
pages 55 - 62
Abstract Over recent years, the
philosophy and methods of marketing have been extended to encompass a
diverse range of activities, one example of which is the marketing of
regions or localities. Territorial or regional marketing is especially
important for rural tourism, where individual attractions are too small and
too widely dispersed to reach a critical mass sufficient to attract guests.
This fragmentation is accompanied by low added value and underdeveloped
services - which further restricts the inherent possibilities. This paper
argues that an integrated approach to rural tourism is needed, and that its
development must be carried out in cooperation with agricultural and local
government interests, both of which could benefit from the increased
economic activity, and both of which contribute to the attraction of a given
locale or area. This integrated approach encourages better land management
and the conservation of the rural cultural heritage. Financing can be made
possible by utilizing the resources of LEADER+, an EU community initiative
whose philosophy will be integrated into the framework of a reformed Common
Agricultural Policy during the 2007-2013 programming period. Keywords:
tourism, ecological function, rural development, cultural landscape.
Preparation of natural polymers
based microcapsules by double crosslinking in double emulsion
Abstract The aim of the paper was
the preparation and characterization chitosan and gelatin based
microcapsules, prepared by double crosslinking (ionic and covalent) of
polymers in an O/W/O double emulsion. The varying ionic crosslinker/ polymer
molar ratio influenced particle size, morphology, swelling degree and their
capacity to release hydrophilic model molecules. Keywords: microcapsules,
chitosan, gelatin, double crosslinking, O/W/O emulsion, drug release.
The simulation for determination of
optimal reflux number using planovski method
TIBERIU-MIHAI STURZU, IOAN MĂMĂLIGĂ
pages 71 - 77
Abstract This paper presents an
algorithm and a computer program for the simulation of optimal reflux number
determination using Planovski method. The program obviously brings
up-to-date the method that was abandoned due to a high quantity of work that
a computer can do now in only a few seconds. Keywords: optimal reflux,
Planovski method, fractionation columns.
Effect of vegetable and animal fats
on oxygen mass transfer in stirred bioreactors
ELENA FOLESCU
pages 79 - 89
Abstract The biological treatment
of wastewaters (for example from food industry) is, nowadays, one of the
most important biotechnological processes. Among these "green technologies",
the use of aerobic microorganisms as degraders of the pollutants is very
often utilised. Hence, oxygen mass transfer is a key parameter involved in
the design and operation of the mixing–sparging bioreactors used, and it can
be analyzed by means of the oxygen mass transfer coefficient (kLa).
In the wastewaters of food industry, oils, vegetable or animal, represents a
great part of the overall pollutants. In this study, was evaluated the
possible use of these contaminants both as oxygen-vectors and as nutrients
in the bioremediation process. So, the influence of a second liquid phase
(from wastewaters) with higher oxygen affinity (vegetable oils and lard) on
kLa in a submerged aerated 4L stirred bioreactor was recorded and
the influence of the following parameters on the oxygen transfer rate was
evaluated: the volumetric fraction of the organic phase, the rotational
speed of the impeller and the aeration flow rate. Keywords: lard, oxygen
mass transfer, oxygen-vector, stirred bioreactor, wastewater treatment,
vegetable oil.
Statistical methods – common
denominator in scientific research
MARIANA ENACHE, CRISTINA DASCĂLU,
GABRIELA APOSTOLESCU, BEATRICE IOAN
pages 91 - 101
Abstract Common knowledge in the
sense of the word, define empirically on the direct experience of each of
us, in a certain physico -chemical space, social, cultural, in a certain
time. Scientific knowledge contributes to determining the nature of the
phenomena and of modes of manifestation of the laws that govern this area.
To do this, knowing the research utilizes a varied instrumentation, which
led to the development of a research methodology. Scientific reasoning has
to be adapted to the scope in which to do research (technical, biological,
medical, teaching, etc.) and according to a specific plan for a specific
kind of scientific thinking. We carried out a study of the
esk research, using sources of
information with the theme scientific research, statistics analysis used in
different fields of research. The importance of statistical methods derives
from the fact that they constitute the only means sometimes subjective data
quantifying, measuring and analysing them after the rigors of science and
especially of generalizing the findings to the entire population from which
the batch analysed using rules of mathematical induction. Considering the
importance of objectives is evident that the design and development of a
statistical study should be made very carefully, selecting the most
appropriate methods of handling and analysing data - providing guarantee the
proper conclusions. Interdisciplinary approach and use customized
statistical methods allow researchers studying subjects with medical
implications reach closer to scientific truth derived from the real data
collected and analysed. Can benefit from such treatments all medical fields,
clinical, clinical or epidemiology and public health, all in support of
health, quality of life. Keywords: scientific research, statistical
analysis, descriptive study, analytical study, interdisciplinary.
Studies of solutions derived from
used catalysts based on vanadium pentoxide
DANIEL SUTIMAN, MIHAELA VIZITIU,
DANIEL MARECI, NICOLAE FOCA
pages 103 - 114
Abstract In this paper, some
results regarding the behavior of used catalysts based on vanadium
penta-oxide, in aqueous solution are presented. The studied solutions are
derived from the reaction between the used catalyst and distilled water in
ratio 1:2. After 48 h of reaction, the solution was filtered in order to
separate the insoluble components. The resulted filtered solutions contain
the soluble components from the waste catalyst, the ions: Fe2+,
Fe3+, V3+, VO22+. These
solutions were submitted to other processes such as: reaction in atmospheric
air at 20°C; heating; oxidizing with hydrogen peroxide and sodium
hypochlorite. The variation of pH and the conductivity values of the
solutions in some reaction steps were also studied. The concentration of the
ions Fe3+ and V5+ was determined by spectroscopic
methods. Concentration of ion was determined gravimetrically. The main
purpose of the study was the separation of ions Fe3+ and V5+
and also the neutralization of the solutions derived from the waste
catalysts. Keywords: wasted catalysts; mixed oxide; spectroscopic and
gravimetric measurements; conductivity; neutralizing process.
2011,
Volume LVII (LXI), Issue 1
Adsorption Potential and Kinetic of
Processes of Hypercrosslinked Polymeric Resins and Activated Carbon for
Toluene Vapors
MARILENA ADELA BUBURUZAN, CEZAR
CATRINESCU, MATEI MACOVEANU
pages 11 - 23
Abstract The purpose of this
paper is to evaluate the adsorption potential of a new type of
non-functionalized hyper-cross-linked polymers Hypersol Macronet, MN 202 and
MN 250 for removing of toluene vapors from saturated atmosphere. The
experiments were performed comparatively with the adsorption of toluene
vapors onto a granular activated carbon, AC 20. The experiments were
performed to determine also loading rates of toluene onto adsorbents. The
results shows that the adsorption capacity,
q, [mg/g], for toluene vapors from
a saturated atmosphere are much greater for MN 250 and MN 202 polymers than
thus for AC 20 (479, 330 and respectively 253 mg/g). Analyses of the rates
data with three theoretical models (pseudo-first and pseudo-second-order
reaction models and the Elovich model) were used to describe the toluene
adsorption kinetics. Adsorption rate constants were determined by graphical
analysis of the proposed models. The study showed that adsorption systems
followed a pseudo-second-order reaction model provides an acceptable
description of the adsorption process. Keywords: adsorption, toluene,
VOCs, hypercrosslinked polymers, kinetics.
Corelations Between Recovered Paper
Quality and Collection Methods
ALINA IOSIP, ELENA BOBU
pages 25 - 41
Abstract In modern times when
environmental issues have taken a considerable extent, has become imperative
necessary recovering and recycling of raw materials used. Replacing virgin
fiber with recycled fibers proved necessary for European paper industry
which has been and will be a model of sustainability. Proof of this are the
statistics compiled by organizations such as CEPI (Confederation of European
Paper Industries), ERPA (European Recovered Paper Association), BIR (Bureau
of International of Recycling), CEN (European Committee for Standardization)
and INGEDE (International Association of Deinking Industry) showing that the
importance of recovered paper as a raw material in the paper industry has
increased dramatically in the last years, reaching in our days to represent
half of all fibers used in paper and board production. An important role in
recycling is attributed to the population which becomes aware of the need
for recovery with significant benefits both economically and environmentally
as well. Considering that use of
recovered paper to paper and board manufacturing is known for a long time,
and with increasing production of paper products has increased the amount of
recovered paper, to efficiently process and use, it is absolutely necessary
to know the origin source, to determine the nature and content of
contaminants, in a few words to follow changes on quality. Quality thus
becomes one of the most important criteria for paper products recycling, a
decisive factor influenced by the collection and sorting methods used.
Taking into account these basic ideas, this paper highlights the main
correlations between quality and recovered paper collection methods,
focusing on: the importance of paper and board recycling, main grades and
sources of recovered paper respectively the influence of different types of
collection systems on recovered paper quality. Keywords: collection,
quality, recovered paper, recycling.
Influence of Aqueous Extract from
the Bark of Picea Abies on
Development of a Yeast Species
Rhodotorula Spp.
ANCA-ROXANA HAINAL, IRINA VOLF,
VALENTIN I. POPA
pages 43 - 51
Abstract Bark of
Picea abies is a residue from the
forest industry with strong negative effects on the environment. The aqueous
extract of this raw material contain valuable polyphenolic compounds which
can be used as carbon source the red yeast. For this purpose, we tested the
effect of different aqueous extracts of spruce bark with various
concentrations in polyphenolic compounds on the development of yeast strains
of Rhodotorula spp. The
experiments followed the evolution of wet biomass yield and compounds with
biological activity produced by this yeast. There were also estimated the
consumption of polyphenols during the fermentative process. The experiments
also concluded that, depending on the concentration of polyphenols,
different results are registered in the biomass yield and pigments
carotenoids, which are correlated with the possibility of metabolism of
carbon source. Keywords:
Rhodotorula spp., spruce bark, polyphenols, β-carotene.
Rheological Modifiers of Natural
Origins Used in Cosmetic Formulations
ANDREI ROŞU, MARICEL DANU, GINA
AMĂRIOAREI, ALINA NANU, CONSTANŢA IBĂNESCU, MARIA LUNGU
pages 53 - 63
Abstract Rheology is an important
aspect of personal care and cosmetic formulations, and can influence the
overall consumer appeal of a product. Rheology impacts a product’s shelf
appeal via suspension, and influences a product’s spray pattern via
viscosity control. It can also create a different type skin feel and can
even take shape in the form of gels. This paper presents the rheological
properties of some rheological modifiers of natural origins used in
cosmetics and personal care products, and highlights how these features
control the stability and sensory attributes of the products. There are a
lot of aspects to consider when selecting a rheology modifier and therefore
requires a good knowledge of their ability to induce desired properties of a
cosmetic product, according to its destination. The current trend of using
natural ingredients in cosmetic formulations also refers to the rheological
additives. Keywords: rheological modifiers, oscillatory shearing regime,
modulus of elasticity, dynamic viscosity, temperature curve.
Evaluation of the Sorption Process
for Acid Orange 7 and Erythrosine B in Soil Using Various Kinetic Models
CAMELIA SMARANDA, LAURA CARMEN
APOSTOL, MARIA GAVRILESCU
pages 65 - 78
Abstract Kinetic studies are of
great concern for understanding the processes and parameters involved in the
sorption of pollutants by soils. Batch sorption kinetic experiments were
performed to study the adsorption of Acid Orange 7 (C.I. 15510;
M =350.32 g.mol-1) and
Erythrosine B (C.I. 45430; M =
879.86 g.mol-1) dyes from aqueous solution using soil from Iaşi
area. The operating variables studied were initial pollutants concentration,
contact time and adsorbent dosage. Kinetic analysis of the different models
has been carried out in order to asses which model provides the best fit
predicted data with experimental results. The pseudo-second-order kinetics
was found to fit the experimental data (R2
> 0.99) and was able to consistently predict the amount of dye adsorbed over
the process period and for the all range of studied concentration.
Keywords: Acid Orange 7, Erythrosine B, dyes, kinetic models, sorption,
soil.
Preliminary Study Concerning the
Anaerobic Digestion of Food Industrial Wastes
DANIELA ŞUTEU, ALEXANDRA CRISTINA
BLAGA, MARINELA BĂDEANU
pages 79 - 85
Abstract Biotechnologies applied
to treat biodegradable waste (aerobic and anaerobic digestion) have the
great advantage that reduces the volume of wastes, producing in exchange two
extremely useful products: biogas and compost. These applications of
biotechnology in environmental protection represent examples of useful
recovery that can be included in the trend categories developed in the
European Union to obtain new sources of energy, replace of organic chemicals
with green products, to improve soil performance without negative impact on
flora and fauna. Keywords: anaerobic digestion, food industrial wastes,
biodegradable wastes, biotechnologies, biogas.
Municipal Solid Waste Management -
Environmental Assessment from Life Cycle Perspective
CRISTINA GHINEA, MARIA GAVRILESCU
pages 87 - 95
Abstract Decision support tool
based on life cycle assessment - LCA-IWM Assessment Tool was applied for
modelling solid waste management at municipality level. Four scenarios were
developed in order to find the best solution for waste management in future
for Iaşi city and for testing the possibility of the LCA-IWM Assessment Tool
to evaluate them. Establishing of the alternative scenarios to the current
system of waste management in the city of Iaşi was done taking into account
the estimated amount of waste that will be generated for the year of
assessment. The scenarios were evaluated in two ways depending on
implementation planning of separate collection of solid waste. The
collection targets to be achieved in the tenth year since the implementation
of separate collection can be either according to the "optimal values" or "target values". The study analyses possible environmental impacts produced
by the treatment, disposal methods of municipal solid waste and potential
improvements of collection. Keywords: assessment tool, life cycle,
separate collection, waste management.
Contact Model Influence on The
Kinetics of Convective Drying Process of α-Al2O3
Catalytic Support
LILIANA LAZĂR, MARCEL VRÂNCEANU, ION
BALASANIAN, STELIAN PETRESCU
pages 97 - 108
Abstract The second part of an
experimental research regarding the kinetics of the process of convective
drying of α-Al2O3 porous granules, manufactured by
tabletting is presented in this work. These granules are used as support for
catalysts synthesis by method of impregnation without interaction. The
convective drying process was conducted in fixed bed by circulating the
drying agent through the bed. The drying curves and the drying rate curves
were obtained by using the experimental data at a drying agent rate of 2.52
m/s, and temperatures ranged between 313 and 343 K. The efficiency of
contact model on the kinetics of convective drying of α-Al2O3
granules used as catalytic support was established based on the comparative
study of experimental results obtained by using two contact models between
the drying agent and the wet material: fixed bed with drying agent
circulating through the bed (I) and fixed bed with drying agent circulating
at the bed surface (II). It has been shown that the contact model (I) leads
to lower times of drying than the contact model (II), and is favourable by
drying temperature point of view. Keywords: kinetics, contact model,
convective drying, catalytic support.
Preliminary Study of Orange 16 Dye
Sorption from Aqueous Solutions onto Industrial Lignin
CARMEN ZAHARIA, DANIELA ŞUTEU
pages 109 - 117
Abstract Sorption studies into
static regime were carried out for the retention of Orange 16 dye onto
industrial lignin powder from aqueous solutions. The influence of some
variables and operational conditions were studied (i.e. stirring regime,
temperature, pH, initial dye concentration, sorbent dose, operation time).
The obtained results of Orange 16 dye sorption onto industrial lignin
indicate the efficient possibility to use this sorbent for dyes removal and
decolorization of textile effluents. Keywords: industrial lignin powder,
Orange 16 dye, sorption.
Photophysical Properties of Some
Oligomers with Isoelectronic Arylenevinylene and Aryleneimine Structures and
Triphenylamine or Carbazole Moieties
TEOFILIA IVAN, LOREDANA VĂCĂREANU,
MIRCEA GRIGORAŞ
pages 119 - 131
Abstract Nine oligomers
containing triphenylamine and carbazole groups and arylenevinylene, imine
and azine structure, have been synthesized by polycondensation reactions
between aromatic aldehydes and bisphosphonate derivatives, diamines or
hydrazine. These oligomers are used as models for study of conducting
polymers since they have a well defined molecular structure, can be highly
purified using common methods known in organic chemistry and processed as
thin films by vacuum evaporation, dip or spin coating. In the same time,
they preserve all the properties and potential applications of the
corresponding polymers. The structural characterization of the synthesized
arylamine oligomers was performed using usual spectroscopic methods such as
1H RMN, IR spectroscopy and the photophysical properties were analyzed by
UV-Vis and fluorescence spectroscopy. Keywords: arylenevinylene;
aryleneimine; azine; triphenylamine and carbazole oligomers; photophysical
properties.
Transition Towards a Sustainable
Economy Based on Industrial Ecology Principles: Romanian Case Study
MĂDĂLINA PETRARU, MARIA GAVRILESCU
pages 133 - 145
Abstract The awareness on the
impact of human activities and the support capacity of natural capital was
gradually set in Romania during the 90’s of the past century. However, at
that time, this concept was unfortunately spread only within few academic
and intellectual groups, the impact on political decision-makers being also
insignificant. The policy documents and measures adopted after Romania
became an EU member, such as the National Development Plan, National
Strategic Reference Framework, Report on the Millennium Development Goals,
were relevant for the implementation of the objectives and principles of
sustainable development. These were necessary because of the changes
carried-out in the industrial systems of Romania that revealed a steadily
decline in different branches as, for example, manufacturing of steel,
chemicals and also in machine production and which have been also
accompanied by a large increase of unemployment. This paper considers that
sustainable development assumes to integrate the social, economic and
environmental aspects in industry, aiming at maximizing the well being of
the present without compromising the needs of the next generation. A new
approach for environmental analysis, known as industrial ecology, or "the
science of sustainability", is applied to measure the problems encountered
during the transition towards a sustainable economy. Methods that should
assist the corporations and organizations in reconfiguring industrial
activities in order to conserve the natural resources and to reduce
pollution are assessed in relation with Romanian context. The role of
industrial ecology in transition towards sustainable development has been
assessed considering the Romanian case study. Keywords: biological
ecosystem, industrial systems, Romania, sustainable development.
Influence of pH on Cr(VI) Reduction
and Removal by Saccharomyces
Cerevisiae
RALUCA-MARIA HLIHOR, MARIANA
DIACONU, MARIA GAVRILESCU
pages 147 - 153
Abstract
S. cerevisiae yeast is widely used
in the food and beverage industry and still represents a concerned
biomaterial in biosorption studies because its unique characteristics in
comparison with other microorganisms for metal removal. In this study, the
effect of pH on Cr(VI) reduction and removal by dead biomass
of S. cerevisiae was investigated
in the pH range of 1-4 and 5 g/L biosorbent at room temperature of 25±2°C.
The results showed that Cr(VI) was completely removed from aqueous solution
and Cr(III) which was not initially present, appeared in the aqueous
solution and increased in proportion to the Cr(VI) depletion. From a
practical viewpoint, the abundant and inexpensive dead yeast biomass has
potential application in the reduction of Cr(VI) to the less toxic Cr(III).
Keywords: biosorption, chromium, pH.
Influence of the Topology and the
Surface Chemistry on the Catalytic Properties of Mesoporous Silicas
Supported CuNi Catalysts
BRÎNDUŞA DRĂGOI, ALEXANDRU CHIRIEAC,
ADRIAN UNGUREANU, EMIL DUMITRIU
pages 155 - 169
Abstract Inorganic SBA-15 and MCF
(mesocellular foams) as well as their organic-inorganic hybrids were used as
supports for Cu and Ni metals to obtain redox catalysts for the
chemoselective hydrogenation of cinnamldehyde inliquid phase. The silicas
supported CuNi catalysts were prepared by incipient wetness impregnation
method. Catalysts with 5 wt % in metals and Cu:Ni mass ratio = 1:1 were used
in this study. The hybrid materials were synthesized by direct synthesis
based on the co-condensation of the tetraethylorthosilicate with different
organosilanes (phenyltrimetoxysilane (Ph), propyltrimethoxysilane (Pr) and
3-mercaptopropyltrimethoxysilane (HS)) in order to control the
hydrophobicity of the support (the hybrid materials of MCF topology obtained
by direct synthesis are not reported in the literature up to now). This
feature is very important because have a direct consequence on the
oxide/metal particle size and dispersion on the support surface and
therefore on the catalytic behavior of the supported catalyst. XRD at low
angle and nitrogen physisorption revealed the formation of the specific
mesostructure for each kind of material, SBA-15 and MCF, respectively while
XRD at high angle of the calcined samples showed the characteristic phases
of NiO and CuO. Moreover, the functionalization of SBA-15 and MCF with
organic groups determined better distribution of the oxides particles in
comparison to the purely siliceous supports. These results are in accord to
the catalytic tests which showed that the catalysts obtained by impregnation
of hydrophobized supports are more active and selective in comparison to the
unfunctionalized ones. Also, it was observed that a MCF topology led to more
active catalysts in comparison to the SBA-15 topology. Keywords: CuNi,
SBA-15, MCF, organic-inorganic hybrids, hydrogenation, cinnamaldehyde.
A New Liquid Chromatographic Method
for Determination of 4-Hydroxybenzyl Alcohol in 2-Isopropoxy Ethanol
Solution
Abstract The objectives of this
study were to develop and validate a method for the HPLC-UV determination of
4-hydroxybenzyl alcohol in 2-isopropoxy ethanol solution. The proposed HPLC
method uses a Zorbax Extend C18 column, at 30°C column temperature. The
mobile phase consisted of 40% acetonitrile and 60% acid acetic 0.2%
solution, at a flow rate of 1.2 mL/min. The analyte detection was an UV
detection at λ = 225±4 nm, with reference λ = 360±8 nm. The described method
was linear over a range of 0.5-100 mg/mL, for 4-hydroxybenzyl alcohol. The
accuracy and precision of the method have been evaluated at a three
concentration levels in the range of 1.5-80 mg/mL. The assay has proven to
be simple and rapid, suitable to determine the 4-hydroxybenzyl alcohol
concentration in 2-isopropoxy ethanol solution. Also, the method can be
useful in the qualitative and quantitative analysis of pharmaceuticals
products obtaining (ex.: the first step in the industrial manufacturing of
bisoprolol fumarate, an important beta-blocker agent, is the syntesis of
4-[(2-isopropoxyethoxi)methyl]phenol by etherification reaction of
4-hydroxybenzyl alcohol with 2-isopropoxy ethanol) (Ramakrishnan et al.
2005). Keywords: 4-hydroxybenzyl alcohol, HPLC, analytical method
validation.
2011,
Volume LVII (LXI), Issue 2
Challenge of Using Natural
Polyphenolic Extracts in Bioremediation
ALINA STÎNGU, IRINA VOLF, VALENTIN
I. POPA
pages 11 - 19
Abstract Different vegetal raw
material such as spruce bark, chestnuts shell and
Asclepias syriaca plant provide a considerably source of natural
bioactive compounds, which can be properly used in several directions such
as: plant growth regulators, cosmetics, pigmentation, foods additives, and
bioremediation. Aqueous extracts obtained from the vegetal raw materials
mentioned above were analyzed in germination test to evaluate the influence
on cadmium bioaccumulation in
Brassica napus plant. It was
observed that the extracts modulated
Brassica napus plant growth and
development, pigments assimilation and cadmium bioaccumulation which depends
on metal ion concentration (5, 12.5, 25 mg/L) and polyphenolic extracts
nature determined by vegetal raw material and total polyphenolic content
(130, 122, 114 mg/L related to gallic acid). Keywords: rape plant, spruce
bark, chestnuts shell, Asclepias syriaca, cadmium.
Study on the Effect of Ferromagnetic
Nanoparticles on Dyes Biodegradation
LAURA CARMEN APOSTOL, LUCIANA
PEREIRA, RAQUEL PEREIRA, M. MADALENA ALVES, MARIA GAVRILESCU
pages 21 - 28
Abstract In this study the
biodecolorisation of two dyes, a xanthene dye, Erythrosine B (Ery B) and an
azo dye, Reactive Red 120 (RR120), was investigated under batch anaerobic
conditions by using non-acclimated anaerobic granular sludge. The effect of
ferromagnetic nanoparticle (FN) (as adsorbent or mediator) on dyes removal
was experienced. Keywords: anaerobic biodegradation, ferromagnetic
nanoparticle, xanthenes dyes, azo dyes.
Landfill Leachate Treatement in
Aerated Lagoons Using Active Sludge
CORNELIU POHONŢU, IGOR CREŢESCU,
MATEI MACOVEANU
pages 29 - 36
Abstract The present paper
presents a biological, efficient and low cost method for landfill leachate
treatment. This method consists in the biodegradation of organic compounds
present in leachate using aerobic microorganisms from activated sludge. At
industrial scale, the process takes place in basins named aerated lagoons.
At laboratory scale, the process took place in artificial aerated
bioreactors, obtaining after seven days a efficiency of 93% for color
removal and 90% for organic compounds mineralization. Keywords: landfill
leachate, treatment, active sludge.
Environmental Impact of Recovered
Paper Quality in Packaging Paper Manufacturing
ALINA IOSIP, ELENA BOBU
pages 37 - 50
Abstract Quality is the major
pre-requisite for extending the use of recovered paper (RP) as a raw
material in paper industry, being a decisive factor for the sustainability
of the recycling process. RP quality is defined mainly by unusable material
content (contaminants) and paper grades entering the composition. Recent
statistics show a quality decreasing trend, especially for recovered paper
resulting from household collection, which could be reversed by consistent
improvement in sorting technology. This study is aiming to evaluate the
effects of RP quality on environmental impact in packaging paper
manufacturing. The concept is based on sorting simulation in order to obtain
different qualities of recovered paper entering in paper mill. A batch of
recovered paper with the lowest contamination (4%) was obtained by manual
sorting and starting from this, other three RP batches (6, 8 and 10%) were
prepared by subsequent contamination with liquid packages. Environmental
impact assessment in all the four simulated cases was performed using LCA
methodology, following all its components stages: goal and scope definition,
inventory analysis, environmental impact and interpretation. Main part of
the article is dedicated to the interpretation phase, where the impact
categories are described in detail and variations of direct emissions that
affect each category are analyzed by for their relative contributions. The
results of this analysis confirmed that recovered paper quality affects the
environment mainly by energy consumption and solid waste generation in
different steps of papermaking technology. Keywords: recovered paper,
sorting, contamination, environmental impact, life cycle assessment.
Studies Upon the Seeds Germination,
Roots Elongation Under Conditions of Soil Pollution with Heavy Metals
PAULA COJOCARU, ANDRZEJ BIALOWIEC,
MATEI MACOVEANU
pages 51 - 58
Abstract The paper present the
importance of using Phytotoxkit tests to determining the maximum dose of
pollutant that do not cause a negative effect on plants from germination and
seedling stage. The advantages of using these tests and in particular the
possibility of using many types of seeds and pollutants were pointed out. We
studied the toxicity of Zinc (Zn) upon seed germination and root elongation
of rape (Brassica napus) using a
reference OECD soil for these types of tests. The concentration of Zn
solution at 100% was 6000 mg/kg d.w. Zinc solutions were applied in
different concentrations from 6.25%, 12.5%, 25%, 50% to 100% and tap water
was used as control (0%) and diluent. After 3 days of incubation in the dark
at 25 ± 1°C the inhibition rate of root elongation for each seed was
determined using for measurement ImageTools3.0. software. Keywords:
phytotoxicity, root elongation, germination.
Alkaline Pulping of Rapeseed (Brassica
napus) Stalks in Sulfate and Soda-AQ Processes
BOGDAN MARIAN TOFANICA, DAN
GAVRILESCU
pages 59 - 68
Abstract Rapeseed stalks (Brassica
napus) have been investigated as a suitable source of cellulosic fibers
for pulping in different alkaline pulping methods. Delignification was
carried out by sulphate and soda-anthraquinone pulping under varying
conditions. The influence of active alkali and cooking temperature on the
fibers yield, screening rejects, and lignin content of pulp was studied.
Time to achieve maximum temperature, cooking time at maximum temperature and
the solid-to-liquid ratios were kept constant in all the experiments.
Results indicated that active alkali was the most important parameter,
temperature having a minor effect on pulp yield and pulp residual lignin
content. The total pulp yields and kappa number was decreased with
increasing the alkali charge ratio and cooking temperature, while in the
same conditions, fiber yield slightly increased till there were no rejected
materials. It was found that kappa number values in soda-anthraquinone pulp
samples were lower than sulphate pulps at similar pulping condition. It is
concluded that the rapeseed stalk have the potential for the purpose of
being used for obtaining cellulosic pulp. Keywords: rapeseed stalks,
nonwood, cellulose, pulp.
Removal of 4-Chlorophenol from
Wastewater Using Ultrasonication Coupled with Ultrafiltration
DANIELA CĂILEAN, CARMEN TEODOSIU
pages 69 - 84
Abstract Priority organic
pollutants represent a category of pollutants, which have a significant
impact on the environment, especially in case of the aquatic component.
Their removal from wastewaters before discharge is one of the concerns
because of their persistence and toxicity. This study considers an
integrated process which comprises 2 processes: ultrasonication and
ultrafiltration for the removal of priority organic pollutants such as
para-chlorophenol (4CP) from wastewater. The objectives of the study were to
investigate the efficiency of the ultrafiltration process on an effluent
with an initial concentration of 75 mg/L 4CP, which has been previously
subjected to a homogenuous Sono-Fenton oxidation process, in terms of phenol
removal efficiencies and to analyze the influence of the ultrafiltration
parameters on the effluent quality such as: time, pressure, operating mode,
membrane material, washing procedures). Keywords: para-chlorophenol,
ultrasonication, ultrafiltration, wastewater.
Influence of Process Conditions on
Reactive Extraction of Carboxylic Acids Obtained by Succinic Fermentation
LENUŢA KLOETZER, ROXANA ROTARU, ANCA
IRINA GALACTION, DAN CAŞCAVAL
pages 85 - 97
Abstract Separation of formic,
acetic and succinic acids from fermentation broth with A.
succinogenes by reactive
extraction showed that it is possible to extract formic and acetic acid,
while succinic acid remains in the raffinate. Reactive extraction of acetic,
formic and succinic acids from mixture with tri-n-octylamine dissolved in
three different solvents was performed. The extraction process was analyzed
by means of the extraction degree and distribution coefficient. In order to
establish the optimal conditions for reactive extraction of succinic, formic
and acetic acids the influence of pH of aqueous phase and the extractant
concentration in the organic phase was analyzed. Indifferent of the
extracted acid, the pH of the aqueous solution has a significant influence
on separation efficiency this being reduced by increasing the pH. The
highest extraction efficiency was obtained when using dichloromethane, and
in the considered series of acids, the highest extraction degree was
obtained for formic acid, followed by acetic and succinic acid. Keywords:
reactive extraction, succinic acid, acetic acid, formic acid,
tri-n-octylamine.
Influence of Cations on Nitrate
Removal Using Purolite Resins
ANCA CEICĂ, LAURA BULGARIU, LILIANA
LAZĂR, IGOR CREŢESCU, ION BALASANIAN
pages 99 - 107
Abstract In this paper, the
influence of the nature of cations (Na+, NH4+,
Ca2+ and Mg2+) on the nitrate removal efficiency using
three anion exchange resin: two non-selective anion exchange resin Purolite
A-100 and Purolite A-847 and a selective resin Purolite A-520E, was
investigated. The experiments were performed in aqueous solutions, in a
concentration range between 24.80 and 372.02 mg NO3- L-1,
at room temperature (19°C), by batch technique. The obtained results have
shows that the nature of cations has an insignificant influence on nitrate
removal efficiency in case of A-100 resin, while in case of A-520 E and
A-847 resins, some differences appears and these are more evident at high
nitrate concentrations. In order to underline these observations the
experimental data were fitted using Langmuir isotherm model, and isotherms
parameters were calculated. Keywords: anionic resins, influence of
cations, nitrates removal, ion exchange.
Isolation and Characterization of
Polyphenols from Spruce Wood Bark
IOANA IGNAT, IRINA VOLF, VALENTIN I.
POPA
pages 117 - 125
Abstract Polyphenolic compounds
are well known for their valuable properties which allow using them in
animal and vegetal systems. Polyphenols are a widespread group of secondary
metabolites found in woody species, including softwood. The concentration of
secondary metabolites in different parts of plants is not the same; in
general, higher amounts of these bioactive compounds occurring in bark,
heartwood, roots, branch bases and wound tissues. The aim of this paper was
to investigate the bark of Picea abies
as a potential source of phenolic compounds. The extraction of polyphenols
was performed using different organic solvents followed by basic hydrolysis.
After total content of polyphenols determination, high performance liquid
chromatography procedure was used to assess the phenolic compounds in spruce
bark extracts. The obtained results allow us to compare the efficiency of
extraction agents from yield and individual compounds separation point of
view. Keywords: polyphenols, spruce bark, extraction, characterization.
Grey Water Footprint Assessment of
the Wastewater Treatment Plants in the Prut-Bârlad Catchment
SIMONA-ANDREEA ENE, CARMEN TEODOSIU
pages 127 - 143
Abstract Freshwater availability
degradation in terms of quantity and quality became a major issue all around
the world. In many cases, similar water problems are produced due to water
consumption and pollution in humankind's activities. The water footprint
concept is considered to be an indicator that gives information about the
direct and indirect water use of products and services, taking into account
water pollutions as well. Water footprint assessment is evaluating those
human activities that influence the quantity or quality of freshwater within
a catchment or river basin. Grey water footprint considers the volume of
water required for the waste assimilation, quantified as the required volume
of water to dilute pollutants in such a way that the quality of the ambient
water stands above agreed national water quality standards.
This paper presents an assessment of
grey water footprint of the wastewater treatment plants based on the
effluent concentration of important pollution indicators (BOD, COD, ammonia,
phenols and detergents) measured on a monthly basis. 22 wastewater treatment
facilities were assessed for the 2006-2007 period in the Prut-Bârlad
catchment. Keywords: grey water footprint, wastewater treatment plant,
water quality.
Behavior Characterization of
Apalight as an Ingredient in Cosmetic Formulations
GINA AMĂRIOAREI (IFTIMIE), ANDREI
ROŞU
pages 145 - 152
Abstract Apalight its an new
cosmetic ingredient consisting of hydroxyapatite (HA) that is a natural
mineral found in nature in the form of calcium apatite with the formula Ca5(PO4)3(OH),
or Ca10(PO4)6(OH)2 to emphasize
the two consisting entities of crystallized form. It was studied the
dispersion capacity of different natural and synthetic polymers and
humectants agents with the purpose to imcorporate and harnessing Apalight in
to a stabile and pleasant cosmetic formula of a finished cosmetic products.
Keywords: humectant agents, dispersion, natural polymers, rheological
agent, particles.
Photo-Sensitive Azo-Polysiloxanic
Micelles
SILVIA GRAMA, GABRIELA LISĂ, NICOLAE
HURDUC
pages 153 - 162
Abstract The paper presents the
synthesis and characterization of some azo-polysiloxanes modified with
quaternary ammonium groups, for generating photo-sensitive micelles, capable
to aggregate/disaggregate under UV irradiation. The amphiphilic polymers
were obtained starting from a polysiloxane with chlorobenzyl groups in the
side-chain. In the first step, the precursor was modified with azo-aromatic
groups (35% substitution degree); the chlorobenzyl groups unreacted after
the first reaction step was quaternized with different tertiary amines. The
structures of the synthesized polymers were confirmed using 1H-NMR
spectroscopy and thermal analysis (thermo-gravimetric and DSC). The
amphiphilic azo-polysiloxanes are capable to generate micelles in water. The
critical aggregation concentration values are 6.5x10-3 g/L and
1.3x10-2 g/L. The disaggregation process under UV irradiation of
the micellar systems was also investigated. For the amphiphilic
azo-polysiloxanes during the photo-isomerization investigation a series of
abnormalities have been observed distinguishing a different behaviour of
polymers depending on the hydrophobic/hydrophilic ratio. Keywords:
amphiphilic polymers, photosensitive micelles, fluorescence spectroscopy.
A Comparison of Kinetic Models
Applied for Cd(II) Removal by S. Cerevisiae
RALUCA MARIA HLIHOR, MARIANA
DIACONU, MARIA GAVRILESCU
pages 163 - 171
Abstract This paper presents a
comparison of chemisorption kinetic models applied for Cd(II) removal from
wastewaters by non-viable biomass of S. cerevisiae. The evaluated models include the pseudo-first order,
the pseudo-second order and Elovich equation. The pseudo-second order model
appears to correlate the data better than the others, probably because of
the potential of the model to include the influence of some determinant
factors (pH and temperature). Keywords: biosorption, chemisorption, heavy
metals, kinetics, non-viable yeast biomass.
Biological Treatment of Wastewater
with High Oil and Grease Content
ROXANA ROTARU, ANCA-IRINA GALACTION,
DAN CAŞCAVAL
pages 173 - 183
Abstract The discharge of
oil-containing wastewater to the environment increases every year due to the
urbanization and industrial development. Biological wastewater treatment is
one of the most important biotechnological applications. This paper presents
a general approach of different types of wastewater treatment processes
using enzymes and microorganisms (bacteria, fungi) as free or immobilized
cells. Keywords: bioreactors, lipid degradation, lipase, wastewater
treatment.
Rheological Properties of Paper
Support Reinforced with Modified Cellulose Ethers
PUIU PETREA, TEODOR MĂLUŢAN, SORIN
CIOVICĂ
pages 185 - 192
Abstract The study targets the
behavior of chemically modified cellulose ethers in the acquisition of new
useful features in different fields of use. Are analyzed some specific
characteristics of consolidation agents of graphic supports: adhesive
properties, physical and mechanical properties of reinforced support.
Keywords: cellulose ethers, adhesive properties, physico-mechanical
properties.
2011,
Volume LVII (LXI), Issue 3
Separation of Carboxylic Acids by
Reactive Extraction
MĂDĂLINA POŞTARU, ANCA-IRINA
GALACTION, DAN CAŞCAVAL
pages 9 - 19
Abstract Carboxylic acids are
obtained by aerobe or anaerobe fermentation processes, with wide
applications in food industry, chemical industry and medicine. The constant
necessities for carboxylic acids and the complexity of this biochemical
processes, require a new separation method, more efficient and with low
costs. This overview presents the separation of some monocarboxylic,
dicarboxylic and policarboxylic acids by reactive extraction and allows us
to highlight some of the advantages to the conventional separation methods. Keywords: reactive extraction, carboxylic acids, organophosphoric
derivates, aliphatic amines.
Sorption Equilibrium Study of
Methylene Blue Dye from Aqueous Media onto Celolignine
DANIELA ŞUTEU, CARMEN ZAHARIA,
TEODOR MĂLUŢAN
pages 21 - 28
Abstract The potential of the
celolignin (the by-product of the pulp industry), for removal the cationic
dye Methylene Blue from aqueous solutions of pH = 6
was evaluated by the batch technique as a
function of dye concentration and temperature of solution. The Freundlich,
Langmuir, Dubinin-Radushkevich and Tempkin adsorption isotherms were used to
describe the equilibrium sorption data and to determine its corresponding
isotherm constants. The results of this study evidenced that the celolignin
has the potential to remove cationic Methylene Blue dye from aqueous
effluents. Keywords: celolignin cationic dye, sorption isotherms.
Performance Study for the
"AQUARIUS-01" Multi-Step Device, in the Process of Obtaining Drinking Water
for Household Applications and Emergency Situations
DAN POPOVICI, CORNELIU ONISCU, ALINA
TROFIN
pages 29 - 41
Abstract
This study’s objectives aim to find the conditions for obtaining drinking,
high purity water, as a fundamental requirement of a modern society. The
paper presents the results obtained with the AQUARIUS-01 multi-step device,
conceived for the processes of transforming raw water into a drinking one,
also for enhancing the qualities of the processed water and for removing the
nitrites and nitrates from the local sources of drinking water, including
the groundwater sources (the wells from rural area). We offer an easy to
apply solution for removing the impurities and especially of the nitrites
and nitrates from the drinking water sources. Keywords:
turbidity, organic
substances content, filtration, nitrites, nitrates.
Layered Double Hydroxides as
Inorganic Versatile and Multifunctional Materials
Abstract Layered double
hydroxides (LDHs) are lamellar mixed hydroxide containing positively charged
main layers and undergoing anion exchange chemistry. LDHs have anionic
exchange capacity and the ability to capture organic and inorganic anions
makes them almost unique as inorganic materials. This article provides an
overview of the LDHs structure and composition, synthesis of these anion
clays, characterization techniques and potential applications of these
materials, including catalysis, ion exchange/adsorption, and medicine, used
as uncalcined or calcined LDHs. Keywords: application, calcination,
layered double hydroxide, hydrotalcite, structure.
Recent Advances on the Separation of
β-Lactamic Antibiotics: Penicilin G
ALEXANDRA CRISTINA BLAGA, SZE KI
CAROL LIN
pages 63 - 76
Abstract Among the different
classes of antibiotics (penicillins, tetracyclines, macrolides,
aminoglycosides and amphenicols), the first ones are the most widely used,
for their broad antibacterial activity. Several new methods besides the
usual organic solvent extraction have been developed over the last few years
for the separation of this type of antibiotics.
Liquid-liquid extraction, combined
with chemical reaction or reextraction- reactive extraction, respectively pertraction, are alternatives
for separations in bioprocessing and can significally improve
the overall yield. Aqueous
two-phase systems (ATPS) used with hydrophilic ionic, AOT-reverse micelles
and a soft separation technology with
bubble mass transfer, solvent sublation were also analyzed for the
separation. Keywords: Penicillin G, reactive extraction,
pertraction, solvent sublation, ATPS, AOT-reverse micelles.
Direct Extraction of Biosynthetic
Products from Fermentation Broths
ALEXANDRA CÂRLESCU, ANCA-IRINA
GALACTION, DAN CAŞCAVAL
pages 77 - 87
Abstract The direct extraction is
a relatively new method for an efficient separation and concentration of
fermentation products without biomass filtration. Therefore, the
fermentation and the subsequent downstream processes are integrated in a
single step and the biosynthetic product is recovered from the fermentation
broth during its formation. This review is mainly a survey of new
technologies including reactive extraction and pertraction. These extraction
processes are used for the recovery of some biosynthetic products from
fermentation broth such as: antibiotics (Penicillin G, erythromycin),
carboxylic acids (propionic acid, lactic acid, succinic acid, butyric acid,
pyruvic acid, citric and acetic acid), alcohols (butanol, ethanol) and amino
acids (phenylalanine, valine). Keywords: biosynthetic products, fermentation broth, in-situ separation, direct
extraction.
Development of Novel Hybrid
Materials Consisting of Functional Block Copolymers and Metals or Metal
Oxide Nanoparticles in Order to Investigate their Electromagnetic Features
MARIA DEMETRIOU, PETRI
PAPAPHILIPPOU, THEODORA KRASIA-CHRISTOFOROU, ALINA NEAMŢU, ROMEO CIOBANU
pages 89 - 94
Abstract The necessity for new
polymers capable of providing stability at the interfaces of materials with
different chemical structures, polarities and cohesion energies has led to
the development of numerous synthetic methodologies for this purpose.
Keywords: functionalized polymers, hybrid materials, Pd and Au
nanoparticles.
A Variant of Modeling and
Optimization for Simple Extraction with Multiple Contacts
TIBERIU-MIHAI STURZU, IOAN MĂMĂLIGĂ,
VIORICA NICU
pages 95 - 104
Abstract The paper depicts an
analytical model that allows the estimation of mass reports of the useful
component in extracts and refined mixtures, the efficiency of each
extractive step and the global efficacy of the n steps, for simple
extraction with multiple contacts, in ideal conditions, imposed owing to
some simplified hypotheses. We realized the assessment of the model, using
the graphic method and presented its possibility of application for the
extraction of acetone out of wastewaters using kerosene, a process for which
we also realized an optimization out of economical reasons. Keywords: efficiency, extractive step, acetone, wastewater,
kerosene.
Total Phenolics and Total Flavonoids
in Romanian Artemisia Species
BIANCA IVĂNESCU, GABRIELA CIOBANU
pages 105 - 110
Abstract The growing appeal for
the biological activities of plant phenolics and flavonoids prompt us to
evaluate their content in three indigenous wild
Artemisia species, commonly used
in phytotherapy for a wide range of conditions. The study includes the
species Artemisia absinthium L.
(wormwood), Artemisia annua L.
(annual wormwood) and
Artemisia vulgaris L. (mugwort),
largely spread in Romanian flora. The total
content of phenolic compounds was assessed by Folin -Ciocalteu
colorimetric method.
The total flavonoids content was determined by using the aluminium chloride
colorimetric assay. Results show that all studied species have high
flavonoids content and total phenolic content. Especially, the ethanol
extract of Artemisia vulgaris is
distinguished by its content in phenolic compounds, almost double than the
other tested extracts. Keywords: phenolics, flavonoids,
Artemisia species.
Studies Concerning the Obtaining and
Characterization of Lignophenols Derivatives
IULIAN-ANDREI GÎLCĂ, ADINA-MIRELA
CĂPRARU, VALENTIN I. POPA
pages 111 - 118
Abstract
This paper presents the results on the
obtaining and characterization of a lignin derivative synthesized by
reaction with cresol. Lignin
(L2,Sarkanda
grass offered
by the Granit Research Development SA company)
was condensed
with p-cresol leading to a lignophenol derivative which is then modified by
carboxymethylation.Thus a product which is soluble in an aqueous 5% NaOH solution was
obtained. Lignin’s condensation with cresol and further carboxymethylation
of the lignocresol derivative was evidenced by FTIR data. Performing this
sequence of reactions was confirmed by FTIR spectroscopy. Also, tomato seeds
germination tests showed that this lignin derivative is not toxic.
Keywords: lignin derivative,
lignophenol, carboxymethylation, lignocresol.
Microwave-Assisted Copolymerization
of Styrene with Methyl Methacrylate and Butylacrylate
CAMELIA MIHĂILESCU, ANA NICONOV,
VICTOR BULACOVSCHI
pages 119 - 128
Abstract The co-polymerization of
styrene with methyl methacrylate and butyl acrylate under the microwave
conditions was investigated. For the studied systems the monomer reactivity
ratios were calculated by using three different methods (Finemann-Ross,
Kelen-Tudos and Yezreliev), and compared with literature reported data.
Finally, the obtained copolymers were characterized thermally and
spectrally. Keywords:
Microwave; Copolymerization; Styrene;
Methylmethacrylate, Buthyl Acrylate.
Photophysical Properties of
Polyrotaxanes Based on Fluorene Copolymers
Abstract
Photophysical properties of
polyrotaxanes based on fluorene copolymers were investigated. The
inclusion complexation results in
improvements of the
solubility as well as in different surface morphology, photophysical, and
thermal properties of the rotaxane copolymer as compared to its
non-complexed homologue.
Keywords: cyclodextrins, threading, fluorene
copolymers, fluorescence, blue-emission.
Preliminary Study Concerning the
Applicability of π-Conjugated Polymers with Rotaxane Architectures
Abstract
The
effect of complexation of a poly
[2,7-(9,9-dioctylfluorene-alt-2,7
fluorene] copolymer into the inner cavity of native β-cyclodextrin (β-CD) on
the electro-optical properties was investigated
and compared with the non-rotaxane copolymer. Our
study demonstrates how the electronic properties of fluorene copolymer can
be tuned by using host
molecules, which could be important for electronic applications.
Keywords: interlocked molecules, cyclodextrins, threading, fluorene
copolymers, blue-emission.
Study on the Influence of
Formulation Parameters on the Pharmacotechnical Characteristics of
Hydrophilic Carbopol Matrix Tablets Using a D-Optimal Experimental Design
Abstract The aim of the present
research involved the analysis of the formulation parameters (concentration
and type of polymer) on the properties of
carbopol matrix tablets with the final goal of preparing modified release
tablets with sodium alendronate. 15 different formulations of matrix tablets
were prepared with Carbopol 71 (C71), Carbopol 971 (C971) and Carbopol 974
(C974), in proportions between 0 – 45%. Tablets were prepared by direct
compression method, using a Korsch EK0
tablet press. Characterization
of tablet parameters involved the following measurements: mass uniformity,
thickness, diameter, hardness and friability. Data fitting and calculation
of statistical indicators in order to validate the experimental design, as
well as the analysis of the experimental design were carried out using the
MODDE 9.0 optimization program. For the study we chose a
D-optimal experimental design with four variables and five levels.
The independent variables were formulation factors
which were abbreviated as follows: C71 (X1), C971 (X2),
C974 (X3) and Ld (X4). Building the factorial matrix
involved coding the variables with numbers related to their concentration
range in the tablet formulations. The tablet characteristics were set as
dependent variables as follows: hardness (Y1),
friability (Y2),
diameter (Y3), thickness (Y4), mass uniformity + % (Y5)
and mass uniformity - % (Y6). The model was validated based on
the statistics coefficients of reproducibility, the model validity, multiple
regression coefficient (R2), according to the ANOVA results. The
results showed good fitting and an appropriate predictability of the
experimental model. Analysis of the full experimental design confirmed a
major influence of the X1and X2 variables
on the analyzed tablet characteristics. Also, significant interactions were
found between variables X1-X2, X1-X4
and X3-X4 respectively, having a high impact on
the dependent variables of the design. Keywords: carbopol, matrix
tablets, sodium alendronate, formulation.
Synthesis and Characterization of a
Succinimide Complex
MIHAELA-DANA TUTULEA, IOAN ROŞCA,
IGOR CREŢESCU, GABRIELA LISĂ
pages 159 - 163
Abstract Zinc (II) sulphate
complex of succinimide ligand has been synthesized in water medium. The
solid coordination compound has been characterized on the basis of elemental
analysis, IR spectra, thermal analysis and crystallographic data. The
elemental analysis data showed the formation of 1:2 [M:L] complex. The
thermal decomposition was found to proceed in two steps. Keywords: zinc
complexes, succinimide.
Thermo-Sensitive Graft Polysiloxanic
Micelles
ANCA DANIELA HODOROG (RUSU),
GABRIELA LISĂ, CONSTANŢA IBĂNESCU, NICOLAE HURDUC
pages 165 - 173
Abstract The paper presents the
synthesis and characterization of some thermo-sensitive complex polymeric
systems, capable to change their properties at supramolecular level, under
thermal stimuli. Amphiphilic copolymers are well known as precursors for the
preparation of micellar drug carriers. The thermo-sensitive polymeric
micelles were obtained by living radical polymerization, the polymerization
reaction occuring by a SET-LRP mechanism starting from a polysiloxane with
chlorobenzyl groups in the side-chain. The amphiphilic polymers are capable
of self-assembling into micelles in water, ability confirmed by fluorescence
spectroscopy and rheological tests (studying the dependence of loss and
storage moduli on temperature). To evaluate the aggregation capacity of the
polymers, the classical method using pyrene fluorescence spectroscopy was
used. Keywords: thermo-sensitivity, micelles, aggregation capacity.
Utilisation of Composite Materials
for the Study of Gas Drying by Adsorption
MARIA SPIRIDON, IOAN SOLOMON,
STELIAN PETRESCU
pages 175 - 183
Abstract This paper describes the
mass transfer kinetics at air drying by adsorption in fixed bed of composite
materials and for this aim it had been utilized two granular composite
materials: MCC1 and MCC1* obtained by impregnation of active carbon with two
calcium chloride solutions: 15 and 30% weight. The adsorption experiments
were carried out using an experimental set-up which contains as principal
element an adsorption column with 0.037 m in diameter and the height of the
granular fixed bed was 0.4 m. The adsorption is realized in dynamic regime,
at certain values of air flow velocity
(1.2; 1.7; 2.2; 2.7 m3/h), temperatures (20, 30, 40, 48ºC) and
relative humidity (24.5; 17; 40; 60; 68; 80%). It had been determined,
experimentally, the variation of the water vapour concentration for both
gaseous and solid faze, and also the variation of the adsorption rate as a
function of time at the specified values, for the composite materials.
Keywords: adsorption, kinetics, composite materials.
Influence of Operational Parameters
on the Removal of 4-Chlorophenol from Wastewater by Heterogeneous Fenton
Process
DANIELA ARSENE, CEZAR CATRINESCU,
CARMEN TEODOSIU
pages 185 - 196
Abstract This study presents an
evaluation of the catalytic performance of AlFe pillared clays for the
catalytic wet hydrogen peroxide oxidation of phenolic aqueous wastes. All
the mixed AlFe oxide PILC displayed a good catalytic activity, but AlFeMt
PILC was the most active, being selected for detailed studies. Important
factors affecting catalyst activity were studied in this paper
i.e.: the effect of pH,
temperature, catalyst loading, 4-CP and hydrogen peroxide concentration. The
experimental results indicate that the use of this catalyst allows a total
elimination of 4-CP and a significant removal of total organic carbon, this
process being a promising advanced wastewater treatment technique for
industrial effluents. Keywords: pillared clays, para-chlorophenol,
hydrogen peroxide, oxidation.
Synthesis and Association Capacity
Evaluation of Some New Donor/Acceptor Azo-Polymers
ALINA RAICU LUCA, GABRIELA LISĂ,
NICOLAE HURDUC
pages 197 - 203
Abstract The aim of paper is to
report the synthesis, characterization and association capacity of some new
polymers containing azo-benzenic groups in the side chain, capable to
response to light stimuli, the result being the modification of
supramolecular architecture of the material. The azo-polymers are attractive
both from
perspective of surface relief gratings for cell culture, and also
from perspective of formation of 3D networks with potential applications in
the drug delivery field.
Keywords: azo-polymers, donor/acceptor groups,
association capacity.
Influence of Copper Ions in Aqueous
Extracts of Vitis Vinifera Grape
Seeds on the Development of
Rhodotorula Mucilaginosa Yeast
ANCA-ROXANA HAINAL, IRINA VOLF,
VALENTIN I. POPA
pages 205 - 211
Abstract The paper presents
results of a study concerning the influence of polyphenolic compounds from
aqueous extracts of Vitis vinifera
(Merlot) seeds and of copper ions added in different concentrations on the
development of Rhodotorula
mucilaginosa yeast. For this purpose, we followed the effects of copper
ions concentration introduced in these extracts along with total
polyphenols. Thus, it was found that the introduction of copper ions in the
culture medium alongside polyphenols influences the biomass yield, its
values decreasing at the same time with the evolution of the culture.
Keywords: Rhodotorula mucilaginosa,
grape seeds, polyphenols, copper ions.
Synthesis and Characterization of
Some Azo Aromatic Acid Chlorides with Liquid Crystalline Properties
GHEORGHE SIMION, DRAGOŞ FLORIN
IUGANU, IRINA CÂRLESCU, DAN SCUTARU
pages 213 - 219
Abstract Five mesogenic groups
with liquid crystalline properties, having the general formula ClOC-C6H4-N=N-C6H4-O-CnH2n+1,
n=6÷10, have been synthesized and characterized. Their mesomorphic
properties were investigated by differential scanning calorimetry (DSC) and
polarized optical microscopy (POM). The synthesized compounds present
enantiotropic liquid crystalline behavior with smectic textures. The
obtained acyl chlorides presented quite unusual low
isotropisation/crystallization temperatures. The thermal stability was
established by using thermogravimetric analysis. The synthesized compounds
may be further used in acylation reactions in the synthesis of new classes
of bent core liquid crystals. Keywords: azo mesogenic groups, liquid
crystals, thermal stability.
Soft-Computing Methodology Based on
Neural Network and Genetic Algorithm Applied to a Photocatalytic
Decomposition Process
CIPRIAN GEORGE PIULEAC, RENATA
FURTUNĂ, SILVIA CURTEANU
pages 221 - 232
Abstract An Artificial
Intelligence methodology based on a combination between a neural network and
a genetic algorithm was applied to the complex optimization problem of a
photocatalytic oxidation process - removal of triclopyr from the synthetic
wastewaters. Both considered modeling and optimization procedures, developed
in a neural network – genetic algorithm structure, were designed using a
database from the literature and own experimental data. The neural network
model, included into the optimization procedure, was a multilayer
feed-forward perceptron type with one hidden layer. The problem was solved
with a standard (simple) genetic algorithm, which computed the optimal
values for reaction conditions (concentrations of TiO2 and H2O2)
in order to determine the minimum final concentration of the pollutant,
obtained in the shortest irradiation time. The validation results proved the
accuracy of the applied methodology. Keywords: Neural network
modeling, genetic algorithm optimization, photocatalytic process oxidation.
2011,
Volume LVII (LXI), Issue 4
Biological Removal of Paraffinic
Hydrocarbons from Petrochemical Industry Wastewaters
ELENA FOLESCU
pages 9 - 31
Abstract This paper is a summary
of various methods to treat oilfield’s wastewaters, especially by
biodegradation processes. These wastewaters contain a mixture of different
organic and inorganic compounds. The contamination by hydrocarbons from
oilfield produced waters represents a global concern for the potential
consequences on ecosystem and human health. For this reason an increasing
attention has been directed toward the research of new strategies and
environmental-friendly technologies to be applied for the remediation of
sediments and water contaminated by hydrocarbons. Produced water is
conventionally treated through different physical, chemical, and biological
methods. Globally, bioremediation is a common choice for remediation of
petroleum hydrocarbon-contaminated sites and wastewaters. There are several
challenges facing biological treatment processes such as the necessity to
monitor the microorganism behavior and to provide the optimum growth
conditions, which has to be done continuously to avoid any downtimes.
Keywords: biodegradation, hydrocarbons,
oilfield, wastewater management.
Characterization of Some
Condensation Silicone Impression Materials
OANA ŢĂNCULESCU, DANIEL ŢÂMPU,
MONICA ANDRONACHE, RALUCA MARIA MOCANU, ADRIAN DOLOCA
pages 33 - 45
Abstract Dimensional stability,
details reproduction and wettability are considered the main features of any
impression material, and need to be taken into consideration to achieve a
good restoration. In our study we focused on condensation silicones for
social and economic reasons, these being the most frequently used materials
in common practice. The used materials were: Stomaflex (Spofa – Czech
Republic), Oranwash – Zetaplus (Zhermack- Italy), Optosil - Xantopren
(Heraeus-Kulzer - Germany), Speedex (Coltène Whaledent- Switzerland). For a
quantitative dimensional stability assessment a new device that eliminates
adhesion and friction was designed. Among the fluid impression materials,
one can notice that the most stable from the dimensional point of view are
those manufactured by Colthène-Whaledent - Speedex and the largest
deformations have been recorded by Spofa - Stomaflex products. In
determining the degree of fidelity of the impression materials, grids of
different sizes have been used as reference. It has been noticed that all
the materials render well the details of the 2 grids (18 μm). The details of
the third grid are rendered well only by Xantopren and Speedex, without
voids or defects. For the hydrophilic character of these materials, we
measured the evolution of the contact angle between the artificial saliva
and materials before setting and after setting. Data has been then recorded
using DSA10 (Krϋss GmbH, Hamburg) droplet analysis. Speedex is the most
hydrophilic material, followed by Xantopren, Oranwash VL, Oranwash L and
Stomaflex. Keywords: condensation silicones, dimensional stability,
details reproduction, hydrophilic character.
Antimicrobial Properties of Paper
Consolidated with Modified Cellulose Ethers
PUIU PETREA, TEODOR MĂLUŢAN, SORIN
CIOVICĂ
pages 47 - 55
Abstract The study concerns the behavior of microorganisms attack in
chemically modified cellulose ethers by cianoethylation. For assessing the
biological potential three test methods have been used: resistance to attack
of microorganisms on consolidated papers, resistance tests to microbial
attack of solution placed on the growth medium and resistance tests to
microbial attack directly in solutions. Evaluating the three methods used
for testing of biologically active potential it is observed that cellulose
ethers chemically modified (m-MC, m-CMC) show a better stability to attack
of microorganisms compared with native cellulose ethers (MC, CMC).
Keywords: Modified cellulose ethers, resistance to microorganisms, paper
consolidated.
The Noise Pollution in Career Roşia
of Jiu
ANDREEA CRISTINA STANCI,
AURORA STANCI, IOAN DUMITRESCU
pages 57 - 62
Abstract The Career Roşia of Jiu
is a source of noise because the main sources of noise pollution are tracked
excavators with rotor and bandconveyors. The excavators with rotor is a
importance source of noise in career, but no in inhabited areas or forest
because of the way the extraction in rung, share on the surface contained
between 38 m and 79 m is a natural barrier against the propagation of noise.
Not the same can be said about using bandconveyors which transport excavated
material, this band reaching distance of 15-20 m from inhabited areas.
Combating noise produced by them can be achieved by in closing acoustic
enclosures. The proposed method of noise reduction over the entire frequency
range, leads to a reduction of pollution noise of up to 35% in function of
the construction and dimension the acoustic enclosures. Keywords:
pollution, noise control, noise attenuation.
Analysis of Environmental Impact for
Industry Products. Case Study: Paper Manufacturing
MĂDĂLINA PETRARU, CRISTINA GHINEA,
HANS BRESSERS, MARIA GAVRILESCU
pages 63 - 74
Abstract Pulp and paper industry
has a high environmental impact that occurs in all phases of the paper
lifecycle, from fibre acquisition to manufacturing and final to disposal.
Reducing paper consumption is an important step to diminish the
environmental impacts. Substitution of virgin fibres with recovered fibres
reduces the demand for wood and requires less energy. For evaluation of the
environmental impacts and potential impacts associated with a paper product
can be used various methodologies like life-cycle assessment (LCA). The goal
of this paper is to determine the environmental performance of paper
products technological process based on the evaluation of four scenarios:
the first scenario consists in paper products manufactured from virgin fibre
and the other three scenarios contain the manufacturing process of paper
with recovered fibre as raw materials and with different environmental
impacts (80%, 60% and 40%). The evaluation was realized using GaBi4 software
that supports every stage of the analysis, from data collection to
quantification of the results and highlights the performance of the
evaluated processes. GaBi4 offers the possibility to characterize the
inventory results in several impact categories based on different
methodologies, such as: CML 2001, CML 96, EDIP 1997, EDIP 2003, EI99, etc.
Keywords: environmental impact, life cycle assessment, recovered paper.
Impact Compounds of Nitrogen and Phosphorus from Wastewater on the
Environment and Methods to Improve
CRISTINA ELENA IURCIUC, MIHAI DIMA, DANIELA ROCA
pages
75 - 82
Abstract Effluents after the
biological stage classical composition presents different forms of nitrogen
(ammonium salts, nitrites, nitrates, organic nitrogen) and phosphorus
(phosphorus organic orthophosphates, polyphosphates) which inside the
receiver are easily assimilated by algae, favoring excessive multiplication
of algae. This directly contributes to increased rate of eutrophication.
Research in recent years by specialists in our country show a significant
increase in surface water and groundwater. Classical procedures wastewaters
retain these compounds of nitrogen and phosphorus at a rate of 2% mechanical
and 30% in the biological stage. In this context the authors, based on
extensive research literature, highlighting the harmful effects of these
pollutants on the environment and efficiency advanced technological methods
to resolve the problem. Keywords: effluent, emissary, eutrophication,
nutrients, pollutants, tertiary.
Construction and Characterization of
Some Composite Layer-by-Layer thin Films Based on Chitosan and Synthetic
Polyanions
CLAUDIU-AUGUSTIN
GHIORGHIȚĂ, DANIEL ȚÎMPU, ECATERINA STELA DRĂGAN
pages 83 - 89
Abstract The objective of this
study was the construction of some nanocomposite films by the layer-by-layer
deposition of chitosan as a polycation and two synthetic polyanions,
differing by the ionic group strengths and molar masses,
i.e. poly(sodium acrylate) with Mv
= 16000 g/mol and poly(sodium 2-acrylamido-2-methylpropanesulfonate) with Mw
= 170000 g/mol. The influence of the polyanion type and of the number of
double layers against the properties of the obtained films has been studied
by atomic force microscopy. The multilayer films showed a smooth surface,
the roughness being smaller than 1 nm. The histograms showed a very small
dimensional dispersion of the surface formations. Keywords:
nanocomposite multilayer films, chitosan, atomic force microscopy.
Separation and Characterization of
Lignin Resulted in Organosolv Pulping
IULIAN-ANDREI GÎLCĂ, ADRIAN CĂTĂLIN
PUIŢEL, VALENTIN I. POPA
pages 91 - 97
Abstract As a result of the
textile bast fiber technological separation process, the secondary products
may be biorefined in order to separate the main chemical components. The
paper describes a lignin separation method and the recovery of the residual
cooking liquor. In order to control the glycerol recovery degree a viscosity
concentration dependence method was proposed. The separated lignins
unmodified or modified by physical or chemical treatments may be used to
obtain nanoparticles. Keywords: biorefining, glycerol,
nano-lignin, recovery.
Study
Conditions on Technological Water-Treatment in Iaşi City and
Trihalomethanes’ (THM) Appearance
MARIA
COHL, CARMEN TEODOSIU, ION BALASANIAN
pages
99 - 108
Abstract Water to be supplied to
consumers must meet the requirements for drinking and is subject to
technological process of treatment which comprises four main steps, water
disinfection by chlorination latter. Water chlorination is the technique
most often used for drinking water disinfection. A consequence of
chlorination disinfection of water by-product of disinfection is the
formation of THM and their formation is the main disadvantaged of water
chlorination. Organic substances, respectively humic acids and fulvic
natural waters containing ketone groups that react with chlorine to form
THM: chloroform, dichlorobromomethane,
chlorodibromomethane and bromoform. Their identification was made in
2007-2010, and the values obtained were within the maximum permissible
concentrations (MAC). Keywords: requirements for drinking, by-product of
disinfection, trihalomethanes THM.
FLORIN BUCĂTARIU, FRANK SIMON,
GHEORGHE FUNDUEANU, ECATERINA STELA DRĂGAN
pages 109 - 116
Abstract A novel route to
synthesize silica//poly(vinyl amine) (silica//PVAm) and silica//chitosan
(silica//CHI) hybrid microparticles containing trypsin attached on the
surface was developed. PVAm and CHI were adsorbed from salt-free aqueous
solution onto silica microparticles with particle and pore diameter of
40-60 μm, and 100 nm, respectively. Then, the enzyme was covalently grafted
to the surface via a glutaraldehyde (GA) cross-linker. Alternatively, a
thick layer was chemisorbed by cross-linking two polyelectrolyte layers with
GA. X-ray photoelectron spectroscopy (XPS), potentiometric and
polyelectrolyte titrations were employed to obtain information about the
polyelectrolyte adsorption and multilayer formation, as well as the amount
of the trypsin that was covalently bound to the functionalized surfaces. The
study showed that only PVAm formed a double layer onto silica
microparticles, while the amount of grafted enzyme did not significantly
vary with the adsorbed amount and polyelectrolyte type. Keywords:
chitosan, poly(vinyl amine), silica, trypsin, XPS.
Rheological Properties of the Ionic
Composite Hydrogels Obtained Below the Freezing Point of the Reaction
Solutions
MARIA VALENTINA DINU, MARIA MARINELA
PERJU, ECATERINA STELA DRĂGAN
pages 117 - 125
Abstract In this work, ionic
composite hydrogels were synthesized by free-radical polymerization using
dextran sulfate (DxS) as a physical entrapped polymer, acrylamide (AAm)
monomer and N,N'-methylene(bis)acrylamide (BAAm) as cross-linking agent. The
viscoelastic properties of these hydrogels were investigated by oscillatory
shear measurements under small-deformation conditions. Changes in the
rheological properties of ionic composite hydrogels based on polyacrylamide
(PAAm) and DxS have been studied in terms of polymerization temperature,
cross-linker ratio and initial monomer concentration. The results showed
that PAAm/DxS hydrogels obtained at room temperature (22ºC) behave like weak
gels, while those obtained below the freezing point of the reaction mixture
(−18ºC) exhibited an enhancement in the storage modulus, irrespective of the
cross-linker ratio. This behavior indicated that by conducting the synthesis
of hydrogels below the freezing point of the reaction solutions a
reinforcement of the elasticity of hydrogels is achieved. Keywords: ionic
composite, hydrogels, rheology.
Nonwoods: Fiber Sources for
Papermaking Pulp Production. Laboratory Trials
BOGDAN MARIAN TOFĂNICĂ, ADRIAN
CĂTĂLIN PUIŢEL, DAN GAVRILESCU
pages 127 - 140
Abstract Until the mid to late
XIXth century, nonwood plant fibers were the main fiber raw
materials for the pulp and paper industry. Increasing demand and
developments in low cost wood pulping resulted in a large expansion of the
wood-based pulp and paper industry during the early to mid XXth
century. Nowadays, due to continuous growth in the demand of virgin fiber
and to some increased environmentalists’ pressure on the pulp and paper
industry, researchers have grown their attention on possible alternative
sources of fiber raw materials such as nonwoods. The paper presents the
experimental results obtained during the investigations on the possibilities
of pulping of nonwoods fiber sources and bleaching of the obtained pulps.
Reed (Phragmites communis), oat straws (Avena sativa) and rapeseed stalks (Brassica napus) were chosen as fibrous raw materials for pulping by
using alkaline processes. The obtained pulps were analyzed from lignin
content, viscosity and papermaking perspectives. Keywords: nonwoods,
pulp, agricultural residues, beatability.
Studies Concerning the Obtaining and
Characterization of Copper Complexes and Lignin Derivatives Used in Birch
Veneer Protection
ADINA-MIRELA CĂPRARU, IULIAN-ANDREI
GÎLCĂ, ELENA UNGUREANU, TEODOR MĂLUŢAN, VALENTIN I. POPA
pages 141 - 146
Abstract The paper presents the results obtained in a study
concerning the obtaining and characterization of hydroxymethyl- epoxy
lignins which were tested in terms of their biocides properties in birch
veener protection. Lignins from annual plants wheat straw (L1) and grass
Sarkanada (L2), offered by the company Granit (Switzerland) was used. By
applying suitable conditions of synthesis, it was possible to obtain lignin
derivatives using the reaction of hydroxymethylation followed by
epoxidation. The resulted products were applied in the treatment of birch
veneer samples. These were successively immersed in solutions containing
copper ions and unmodified and modified lignins with concentration of 5%
dissolved furfuryl alcohol. The biostability of veneer samples thus treated
were appreciated through their burial in soil for six months and
characterized by mass loss and contact angle. The obtained results show that
the treatment of birch veneer with complexes of hydroxymethyl-epoxy lignin’s
with copper offer high stability of the substrate timber products in
comparison with unmodified products. Keywords: lignin,
hidroxymetylation, epoxydation, birch veener, biostability.
Dissolved Oxygen Concentration
Profiles in a Mbbr Reactor
IOANA CORINA MOGA
pages 147 - 156
Abstract The MBBR (Moving Bed
Biofilm Reactor) biofilm technology is based on specially designed plastic
biofilm carriers or biocarriers
that are suspended and în continuous movement within a tank or
reactor of specified volume.
The industrial and municipal wastewater is led to the MBBR treatment reactor
where biofilm, growing within the internal structures of the biocarriers,
degrade the pollutants. These pollutants that need to be removed în order to
treat the wastewater are food or
substrate for growth of the biofilm. The biocarrier design is
critical due to requirements for good mass transfer of
substrate and oxygen to the
microorganisms and there is a continuous R&D în the area of the
MBBR biofilm technology. The design of associated aerators,
grids, sieves, spray nozzles and other integral parts to the reactor is also
of great importance în making up the system as a whole. That is way this
paper presents several experimental researches in order to determine the
efficiency of the aeration system. The quantity of the dissolved oxygen is
determined for a MBBR reactor. Keywords: aeration system, MBBR
bioreactor, dissolved oxygen, dispersion.
Abstract Layered double
hydroxides (LDHs) or anionic clays which have drawn attention especially
through different practical applications: adsorbers, ion exchangers, systems
with controlled delivery of active principles as well as selective catalysts
in different chemical reactions such as: dehydrogenation, alkylation,
reduction, addition to different bonds. Thermal treatments applied to these
materials lead to obtaining mixed oxides used mainly in catalysis. This
article focuses on a general presentation of the LDHs synthesis methods,
LDHs modern characterizing techniques as well as key factors which influence
the obtaining of LDHs precursors with application in catalyst processes.
Keywords: layered double hydroxides, catalysis, hydrotalcite, mixed oxides,
noble metals.
The Walnut Tree (Juglans Regia L) Characterization and Uses
CLAUDIA COBZARU
pages 171 - 186
Abstract
The walnut tree belongs to the
Juglandaceae tribe
cultivated especially for the nutritive value of the leaves and fruits. The
leaves contain a great number of elements, namely: vitamin C, flavonoids,
juglone, carotene, tannins, essential oil etc. Due to these components the
walnut leaves show astringent and hypoglycemic properties being applied in
the phytotherapy and cosmetic fields. On the other hand the kernel is one of
the main aliments recommended for completing the diet since it contains many
nutrients such as: fatty compounds, proteins, minerals, etc. A great number
of studies regarding the nutritive value and uses of the walnut are to be
found in scientific literature and some comments on their content are
presented in the present paper.
Keywords: walnut tree, characterization, medicinal and cosmetic
applications.
BOOK REVIEW: Cosmetically Active Ingredients:
Recent Advances. Edited by
Cosmetics &Toiletries Allured Books, 2011, ISBN: 978-1-932633-87-0.
review by CORINA CERNĂTESCU
pages
187-190
2010,
Volume LVI (LX), Issue 1
The New Complex Compounds for
Textile Industry: Cu(II) with 2-Amino-6-Methoxybenzotyazol-SodiumSulfonate→1-Naphtol-4-Sodium Sulfonate
LAURA CHIRILĂ, DOINA SIBIESCU, ROMEN
BUTNARU, MIHAELA AURELIA VIZITIU
pages 11 - 16
Abstract This paper presents the
obtaining and the study of the compounds resulted from the interaction of
Cu(II) with: 2 amino- 6-methoxybenzotiazol sodium sulfonate →1
naphtol-4-sodium sulfonate as ligand. The ligand is of azoic complexable
dyes type. The methods used for analyzing the obtained complex compounds
were: pH¬metry, conductometry and UV- VIS absorption spectroscopy.The
combination ratios and the stability constants of the resulted compounds
were determined using the molar ratio method (J.H.Yoe and A.L.Jones) and
Harvey-Manning method. Keywords: Cu(II) complex compound,
2-amino-6-methoxybenzotiazol sodium sulfonate acid→1 naphtol-4-sodium
sulfonate as ligand, UV-VIS absorption spectroscopy.
Removal of Nickel(II) from Aqueous
Solituons by Adsorption on Peat
CORNELIU CARAMALĂU, LAURA BULGARIU,
MATEI MACOVEANU
pages 17 - 27
Abstract In this study is
analyzed the effectiveness of Romanian peat as available and cheaper
adsorbent in removal of nickel(II) ions from aqueous solutions. The
adsorption experiments were done in batch system, in order to establish the
influence of initial solution pH, peat dose, initial nickel(II)
concentration and contact time, on the adsorption efficiency. Two adsorption
isotherm models, Langmuir and Freundlich, have been used to determine the
best-fitting model for the experimental data, and various adsorption
parameters (such as: qmax, KL and G) have been
calculated. The results of this study indicate that Romanian peat has the
potential o become an effective and economical adsorbent for the removal of
nickel(II) ions from industrial waste waters. Keywords: adsorption, nickel(II) ions, peat, isotherms.
Synthesis and Caracterisation of
Some Asimetric [1,3,4]-Oxadiazole Derivatives with Liquid Crystalline
Properties
ELENA-RALUCA CIOANCĂ, DANIELA
WILSON, DAN SCUTARU
pages 29 - 39
Abstract The synthesis and
structural characterization of some asymmetric [1 ,3,4]oxadiazole
derivatives containing azo linkage are reported. Compounds were prepared by
esterification of 2-(4-methoxyphenyl)-5-(4-hydroxyphenyl)-[1,3,4]oxadiazol
with a series of 4-(4-alkoxyfenilazo)-benzoic acids containing with 6 10 and
18 carbon atoms. The structural characterization of these compounds was
established by using spectroscopic analysis (1H-NMR, 13C-NMR, IR
spectroscopy and mass spectroscopy). All the reported compounds present
liquid crystalline properties under polarized optical microscopy
investigations. Keywords: asymmetric [1, 3, 4]oxadiazol derivatives,
liquid crystalline compounds.
New Compound of Cu(II) with Ligand 1-(3,5-Dibromine-2-Hydroxy Phenil)-2-(4-Methyl Phenyl)-Sulfanyl
Ethanone
IRINA SPĂTĂRESCU, IOAN ROŞCA, ADRIAN
CĂILEAN, DOINA SIBIESCU, GABRIELA APOSTOLESCU
pages 41 - 48
Abstract The new coordination
compound obtained from the chemical reaction between the cation Cu(II) and
the ligand 1-(3,5- dibromine-2-hydroxy phenil)-2-(4-methyl phenyl)-sulfanyl
ethanone in the molar ratio of 1:2 was characterized by the: chemical
analysis, thermogravimetry, infrared absorption spectroscopy and electronic
spin resonance spectra. The obtained results have proved that the central
atom Cu(II) is tetracoordinated with oxygen atoms provided by the phenolic
and carbonyl group of the used ligand. The studied compound presents a high
level of thermal stability, and this is the reason why it decomposes in the
temperature range of 200−550ºC during three stages. Keywords: Copper(II), thermogravimetry, compound
paramagnetic.
Behaviour in Aqueous Solution of the
Complex Cu(II) and N-Hydroxy-Succinimide
MIHAELA-DANA TUTULEA, DOINA
SIBIESCU, IOAN ROŞCA, IGOR CREŢESCU
pages 49 - 54
Abstract This paper presents the
preparation of the complex compounds based on Cu(II) and
N-hydroxy-succinimide, and respectively a study of the complex stability
depending on some experimental factors. The studies were performed using the
pH-metry, conductometry and the UV-VIS absorption spectroscopy. The
combination ratio, central atom:ligand and the stability constants for the
new obtained compounds were determined using "molar ratio method" (J.H.Yoe
and A.L.Jones), and Harvay-Manning method. It was determined the pH range
coresponding to the stability of the above mentioned complexes. Keywords: Cu(II) complex, UV-VIS spectrometry,
stability constant, N-hydroxy¬succinimide.
New Hydrophylized Catalysts Based on
Phthalocyanine Structures Modified with Peptide
Abstract The phthalocyanines
alone or supported on different inorganic substrates are used as catalysts
for the oxidation processes of different types of compounds. The paper
presents the synthesis of the substituted phthalocyanine structures with
peptide residues in order to increase the solubility in organic solvents of
these phthalocyanines by the side chain or the terminal functional groups,
making them adequate for homogeneous and pseudohomogeneous catalysis. The
synthesis of the phthalocyanines was realized by coupling cobalt and copper
tetraamino-phthalocyanines with amino acids and dipeptides, and the optimal
reaction conditions were established. A comparative study between the
catalytic activity of modified phthalocyanines and classical oxidation
catalysts (naphtenates) in the liquid phase oxidation of p- tert-butyl
toluene was realized. The synthesized phthalocyanines present a lower
activity than naphtenates. Keywords: phthalocyanines, peptides, oxidation
catalysts.
Termogravimetric Analysis of Mineral
and Synthetic Oils
Abstract The current trend in
automotive industry is to use more powerful and more efficient engines. To
achieve this goal, lubricants must also meet the growing requirements of the
new engines. As the temperature of the engine increases and the capacity of
oil tank decreases, the oils should work better in current engines. This
study aims the thermal characterization, in dynamic conditions, of mineral
and synthetic oils. For this purpose we have used dynamic thermal analysis
(TG, DTG, DTA). The results show a one, two or three steps degradation
following a complex mechanism. The mass loss differs depending on the sample
composition and the atmosphere in which the thermal decomposition was performed. Keywords: thermal stability, mineral and synthetic
oils, thermal characteristics.
Polymeric Composite Systems with
Potential Medical Applications
GIANINA DODI, MARCEL IONEL POPA,
DOINA HRIŢCU
pages 73 - 79
Abstract Over the last few
decades, polysaccharides have gained increasing attention in the biomedical,
drug delivery and biotechnology fields. Chitosan is a natural copolymer
composed of glucosamine and N-acetyl glucosamine units linked by (1–4)
glycosidic bonds that has amine and hydroxilic groups available for the
attachement of a compound of interest. A number of studies concentrate on
the chemical modifications of biocompatible and biodegradable natural
polymers because of the significant advantages regarding the adsorbtion and
possibility of interactions with biological active compounds. In this paper,
we obtain a biomaterial with improved properties by chemical modification
and the use of this polymer in colloidal nanoparticulate systems synthesis
used in different fields.
Keywords: polysaccharides, chitosan, chemical modification, nanoparticulate
systems.
HPLC Determination of Some Anthocyanins from Red Grapes
NADIA PĂUN, VIOLETA NICULESCU, RADU
TAMAIAN, MARCEL IONEL POPA
pages 81 - 85
Abstract Anthocyanins are
polyphenolic compound and water-soluble pigments which assure the red,
purple, and blue coloration of many fruits, vegetables, and cereal grains.
Anthocyanins from red grapes not only play an important role in the colour
quality of red wines but they also have many beneficial effects on human
health, e.g., reduction of coronary heart disease incidence, or
anticarcinogenic and antioxidant properties. Literature mentions that the
skin of red grapes is considered a good source of phenols. HPLC anthocyanin
analysis can be effectively applied to determine the authenticity of various
anthocyanin containing fruit juices. We developed parallel HPLC methods with
MS and PDA detection in order to identify some anthocyanins from red grape
juice. Our study showed the presence of six anthocyanins in the juice samples. Keywords: anthocyanins, grapes, chromatography.
Aspects of Environmental Legislation
Application Concerning the Municipal Wastes Landfills Into Iaşi County Area
CARMEN ZAHARIA, GETA IRIMIŢA
pages 87 - 97
Abstract The paper presents some
aspects of how was the environmental legislation applied in the case of
municipal wastes landfills into Iaşi County area. The sustainable management
of municipal wastes imposed the implementation of wastes legislation and
also collecting of reliable data of waste production and characteristics
together with the waste treatment facilities, sustainable waste management,
establishment of recycling routes and opening the market for recycling
materials, and minimization of changes for the municipal waste storage area.
In this paper is evaluating how the application of environmental legislation
was influencing the system of municipal waste management in Iași County
area, but especially the municipal wastes storage/deposition onto existing
municipal landfills. Keywords: environmental legislation, solid wastes,
Romanian landfills, sustainable management of municipal solid wastes.
Kinetic Study of the Tartaric Acid
Separation from Aqueous Solution
with a New Impregnated Ion Exchanger
NATALIA MARCHITAN, GHEORGHE DUCA, ALIONA MEREUŢA, ILIE SIMINICEANU
pages 99 - 107
Abstract A new adsorbent has been
prepared from Amberlite IRA-67 impregnated with the liquid ion-exchanger
Amberlite LA-2 dissolved in n-hexane to recover tartaric acid (TA) from
aqueous solution. The experiments done on a batch equipment proved the
effectiveness of the new material: the separation degree of TA was 100% in a
contact time less than 30 min for the following values of the 6 main
factors: solid/liquid loading >1 g/L, T = 294 K, initial pH 2.5, initial TA
concentration >1 g/100 mL, particle diameter 0.4−1.2 mm, stirring 200 min-1.
The apparent activation energy has been obtained from the pseudo-second
order rate constant. Its value (18.695 kJ/mol) indicated a mass transport
phenomenon as rate determining step. Finally, the reasonable kinetic data
correlation with the Weber-Morris model as well as with the Dumwald-Wagner
model has shown that, under the investigated conditions, the slowest step of
the process was the intraparticle
diffusion. Keywords: adsorption kinetics, activation energy, rate
determining step, batch experiments, particle diffusion control.
Synthesis and Characterization of a
New Coordination Compound of Mn(II)
SIMONA TURCUMAN (ANTIGHIN), DOINA
SIBIESCU, IOAN ROŞCA, MIHAELA VIZITIU
pages 109 - 116
Abstract In this paper, the
synthesis and characterization of a new complex compound of Mn(II) with a
ligand derived from morfolin-4-carboditioic acid-2-(3,5-
dibrome-4-methyl-2-hydroxy-phenyl)-2-hydroxy-ethyl-ester, in molar ratio
ligand: central atom 2:1 are presented. Characterization of the new compound
was accomplished applying the following methods: chemical analysis,
derivatography, infrared absorption spectroscopy and electron spin
resonance. Keywords: morfolin-4-carboditioic
acid-2-(3,5-dibrome,4-methyl,2-hydroxy-phenyl)- 2-hydroxy-ethyl-ester,
gravimetric determining.
Operational Conditions Studies
Concerning Complexation Ability of Wheat Straw Lignin for Copper(II) Ions
TATIANA TODORCIUC, LAURA BULGARIU,
VALENTIN I. POPA
pages 117 - 126
Abstract This study investigated
the interaction of lignin with copper (II) ions in batch system. In order to
assess the complexation ability of lignin polymer, the adsorption process
was studied by varying the operational conditions: the initial pH of the
solution, the influence of the initial copper (II) concentration and lignin
dosage. The maximum retention was registered at pH 6.0 (considered optimum
for the investigated system), and temperature of 19.5°C when the obtained
value was 9.59 mg Cu(II)/g lignin. The pH dependant retention suggests that
copper (II) ions are retained probably due to ion- exchange mechanism. The
experimental data were analyzed using two isotherm adsorption models
(Langmuir and Freundlich), and the results fitted better to Langmuir
equation, which suggests that adsorption process occurs predominantly by
chemical interaction between metal ion (Cu2+) and available functional
groups from lignin surface. Keywords: wheat straw lignin, copper (II),
complexation.
Spectrophotometric Method for Nitrate Analysis
LAURA BULGARIU, ANCA CEICĂ, ION BALASANIAN
pages 127 - 135
Abstract In this study a simple
spectrophotometric method is proposed for the rapid determination of nitrate
using chromotropic acid, directly in aqueous solutions. The reaction between
nitrate ions and chromotropic acid occurs immediately in strong acid media
(95 − 97% H2SO4 solution). The complex shows a maximum of adsorption at 412
nm against a blank solution, and the absorbance remains stable for at least
48 h. The method allows the nitrate determination over the range 0.62 – 9.25
mgLF1, with a molar absortivity of 2.34 103 LmolF1cmF1 and detection limit
of 0.35 1 ppm. The validation of spectrophotometric method was done by
recovery test of nitrate in tap water. The experimental results show that
the proposed method can be successfully applied to the determination of
nitrate in water samples. Keywords: nitrate determination, chromotropic acid,
spectrophotometric method, aqueous solution.
Comparative Study Concerning the
Retention Thermodynamics of Some Heavy Metal Ions on Hemp Fibers
LAVINIA TOFAN, CARMEN PĂDURARU,
IRINA VOLF
pages 137 - 145
Abstract This study reveals the
results of a thermodynamic characterization of the sorption process of
Cd(II), Cu(II) and Cr(III) ions from diluted aqueous solutions by hemp
fibers, both in natural and modified forms. Hemp is a commonly available and
inexpensive cellulosic material. The thermodynamic parameters, free energy
change (∆G) enthalpy change (∆H) and entropy change (∆S) have been
calculated on the basis of Langmuir constants. The negative values of ∆G
validate the feasibility and the spontaneity of the Cd(II) sorption process
by natural hemp and Cu(II)retention on hemp and bleached hemp impregnated
with benzoioxime, respectively. In these static sorption systems, the
positive values of ∆H show the endothermic nature of the Cd(II) and Cu(II)
retention by hemp. The results of this study suggest that hemp fibers may be
a promising sorbent provided for environmental technologies in the future. Keywords: heavy metal, hemp, bleached hemp, sorption
process.
Formation and Flocculation
Properties of Polyelectrolyte Complex Dispersions Based on Synthetic Polycations
IONEL ADRIAN DINU, MARCELA MIHAI,
ECATERINA STELA DRĂGAN
pages 147 - 154
Abstract Nonstoichiometric
interpolyelectrolyte complexes as colloidal dispersions were prepared by the
interaction of synthetic polycations which possess ammonium quaternary
centers attached to an acrylic macromolecular chain, derived from
poly(N,N¬dimethylaminoethyl methacrylate), with two random copolymers of
sodium 2- acrylamido-2- methylpropanesulfonate with t-butylacrylamide, the
molar ratio between the positive and negative charges ranging between 0.05
and 0.4. The characterization of complex dispersions as a function of
polyelectrolyte characteristics was performed by turbidimetric titration and
dynamic light scattering. The nonstoichiometric complex nanoparticles were
tested in the destabilization of kaolin model dispersion and proved to be
more efficient than polycations alone, especially as concern the broadness
of the flocculation window.
Keywords: poly(dimethylaminoethyl methacrylate), nonstoichiometric
interpolyelectrolyte complexes, kaolin, flocculation.
Polyelectrolyte Complex Particles
Based on Synthetic and Natural Polycations
MARCELA MIHAI, ECATERINA STELA
DRĂGAN
pages 155 - 162
Abstract The most important
parameters for the applications of polyelectrolyte complexes as colloidal
dispersion are the polymer concentration, the size of nanoparticles and
their storage stability. In this context we have studied the influence of
polycation structure on the stoichiometry, size and morphology of complex
colloidal dispersions obtained from an ionic/non=ionic random copolymer of
2=acrylamido=2= methylpropanesulfonate as polyanion and synthetic (PCA5) or
natural (chitosan) polycations. To get a direct image on the formation
mechanism of the complex nanoparticles, colloidal titration, turbidimetry,
dynamic light scattering and atomic force microscopy have been used. The
availability of the polycation to neutralize the polyanion charges, and thus
to influence the particles characteristics, was strongly influenced by its
chain flexibility. Keywords:
polyelectrolyte complex dispersions, optical density, dynamic light
scattering, atomic force microscopy, chitosan.
Flocculation Properties of
Polyelectrolyte Complex Dispersions Based on Synthetic and Natural
Polycations
MARCELA MIHAI, ECATERINA STELA
DRĂGAN
pages 163 - 170
Abstract The flocculation of
kaolin by positively charged nonstoichiometric polyelectrolyte complex
(NIPEC) nanoparticles formed by the interaction of an ionic/nonionic random
copolymer of sodium 2-acrylamido-2-methylpropanesulfonate with some
polycations either synthetic (integral type) or natural (chitosan),
comparative with staring polycations has been evaluated. The NIPEC
nanoparticles were more effective than polycations in the kaolin separation,
especially at low molar ratios between charges, when the flocculation window
was more then double at an optimum dose lower than that of starting
polycations. The main advantage of NIPECs is the increase of critical
concentration for kaolin re- stabilization, the NIPEC particles adsorbed on
the kaolin surface protecting them more efficient against re-dispersion.
Keywords: polyelectrolyte complex dispersions, flocculation, kaolin,
chitosan.
Adsorption of Heavy Metals on Ionic
Composites Based on Chitosan
MARIA VALENTINA DINU, ECATERINA
STELA DRĂGAN
pages 171 - 178
Abstract The adsorption of Co2+
and Ni2+ ions, from aqueous solutions, on ionic composites based on chitosan
and clinoptilolite, a widespread natural zeolite, has been investigated. The
factors influencing the adsorption capacity of the ionic composites such as
the initial pH, contact time and the initial concentration of M2+ were
examined. The kinetics of adsorption process and the adsorption isotherms
parameters were evaluated.
Keywords: chitosan, ionic composite, heavy metals, adsorption.
Electrochemical Aspects of Ti-Ta Alloys in Hank’s Balanced Salt Solution with Albumin Protein
DANIEL MARECI, ROMEU CHELARIU, GEORGIANA CIURESCU, DANIEL SUTIMAN,
IULIA CLAUDIA MÎRZA ROŞCA
pages 179 - 189
Abstract Corrosion behaviour of
the studied Ti-Ta alloys with Ta contents of 30, 40 and 50 wt.% together
with the currently used metallic biomaterials commercial pure titanium
(Cp-Ti) were investigated for biomedical applications. All the samples were
tested by potentiodynamic polarization curves and electrochemical impedance
spectroscopy (EIS) in Hank’s Balanced Salt Solution (HBSS) with albumin
protein at 25ºC. The experimental results confirm that the electrochemical
behaviour of the studied Ti-Ta alloys is better to that Cp-Ti, suggesting
their promising potential for biomedical applications. Keywords: Ti-Ta
alloy, corrosion resistance, potentiodynamic polarization, EIS.
Evaluation of the Adsorption
Potentials and Kinetics of Two Hypercrosslinked Polymeric Resins and
Activated Carbon for Hexane
Vapors
MARILENA ADELA BUBURUZAN, CEZAR
CATRINESCU, MATEI MACOVEANU
pages 191 - 202
Abstract The adsorption
potentials of a new type of non-functionalized hyper¬cross-linked polymers
Hypersol Macronet, MN 202 and MN 250 for removing of n- hexane vapors from
saturated atmosphere were evaluated. The experiments were performed
comparatively with the adsorption of n-hexane vapors onto a granular
activated carbon, AC 20. The experiments were performed to determine also
loading rates of n- hexane onto adsorbents. The results shows that the
adsorption capacity, q (mg/g), for n- hexane vapors from a saturated
atmosphere are greater for MN 250 and MN 202 polymers than thus for AC 20
(350, 290 and respectively 200 mg/g). Analyses of the rates data with three
theoretical models (pseudo-first and pseudo-second-order reaction models and
the Elovich model) were used to describe the n- hexane adsorption kinetics.
Adsorption rate constants were determined by graphical analysis of the
proposed models. The study showed that adsorption systems followed a
pseudo-second-order reaction model provides an acceptable description of the
adsorption process. Keywords: adsorption, hyper-cross-linked polymers,
hexane, kinetics, VOCs.
2010,
Volume LVI (LX), Issue 2
Assessment of Combined Wastewater
Treatment for 4-Chlorophenol
Removal
DANIELA CĂILEAN, CARMEN TEODOSIU
pages 11 - 19
Abstract Priority organic
pollutants are a class of chemicals which are hazardous for the human health
and the environment and also very resistant to conventional wastewater
treatment, this being the reason why advanced treatment processes (such as
ultrasonication and ultrafiltration) are used for their removal. Both
processes have good results in the degradation of priority organic
pollutants such as 4-chlorophenol. Several common advantages of these
processes may be mentioned, i.e. small usage of chemical reagents, decrease
of secondary pollution, lack of special conditions for temperature and
pressure for ultrasonication, lack of chemical reactions leading to toxic
products or intermediates, good degree of separation and recovery, high
retention rate and selectivity for ultrafiltration. The aim of this
preliminary laboratory- scale study is to analyze the conditions for the
efficient removal of 4-chlorophenol from wastewater by advanced treatment
under different initial conditions, using a membrane process-
ultrafiltration and/or ultrasonication. Experimental results show an average
4-chlorophenol removal efficiency of 40 %. Keywords: 4-chlorophenol,
ultrafiltration, ultrasonication, wastewater treatment.
Models for Sustainable Waste
Management
CRISTINA GHINEA, MARIA GAVRILESCU
pages 21 - 36
Abstract The purpose of this
paper is to review the types of models that are currently being used in the
area of waste management and to highlight some major advantages and
shortcomings of these models. The study is based on the reality that, for a
waste management model to be sustainable, it must consider environmental,
economic and social aspects. Most of the waste management models identified
in the literature, especially for municipal waste, are decision support
models, divided into three categories: based on cost benefit analysis, based
on life cycle assessment and based on multicriteria decision making. The
study analyses the model abilities to compare different waste management
strategies, waste treatment methods and waste process technologies, as well
as their potential environmental impacts. Also, using waste management
models, the most environmentally sustainable solution could be identified
which may differ among waste materials and regions and can add valuable
information about environmental achievements from each process in a solid
waste management system.
Keywords: model, recycling, sustainability, waste management.
Equilibrium Study of Cd(II) Sorption from Aqueous Solution onto Soil: Effect of Temperature
RALUCA MARIA HLIHOR, VASILE LUCIAN
PAVEL, DUMITRU BULGARIU, MARIA
GAVRILESCU
pages 37 - 46
Abstract Cadmium is a
non-essential element and one of the most hazardous trace elements, being
considered a "priority metal" from the standpoint of potential hazard to
human health. Toxic metal ions such as Cd(II) can eventually reach the top
of food chain and thus, become a risk factor for peoples health. Sorption of
Cd(II) ions from aqueous solution onto soil was studied as a function of
temperature using a batch technique. Langmuir and Freundlich models were
applied to describe sorption isotherm of metal ions. The maximum sorption
capacity (qmax) increase with the increasing of temperature (5.37 mg/g at
284 K and 9.06 mg/g at 314 K) which suggested that Cd(II) sorption from
aqueous solution onto soil was dependent on temperature. The thermodynamic
parameters, enthalpy (AH º), entropy (AS º) and Gibbs free energy (AG º)
were calculated from the temperature – dependent sorption isotherms. Keywords: equilibrium, heavy metal, soil, sorption,
thermodynamic parameters.
Influence of Some Parameters on
Sorption of Erythrosine B onto Soil
LAURA CARMEN APOSTOL, FLORENTINA
ANCA CĂLIMAN, MARIA GAVRILESCU
pages 47 - 56
Abstract An equilibrium study
concerning the sorption of the dye Erythrosine B in an aqueous solution,
onto a Romanian soil was performed in a batch system. The influence of two
parameters as temperature and pH of the dye containing solution has been
investigated. The thermodynamic parameters were determined as well.
Keywords: dyes, parameters, soil, sorption.
Pneumatic (Bio)Reactors Applied in Environmental Protection
PETRONELA COZMA, MARIA GAVRILESCU
pages 57 - 76
Abstract This paper is an
overview on the most recent application of pneumatic (bio)reactors in
environmental protection. In the last decades pneumatic bioreactors have
extensively been studied and applied in chemical and biotechnological
process as well as in environmental protection because of their functional
and economics advantages, such as: simple design and construction, high
efficiency of homogenization and intense mixing for heat and mass transfer
and low power consumption. This analysis considers the pneumatic bioreactors
ranking in two main categories: bubble columns and air-lift bioreactors.
These heterogeneous reactors are examined considering their intensive
application as multiphase contactors and (bio)reactors in chemical,
biochemical industries and environmental remediation. Investigation of
design parameters characterizing the operation and transport phenomena is
considered opportune for a better understanding of the hydrodynamic
properties, heat and mass transfer mechanisms and flow regime
characteristics ongoing during the operation. In particular, air-lift
reactors have received much attention because of their unique hydrodynamic
characteristics, which make them more attractive than bubble column reactors
for many processes. Aerobic bio- treatment of the wastewater, gaseous
streams and contaminated soils may be successfully performed in three-phase
flow pneumatic bioreactors. Keywords: airlift reactor, bubble column,
wastewater treatment.
Overview on the Economic Assessment
of Pollution Prevention/Cleaner
Production Practices
MĂDĂLINA PETRARU, MARIA GAVRILESCU
pages 77 - 93
Abstract The paper provides a
synthetic study concerning the technical and economic assessment of
pollution prevention/cleaner production practices based on the available
technologies in some relevant industries and highlights critical factors
influencing strategic decisions on the adoption of Best Available
Technologies in the light of IPPC Directive. A baseline for comparative
purposes is established to properly determine the cost of any project.
Changes in material consumption, equipment, technology, utility demands,
manpower etc., for the considered pollution prevention options can be
evaluated as either more or less expensive than the baseline. The benefit to
cost ratio (B/C) is taken as a basic measure, which indicates if a project
is economically worthwhile to invest in. The present value of net benefits
(PVNB) shows the worth of a pollution prevention project in terms of a
present value sum. Even if the analysis confirms the potential of pollution
prevention/cleaner production practices to generate significant cost savings
with a short payback time, it highlights the need of funds for research and
to access the know-how necessary to implement new and cleaner technologies.
Keywords: economic aspects, pollution prevention, clean production.
Study Concerning the Amortization of
the Environmental Expenses
LILIANA TOPLICEANU, DIANA SMEU
pages 95 - 104
Abstract The paper explores the
connection and the dispute between economic growth and ecology. Investments
in infrastructure to combat the environmental impact must be considered
since the design phase of the economic purpose and the study case presented
highlights this idea. Keywords: environment, economy, expenses
amortization.
About the Connection Between
Environment and Economy
LlLIANA TOPLICEANU
pages 105 - 109
Abstract Environmental
degradation caused by industrialization led to the emergence of the green
economy concept. According to this, any economic activity should be analyzed
and accompanied by measures to protect environment Keywords:
environment, sustainable development, economy.
Use of Native Epigeic Mosses to
Study Atmospheric Deposition of Pb and Cd
IONELA MEZDREA COJOCĂREANU PATA,
MATEI MACOVEANU
pages 111 - 120
Abstract It were investigated
some atmospheric sediments of lead and cadmium in mining areas of Dorna
Basin by passive monitoring with six species of native epigeic moss (Mnium
hornum, Mnium cuspidatum, Mnium punctatum, Polytrichum strictum, Thamnium
alopecurum si Cephalozia bicuspidate) in two stages: April - September 2005
and October 2005 - March 2006. These determinations were achieved in 4
locations: Dealul Boambei, Saru Dornei, Sări%orul Mic, Neagra Sarului. In
the same time was determined the concentration of these elements in soil. It
was noticed a decrease of lead and cadmium concentrations in the second
stage comparing to the first. The concentration factor (CF) values shows a
maximum accumulation in the selected epigeic mosses. There are presented
external and internal factors that affect passive absorption of the heavy
metals in the atmosphere. High capacity retention of the same moss species
is due to both environment mental factors and high content of the complex
compounds in their composition. Keywords: atmospheric deposition, heavy
metals, biomonitoring.
Complexing Hg(II) with
N,N’-Bis(Saliciliden)-Methin-Methyl-Diamine and Characterization of the New Compound
IRINA SPĂTĂRESCU, IOAN ROSCA, DOINA
SIBIESCU, MIHAELA AURELIA VIZITIU
pages 121 - 127
Abstract In this paper are
presented the results of the synthesis and characterization of the new
compound resulted from the interaction between Hg(II) and
N,N’-bis(saliciliden)-methin-methyl-diamine. The methods used for study are:
elemental chemical analysis, IR absorption spectroscopy, thermal-gravimetry
analysis. The obtaining reaction of the new compound can be used in analytic
gravimetric determining of
Hg(II). Keywords: Hg(II); N,N’-bis(saliciliden)-methin-methyl-diamine;
synthesis; thermal¬gravimetrical analysis.
Modeling of Dispersions of Powder
Emissions from the Industrial Area of Vaslui
MIHAELA BUDIANU, MATEI MACOVEANU
pages 129 - 138
Abstract The toxicity of the
heavy metals being well-known, the study concerning their environmental
impacts is more and more increased. The heavy metals originate from
different sources but one may state that the most significant one is the
emission of heavy metals by the economic agents. Regarding the study of the
heavy metals transfer to soil, a great attention is given to the dispersion
of the pollutants emanated by different sources. This paper presents the
data of a study on the dispersion of the powders emitted by 14 point sources
from 5 economical agents: SC STEMAR SA Vaslui, SC TERMICA SA Vaslui, SC
Fabrica de căramizi SRL Vaslui, SC ULEROM SA Vaslui, SC VASCAR SA Vaslui,
using the ECO 95ep program for modeling the dispersion of a pollutant caused
by a point source. Keywords: heavy metals, pollutants dispersion,
dispersion models, suspended powders.
Research on the Concentration of
Phenols and Heavy Metals in the Danube Water
NICOLETA ROADEVIN, CONSTANTIN STANCIU, IONUł RĂDULESCU
pages 139 - 146
Abstract The condition of the
ecosystems, purification and biological purification and human health are
all impacted by a number of toxic substances. These include phenols, heavy
metals and inorganic salts. The study outlines the evolution of the phenols,
heavy metals concentrations and the cause of their variations throughout
1998<2008. The rates obtained for the monitored indicators (2008) place
Brăila county river waters under class II of surface water quality. Key word: toxic substances, heavy
metals, phenols, ecosystems, purification.
Wastewater Treatment By Adsorption
on the Multipurpose Carbon Materials
PETRE CHIPURICI, ADINA IONUȚA
GAVRILĂ, IOAN CĂLINESCU, GEORGETA
PREDEANU, ANCA MIHAELA BULEARCĂ
pages 147 - 155
Abstract The multipurpose carbon
materials (MCM) are porous products resulted from the carbonization and
activation of the following materials used in our study: peach and plum
kernels, particleboard PAL and soybean hulls. The paper presents a method
for the removal of anionic surfactant (Dodecyl sulfate sodium salt) from
aqueous solutions by adsorption onto MCM using dynamic conditions. The
anionic surfactant has usually been determined by spectrophotometric
methods, using Methylene Blue. Experimental studies have been demonstrated
the possibility of surfactant removal by adsorption onto MCM. The
breakthrough point depends on the MCM parent type; the treated water volume increases with
the adsorbent column height and with the decreasing
of the concentration and supply flow. Keywords: anionic surfactant, waste water treatment,
adsorption, activated carbon.
The Synthesis and the Study in Solid Stade of a New Coordination Compound of Ni(II) with Organic Ligand
SIMONA TURCUMAN (ANTIGHIN), DOINA
SIBIESCU, IOAN ROSCA, MIHAELA
VIZITIU
pages 157 - 165
Abstract In this paper, the
synthesis and study of a coordinative compound resulted from the reaction
between the ligand 1-(3- brome-2-hiyroxy-4-methyl-phenyl)-2-
(4–brome-phenylsulfanyl)-etanone, with Ni(II) in the molar ratio 2:1, is
presented. In order to characterize the new compound, the following methods
were used: chemical analysis, thermal gravimetric measurements, IR
absorption spectroscopy and electronic spin resonance. The experimental
results show that the obtaining reaction of the new compound can be useful
for gravimetric determining of Ni(II) with ± 0.27% errors. Keywords:
organic ligand, complex compound, Ni(II), gravimetric analysis.
A New Coordination Compound of
Ni(II) with Ligand Derived from 1 -
(3,5-Dibromo-2-Hydroxy-4-Methyl-Phenyl)-2-(Naphtylsulphanyl)-Ethanone
SIMONA TURCUMAN (ANTIGHIN), DOINA
SIBIESCU, IOAN ROSCA
pages 167 - 174
Abstract In this paper, the
authors continue the researches on obtaining new coordination compounds from
transitional metals, by presenting a new complex containing Ni(II) and a
ligand derived from 1-(3,5-dibromo-2-hydroxy-4-methyl-phenyl)- 2-
(naphtylsulphanyl)-ethanone. This new complex was synthesized in aqueous
solution by mixing 250 mL 10-2M of NiCl2 and respectively 250 mL 2 10-2M of
1-(3,5-dibromo-2- hydroxy-4-methyl-phenyl)-2-(naphtylsulphanyl)- ethanone,
and stirring them at room temperature. The study of this compound was
performed with the following methods: chemical analysis, thermogravimetry,
IR absorbtion spectroscopy, electronic spectroscopic resonance (RES) and
X-ray diffraction. The complex crystallizes in the triclinic system with
Ni(II), as central atoms, hexa-coordinated in octahedral structures. The
obtaining reaction of this new complex can be used in gravimetric
determination of Ni(II) with an error of ± 0,35%. Keywords: Ni(II),
1-(3,5-dibromo-2-hydroxy-4-methyl-phenyl)-2-(naphtylsulphanyl)- ethanone,
reagent of precipitating, , thermogravimetry, IR absorbtion spectroscopy,
X-ray diffraction , RES.
A Mathematical Modeling of Metallic Surfaces
Degreasing Process
GIANNINA ACATRINEI (MERLAN),
TIBERIU-MIHAI STURZU, MATEI MACOVEANU,
MIHAI NICU
pages 175 - 182
Abstract Metal products need
degreasing processes for removing fat substances out of their surfaces,
especially before a mechanical or chemical processing of their surfaces. The
paper depicts the fact that degreasing process leads to a low decrease of
tensile strength and it offers mathematical models for the study of
process’s parameters influence. Mathematical models were established using
passive experiments and a compound-central routable program of second order,
being validated on the basis of some statistical tests. Keywords:
degreasing process, tensile strength, compound-central routable program of
second order, level contours, 3- D representation.
Sorption and Desorption
Characteristics of Acid Orange 7
on Soil
CAMELIA SMARANDA, MARIA GAVRILESCU,
DUMITRU BULGARIU
pages 183 - 191
Abstract The paper describes the
sorption and desorption of an anionic azo dye, Acid Orange 7, from aqueous
solutions onto soil from Iași area. The adsorption - desorption experiments
were conducted by the batch mode data were analyzed with different
mathematical models to describe the characteristics and mechanism of
adsorption - desorption of dye in soil. The results showed that the
adsorption-desorption isotherms of Acid Orange 7 fitted for the Freundlich
model well, and the physical reaction presents the main contribution during
the adsorption-desorption process. For desorption studies were used
distilled water, 0.01 M calcium chloride solution and ethyl alcohol 20%; and
four desorption cycles were carried out. Also, the effect of pH of the dye
solution on the amount of dye sorbed and desorbed was studied; the increase
in initial pH of the dye solution decreased the amount of dye sorbed on
soil. Keywords: sorption, desorption, Acid Orange 7, isotherms,
hysteresis.
Institutional Aspects Regarding
Water and Wastewater Infrastructure Assessment in the North-Eastern Region of Romania
CAMELIA ARDELEANU, CARMEN TEODOSIU
pages 193 - 200
Abstract There is a continue need
to ensure better services capable to reach EU standards in water supply and
wastewater sector. This requires the adoption and implementation of adequate
development policies, focused on people real needs, and accessibility of
services. "Regionalization" is a key aspect of development policy for water
services. This policy aims to improve the sector performances through better
management and professionalism. The eligibility criteria for accessing
European funds for water sector require a regional operator to be
established by the local authority’s beneficiary. From an institutional
point of view, the framework of regionalization comprises three key
elements: Intercommunity Development Association (IDA), Regional Operator
Company (COR) and Delegation of Management Services contract. This paper
presents an analysis of the institutional needs for water and wastewater
infrastructure and the problems in establishing these institutional
requirements, in the North - Eastern Region of Romania. Keywords: Regionalization, Intercommunity Development
Association (IDA), Regional Operator Company (COR), Delegation of Management
Services contract.
The Optical Features of Silver - Layered Double Hydroxides Nanostructured
Ensembles Studied By UV-Vis Spectroscopy
CRISTIAN DRANCA, GABRIELA CARJA,
SOFRONIA DRANCA
pages 201 - 208
Abstract Nanosized silver-LDH
nanostructured ensembles were obtained by a facile, environmentally friendly
synthesis route. MgAlLDH and ZnAlLDH were used as biocompatible matrices
with porous properties. UV-Vis spectroscopy was used to study the optical
properties of the nanoparticles of silver supported on the clay. The
absorption band recorded in the UV-Vis spectral range is assigned to silver
surface plasmon (SPR) of nanosized silver. Keywords: layered double
hydroxides, silver nanoparticles, optical properties, nanostructured
ensembles, SPR.
2010,
Volume LVI (LX), Issue 3
About the Reactivity of Some
Chemical Elements
SAVEL IFRIM
pages 9 - 15
Abstract Chemical reactivity of
atoms or molecules is not determined by the valence electrons only or by the
presence of chemical functions alone. This property is due to the whole
electronic structure of atoms and to the entire chemical structure of
molecules respectively. To trigger any chemical reaction electron travels
have to occur. Alkali metal atoms are able to easily dispose of their
valence electrons, due to a very low ionization potential compared with the
ionization potentials for the removal of a second or a third electron. A
similar behaviour exists for alkaline earth metals. When disposing of
valence electrons of an alkaline earth metal atom, the ionization energies
needed are relatively low. To remove the third electron, these energies are
much higher. Given the peripheral electronic density (σ) in the case of
alkali atoms and alkaline earth ones, one can note that this is very small
compared to the same peripheral density of the corresponding cations (σ+).
So on the surface of monovalent or bivalent cations there is an
electro-negative force that generates an action of rejection or expulsion of
the valence electrons, which is manifested by very rapid oxidation of these
metals. Their oxidation does not occur in the presence of alkanes. This
general property of metals to easily form an oxide film by mere contact with
air is explained by the electronic structure of atoms which generates a
force of rejection or expulsion of peripheral electrons. One can say that
the principle of peripheral electron rejection is at work. Keywords: chemical reactivity, ionization potential,
peripheral electronic density.
Possibilities of Recovery Vanadium
Pentaoxide from Waste Catalysts Used in Sulfuric Acid Industry
NECULAI FOCA, DANIEL SUTIMAN,
MIHAELA-AURELIA VIZITIU, DANIEL MARECI
pages 17 - 26
Abstract In this paper, are
presented experimental data regarding divanadium pentaoxide (V2O5)
from used V2O5 catalysts resulted in the obtaining
process of sulfuric acid. An oxidizing method of different vanadium species
(V3+, V4+) from solutions resulted in the reactions
between used catalysts – distilled water with sodium hypochlorite, is
presented in this work. The solutions treated with this oxidizing reagent
contain finally Fe3+ and V5+, as main cations. In
order to obtain V2O5 of high purity, the separation of
V5+ from Fe3+ is necessary. This process can be
accomplished by chemical methods or, more efficiently, by the ionic change
method. In this paper, some dosage methods for V(V) and Fe(III) from
solutions of waste catalysts are presented. Also, some chemical
precipitating methods of vanadium (V) from solutions are discussed.
Divanadium pentaoxide is the only vanadium oxide used in the oxidizing
process of SO2 to SO3, in sulfuric acid industry. The
catalysts used in this process is a mix of oxides: V2O5-K2O(Na2O)-Fe2O3-SiO2.
The active component is V2O5, the promotor is K2O
or Na2O and the inert support is
SiO2. Keywords: waste catalyst, divanadium pentaoxide,
sodium hypochlorite, pH; spectrophotometric methods, exchanging ion resins.
Method to Assessing the Degradation
in Soil of Lignocellulosic Composites for Seedling Pots
MIHAIL LUPEI, FLORIN CIOLACU, ELENA
BOBU
pages 27 - 36
Abstract This paper is part of a
larger study that aims to develop and evaluate a technology for obtaining a
composite based on fibrous materials, that can be used as biodegradable
nutritional pots for seedling, and which must fulfill the current needs of
agriculture, and environmental protection requirements also. Difficulty in
obtaining optimal proprieties of these materials consists in achieving good
strength properties, in both dry and wet states, for first stage of seeding
process, simultaneously with a potential for gradual degradation of the pots
after their transfer in the soil. The aim of this work was to develop
a method to simulating the aerobic and anaerobic degradation of seedling pot
material in soil. In this respect, special equipment was developed,
consisting of a container as support for seedling soil and a system for
climate conditioning (soil humidity and temperature). This equipment was
used to evaluate degradation in time of composites for seedling pots
obtained with different additives for controlling dry and wet strength
properties. The results of these experiments have as shown that method is
adequately to assess the effectiveness of strength additives and to optimize
the properties of composite for seedling pots. Keywords: biodegradable pots, seedling, strength, additives,
degradation.
The Analysis of the Voltage Balance
and of Energy Consumption in the Process of Chrome Electrodeposition
LILIANA LAZĂR, FLORIN BANDRABUR
pages 37 - 47
Abstract The assessment of the
performances of an electrochemical reactor (electrolyser), as well as of the
process efficiency is achieved by the energy yield necessary for obtaining a
certain amount of reaction product, meaning the amount of chrome
electrodeposited onto a metallic support. The practical energy consumption
is directly proportional with the terminal voltage of the electrolyser. This
depends on the electrolyte composition and the operating parameter and is
significantly influenced by the voltage drop through the electrolyte. For an
electrochemical reactor that functions at a certain temperature, the proper
selection of the distance between the electrodes, in order to decrease the
voltage drop through the electrolyte and, consequently, the energy
consumption, is essential. The analysis of the voltage balance for the
process of chromium electroplating in order to establish the mathematical
relationship of the voltages at the terminals of the electrolyser and the
specific consumption of electric energy in function of the distance between
the electrodes and the thickness of chrome electrochemical deposited is
performed in this paper. Keywords: chromium electroplating, voltages
balance, specific energy consumption.
Aldehyde Condensation Polymers of
Ketones. II. Synthesis and Characterization of Modified Acetone –
Formaldehyde Resin
ANA NICONOV, CAMELIA MIHĂILESCU,
CONSTANŢA IBĂNESCU, SIMONA BISTRICEANU, VICTOR BULACOVSCHI
pages 49 - 59
Abstract A new resin based on
acetone-formaldehyde condensate and small quantities of 4-hexyl-resorcinol
was prepared and characterized by FT-IR and thermogravimetry. A rheological
study of the prepared viscous resin was also accomplished and the obtained
data were compared with those obtained for acetone-formaldehyde resin.
Keywords: hexylresorcinol, acetone, formaldehyde, condensation, rheology.
Artemisinin, a Novel Antimalarial
Drug from Nature
BIANCA IVĂNESCU, GABRIELA CIOBANU
pages 61 - 71
Abstract Artemisinin is a modern,
potent and very efficient drug used in treatment of malaria. It is effective
even against multi- drug resistant strains of the malaria parasite and in
cases of cerebral malaria. Artemisinin or qinghaosu is a sesquiterpene
lactone produced by the aerial parts of
Artemisia annua L. (Asteraceae
family), a plant that has been used to treat fever and malaria for more
than 2000 years in China. Nowadays, artemisinin and its derivatives are
recommended by the World Health Organisation to be used as first choice
therapy in the treatment of malaria as part of ACT (artemisinin combination
therapy). The drug is also effective against other parasites (Toxoplasma, Schistosoma, and
Leishmania) and has anticancer properties useful in breast cancer, leukaemia, colon and small-cell lung
carcinomas. Keywords: artemisinin,
Artemisia annua, antimalarial.
Characterization of Ceria–(Ni, Fe,
Co) Mixed Oxides Synthesised Via Solid State Reaction
GABRIELA ANTOANETA APOSTOLESCU,
ISABELA CONSTANŢA LUCHIAN, NICOLAE APOSTOLESCU, JEANINA COZMA
pages 73 - 80
Abstract This paper present some
experimental data regarding synthesis of efficient and inexpensive smart
materials that can be used in several areas of heterogeneous catalysis,
components for solid oxide fuel cells, amperometric sensors, gas storage
materials as powders or thin and thick films. Mixed metals oxide materials
are synthesised via solid state process starting from high-purity Fe2(C2O4)3,
NiC2O4, CoC2O4 and Ce2(C2O4)3.
The synthesized materials were carried out employing scanning electron
microscopy (SEM and FESEM), FTIR spectroscopic analysis and thermo
gravimetric analysis (TGA).
Keywords: ceria mixed oxides, solid state reaction, thermal analysis.
2010,
Volume LVI (LX), Issue 4*
Study of the Influence of Degreasing
Metallic Surfaces Process Parameters on Elongation at Break
Abstract The paper offers some
mathematical models which show the relationships between elongation at break
and the parameters of degreasing process. Using a Central-Compound Routable
Program of second degree, one found the mathematical model of elongation at
break and the three parameters of degreasing process that were studied.
Because there were found optimal points inside of the domain taken into
analysis, the paper permits drawing of interesting conclusions on the
management of metallic surfaces degreasing process. Keywords: degreasing
process, elongation at break, central-compound routable program of second
order, level curves, 3D representation.
Overview of the Romanian Standards
in Sensory Analysis
Abstract Sensory analysis
standards are indispensable instruments in the assessment of consumer
products by the use of the human senses: sight, hearing, smell, taste and
touch. Paper presents an overview of Romanian standards in sensory analysis
and a compare between Romanian and international standards. Sensory analysis
standards help developers and producers in the evaluation of their products
to ensure product quality, consumer satisfaction, and marketing success.
Keywords: sensory analysis, standards.
Synthesis and Characterization of Cu
(II), Ni (II) Metal Complexes of Some Bis Schiff Bases
LUCIA TĂTARU, CORINA MĂLUŢAN, MIHAI
VÂŢĂ, GABRIELA RUSU
Abstract This paper presents the
synthesis of bis Schiff bases by condensation of the β-hydroxy-α-naphthalic
aldehyde with aromatic diamines, in acid catalysis, the molar ratio 2:1,
major compounds in the coordinative chemistry. Bis Schiff bases have been
converted to chelated metal complexes (Cu+2, Ni+2).
Characterization of bis Schiff bases and metal complexes was achieved by
FT-IR, UV-VIS spectroscopy, and thermogravimetric analysis. Keywords: bis
Schiff bases, metal complexes, Cu(II), Ni(II).
Abstract In this study the
adsorption of lead(II) from aqueous solutions on chitosan was investigated,
from kinetic point of view. The influence of contact time, in optimum
experimental conditions was studied in batch experiments. The obtained
results have shown that the chemical interactions between metal ions and
functional groups from chitosan surface might be the rate-limiting
elementary process. The experimental data were analyzed using three kinetics
models: pseudo-first order Lagregen model, pseudo-second order Ho model and
intra-particle diffusion model. On the basis of these models, the kinetics
parameters (rate constant and equilibrium adsorption capacity) for lead(II)
ions adsorption on chitosan were calculated. Keywords: lead(II),
adsorption, chitosan, kinetics.
Iron Containing Layered Double
Hydroxides: Structural, Textural Properties and Applications as Catalysts in
Decolorization of Some Waters by Heterogenous Oxidative Processes
Abstract The paper presents a
laboratory study of the structural, textural properties of double layered
hydroxides containing iron together with their preliminary experimental
applications in some advanced processes of heterogenous catalytic oxidation
with hydrogen peroxide applied for water resources loaded with organic
Orange 16 dye. The influence of different operational variables (i.e.
stirring regime, pH, H2O2 concentration, concentration of catalyst based on
layered double hydroxides containing Fe(III)/Fe(II), dye concentration,
oxidation time) was experimentally studied in order to find the best values
for high decolorization efficiency. A laboratory scale set-up decolorization
experiment was performed for these values of the studied variables in the
case on an effluent loaded with 80 mg/L Orange 16 dye. The highest
decolorization efficiency (> 70 %) was performed at pH (1.8), continuous
stirring regime (50 rpm), temperature of 19-20°C, with 0.176 M H2O2, 1.2 g
catalyst/L, and after 30 min of advanced heterogenous oxidation.
Keywords: layered double hydroxides containing iron (FeLDH), azo dye,
decolorization, heterogenous advanced oxidation process.
Preliminary Study of Decolourization
of Some Textile Effluents by Homogenous Oxidative Processes
Abstract The paper presents a
preliminary laboratory study of some homogenous oxidation processes with
hydrogen peroxide (i.e. advanced oxidation with Fenton reagent) applied for
wastewaters loaded with textile Orange 16 dye. The influence of different
operational variables (i.e. stirring regime, temperature, pH, H2O2
concentration, ferrous ions concentration, dye concentration, oxidation
time) was studied in order to find the most indicated values for high
decolourization efficiency. A laboratory scale set-up decolourization
experiment was performed for these proposed values in the case of an
effluent loaded with 80 mg/L Orange 16 dye. The highest decolourization
efficiency (> 97 %) was performed at pH (5.3), temperature of 19-20°C,
continuous stirring regime (50 rpm), with 35.29 mM H2O2, 0.68 mM Fe2+,
and after only 5 min of homogenous advanced oxidation. Keywords: textile
effluent, decolourization, Orange 16 dye, homogenous advanced oxidation,
Fenton reagent.
Life Cycle Assessment of Water and
Wastewater Treatment Systems: an Overview
GEORGE BARJOVEANU, IULIA MARIA
COMANDARU, CARMEN TEODOSIU
Abstract Given the urgent need
for reliable assessment instruments that can contribute to decision making
processes within sustainable water resources management and reported
capabilities of the Life cycle assessment (LCA) in this field, this paper
presents the state-of-art regarding LCA methodology use in the analysis and
evaluation of water supply and wastewater treatment systems. The literature
review has shown that the use of current LCA methods are mainly focused on
comparing the environmental impacts of existing or projected water and/or
wastewater treatment technologies. The majority of these studies have
focused on the energy consumption of various treatment technologies, and
especially of the membrane processes. The LCA use in analyzing water
services systems has grown significantly in the last years, but there are
still some issues that can be improved including economic indicators and
refining the impact categories by developing appropriate indicators and
weighting scales for a true and reliable life cycle impact assessment.
Keywords: LCA, water supply systems, wastewater treatment systems.
Arsenate Removal from Aqueous
Solutions by Using Rhamus Frangula
and Calami Rhizoma
GABRIELA LEHUŢU, GABRIELA CÂRJĂ,
NICOLAE APOSTOLESCU
Abstract This paper reports the
feasibility of using micro-particles of dried plants to remove As(V) from
aqueous solutions under different experimental conditions. For this purpose,
micro-particles of both Rhamus
frangula and Calami rhizoma
plants have been separately used as natural adsorbents without any
pre-treatment. Effect of various process parameters, namely adsorbent
dosage, contact time and initial arsenate solution concentration have been
studied in batch system. The experimental data were analyzed using
Freundlich adsorption isotherm model. The results revealed that As(V) is
considerably adsorbed on both dried plants and the adsorption process was
dependent on the physical–chemical characteristics of the adsorbent,
adsorbate concentration and other studied parameters; therefore it could be
an economical method for arsenate removal from aqueous systems. Keywords:
Arsenate, dried plants, adsorption parameters.
Abstract Forskolin is the main
ingredient in the Ayurvedic herb Coleus Forskolii. Coleus is a member of
mint family and grows mainly in the subtropical arias in India, Burma and
Thailand. Forskolin has been used in the treatment of allergies, respiratory
problems, cardiovascular disorders, glaucoma, psoriasis, hypothyroidism,
weight loss etc. Forskolin increased cyclic AMP and appears to have
additional actions that are due to its ability to alter a number of membrane
transport proteins. In these review are included a comprehensive account of
morphology, distribution, medicinal and cosmetic uses and pharmacological
aspects for forskolin. Keywords: Coleus Forskolii, Forskolin, morphology
and distribution, medicinal and cosmetic applications.
Abstract Coleus Forskolii is one
of two hundreds species of Coleus from all over the world. These plants grow
in tropical and subtropical regions in Asia, Africa and Australia. The main
active compound from Coleus F. is a diterpene named Forskolin, found in the
roots of the plant. The roots decoction and paste were used in the past in
traditional treatment of many diseases. Nowdays Forskolin is used in the
treatement of eczemas, psoriazis, cardiovascular disorders, glaucoma,
hypertension etc. The isolation of forskolin is realized by the means of
organic solvent extraction, followed by purrification through column
chromatography, using activated charcoal as an absorbent. The forskolin was
analyzed and characterized by TLC, HPTLC, HPLC, FTIR and electrospray
ionization MS. Keywords: Coleus Forskolii, Forskolin, extraction and
purification methods, physico-chemical characterization.
Removal of Nitrates From Water in
the Presence of Competitors Anions Using Purolite Resins
ANCA CEICĂ, LAURA BULGARIU, LILIANA
LAZĂR, IGOR CREŢESCU, ION BALASANIAN
Abstract In this paper was
studied the influence of competitors anions, chloride and sulphate ions in
the nitrates retention process from aqueous solutions, using three anion
exchange resin: two non-selective anion exchange resin Purolite A-100 and
Purolite A-847 and a selective resin, specially designed for the removal of
nitrates from waters, Purolite A-520E. The resins performance was determined
for aqueous solutions containing 50 mg NO3-/L and 100
mg NO3-/L nitrate concentrations, using batch mode
study. To determine the influence of sulphate ions on the nitrate retention,
the sulphate concentrations were increased gradually, in the range of 20 –
90 mg SO42-/L, and for the influence of chloride ions
their concentration was 19 – 115 mg Cl-/L. For all three resins
studied was observed the negative influence of individual competing anions
by decreasing of retentions capacity of nitrates. For each resin was
determined the concentrations of competitors ions which does not affect the
retention capacity of nitrates. Keywords: anionic resins, competing
anions (Cl-, SO42-), nitrates removal, ion
exchange.
Power Plant Ash Used as Adsorbent
Material
MARIA HARJA, GABRIELA BUEMA, EUGENIA
DONIGA, MARINELA BĂRBUŢĂ, DANIEL MIRCEA SUTIMAN
Abstract Ash, generated during
the combustion of coal, is an industrial waste which is recognized as an
environmental pollutant. In present days, approximately 70 to 75 percent of
generated fly ash is still disposed in landfills or storage lagoons. Much of
this ash, however, is capable to be recovered and used. Some of these
applications are: additives for heavy metals immobilization used in
wastewater treatment; valuable metals extraction, such as Al, Si, Fe, V, Ni,
Zn; sorbents for flue gas desulfurization; fireproof materials; production
for soil amendment; filter material; ceramic products obtaining. Even the
fly is considered a pollution source, it has practical applications in
environmental protection. From these applications it was studied the
recovery of this waste by: direct utilization for heavy metals and dye
retentions. It was demonstrated that the fly ash does not pollute ground
water. Experiences were effectuated at constant temperature in continue
systems: column recrosses of liquid and stirrer reactor. For the different
fly ash/ deionization water ratios the chemical composition and solution
conductivity variations in time were determined. Removal for lead was 97%
after 40 min. In the case of Astrazone blue the obtained removal was 98%
after 60 min. Keywords: capitalization, dye, fly ash, lead, removal.
Integrated Design and Control of
Glycerol Etherification Processes
Abstract The feasibility of an
industrial-scale, acid-catalyzed process for etherification of glycerol with
i-butene is analyzed. A simplified mass balance of the process is derived
using a kinetic model for the reactor and black-box model for the separation
section. Degree of freedom analysis is used to suggest plantwide control
structures. Sensitivity analysis of the steady state model shows that the
system exhibits both state multiplicity and regions where no solution
exists. The nominal operating point is chosen to avoid high sensitivity to
disturbances and to guarantee feasibility when operation and design
parameters change or are uncertain. Detailed design is performed using
AspenPlus. The stability and robustness in operation are checked by rigorous
dynamic simulation in AspenDynamics. Keywords: glycerol ethers, process
design, process control, nonlinear behavior.
Removal of CO2 From Gas
Streams In Airlift Reactors
Abstract Emissions of carbon
dioxide (CO2) and other greenhouse gases have become a major
environmental issue due to their intensive contribution on the global
warming. In the last decades the removal of CO2 from gas mixtures
has become an important industrial operation due to the necessity of
different gases purification and from recovery reasons taking into accounts
the large applications of CO2 in chemical and food industry.
Various techniques have applied for CO2 removal. These
technologies are based on different physical, chemical or biological
processes. In addition several types of contactors have been reported for CO2
removal such as stirred tanks, packed columns, bubble columns and membrane
contactors. This paper discusses the most recent application of airlift
reactors in flue gas treatment, in particular the potential of application
for the effective CO2 removal from contaminated flue gases taking
into account the most important advantages of these devices: simple design
and construction, no moving parts, high mass and heat transfer, intensive
mixing, low shear stress to cells, low energy consumption, low operational
costs. The most relevant characteristics and properties of CO2 as
well as the most applied technologies for CO2 removal are
reviewed in this paper, based on the information from literature data.
Keywords: airlift reactor, absorption, CO2 removal.