Search results for "Electro-Fenton"
showing 10 items of 21 documents
Effect of air pressure on the electro-generation of H2O2 and the abatement of organic pollutants in water by electro-Fenton process
2015
Abstract The electro-generation of H 2 O 2 and the abatement of the model organic pollutant Acid Orange 7 (AO7) in water by an electro-Fenton process were performed under moderate air pressures (up to 11 bar) for the first time to our knowledge. An increase of the pressure gave rise to a drastic enhancement of the concentration of hydrogen peroxide. In systems pressurized with air at 11 bar, the electro reduction of oxygen at a graphite cathode gave rise to a concentration of H 2 O 2 of about 12 mM, about one order of magnitude higher than that achieved at atmospheric pressure. This result is attributed to the mass transfer intensification induced by the higher local concentration of molecu…
Effect of the air pressure on electro-Fenton process
2019
Electro-Fenton process is considered a very promising tool for the treatment of waste waters contaminated by organic pollutants refractant or toxic for microorganisms used in biological processes [1-6]. In these processes H2O2 is continuously supplied to an acidic aqueous solution contained in an electrolytic cell from the two-electron reduction of oxygen gas, directly injected as pure gas or bubbled air. Due to the poor solubility of O2 in aqueous solutions, two dimensional cheap graphite or carbon felt electrodes give quite slow generation of H2O2, thus resulting in a slow abatement of organics. In this context, we report here a series of studies [7-9] on the effect of air pressure on the…
TRATAMIENTO ELECTROQUIMICO DE CONTAMINANTES ORGANOCLORADOS ALIFATICOS. ELUCIDACION DE LOS CAMINOS DE REACCION.
2011
Los hidrocarburos alifáticos clorados conjugan toxicidad con una alta estabilidad química, capacidad de bioacumulación y difusión de largo alcance. Los cloroetanos son particularmente ubicuos en la industria y en los productos domésticos, y su introducción en el medio ambiente puede entrañar riesgos para los seres vivos. Actualmente, la USEPA (US Environmental Protection Agency) está llevando a cabo el llamado “Endocrine Disruptor Screening Program (EDSP)”, en el cual tanto el 1,2-dicloroetano (DCA) como el 1,1,2,2-tetracloroetano (TCA) son considerados prioritarios debido a sus efectos potenciales sobre el sistema endocrino. El DCA se encuentra también en la lista de substancias prioritari…
Abatement of Acid Orange 7 in macro and micro reactors. Effect of the electrocatalytic route
2014
Abstract The electrochemical treatment of aqueous solutions contaminated by Acid Orange 7 (AO7) was widely studied with the main objective to evaluate as the electrocatalytic route affects the performances of the degradation process in macro and microfluidic cells. Direct anodic oxidation (EO), electro-Fenton (EF), electro-generation of active chlorine (IOAC) and coupled processes were investigated in macro and microfluidic reactors in order to select more effective conditions for the treatment of such compound. The effect of numerous operative parameters (such as nature of the electrode materials, coupling of processes, flow rate, current density and inter-electrode distance) on the perfor…
Electrochemical treatment of paper mill wastewater by electro-Fenton process
2019
Abstract The electrochemical oxidation of organics in paper mill wastewater belonging to Halfa industries (Tunisia) was performed by galvanostatic electrolyses using electro-Fenton (EF) process. The effect of several operating parameters, such as applied current density, electrodes material, air pressure and the presence of sodium chloride (NaCl) was evaluated. In particular, carbon felt (CF), modified carbon felt (MCF) and gas diffusion electrode (GDE) were used as cathode while Ti/IrO2-Ta2O5 and Boron Doped Diamond (BDD) as anode. Total Organic Carbon (TOC) measure was chosen as reference parameter to assess the extent of the treatment. The experimental results show that, by adopting the …
Removal of Phenol from Water in the Presence of NaCl in Undivided Cells Equipped with Carbon Felt or Ni Cathodes: Effect of Air Pressure
2022
Recently, the electrochemical treatment of wastewater polluted by recalcitrant organics and containing chlorides was shown to be significantly improved adopting proper operative conditions such as suitable anodes and cathodes and low current density. In particular, the use of suitable cathodes such as carbon felt or silver could increase the removal of TOC and reduce the formation of chlorinated by-products. In this study, attention was focused on the utilization of carbon felt cathodes with the main aim to evaluate the effect of air pressure on the process using phenol as model organic pollutant. It was shown that, in the presence of carbon felt cathode, the use of pressurized air allows b…
Treatment of aqueous solutions of oxytetracycline by different electrochemical approaches: anodic oxidation, pressurized electro-Fenton and oxidation…
2023
The tetracycline group (TCs) includes the most common antibiotics for treatment of both human and animal infections. TCs are resistant to biological degradation; hence, conventional wastewater treatments are unable to remove these contaminants. Here, the utilization of different electrochemical processes, such as electro-Fenton (EF), direct anodic oxidation (AO) and indirect oxidation by electrogenerated active chlorine (EAC), for the treatment of aqueous solutions of oxytetracycline (OTC), which is one of the TCs, was studied. The effect of various operating conditions was evaluated to optimize the selected processes. EAC gave the fastest abatement of OTC, but the lowest removal of TOC and…
Electro-generation of H2O2 and abatement of organic pollutant in water by an electro-Fenton process in a microfluidic reactor
2013
The electro-generation of H2O2 and the abatement of the model organic pollutant Acid Orange 7 (AO7) in water by an electro-Fenton process were performed both in a conventional undivided macro cell and, for the first time, in a microfluidic reactor. Under optimized operative conditions, the reduction of oxygen in the microdevice gave rise, using graphite cathode, to a concentration of H2O2 of about 6 mM, one order of magnitude higher than that achieved in conventional cells. Similarly, when electro-Fenton was performed in the microfluidic reactor a dramatic increase of the abatement of COD was achieved with respect to that obtained in a conventional cell. Keywords: Wastewater treatments, Mic…
Effect of air pressure on the electro-Fenton process at carbon felt electrodes
2018
Abstract The effect of air pressure on electro-Fenton (PrEF process) was evaluated using two organic substances (maleic acid and Acid Orange 7) as model organic pollutants. First experiments were performed using a conventional carbon felt (CF) cathode. At room pressure, a slow removal of maleic acid was obtained, together with the generation of formic acid. Conversely, using pressurized air, the removal of maleic acid was dramatically accelerated and the formation of formic acid was not detected. The utilization of a carbon felt modified by the deposition of carbon black + PTFE mixture (MCF) and of pressurized air allowed to achieve even faster and almost total (>95%) removal of total organ…
Innovative chemical processes for the treatment of water polluted by recalcitrant organic substances
2012
In the last years, many research groups have focused their attention on the innovative chemical processes adopted for the treatment of water effluents polluted by recalcitrant organic substances, i.e., substances resistant to biological treatment. The electrochemical oxidation is one of the most studied technologies because it presents high versatility and low cost, it is realized under mild conditions of pressure and temperature and generally it does not involve the use of toxic substances [1]. In this work, the comparative performance of different electrochemical approaches such as direct oxidation processes, oxidation by means of electrogenerated chlorine and electro-Fenton was investiga…