DENIS CUTCOVSCHI, “Gheorghe Asachi” Technical University of Iaşi,
“Cristofor Simionescu” Faculty of Chemical Engineering and Environmental
Protection, Iaşi, Romania SOFRONIA BOUARIU, “Gheorghe Asachi” Technical
University of Iaşi, “Cristofor Simionescu” Faculty of Chemical Engineering
and Environmental Protection, Iaşi, Romania GABRIELA CARJA, “Gheorghe
Asachi” Technical University of Iaşi, “Cristofor Simionescu” Faculty of
Chemical Engineering and Environmental Protection, Iaşi, Romania,
gabriela.carja@academic.tuiasi.ro
Abstract Layered double hydroxides (LDHs) are a unique class of
inorganic compounds, presenting positively charged layers arranged in a
brucite-like structure. These materials are highly versatile due to their
ability to host various anions in the interlayer spaces and accommodate
diverse cations in the layers. As a result, LDHs have broad applications in
fields like drug delivery, water purification, and catalysis. A key
characteristic of LDHs is their structural “memory effect,” which allows
them to restore their original structure after calcination. Factors such as
temperature, pressure, pH, and the specific anions and cations involved
significantly affect the properties of LDHs during regeneration. This work
provides an in-depth review of the properties and uses of LDHs regenerated
through the memory effect, offering insights into how their
physical-chemical features can be tailored. Keywords: Layered double
hydroxide, mixed oxides, structural recovery, memory effect
LUCIAN PĂUNESCU, Daily Sourcing & Research SRL Bucharest, Romania,
lucianpaunescu16@gmail.com ENIKÖ VOLCEANOV, National University of Science and Technology
“Politehnica”, Faculty of Engineering in Foreign Language, Bucharest,
Romania; Metallurgical Research Institute SA Bucharest, Romania BOGDAN
VALENTIN PĂUNESCU, Consitrans SA Bucharest, Romania
Abstract Fly ash-geopolymer foam was made under the conditions of
choosing an alkaline activator solution composed of potassium hydroxide and
potassium silicate compared to the sodium-based ones usually used. The
adopted expanding agent was sodium perborate substituting the known hydrogen
peroxide (H2O2), silica fume was chosen due to its ability for increasing
the foam strength, and olive oil was the agreed surfactant replacing more
effective but more expensive materials. The results showed porous products
with excellent heat-insulating properties and simultaneously satisfactory
compression and flexural resistance obtained at an early age (7 days) the
quality level being almost similar to that of the best products worldwide.
Keywords: fly ash, geopolymer foam, sodium perborate, silica fume,
heat-insulating properties
CLAUDIA COBZARU, “Gheorghe Asachi” Technical University of Iaşi,
“Cristofor Simionescu” Faculty of Chemical Engineering and Environmental
Protection, Iaşi, Romania MAGDALENA ALUPOAE, “Gheorghe Asachi” Technical
University of Iaşi, “Cristofor Simionescu” Faculty of Chemical Engineering
and Environmental Protection, Iaşi, Romania GABRIELA-ANTOANETA
APOSTOLESCU, “Gheorghe Asachi” Technical University of Iaşi, “Cristofor
Simionescu” Faculty of Chemical Engineering and Environmental Protection,
Iaşi, Romania MĂLINA-MARIA CERNĂTESCU, “Grigore T. Popa” University of
Medicine and Pharmacy Iași, Iași, Romania CORINA CERNĂTESCU, “Gheorghe
Asachi” Technical University of Iaşi, “Cristofor Simionescu” Faculty of
Chemical Engineering and Environmental Protection, Iaşi, Romania,
corina.cernatescu@academic.tuiasi.ro
Abstract The extract of linden flowers was obtained by maceration in
sunflower oil and, then, the extract was incorporated into a cold cream. The
photodegradation, TGA-DTGA analyses as well as the iodine, acidity and
saponification index, performed on the oily extract showed that it contains
active plant compounds that can contribute to its long-term use. The
cosmetic cream obtained with the oily extract of linden flowers demonstrated
that, from a qualitative point of view, it is moisturizing and nourishing,
beneficial for the skin but with a short shelf life (6 weeks). Keywords:
oily maceration, linden flowers, cold cream, photodegradation
ANDREEA MONORANU, “Gheorghe Asachi” Technical University of Iași,
Faculty of Civil Engineering, Iași, Romania,
andreea.monoranu@student.tuiasi.ro GHEORGHE GUGIUMAN, “Gheorghe
Asachi” Technical University of Iași, Faculty of Civil Engineering, Iași,
Romania SILVIU CRISTIAN IRICIUC, “Gheorghe Asachi” Technical University
of Iași, Faculty of Civil Engineering, Iași, Romania GELU-RĂZVAN GIMIGA,
“Gheorghe Asachi” Technical University of Iași, Faculty of Civil
Engineering, Iași, Romania
Abstract It has been known since ancient times that a good
infrastructure is needed to develop an area. But because there are more and
more areas in continuous development, raw materials are consumed with
acceleration and the planet is becoming progressively occupied by waste, we
are trying to find other materials than the classic ones to use in road
construction. Ordinary asphalt mixtures have aggregates of different grades,
filler and bitumen in their composition. If normally the aggregates used for
the production of asphalt are extracted from nature, in this study we showed
how we produced an asphalt with aggregates from crushed steel slag, an
industrial waste, obtained after the manufacture of steel. Inside the
article you will discover the establishment of recipes for asphalt mixtures
with crushed steel slag, the making of samples and their testing according
to the norms in force. The results obtained are encouraging, some
characteristics of this asphalt being better than the asphalt prepared with
classic aggregates. The use of crushed steel slag in areas where there are
dumps with this waste could generate a double benefit: the release of some
storage spaces and the production of a cheaper asphalt. Keywords: steel
slag, asphalt mixture, recycle, waste
LUCIAN PĂUNESCU, Daily Sourcing & Research SRL Bucharest, Romania,
lucianpaunescu16@gmail.com ADRIAN IOANA, National University of Science and Technology
“Politehnica”, Faculty of Science and Materials Engineering Bucharest,
Romania ENIKÖ VOLCEANOV, National University of Science and Technology
“Politehnica”, Faculty of Engineering in Foreign Language Bucharest,
Romania; Metallurgical Research Institute SA Bucharest, Romania
Abstract The paper refers to a method of lignin removing in the
biomass structure to obtain a wooden material with excellent heat-insulating
properties suitable for use as an insulating material in construction. In
principle, the method is almost similar to that applied in the pulp and
paper industry, but with a different technological purpose. The chemical
activation of maple wood waste was obtained through contact with an aqueous
alkaline environment containing NaOH and Ca(OH)2 the effect being
significant reduction of thermal conductivity compared to non-chemically
treated wood. The originality is the use for the first time of maple wood as
recycled sawdust. The process temperature was 90° C for 8 hours. Results were
remarkable, the optimal product having density of 0.21 g·cm-3 and heat
conductivity of 0.029 W·m-1·K-1. In quality terms, the delignified wood
features were almost similar with other foamed wooden products.
Keywords: maple wood, removing lignin, biomass, alkaline environment,
thermal conductivity
ELENA UNGUREANU, “Ion Ionescu de la Brad” Iași University of Life Sciences,
Iași, Romania BOGDAN-MARIAN TOFĂNICĂ, “Ion Ionescu de la Brad” Iași
University of Life Sciences, Iași, Romania,
b.m.tofanica@gmail.com MARIA-EMILIANA FORTUNĂ, “Petru Poni” Institute of Macromolecular Chemistry,
Iași, Romania OVIDIU C. UNGUREANU, “Vasile Goldis” West University of Arad,
Arad, Romania IRINA VOLF, “Gheorghe Asachi” Technical University of Iași,
Iași, Romania
Abstract In the
context of sustainable development, the present study proposes a novel
approach to minimise the harmful effects of pollutant sources, such as heavy
metal ions, and to effectively utilise bioresources in the same time. The
study proposes the retention of Cu(II) ions in static conditions using
Sarkanda grass lignin, a biomass residue, representing a renewable natural
resource and a versatile biomaterial. This complex compound demonstrates
thermodynamic, and biological efficiency. The experimental data obtained
suggest potential applications in the treatment of wastewater, offering a
sustainable alternative to the already established, but more expensive,
technologies. This research supports the expansion of the use of
biomaterials for environmental remediation, highlighting the importance of
minimising waste and conserving natural resources in support of a circular
bioeconomy. Future research will focus on optimizing the retention process,
evaluating the long-term stability of the material, and exploring the
scalability of this technology for industrial wastewater treatment.
Keywords: bioremediation, lignin, Cu(II) ions, retention, Lypercosium
esculentum, circular bioeconomy
CLAUDIU-IONEL CHICUȘ, “Gheorghe Asachi” Technical University of Iași,
Faculty of Civil Engineering and Building Services, Iași, Romania,
claudiu-ionel.chicus@student.tuiasi.ro GHEORGHE GUGIUMAN, “Gheorghe
Asachi” Technical University of Iași, Faculty of Civil Engineering and
Building Services, Iași, Romania SILVIU CRISTIAN IRICIUC, “Gheorghe
Asachi” Technical University of Iași, Faculty of Civil Engineering and
Building Services, Iași, Romania GELU-RĂZVAN GIMIGA, “Gheorghe Asachi”
Technical University of Iași, Faculty of Civil Engineering and Building
Services, Iași, Romania
Abstract The use of plastic waste in construction represents an
innovative solution for reducing the environmental impact of these
materials. One of the most commonly recycled plastic types in construction
is polyethylene terephthalate (PET), due to its durability, lightweight
nature, and availability. In the construction industry, plastic waste and
PET are incorporated either into cement concrete or asphalt mixtures,
contributing to improved mechanical performance and the sustainability of
these materials. In cement concrete, the addition of PET fibers can enhance
crack resistance, durability, and flexibility while also reducing the need
for conventional materials. In the case of asphalt mixtures, PET is used in
the form of fibers or recycled aggregates, playing a role in enhancing road
performance and extending their service life. In this study, experiments
were conducted on the BADPC 22.4 asphalt mixture. In the first stage, the
optimal bitumen content was determined, and for this content, the asphalt
mixture was reinforced with PET fibers in proportions of 2%, 4%, 6%, 8%, and
10% to analyze their influence on the material's physical and mechanical
properties. Keywords: laboratory studies, binder, roads, PET
VALENTINA GABI MIRON (STĂNESCU), “Gheorghe Asachi” Technical University
of Iași, Faculty of Industrial Design and Business Management, Iași, Romania
NIKI VLAD MANCAȘI, “Gheorghe Asachi” Technical University of Iași,
Faculty of Industrial Design and Business Management, Iași, Romania VASILICA POPESCU, “Gheorghe Asachi” Technical University of Iași, Faculty of
Industrial Design and Business Management, Iași, Romania,
vasilica.popescu@academic.tuiasi.ro ANDREI POPESCU, “Gheorghe
Asachi” Technical University of Iași, Faculty of Industrial Design and
Business Management, Iași, Romania; “Gheorghe Asachi” Technical University
of Iași, Faculty of Mechanical Engineering, Iași, Romania
Abstract Protecting the environment is an international issue that
depends a lot on the involvement of each of us through actions to collect
and recycle different used products. The purpose of this paper is to show
that used cooking oils should be collected to be transformed into ecological
laundry care products: soaps. The laundry soaps prepared by us were obtained
through hot saponification processes, using the mixture of palm and coconut
oils, unused and used/waste, in all 4 possible combinations. The
characterization of the vegetable oils was carried out by determining the
saponification value (SAP) and the iodine number (IN). The obtained soaps
were characterized physically and chemically by determining pH, foam, color,
density, cleaning/washing capacity inclusive the SAP, IN, INS (Iodine Number
Saponification) values for oils mixture from soaps. The tested ecological
soaps are excellent products for washing clothes because each has a low
foaming and an excellent cleaning capacity. KeKeywords: laundry soaps,
palm oil, coconut oil, recycling, cleaning capacity