Publications by authors named "Abdeltif Amrane"

62 Publications

Biosorption of cationic and anionic dyes using the biomass of Aspergillus parasiticus CBS 100926.

Water Sci Technol 2021 Feb;83(3):622-630

Department of Environmental Engineering, Mersin University, Mersin, 33343, Turkey.

Aspergillus parasiticus (A. parasiticus) CBS 100926 was used as a biosorbent for the removal of Methylene Blue (MB), Congo Red (CR), Sudan Black (SB), Malachite Green Oxalate (MGO), Basic Fuchsin (BF) and Phenol Red (PR) from aqueous solutions. The batch biosorption studies were carried out as a function of dye concentration and contact time. The biosorption process followed the pseudo-first-order and the pseudo-second-order kinetic models and the Freundlich and Langmuir isotherm models. The resulting biosorbent was characterized by Scanning Electron Microscopy (SEM), X-Ray Diffractometer and Fourier Transformer Infrared Spectroscopy (FTIR) techniques. The results of the present investigation suggest that A. parasiticus can be used as an environmentally benign and low cost biomaterial for the removal of basic and acid dyes from aqueous solution.
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http://dx.doi.org/10.2166/wst.2021.005DOI Listing
February 2021

Effect of mixed culture of yeast and microalgae on acetyl-CoA carboxylase and Glycerol-3-phosphate acyltransferase expression.

J Biosci Bioeng 2021 Apr 17;131(4):364-372. Epub 2020 Dec 17.

Université de Rennes, Ecole Nationale Supérieure de Chimie de Rennes, CNRS, ISCR-UMR 6226, F-35000 Rennes, France.

In recent years, some studies have reported that co-culturing green algae and yeast improve lipid and biomass concentration. In this study, a co-culture of the oleaginous yeast Rhodotorula glutinis and the microalgae Chlorella vulgaris was consequently conducted with inoculation of microalga and yeast in growth and stationary phases, respectively. For the first time, the expression of two pivotal enzymes in fatty acids synthetic pathway, acetyl-CoA carboxylase and Glycerol-3-phosphate acyltransferase, was evaluated. To evaluate the synergistic impacts of the mixed culture on the enzymes expression, several co-culture models were designed, including the use of different ratio of microalgae to yeast or the use of residual cell-free medium of yeast; a positive impact on enzymes overexpression was shown in the case of the co-culture of the two microorganisms, and when the remaining cell-free medium of yeast was added to the microalgal culture. The results of in vitro co-culture demonstrated increased 6- and 5-fold of nervonic acid (C24:1) and behenic acid (C22:0) concentrations, respectively, in 2:1 microalgae to yeast co-culture as compared to the monoculture batches. Addition of yeast residual cell-free medium in the 2:1 ratio to the microalgal culture enhanced 9 and 6 times nervonic acid (C24:1) and behenic acid (C22:0) amounts, respectively.
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http://dx.doi.org/10.1016/j.jbiosc.2020.11.006DOI Listing
April 2021

Bio-based and cost effective method for phenolic compounds removal using cross-linked enzyme aggregates.

J Hazard Mater 2021 02 17;403:124021. Epub 2020 Sep 17.

Univ Rennes, Ecole Nationale Supérieure de Chimie de Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes)-UMR 6226, F-35000 Rennes, France.

This work aimed at presenting a green method using a new source of peroxidase isolated from Raphanus sativus var. niger (RSVNP) in immobilized form, for the treatment of wastewater. To ensure stability and enzymatic activity in the biodegradation process, RSVNP was immobilized as a cross-linked enzyme aggregate (CLEAs). With more than 29% of recovered activity and 85% aggregation yield, acetone was selected as the best precipitating agent. The formed protein aggregates required 2% (v/v) of glutaraldehyde (GA) concentration and a ratio of 9:1 (v/v) enzyme (E) amount to cross-linker (E/GA). Compared to the free enzyme, RSVNP-CLEAs were found more chemically and thermally stable and exhibited good storage stability for more than 8 weeks. In addition, RSVNP-CLEAs were evaluated for their ability to remove phenol and p-cresol from aqueous solution by varying several operating conditions. A maximal yield (98%) of p-cresol conversion was recorded after 40 min; while 92% of phenol was degraded after 1 h duration time. The reusability of RSVNP-CLEAs was tested, displaying 71% degradation of phenol in the third batch carried out and more than 54% was achieved for p-cresol after four successive reuses in the presence of hydrogen peroxide at 2 mM concentration.
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http://dx.doi.org/10.1016/j.jhazmat.2020.124021DOI Listing
February 2021

Artificial neural network modeling of cefixime photodegradation by synthesized CoBiO nanoparticles.

Environ Sci Pollut Res Int 2021 Mar 25;28(12):15436-15452. Epub 2020 Nov 25.

Univ Rennes - ENSCR / UMR CNRS 6226 "Chemical Sciences of Rennes" ENSCR, Campus de Beaulieu, 11, allée de Beaulieu - CS 50837 - 35708 Rennes, 35708, Rennes, France.

CoBiO (CBO) nanoparticles were synthesized by sol-gel method using polyvinylpyrrolidone (PVP) as a complexing reagent. For a single phase with the spinel structure, the formed gel was dried and calcined at four temperatures stages. Various methods were used to identify and characterize the obtained spinel, such as X-ray diffraction (XRD), scanning electron micrograph (SEM-EDX), transmission electron microscope (TEM), Fourier transform infrared (FT-IR), X-ray fluorescence (XRF), Raman, and UV-Vis spectroscopies. The photocatalytic activity of CBO was examined for the degradation of a pharmaceutical product cefixime (CFX). Furthermore, for the prediction of the CFX degradation rate, an artificial neural network model was used. The network was trained using the experimental data obtained at different pH with different CBO doses and initial CFX concentrations. To optimize the network, various algorithms and transfer functions for the hidden layer were tested. By calculating the mean square error (MSE), 13 neurons were found to be the optimal number of neurons and produced the highest coefficient of correlation R of 99.6%. The relative significance of the input variables was calculated, and the most impacting input was proved to be the initial CFX concentration. The effects of some scavenging agents were also studied. The results confirmed the dominant role of hydroxyl radical OH in the degradation process. With the novel CoBiO/ZnO hetero-system, the photocatalytic performance has been enhanced, giving an 80% degradation yield of CFX (10 mg/L) at neutral pH in only 3 h.
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http://dx.doi.org/10.1007/s11356-020-11716-wDOI Listing
March 2021

A comparative study of ceramic nanoparticles synthesized for antibiotic removal: catalysis characterization and photocatalytic performance modeling.

Environ Sci Pollut Res Int 2021 Mar 17;28(11):13900-13912. Epub 2020 Nov 17.

Univ Rennes-ENSCR/UMR CNRS 6226, Campus de Beaulieu, av. du Général Leclerc, 35700, Rennes, France.

The heterogeneous photocatalysis process has been known to provide significant levels of degradation and mineralization of emerging contaminants including antibiotics. For that, nanoparticle CuCrO (CCO) ceramics were successfully prepared via sol-gel (SG) and co-precipitation (CP) methods to obtain spinel with desired structural features and properties and also to improve the photocatalytic performances. The CCO crystallite phase was produced at 750 °C all ceramics, disregarding the synthesis route. CCO physical and chemical properties were checked by X-ray diffraction (XRD) with Rietveld refinement, Brunauer-Emmett-Teller (BET), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), transmission electron microscope (TEM), and diffuse reflectance solid (DRS). The XRD patterns demonstrated that the synthesized catalysts displayed a small crystallite size between 17.45 and 26.24 nm for SG and 20.97 and 36.86 nm for the CCO samples. The observation by SEM and TEM of the nanopowders showed a typical morphology with comparable particle sizes for both synthesized routes (20-30 nm). SG agglomeration rates were higher, and particles stick together more efficiently considering the CP method, while the CCO method led to a more significant porosity. Their photocatalytic and adsorption performances were examined for cefaclor (CFC) removal chosen as a target pharmaceutical contaminant in water. The results obtained by the methods differed since nanoparticles prepared by SG led to high photocatalytic activity. In contrast, a high CFC adsorption was observed for those prepared via the CP method, and that agreed with the findings of the characterization analysis. The kinetics of the adsorption process was found to follow the pseudo-second-order rate law. In contrast, the data of the photodegradation process were further found to comply with the Lagergren kinetic law. Nevertheless, the global reaction rate is probably controlled by the intra-particular diffusion of CFC, regardless of the elimination process.
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http://dx.doi.org/10.1007/s11356-020-11616-zDOI Listing
March 2021

Combining photocatalytic process and biological treatment for Reactive Green 12 degradation: optimization, mineralization, and phytotoxicity with seed germination.

Environ Sci Pollut Res Int 2021 Mar 20;28(10):12490-12499. Epub 2020 Oct 20.

Ecole Polytechnique Fédérale de Lausanne, CH-1015, Lausanne, Switzerland.

In this study, we show that the combination of a photocatalytic process (as a pretreatment step) combined with the conventional biological treatment of wastewaters can improve the process and achieve satisfactory efficiency. In this context, Reactive Green 12 (RG-12) solutions were photocatalytically pretreated using TiO-impregnated polyester as supported catalyst under UV light in batch reactor. Photocatalysis as pretreatment (during 4 and 8 h of irradiation) was combined with 7 days of aerobic biological treatment using activated sludge. As first assays, respiratory tests revealed that the removal of RG-12 was improved by 5.4% and 11.7% for the solutions that were irradiated for 4 and 8 h in the presence of TiO, respectively. However, 34.5% and 19% of dye solution was discolored after 7 days of biological treatment for the pretreated solutions during 4 and 8 h of UV light exposure, respectively. The discoloration efficiency obtained by the combined processes achieved 59.6% and 74.9% for the samples under photocatalysis during 4 and 8 h, respectively. A significant decrease in chemical oxygen demand (COD) of about 74.9% was achieved after photocatalysis/biodegradation processes. In addition, a decrease in the phytotoxicity was obtained as followed by the germination index (GI) values of cress seeds that increased from 46.2 to 88.7% after 8 h of photocatalysis and then to 92.8% after further 7 days of biological treatment.
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http://dx.doi.org/10.1007/s11356-020-11282-1DOI Listing
March 2021

Paracetamol degradation by photo-activated peroxydisulfate process (UV/PDS): kinetic study and optimization using central composite design.

Water Sci Technol 2020 Oct;82(7):1404-1415

Laboratoire de Génie de l'Environnement (LGE), Faculté de Technologie, Université de Bejaia, 06000 Bejaia, Algeria E-mail:

In this study, peroxydisulfate (PDS) was successfully activated by UV-irradiation for the degradation of paracetamol (PCT) frequently detected in the environment. Results showed that increasing the initial PDS concentration from 5 to 20 mM promote the removal of PCT from 49.3% to 97.5% after 240 min of reaction time. As the initial PCT concentration increased from 0.066 to 0.132 mM, the degradation efficiency of PCT decreased from 98% to 73% after 240 min of reaction time, while the optimal pH was found to be 6. It is apparent that the degradation rate of PCT was favored by the lamp power regardless of the initial PCT concentration, for 0.132 mM of PCT, the degradation efficiency increased from 73% to 95% when the lamp power increased from 9 to 30 W, respectively. The kinetic of degradation of the PCT was described by a pseudo-second order kinetic model. The model obtained by central composite design led to the following optimal conditions for PCT degradation: 0.132 mM initial PCT concentration, 20 mM PDS dose, pH solution 6 and lamp power 30 W led to the removal of 92% of PCT at 25 °C within 240 min of reaction time.
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http://dx.doi.org/10.2166/wst.2020.412DOI Listing
October 2020

Novel FeTiO/reduced graphene oxide heterojunction photocatalyst with improved adsorption capacity and visible light photoactivity: experimental and DFT approach.

Environ Sci Pollut Res Int 2021 Feb 16;28(7):8507-8519. Epub 2020 Oct 16.

Univ Rennes, Ecole Nationale Supérieure de Chimie de Rennes CNRS, ISCR - UMR6226, F-35000, Rennes, France.

The design of high-efficiency materials is a major challenge for the degradation of organic pollutants. In this work, type II p-n heterojunction photocatalyst FeTiO/rGO, with enhanced performance, was successfully prepared through simple process. The FeTiO/rGO composites were prepared by hosting several amounts of reduced graphene oxide (rGO) into pseudobrookite nanocrystals (FeTiO) which were priorly synthesized by a solid-state reaction. The morphology and the properties of the as-prepared composites were characterized through different techniques. The fixation of rGO sheets on FeTiO was proved using the X-ray diffraction analysis (XRD). The results of the scanning electron microscope (SEM) analysis showed a good mixing of rGO with FeTiO. The X-ray fluorescence (XRF) confirmed the purity of the pristine FeTiO. The dynamic light scattering (DLS) illustrated a strong tendency to aggregation. Ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS) analysis was performed to characterize the electronic aspect as the gap and the Urbach energies. Finally, computational density functional theory (DFT) calculations were carried out to confirm the experimental results. The adsorptive and photoactivity of FeTiO/rGO heterojunction photocatalysts were evaluated by methylene blue (MB) degradation under visible light irradiation. The highest MB degradation rate was achieved for FeTiO/rGO photocatalyst with the highest value of the elimination rate.
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http://dx.doi.org/10.1007/s11356-020-11221-0DOI Listing
February 2021

Effect of light intensity and wavelength on nitrogen and phosphate removal from municipal wastewater by microalgae under semi-batch cultivation.

Environ Technol 2020 Oct 13:1-7. Epub 2020 Oct 13.

Univ Rennes, Ecole Nationale Supérieure de Chimie de Rennes, CNRS, ISCR - UMR 6226, Rennes, France.

Domestic, agricultural and industrial water activities lead to organic and inorganic pollution of the environment. Biotreatment of municipal wastewater with the potential production of biomass is a valuable feature of microalgae. In this study we evaluated the effects of wavelength and light intensity on phosphate and ammonium removal on the one hand, and biomass and protein production on the other hand by in municipal wastewater treatment under semi batch cultivation. was inoculated at 40% in artificial wastewater open pond system. Red, blue and purple light with 3800, 4800 and 5800 lux light intensity under 12 h light and 12 h darkness were investigated. Cultivation was conducted in semi-batch conditions; after four days cultivation, one third of the culture was replaced with fresh medium. The highest biomass and protein concentrations were observed under blue light at 5800 lux light intensity, 5.45 and 3 g/l respectively cumulatively; while the highest amount of phosphate and ammonium removal were about 145 and 218 mg/l under purple light at 5800 lux intensity, respectively. The amounts of biomass and protein produced, as well as phosphate and ammonium removed, are therefore impacted by wavelength, light intensity, results show that light intensity and wavelength can be customized to reach on the one hand the highest biomass and protein production, and on the other hand to maximize the removal of phosphorous and ammonium.
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http://dx.doi.org/10.1080/09593330.2020.1829087DOI Listing
October 2020

Electrochemical Processes Coupled to a Biological Treatment for the Removal of Iodinated X-ray Contrast Media Compounds.

Front Chem 2020 31;8:646. Epub 2020 Jul 31.

Univ Rennes, CNRS, ISCR-UMR 6226, Rennes, France.

Iodinated X-ray contrast media (ICM) compounds are a form of intravenous radiocontrast containing iodine, which are rapidly eliminated via urine or feces. The issue with the accumulation of ICM has received considerable critical attention since they are ubiquitously distributed in municipal wastewater effluents and in the aquatic environment and are not significantly eliminated by most biological sewage treatment processes. Among the methods that have been tested to eliminate ICM, electrochemical methods have significant advantages, since they can selectively cut the carbon-iodine bonds that are suspected to decrease their biodegradability. On the production sites, the recovery of iodine ions due to the carbon-iodine cleavage can be envisaged, which is particularly interesting to reduce the cost of the ICM production process. The coupling of an electrochemical process and a biological treatment can be carried out to mineralize the organic part of the formed by-products, allowing the recovery of the iodide ions. Therefore, the degradation of diatrizoate, a typical ionic ICM compound, by an electrochemical process was the purpose of this study. The electrochemical reduction of diatrizoate was performed using a flow cell with a graphite felt electrode at different potentials. The removal yield of diatrizoate reached ~100% in 2 h and the main product, 3,5-diacetamidobenzoic acid, was quantitatively formed, showing that diatrizoate was almost completely deiodinated. According to the BOD/COD ratio, the biodegradability of diatrizoate after electrolysis was considerably improved. Cyclic voltammetry analysis of the electroreduced solution showed several oxidation peaks. The electrochemical oxidation of the by-products formed after the first treatment by electroreduction was then performed at three different potentials to study the influence of electrochemical oxidation on biodegradability. Results showed that the degradation yield of the deiodinated by-products increased with the potential and reached 100% at 1.3 V/SCE. Four different biological treatments were implemented during 21 days in stirred flasks with fresh activated sludge. The evolution of the mineralization during the biological treatment highlighted the biorecalcitrance of diatrizoate as previously estimated by the BOD/COD ratio. Interestingly, the mineralization yield increased from 41 to 60% when electrochemical oxidation at 1.3 V/SCE was implemented after electroreduction.
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http://dx.doi.org/10.3389/fchem.2020.00646DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7413141PMC
July 2020

Use of hydrocarbons sludge as a substrate for the production of biosurfactants by Pseudomonas aeruginosa ATCC 27853.

Environ Monit Assess 2020 Apr 15;192(5):287. Epub 2020 Apr 15.

Univ. Rennes, Ecole Nationale Supérieure de Chimie de Rennes, CNRS, ISCR - UMR6226, 35000, Rennes, France.

The purpose of this study was to elucidate the capacity of a Pseudomonas aeruginosa strain to metabolize hydrocarbons sludge in the production of biosurfactants to fight against environmental threats. The performance of the treatment consisted in monitoring the inductive metabolism of the strain during 48 h at a temperature of 37 °C which constitutes an opportunity of treatment of various hydrocarbons contained in crude oil and spilled in the ecosystem to prevent pollution and damage. The results showed that a treatment rate of 96,8% and an emulsification index of 71.8% were obtained corresponding to a phosphate buffer concentration of 30 mmol/L. The main role of the biosurfactants produced was to emulsify the medium and to absorb the oils contained in the hydrocarbons sludge. This allowed to stabilize hydrocarbon oils and favored the inductive metabolism of P. aeruginosa. Furthermore, physicochemical and Fourier transform infrared spectroscopy (FTIR) analysis showed that the produced biosurfactants were of rhamnolipid type. They showed promising surfactant properties, such as a strong reduction in the surface tension of water from 72 to 40.52 mN/m, a high reactivity in the culture medium at pH 7, a high osmotolerance up to 150 g/L of salt, and a critical micellar concentration of 21 mg/L.
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http://dx.doi.org/10.1007/s10661-020-08269-3DOI Listing
April 2020

Efficient Dechlorination of α-Halocarbonyl and α-Haloallyl Pollutants by Electroreduction on Bismuth.

Environ Sci Technol 2020 01 27;54(1):559-567. Epub 2019 Dec 27.

Univ Rennes, CNRS, ISCR-UMR 6226, F-35000 Rennes, France.

The electrocatalytic activity of bismuth considered as a low-cost and green electrode material was studied in reductive dechlorination processes. Cyclic voltammetry analyses showed that the Bi electrode exhibited a high catalytic activity to reduce alachlor, a chlorinated herbicide, in the aqueous medium at different pH values. Bulk electrolyses were performed at different potentials and pH values. Alachlor was reduced in deschloroalachlor, its dechlorinated derivative, with a high selectivity (96%) and a current efficiency of 48%. The reductive dechlorination of other chlorinated compounds with an activated carbon atom was then studied, showing that the bismuth electrode catalyzed the electroreduction of chloroacetamides, α-halocarbonyl, and α-haloallyl pollutants. Cyclic voltammetry experiments allowed us to propose a mechanism explaining the high catalytic activity of bismuth to reduce these families of compounds.
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http://dx.doi.org/10.1021/acs.est.9b05732DOI Listing
January 2020

Synthesis of novel biocomposite powder for simultaneous removal of hazardous ciprofloxacin and methylene blue: Central composite design, kinetic and isotherm studies using Brouers-Sotolongo family models.

J Hazard Mater 2020 04 12;387:121675. Epub 2019 Nov 12.

Univ Rennes, École Nationale Supérieure de Chimie de Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes) - UMR 6226, F-35000 Rennes, France.

Over the past decades, extensive efforts have been made to use biomass-based-materials for wastewater-treatment. The first purpose of this study was to develop and characterize regenerated-reed/reed-charcoal (RR-ChR), an enhanced biosorbent from Tunisian-reed (Phragmites-australis). The second aim was to assess and optimize the RR-ChR use for the removal of binary ciprofloxacin antibiotic (CIP) and methylene blue dye (MB), using Central Composite Design under Response Surface methodology. The third purpose was to explain the mechanisms involved in the biosorption-process. The study revealed that the highest removal-percentages (76.66 % for the CIP and 100 % for the MB) were obtained under optimum conditions: 1.55 g/L of adsorbent, 35 mg/L of CIP, 75 mg/L of MB, a pH of 10.42 and 115.28 min contact time. It showed that the CIP biosorption mechanism was described by Brouers-Sotolongo-fractal model, with regression-coefficient (R) of 0.9994 and a Person's Chi-square (X) of 0.01. The Hill kinetic model better described the MB biosorption (R = 1 and X = 1.0E-4). The isotherm studies showed that the adsorbent surface was heterogeneous and the best nonlinear-fit was obtained with the Jovanovich (R = 0.9711), and Brouers-Sotolongo (R = 0.9723) models, for the CIP and MB adsorption, respectively. Finally, the RR-ChR lignocellulosic-biocomposite-powder could be adopted as efficient and cost-effective adsorbent.
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http://dx.doi.org/10.1016/j.jhazmat.2019.121675DOI Listing
April 2020

Central composite design applied to paracetamol degradation by heat-activated peroxydisulfate oxidation process and its relevance as a pretreatment prior to a biological treatment.

Environ Technol 2021 Feb 4;42(6):905-913. Epub 2019 Aug 4.

Laboratoire de Génie de l'Environnement (LGE), Faculté de Technologie, Université de Bejaia, Bejaia, Algeria.

In this study, the degradation of paracetamol (PCT) by thermo-activated peroxydisulfate (PDS) and the feasibility of coupling thermo-activated peroxydisulfate to activated sludge culture were examined. The effect of the relevant parameters on the thermo activated peroxydisulfate process, namely temperature, PDS concentration, initial pH and initial PCT concentration was investigated. As observed, the solution pH did not have a significant effect on the PCT degradation. The temperature increased the degradation of PCT, while an increase of the initial PCT concentration impacted negatively its degradation yield. The PDS concentration showed an optimal value of 8 mM. The operating parameters were then optimized by using a central composite design (CCD). After performing a screening of the various factors, response surface analysis led to the following optimal conditions for the yield of PCT degradation: 0.33, 5 mM, pH = 6 and 68°C for the initial PCT concentration, the initial peroxydisulfate concentration and the temperature respectively, leading to the removal of 94.2% of PCT. Under these conditions, the BOD/COD ratio increased from 0.008 initially to 0.34 after 10 h. Showing a significant improvement of the biodegradability; consequently and even if the limit of biodegradability (0.4) was not achieved, a biological treatment could be promisingly considered.
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http://dx.doi.org/10.1080/09593330.2019.1649308DOI Listing
February 2021

Electro Fenton removal of clopyralid in soil washing effluents.

Chemosphere 2019 Dec 24;237:124447. Epub 2019 Jul 24.

Chemical Engineering Department. Research Institute for Chemical and Environmental Technology (ITQUIMA). University of Castilla- La Mancha, 13071, Ciudad Real, Spain. Electronic address:

The removal of a commercial herbicide, based on clopyralid, by means of Electro-Fenton (EF) was studied using a soil washing effluent obtained using synthetic ground water as washing fluid. From the results, it was observed that the degradation and mineralization yields of clopyralid were high, even without the addition of supporting electrolyte. The groundwater could be then used as a sustainable supporting electrolyte. The influence of the minerals constituents, the current and the ferrous ions regeneration was evaluated. The highest hydrogen peroxide production was achieved working at 200 mA but regeneration of ferrous ions was not efficient at this current. Iodide ions were one of the main responsible in the EF efficiency decrease due to their reaction with the produced hydrogen peroxide. Electrochemical study proved that clopyralid was not electroactive and that its degradation was mainly due to radical oxidation. Long duration electrolysis carried out at 200 mA in groundwater provided an improvement of the solution biodegradability after 480 min that can be linked to a significant increase in the carboxylic acids production. These results support the feasibility of applying an EF process in order to carry out a subsequent biological mineralization.
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http://dx.doi.org/10.1016/j.chemosphere.2019.124447DOI Listing
December 2019

Effect of temperature in Chitin and Chitosan production by solid culture of Penicillium Camembertii on YPG medium.

Int J Biol Macromol 2019 Jul 17;133:998-1007. Epub 2019 Apr 17.

Univ Rennes, Ecole Nationale Supérieure de Chimie de Rennes, CNRS, UMR 6226, F-35000 Rennes, France.

This study was devoted to polysaccharides extraction (Chitin and Chitosan) from Penicillium camembertii cell wall. A culture on solid medium was adopted under carefully selected conditions, appropriate to mycelium growth: duration 6 days, medium YPGA and pH 5. The temperature was adjusted (20 °C to 28 °C) in order to study the effect of temperature on Chitin/Chitosan production. Biomass decreased with increasing temperatures: 13 g/L at 20 °C and 11.6 g/L at 28 °C. For all tested temperatures, the yields of insoluble alkaline fractions (AIM) were almost identical (200 mg/g). The solubility of fractions in 2% acetic acid allowed obtaining two fractions: an insoluble fraction (AcIM) with 18% of maximum yield and soluble fraction (AcSM) with 1% yield. The SEM micrographs of AcIM fractions were similar to AIM fractions. These showed a compact structure different from commercial Chitin. The presence of Chitin in P. Camembertii cultured in YPGA medium was also confirmed by ATR spectroscopy.
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http://dx.doi.org/10.1016/j.ijbiomac.2019.04.116DOI Listing
July 2019

Influence of the construction of porous spargers on lovastatin production by Aspergillus terreus ATCC 20,542 in a laboratory bubble column.

Bioprocess Biosyst Eng 2019 Jul 4;42(7):1205-1213. Epub 2019 Apr 4.

Univ Rennes, Ecole Nationale Supérieure de Chimie de Rennes, CNRS, ISCR-UMR 6226, 35000, Rennes, France.

In bubble column bioreactors, the hydrodynamic behavior like mixing time, bubble size and morphology of filamentous fungi are influenced by the construction of spargers. Sparger pore size is an important factor influencing formation of bubbles. In this study for the first time, a 5-L bubble column bioreactor with different porous spargers was used to investigate the effect of mean air bubble diameter (at 0.36, 0.18 and 0.09 cm) on fungal growth, broth viscosity, fungal pellet morphology and lovastatin production by the filamentous fungus Aspergillus terreus. All cultivations were carried out at air flow rate equal to 0.5 L L min. The viscosity of the broth was influenced by both biomass concentration and size of the fungal pellets. The highest values of viscosity were observed at bubbles of 0.09 cm diameter after 192 h of cultivation. The largest fluffy pellets and the highest yield of lovastatin (443 mg/L) were obtained at air bubbles diameter of 0.18 cm. Lovastatin yield on biomass growth in this condition was, respectively, 1.7-fold and 3.5-fold higher than in the cultivations performed with air bubbles of 0.36 and 0.09 cm diameters. These laboratory scale experiment indicates that air bubble diameter has the impact on lovastatin production and A. terreus culture conditions.
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http://dx.doi.org/10.1007/s00449-019-02118-5DOI Listing
July 2019

Photocatalytic Performance of CuO/TiO₂ Deposited by HiPIMS on Polyester under Visible Light LEDs: Oxidants, Ions Effect, and Reactive Oxygen Species Investigation.

Materials (Basel) 2019 Jan 29;12(3). Epub 2019 Jan 29.

Ecole Polytechnique Fédérale de Lausanne, EPFL-STI-LTP, Station 12, CH-1015 Lausanne, Switzerland.

In the present study, we propose a new photocatalytic interface prepared by high-power impulse magnetron sputtering (HiPIMS), and investigated for the degradation of Reactive Green 12 (RG12) as target contaminant under visible light light-emitting diodes (LEDs) illumination. The CuO/TiO₂ nanoparticulate photocatalyst was sequentially sputtered on polyester (PES). The photocatalyst formulation was optimized by investigating the effect of different parameters such as the sputtering time of CuO, the applied current, and the deposition mode (direct current magnetron sputtering, DCMS or HiPIMS). The results showed that the fastest RG12 degradation was obtained on CuO/TiO₂ sample prepared at 40 A in HiPIMS mode. The better discoloration efficiency of 53.4% within 360 min was found in 4 mg/L of RG12 initial concentration and 0.05% Cu/PES as determined by X-ray fluorescence. All the prepared samples contained a TiO₂ under-layer with 0.02% Ti/PES. By transmission electron microscopy (TEM), both layers were seen uniformly distributed on the PES fibers. The effect of the surface area to volume (dye volume) ratio (SA/V) on the photocatalytic efficiency was also investigated for the discoloration of 4 mg/L RG12. The effect of the presence of different chemicals (scavengers, oxidant or mineral pollution or salts) in the photocatalytic medium was studied. The optimization of the amount of added hydrogen peroxide (H₂O₂) and potassium persulfate (K₂S₂O₈) was also investigated in detail. Both, H₂O₂ and K₂S₂O₈ drastically affected the discoloration efficiency up to 7 and 6 times in reaction rate constants, respectively. Nevertheless, the presence of Cu (metallic nanoparticles) and NaCl salt inhibited the reaction rate of RG12 discoloration by about 4 and 2 times, respectively. Moreover, the systematic study of reactive oxygen species' (ROS) contribution was also explored with the help of iso-propanol, methanol, and potassium dichromate as OH radicals, holes (h⁺), and superoxide ion-scavengers, respectively. Scavenging results showed that O₂ played a primary role in RG12 removal; however, OH radicals' and photo-generated holes' (h⁺) contributions were minimal. The CuO/TiO₂ photocatalyst was found to have a good reusability and stability up to 21 cycles. Ions' release was quantified by means of inductively coupled plasma mass spectrometry (ICP-MS) showing low Cu-ions' release.
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http://dx.doi.org/10.3390/ma12030412DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6385099PMC
January 2019

Iron oxide nanoparticles as heterogeneous electro-Fenton catalysts for the removal of AR18 azo dye.

Environ Technol 2020 Jun 15;41(16):2146-2153. Epub 2018 Dec 15.

Univ Rennes, Ecole Nationale Supérieure de Chimie de Rennes, CNRS, ISCR - UMR6226, Rennes, France.

Heterogeneous electro-Fenton mineralization of Acid Red 18 (AR18) in aqueous solution was studied with magnetite FeO (MNPs) and haematite FeO (HNPs) nanoparticles as catalysts. High mineralization yields of AR18 were obtained with magnetite, 81% TOC removal after 180 min of electrolysis in 40 mg L FeO, pH 3.0, at 50 mA of current intensity and in 50 mM NaSO. In order to explain the obtained mineralization yield achieved with MNPs, the quantification of hydrogen peroxide (HO), hydroxyl radical (•OH) and iron leaching were performed at 50 and 100 mA. From the high iron concentration found in the bulk solution and the slight impact of the catalyst mass concentration on TOC removal, the formation of hydroxyl radicals occurs mainly through homogeneous process. In the presence of hydroxyl radical scavenger, degradation remained total after 15 min showing the involvement of a direct electrochemical oxidation of the dye at the electrode surface. The hydroxyl radical oxidation is responsible for at least 50% of mineralization.
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http://dx.doi.org/10.1080/09593330.2018.1557258DOI Listing
June 2020

Metronidazole removal by means of a combined system coupling an electro-Fenton process and a conventional biological treatment: By-products monitoring and performance enhancement.

J Hazard Mater 2018 10 4;359:85-95. Epub 2018 Jul 4.

Univ Rennes, Ecole Nationale Supérieure de Chimie de Rennes, CNRS, ISCR - UMR6226, F-35000 Rennes, France.

In order to mineralize Metronidazole (MTZ), a process coupling an electro-Fenton pretreatment and a biological degradation was implemented. A mono-compartment batch reactor containing a carbon-felt cathode and a platinum anode was employed to carry out the electro-Fenton pretreatment of MTZ. A total degradation of MTZ (100 mg L) was observed at 0.07 mA.cm after only 20 min of electrolysis. Yet, after 1 and 2 h of electrolysis, the mineralization level remained low (16.2% and 32% respectively), guaranteeing a significant residual organic content for further biological treatment. LCMS/MS was used to determine the intermediates by-products and hence to propose a plausible degradation pathway. An increase from 0 to 0.44 and 0.6 for 1 and 2 h of electrolysis was observed for the BOD/COD ratio. Thus, from 1 h of electro-Fenton pretreatment, the electrolysis by-products were considered biodegradable. A biological treatment of the electrolysis by-products after 1 and 2 h was then realized. The mineralization yields reached very close values, about 84% for 1 and 2 h of electrolysis after 504 h of biological treatment, namely close to 89% for the overall process, showing the pertinence of the proposed coupled process.
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http://dx.doi.org/10.1016/j.jhazmat.2018.07.006DOI Listing
October 2018

Reactive oxygen and iron species monitoring to investigate the electro-Fenton performances. Impact of the electrochemical process on the biodegradability of metronidazole and its by-products.

Chemosphere 2018 May 13;199:486-494. Epub 2018 Feb 13.

Univ rennes, Ecole Nationale Supérieure de Chimie de Rennes, CNRS, ISCR - UMR6226, F-35000 Rennes, France.

In this study, the monitoring of reactive oxygen species and the regeneration of the ferrous ions catalyst were performed during electro-Fenton (EF) process to highlight the influence of operating parameters. The removal of metronidazole (MTZ) was implemented in an electrochemical mono-compartment batch reactor under various ranges of current densities, initial MTZ and ferrous ions concentrations, and pH values. It was found that under 0.07 mA cm, 0.1 mM of ferrous ions and pH = 3, the efficiency of 100 mg L MTZ degradation and mineralization were 100% within 20 min and 40% within 135 min of electrolysis, respectively. The highest hydrogen peroxide and hydroxyl radical concentrations, 1.4 mM and 2.28 mM respectively, were obtained at 60 min electrolysis at 0.07 mA cm. Improvement of the biodegradability was reached from 60 min of electrolysis with a BOD/COD ratio above 0.4, which was reinforced by a respirometric study, that supports the feasibility of coupling electro-Fenton and biological treatment for the metronidazole removal.
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http://dx.doi.org/10.1016/j.chemosphere.2018.02.075DOI Listing
May 2018

A combination of absorption and enzymatic biodegradation: phenol elimination from aqueous and organic phase.

Environ Technol 2019 Feb 14;40(5):625-632. Epub 2017 Nov 14.

c Laboratoire de Génie de la Réaction, Faculté de Génie Mécanique et Génie des Procédés , Université Houari Boumediene , Bab Ezzouar , Algeria.

Peroxidase from Brassica rapa was immobilized as cross-linked enzyme aggregates (CLEAs) and used to treat air containing phenol as a model molecule of volatile organic compounds (VOCs). Prior to an enzymatic treatment, phenol was absorbed into an aqueous or organic phase (silicone oil) to reach concentrations ranging from 20 to 160 mg/L. The process was carried out by introducing a desired weighing of BRP-CLEAs into preparations and reaction was started by injecting HO solution to the medium. Optimization of the reaction conditions in the organic solvent revealed an optimal contact time of 60 min, 60 mg/L of phenol concentration and 3 mM HO, leading to a maximum removal yield of 70% for 3.4 UI/mL of BRP-CLEAs. These results were compared to those obtained in an aqueous medium that showed 90% of degradation yield after 40 min in the following conditions, 90 mg/L of initial phenol amount, 2 mM of HO and 2.5 UI/mL of BRP-CLEAs. Parameters of the Michaelis-Menten model, Km and Vmax, were also determined for the reaction in both phases. Phenol removal by BRP-CLEAs in silicone oil succeeded with 70% of conversion yield. It is promising regarding the transposition of such enzymatic process to hydrophobic VOCs.
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http://dx.doi.org/10.1080/09593330.2017.1400110DOI Listing
February 2019

Health risk assessment of heavy metal intake due to fish consumption in the Sistan region, Iran.

Environ Monit Assess 2017 Oct 25;189(11):583. Epub 2017 Oct 25.

Department of Environmental Health Engineering, Gonabad University of Medical Sciences, Gonabad, Iran.

The heavy metal (Pb, Cd, Cr, and Ni) content of a fish species consumed by the Sistan population and its associated health risk factors were investigated. The mean concentrations of Pb, Cd, and Cr were slightly higher than the standard levels. The Ni content of fish was below the maximum guideline proposed by the US Food and Drug Administration (USFDA). The average estimated weekly intake was significantly below the provisional tolerable intake based on the FAO and WHO standards for all studied metals. The target hazard quotients (THQ) of all metals were below 1, showing an absence of health hazard for the population of Sistan. The combined target hazard quotient for the considered metals was 26.94 × 10. The cancer risk factor for Pb (1.57 × 10) was below the acceptable lifetime carcinogenic risk (10). The results of this study reveal an almost safe level of Pb, Cd, Cr, and Ni contents in the fish consumed by the Sistan population. Graphical abstract ᅟ.
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http://dx.doi.org/10.1007/s10661-017-6286-7DOI Listing
October 2017

QSAR modeling in ecotoxicological risk assessment: application to the prediction of acute contact toxicity of pesticides on bees (Apis mellifera L.).

Environ Sci Pollut Res Int 2018 Jan 24;25(1):896-907. Epub 2017 Oct 24.

Ecole Nationale Supérieure de Chimie de Rennes, CNRS, UMR 6226, Université de Rennes 1, 11 allée de Beaulieu, 35708, Rennes Cedex 7, CS 50837, France.

Despite their indisputable importance around the world, the pesticides can be dangerous for a range of species of ecological importance such as honeybees (Apis mellifera L.). Thus, a particular attention should be paid to their protection, not only for their ecological importance by contributing to the maintenance of wild plant diversity, but also for their economic value as honey producers and crop-pollinating agents. For all these reasons, the environmental protection requires the resort of risk assessment of pesticides. The goal of this work was therefore to develop a validated QSAR model to predict contact acute toxicity (LD) of 111 pesticides to bees because the QSAR models devoted to this species are very scarce. The analysis of the statistical parameters of this model and those published in the literature shows that our model is more efficient. The QSAR model was assessed according to the OECD principles for the validation of QSAR models. The calculated values for the internal and external validation statistic parameters (Q and [Formula: see text] are greater than 0.85. In addition to this validation, a mathematical equation derived from the ANN model was used to predict the LD of 20 other pesticides. A good correlation between predicted and experimental values was found (R  = 0.97 and RMSE = 0.14). As a result, this equation could be a means of predicting the toxicity of new pesticides.
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http://dx.doi.org/10.1007/s11356-017-0498-9DOI Listing
January 2018

Combination of the Electro/Fe/peroxydisulfate (PDS) process with activated sludge culture for the degradation of sulfamethazine.

Environ Toxicol Pharmacol 2017 Jul 1;53:34-39. Epub 2017 May 1.

Ecole Nationale Supérieure de Chimie de Rennes, Université Rennes1, CNRS, UMR 6226, Avenue du Général Leclerc, CS 50837, 35708 Rennes Cedex 7, France.

In this paper, the major factors affecting the degradation and the mineralization of sulfamethazine by Electro/Fe/peroxydisulfate (PDS) process (e.g. current density, PDS concentration, Fe ions concentration and initial sulfamethazine (SMT) concentration) were evaluated. The relevance of this process as a pretreatment prior to activated sludge culture was also examined. Regarding the impact on SMT degradation and mineralization, the obtained results showed that they were significantly enhanced by increasing the current density and the PDS concentrations in the ranges 1-40mAcm and from 1 to 10mM respectively; while they were negatively impacted by an increase of the initial SMT concentration and the Fe concentration, from 0.18 to 0.36mM and from 1 to 4mM respectively. The optimal operating conditions were therefore 40mAcm current density, 10mM PDS concentrations, 1mM Fe, and 0.18mM SMT. Indeed, under these conditions the degradation of SMT and its mineralization yield were 100% and 83% within 20min and 180min respectively. To ensure a significant residual organic content for activated sludge culture after Electro/Fe/PDS pre-treatment, the biodegradability test and the biological treatment were performed on a solution electrolyzed at 40mAcm, 10mM PDS concentrations, 1mM Fe, and 0.36mM SMT. Under these conditions the BOD/COD ratio increased from 0.07 to 0.41 within 6h of electrolysis time. The subsequent biological treatment increased the mineralization yield to 86% after 30days, confirming the relevance of the proposed combined process.
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http://dx.doi.org/10.1016/j.etap.2017.04.022DOI Listing
July 2017

Direct and indirect electrochemical reduction prior to a biological treatment for dimetridazole removal.

J Hazard Mater 2017 Aug 9;335:10-17. Epub 2017 Apr 9.

Institut des Sciences Chimiques de Rennes, Université de Rennes 1, UMR-CNRS 6226, Equipe MaCSE, Campus de Beaulieu, 35042 Rennes Cedex, France. Electronic address:

Two different electrochemical reduction processes for the removal of dimetridazole, a nitroimidazole-based antibiotic, were examined in this work. A direct electrochemical reduction was first carried out in a home-made flow cell in acidic medium at potentials chosen to minimize the formation of amino derivatives and then the formation of azo dimer. Analysis of the electrolyzed solution showed a total degradation of dimetridazole and the BOD/COD ratio increased from 0.13 to 0.24. An indirect electrochemical reduction in the presence of titanocene dichloride ((CH)TiCl), which is used to reduce selectively nitro compounds, was then investigated to favour the formation of amino compounds over hydroxylamines and then to prevent the formation of azo and azoxy dimers. UPLC-MS/MS analyses showed a higher selectivity towards the formation of the amino compound for indirect electrolyses performed at pH 2. To confirm the effectiveness of the electrochemical reduction, a biological treatment involving activated sludge was then carried out after direct and indirect electrolyses at different pH. The enhancement of the biodegradability was clearly shown since mineralization yields of all electrolyzed solutions increased significantly.
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http://dx.doi.org/10.1016/j.jhazmat.2017.04.028DOI Listing
August 2017

Sulfamethazine removal by means of a combined process coupling an oxidation pretreatment and activated sludge culture - preliminary results.

Environ Technol 2017 Nov 12;38(21):2684-2690. Epub 2017 Jan 12.

a Institut des Sciences Chimiques de Rennes , Université de Rennes 1, UMR-CNRS 6226 , Rennes , France.

A coupled electrochemical process and biological treatment was used to remove a biorecalcitrant antibiotic: sulfamethazine (SMT). The pretreatment was performed in a home-made flow cell involving graphite felt as a working electrode at potentials of 1 and 1.6 V/saturated calomel electrode (SCE); it was followed by a biological process involving activated sludge purchased from a local wastewater treatment plant. Activated sludge cultures of pretreated and non-pretreated SMT solution were carried out for 3 weeks, and different parameters were monitored, especially total organic carbon (TOC) and SMT concentrations. high-performance liquid chromatography results revealed that the target molecule was not assimilated by activated sludge. However, and confirming the improvement previously observed for the biological oxygen demand/chemical oxygen demand (BOD/COD) ratio, from 0.08 before electrolysis to 0.58 after electrolysis, a pretreatment step in oxidation at 1.6 V/SCE led to a fast decrease of TOC during the subsequent biological treatment, since the mineralization yields increased from 10% for a non-pretreated SMT solution to 76.6% after electrolysis in oxidation (1.6 V/SCE), confirming the efficiency of coupling the electro-oxidation process with a biological treatment for the mineralization of SMT. Moreover, when the electrolysis was performed at 1 V/SCE, no biodegradation was observed, underlining the importance of the electrochemical pretreatment.
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http://dx.doi.org/10.1080/09593330.2016.1273395DOI Listing
November 2017

Identification of strain isolated from dates (Phœnix dactylifera L.) for enhancing very high gravity ethanol production.

Environ Sci Pollut Res Int 2017 Apr 12;24(11):9886-9894. Epub 2016 Nov 12.

Université de Rennes 1, ENSCR, CNRS, UMR 6226, Avenue du Général Leclerc, CS 50837, 35708, Rennes Cedex 7, France.

Ethanol production from by-products of dates in very high gravity was conducted in batch fermentation using two yeasts, Saccharomyces cerevisiae and Zygosaccharomyces rouxii, as well as a native strain: an osmophilic strain of bacteria which was isolated for the first time from the juice of dates (Phoenix dactylifera L.). The phylogenetic analysis based on the 16S ribosomal RNA and gyrB sequence and physiological analysis indicated that the strain identified belongs to the genus of Bacillus, B. amyloliquefaciens. The ethanol yields produced from the syrup of dates (175 g L and 360 g L of total sugar) were 40.6% and 29.5%, respectively. By comparing the ethanol production by the isolated bacteria to that obtained using Z. rouxii and S. cerevisiae, it can be concluded that B. amyloliquefaciens was suitable for ethanol production from the syrup of dates and can consume the three types of sugar (glucose, fructose, and sucrose). Using Z. rouxii, fructose was preferentially consumed, while glucose was consumed only after fructose depletion. From this, B. amyloliquefaciens was promising for the bioethanol industry. In addition, this latter showed a good tolerance for high sugar concentration (36%), allowing ethanol production in batch fermentation at pH 5.0 and 28 °C in date syrup medium. Promising ethanol yield produced to sugar consumed were observed for the two osmotolerant microorganisms, Z. rouxii and B. amyloliquefaciens, nearly 32-33%, which were further improved when they were cocultivated, leading to an ethanol to glucose yield of 42-43%.
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http://dx.doi.org/10.1007/s11356-016-8018-xDOI Listing
April 2017

Removal of herbicidal ionic liquids by electrochemical advanced oxidation processes combined with biological treatment.

Environ Technol 2017 May 12;38(9):1093-1099. Epub 2016 Sep 12.

a Poznan University of Technology, Institute of Chemistry and Technical Electrochemistry , Poznan , Poland.

Recently a new group of ionic liquids (ILs) with herbicidal properties has been proposed for use in agriculture. Owing to the design of specific physicochemical properties, this group, referred to as herbicidal ionic liquids (HILs), allows for reducing herbicide field doses. Several ILs comprising phenoxy herbicides as anions and quaternary ammonium cations have been synthesized and tested under greenhouse and field conditions. However, since they are to be introduced into the environment, appropriate treatment technologies should be developed in order to ensure their proper removal and avoid possible contamination. In this study, didecyldimethylammonium (4-chloro-2-methylphenoxy) acetate was selected as a model HIL to evaluate the efficiency of a hybrid treatment method. Electrochemical oxidation or electro-Fenton was considered as a pretreatment step, whereas biodegradation was selected as the secondary treatment method. Both processes were carried out in current mode, at 10 mA with carbon felt as working electrode. The efficiency of degradation, oxidation and mineralization was evaluated after 6 h. Both processes decreased the total organic carbon and chemical oxygen demand (COD) values and increased the biochemical oxygen demand (BOD) on the COD ratio to a value close to 0.4, showing that the electrolyzed solutions can be considered as 'readily biodegradable.'
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http://dx.doi.org/10.1080/09593330.2016.1217941DOI Listing
May 2017

Competitive adsorption of fluoride and natural organic matter onto activated alumina.

Environ Technol 2016 Sep 7;37(18):2326-36. Epub 2016 Mar 7.

a Desalination and Water Treatment Research Unit, Faculty of Sciences of Tunis , University of Tunis El Manar , Tunis , Tunisia.

Natural organic matter (NOM) is a major water constituent that affects the performance of water treatment processes. Several studies have shown that NOM can be adsorbed on the surface of oxides and may compete with other ions. The overall goal of this study was essentially to investigate the competitive adsorption between fluoride and NOM on activated alumina (AA). For this purpose, a humic acid (HA) was used as a model compound for NOM. The interaction of NOM with fluoride, the simultaneous competitive adsorption, and the effect of preloading AA with NOM were investigated. The specific absorbance of HA was determined at 254 nm. Size-exclusion chromatography measurements confirmed the adsorption of aromatic fractions of NOM onto AA. The presence of HA in the system inhibited fluoride sorption onto AA and the removal yield using fresh AA decreased from 70.4 % to 51.0 % in the presence of HA. The decrease was more pronounced using AA preloaded with HA, reaching 37.7 %. The interference of coexisting ions and their effect on fluoride removal capacity were evaluated, showing a severe impact of the presence of phosphate on the removal capacity unlike nitrates and sulfates, which slightly improved the fluoride sorption.
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http://dx.doi.org/10.1080/09593330.2016.1149521DOI Listing
September 2016