2017, Volume 63(67), Issue 1 (March)

Contents

pages 1- 8    Download

Leaching Kinetics of a Fluidized Bed with High Salt Concentration

MARCELA POPA, "Gheorghe Asachi" Technical University of Iaşi, Faculty of Chemical Engineering and Environmental Protection
EUGENIA TEODORA IACOB-TUDOSE, "Gheorghe Asachi" Technical University of Iaşi, Faculty of Chemical Engineering and Environmental Protection
IOAN MĂMĂLIGĂ, "Gheorghe Asachi" Technical University of Iaşi, Faculty of Chemical Engineering and Environmental Protection, imamalig@tuiasi.ro

pages 9 - 21     Download

Abstract
The purpose of this study was to determine the mass transfer coefficient in the extraction of a solute from a solid matrix by contacting it with a solvent in a fluidized bed. The solvent used to remove the solute is, at the same time, fluidizing agent. The results presented had been obtained for the dissolution of a high concentration of a solute in the solid phase by using the recirculating extraction fluid phase.
Keywords: mass transfer coefficients; solid-liquid extraction; fluidized bed; extraction with fluid recirculation.

Characteristics of Oil Obtained from Grape Seeds Separated from Dried and Fresh Marc    

CLAUDIA COBZARU, "Gheorghe Asachi" Technical University of Iaşi, Faculty of Chemical Engineering and Environmental Protection
MIHAELA ALINA MATCABOJĂ (GHERASIM), "Gheorghe Asachi" Technical University of Iaşi, Faculty of Chemical Engineering and Environmental Protection
ADRIANA MARINOIU, National R&D Institute for Cryogenics and Isotopic Technologies-ICIT, Râmnicu Vâlcea
GABRIELA ANTOANETA APOSTOLESCU, "Gheorghe Asachi" Technical University of Iaşi, Faculty of Chemical Engineering and Environmental Protection
RAMONA ELENA TATARU FĂRMUȘ, "Gheorghe Asachi" Technical University of Iaşi, Faculty of Chemical Engineering and Environmental Protection
CORINA CERNĂTESCU, "Gheorghe Asachi" Technical University of Iaşi, Faculty of Chemical Engineering and Environmental Protection, ccernatescu@yahoo.com   

pages 23 - 28     Download

Abstract
In this study, oil was extracted from seeds separated from dried and fresh marc, in controlled conditions, marc being a residue from homemade wine manufacturing process. The organoleptic and physico-chemical characteristics show that this oil belongs among vegetable food oils. Also, marc, considered to be a waste product from wine manufacturing, can be an alternative source for making edible oil.
Keywords: marc; oil; grape seeds.

Studies on the Photocatalytic Decomposition of Organic Dyes Using Mesoporous Metal Oxides

NICOLAE APOSTOLESCU, "Gheorghe Asachi" Technical University of Iaşi, Faculty of Chemical Engineering and Environmental Protection
RAMONA ELENA TATARU FĂRMUȘ, "Gheorghe Asachi" Technical University of Iaşi, Faculty of Chemical Engineering and Environmental Protection
CORINA CERNĂTESCU, "Gheorghe Asachi" Technical University of Iaşi, Faculty of Chemical Engineering and Environmental Protection
CLAUDIA COBZARU, "Gheorghe Asachi" Technical University of Iaşi, Faculty of Chemical Engineering and Environmental Protection
MIHAELA AURELIA VIZITIU, "Gheorghe Asachi" Technical University of Iaşi, Faculty of Chemical Engineering and Environmental Protection
GABRIELA ANTOANETA APOSTOLESCU, "Gheorghe Asachi" Technical University of Iaşi, Faculty of Chemical Engineering and Environmental Protection, ganto@ch.tuiasi.ro   

pages 29 - 37    Download

Abstract
In this study, the ultraviolet irradiation behaviour of three dyes (methylene blue - MB, phenol red - FR and crystal violet - CV) is presented in the presence of a mesoporous oxide material based on ZnO-CeO2. The three dyes were degraded to the corresponding leucoderivates in different times, methylene blue (conc. 10-5M) in 25 min, crystal violet (conc. 2·10-5M) in 90 min, and phenol red (conc. 4.5·10-5M) in 140 min. Also, the calculated photodegradation yield showed that MB and CV degraded by 98% and RF only by 78%. It was also investigated the influence of the photocatalyst concentration on the reaction rate for MB.
Keywords: crystal violet; photodegradation; phenyl red; methylene blue.

Studies Regarding Au(III) Extraction in Aqueous Two Phase Systems Based on Polyethylen Glycol with Different Molecular Weights

MĂDĂLINA GHERCĂ, "Gheorghe Asachi" Technical University of Iaşi, Faculty of Chemical Engineering and Environmental Protection
LAURA BULGARIU, "Gheorghe Asachi" Technical University of Iaşi, Faculty of Chemical Engineering and Environmental Protection, lbulg@ch.tuiasi.ro

pages 39 - 47     Download

Abstract
This study presents the efficiency of Au(III) ions extraction in aqueous two phase systems (ATPS) based on polyethylene glycol (PEG) 40% (w/w) and (NH4)2SO4 40% (w/w), in the presence of chloride ions with a concentration of 0.5 mol/L as extracting agents and a pH of 4.5 of the inorganic salt. The influence of two experimental parameters was studied: PEG molecular weight and volume ratio between the two phases. Experimental results showed that with the increasing of the PEG molecular weight the quantity of Au(III) ions extracted in PEG rich phase increases (67.78% for PEG(2000), 75% for PEG(4000) and 86.19% for PEG(6000), values obtained for a volume ratio (NH4)2SO4 : PEG of 5:4). Also, the extraction efficiency showed an important decrease for a (NH4)2SO4 : PEG volume ratio >2 because of the hydrophobicity of the environment that decreases.
Keywords: Au(III) ions extraction; aqueous two phase systems; PEG; green chemistry.

Polyphenolic Content Evaluation in Branches of Rosa Canina L. and Hippophae Rhamnoides L. Species

OANA TEODORA CIUPERCĂ, "Gheorghe Asachi" Technical University of Iaşi, Faculty of Chemical Engineering and Environmental Protection, Research and Processing Centre for Medicinal Plants "Plantavorel" S.A., Piatra Neamț
CARMEN ELENA ȚEBRENCU, Research and Processing Centre for Medicinal Plants "Plantavorel" S.A., Piatra Neamț
IRINA VOLF, "Gheorghe Asachi" Technical University of Iaşi, Faculty of Chemical Engineering and Environmental Protection, iwolf@ch.tuiasi.ro

pages 49 - 58     Download

Abstract
This study evaluated the branches of Rosa canina L. and Hippophae rhamnoides L. in order to highlight new sources of polyphenols, condensed tannins and flavonoids. The phytochemical screening and ultraviolet-visible and Fourier transform infrared spectroscopy analysis on biomass showed the presence of fine chemical constituents like polyphenols, flavonoids (rutin) and condensed tannins (catechin, epicatechin). The biomass has been evaluated to quantify the total polyphenols (gallic acid) and tannins (tannic acid) by instrumental methods (UV-VIS spectrometry). The results showed that the branches of R. canina contain polyphenols (1.77±0.067%g gallic acid equivalent/g) and tannins (1.45±0.029%g tannic acid equivalent/g), whilst the branches of H. Rhamnoides are somewhat richer (1.87±0.058%g gallic acid equivalent/g and 1.94±0.038%g tannic acid equivalent/g). These results open perspectives for advanced valorization of R. canina and H. rhamnoides branches, already known only for phytotherapeutical and nutritional potential of their fruits.
Keywords: Rosa canina; Hippophae rhamnoides; branches; polyphenols; tannins; phytochemical screening.

Magnetic Activated Carbon Composites Used as Fenton Like Catalysts for Photodegrading Organic Compounds in Aqueous Solutions

ANDREEA VAJDA, "Gheorghe Asachi" Technical University of Iaşi, Faculty of Chemical Engineering and Environmental Protection
MARIUS SEBASTIAN SECULA, "Gheorghe Asachi" Technical University of Iaşi, Faculty of Chemical Engineering and Environmental Protection, mariussecula@ch.tuiasi.ro
LAURA HAGIU-ZALESCHI, "Gheorghe Asachi" Technical University of Iaşi, Faculty of Chemical Engineering and Environmental Protection
GABRIELA CARJA, "Gheorghe Asachi" Technical University of Iaşi, Faculty of Chemical Engineering and Environmental Protection
IOAN MĂMĂLIGĂ, "Gheorghe Asachi" Technical University of Iaşi, Faculty of Chemical Engineering and Environmental Protection

pages 59 - 65     Download

Abstract
The main goal of the present work consists in investigating the performance of several magnetic activated carbon composites towards the photo-Fenton degradation of Ibuprofen molecule. Three Granular Activated Carbon (GAC) matrices having different pHPZC were employed to prepare the magnetic GACs using the co-precipitation method. UV light irradiation tests were carried out to determine the performance of the prepared magnetic composites towards the degradation of Ibuprofen molecule in aqueous solution in the presence of Hydrogen Peroxide. The photo-Fenton tests were conducted after the adsorption equilibrium has been established. The magnetic GAC composites prepared with acid-surfaced matrix L27 GAC was found to enhance significantly the degradation process of Ibuprofen molecule.
Keywords: Magnetic composites; photocatalysis; Fenton reaction; Ibuprofen; micropollutant

Modelling the Free Radical Polymerization of Styrene Using Artificial Neural Networks    

LUCIANA GHIBA, "Gheorghe Asachi" Technical University of Iaşi, Faculty of Chemical Engineering and Environmental Protection
ELENA-NICULINA DRĂGOI, "Gheorghe Asachi" Technical University of Iaşi, Faculty of Chemical Engineering and Environmental Protection
SILVIA CURTEANU, "Gheorghe Asachi" Technical University of Iaşi, Faculty of Chemical Engineering and Environmental Protection, scurtean@tuiasi.ro

pages 67 - 81     Download

Abstract
In this work, the modeling of free radical polymerization of styrene is performed using two approaches: phenomenological and empirical. In the last case, artificial neural networks are used, applying two working strategies. First, a single model with three outputs (monomer conversion, numerical molecular weight and gravimetrical molecular weights) based on time, temperature and initial concentration of the initiator (model inputs) was determined. Due to the unacceptable performance results for the molecular weights, a second strategy is developed, modelling each output, separately, as function of the three inputs. Different artificial neural network topologies were tested, the two hidden layer networks performing the best for all the outputs.
Keywords: styrene; modelling; prediction; artificial neural networks.