Anodic oxidation by electrical power pulses for alachlor degradation.

This article explores the benefits of electrochemical oxidation in pulsed mode, using potential, current, and power pulses. While potential and current pulse electrochemical technology has been previously studied for wastewater treatment, no study has included power pulses until now. The objective of this work is to highlight the advantages of power pulses by applying this pulse type to the electrochemical oxidation of a probe molecule, alachlor.

Removal of Iodine-Containing X-ray Contrast Media from Environment: The Challenge of a Total Mineralization.

Iodinated X-ray contrast media (ICM) as emerging micropollutants have attracted considerable attention in recent years due to their high detected concentration in water systems. It results in environmental issues partly due to the formation of toxic by-products during the disinfection process in water treatment. Consequently, various approaches have been investigated by researchers in order to achieve ICM total mineralization.

Review: Clay-Modified Electrodes in Heterogeneous Electro-Fenton Process for Degradation of Organic Compounds: The Potential of Structural Fe(III) as Catalytic Sites.

Advanced oxidation processes are considered as a promising technology for the removal of persistent organic pollutants from industrial wastewaters. In particular, the heterogeneous electro-Fenton (HEF) process has several advantages such as allowing the working pH to be circumneutral or alkaline, recovering and reusing the catalyst and avoiding the release of iron in the environment as a secondary pollutant. Among different iron-containing catalysts, studies using clay-modified electrodes in HEF process are the focus in this review.

A novel system coupling an electro-Fenton process and an advanced biological process to remove a pharmaceutical compound, metronidazole.

The objective of this study was to improve the mineralization of metronidazole, a recalcitrant antibiotic by the development of a new combined process coupling electro-Fenton and a biological process. For biotreatment, various strategies were considered bioaugmentation, bioacclimatation and biostimulation alone or combined. So, the novelty of this strategy is to combine advanced oxidation process with advanced biological process.

A New Approach to Produce Succinic Acid Through a Co-Culture System.

Microorganisms can produce a wide range of bio-based chemicals that can be used in various industrial applications as molecules of interest. In the present work, an analysis of the power production by pure culture, co-culture, and sequential culture was performed. In this study, both the mono-culture and the co-culture strategies of Actinobacillus succinogenes with Saccharomyces cerevisiae as carbon sources to produce succinic acid using glucose and fructose were examined.

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

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.

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

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.

Electro Fenton removal of clopyralid in soil washing effluents.

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.

Hybrid electrochemical and biological treatment of herbicidal ionic liquids comprising the MCPA anion.

The present study was focused on the application of an electrochemical oxidation process combined with biodegradation for the removal of novel Herbicidal Ionic Liquids (HILs) -promising protection plant products which incorporate herbicidal anions and ammonium cations. The influence of carbon chain length (n = 8, 10, 12, 14, 16, 18) in the dialkyldimethylammonium cations on electrochemical oxidation kinetics, degradation efficiency and biodegradation by activated sludge was investigated. It was established that the applied cation influenced the heterogeneous rate constant and diffusion coefficient of electrochemical oxidation.

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

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.

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

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.

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.

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.

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

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.

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

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.

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

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.

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

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.

Degradation of enoxacin antibiotic by the electro-Fenton process: Optimization, biodegradability improvement and degradation mechanism.

This study aims to investigate the effectiveness of the electro-Fenton process on the removal of a second generation of fluoroquinolone, enoxacin. The electrochemical reactor involved a carbon-felt cathode and a platinum anode. The influence of some experimental parameters, namely the initial enoxacin concentration, the applied current intensity and the Fe(II) amount, was examined.

Removal of a mixture tetracycline-tylosin from water based on anodic oxidation on a glassy carbon electrode coupled to activated sludge.

The purpose of this study was first to examine the electrochemical oxidation of two antibiotics, tetracycline (TC) and tylosin (Tylo), considered separately or in mixture, on a glassy carbon electrode in aqueous solutions; and then to assess the relevance of such electrochemical process as a pre-treatment prior to a biological treatment (activated sludge) for the removal of these antibiotics. The influence of the working potential and the initial concentration of TC and Tylo on the electrochemical pre-treatment process was also investigated. It was noticed that antibiotics degradation was favoured at high potential (2.

Photocatalytic degradation of bezacryl yellow in batch reactors--feasibility of the combination of photocatalysis and a biological treatment.

A combined process coupling photocatalysis and a biological treatment was investigated for the removal of Bezacryl yellow (BZY), an industrial-use textile dye. Photocatalytic degradation experiments of BZY were carried out in two stirred reactors, operating in batch mode with internal or external irradiation. Two photocatalysts (TiO2P25 and TiO2PC500) were tested and the dye degradation was studied for different initial pollutant concentrations (10-117 mg L(-1)).

Electro-Fenton pretreatment for the improvement of tylosin biodegradability.

The feasibility of an electro-Fenton process to treat tylosin (TYL), a non-biodegradable antibiotic, was examined in a discontinuous electrochemical cell with divided cathodic and anodic compartments. Only 15 min electrolysis was needed for total tylosin degradation using a carbon felt cathode and a platinum anode; while 6 h electrolysis was needed to achieve high oxidation and mineralization yields, 96 and 88 % respectively. Biodegradability improvement was shown since BOD₅/COD increased from 0 initially to 0.

Integration of photocatalysis and biological treatment for azo dye removal--application to AR183.

The feasibility of coupling photocatalysis with biological treatment to treat effluents containing azo dyes was examined in this work. With this aim, the degradation of Acid Red 183 was investigated. The very low biodegradability of AR183 was confirmed beforehand by measuring the biological oxygen demand (BOD5).

Relevance of an electrochemical process prior to a biological treatment for the removal of an organophosphorous pesticide, phosmet.

The aim of this study was to examine the feasibility of coupling an electrochemical pre-treatment with a biological step in order to degrade phosmet, an organophosphorous pesticide. Preliminary biodegradation experiments showed that the target molecule was not assimilated by activated sludge. The pre-treatment consisted of potentiostatic electrolysis (-1.

Substrate and metabolite diffusion within model medium for soft cheese in relation to growth of Penicillium camembertii.

Penicillium camembertii was cultivated on a jellified peptone-lactate based medium to simulate the composition of Camembert cheese. Diffusional limitations due to substrate consumption were not involved in the linear growth recorded during culture, while nitrogen (peptone) limitation accounted for growth cessation. Examination of gradients confirmed that medium neutralization was the consequence of lactate consumption and ammonium production.