This work reports the first investigation on the use of EDDS as chelating agent in photoelectro-Fenton (PEF) treatment of water at near-neutral pH. As a case study, the removal of the antidepressant fluoxetine was optimized, using an electrochemical cell composed of an IrO-based anode an air-diffusion cathode for in-situ HO production. Electrolytic trials at constant current were made in ultrapure water with different electrolytes, as well as in urban wastewater (secondary effluent) at pH 7.
View Article and Find Full Text PDFThe treatment of olive oil mill wastewater (OOMW) by novel sequential processes involving electrocoagulation (EC) followed by electro-Fenton (EF) or photoelectro-Fenton (PEF) under UVA irradiation has been studied using a boron-doped diamond anode and an air-diffusion cathode for HO electrogeneration. Their performance was monitored from the removal of total organic carbon (TOC), chemical oxygen demand, turbidity, total solids and total nitrogen, as well as from the energy consumption. Preliminary EC assays were performed with one pair of electrodes made of Al, Fe, AISI 304 or AISI 316L.
View Article and Find Full Text PDFThe electrochemical degradation of tetracaine hydrochloride has been studied in urban wastewater. Treatments in simulated matrix with similar ionic composition as well as in 0.050 M NaSO were comparatively performed.
View Article and Find Full Text PDFThe degradation of 4-hydroxyphenylacetic acid, a ubiquitous component of olive oil mill wastewater (OOMW), has been studied by anodic oxidation with electrogenerated HO (AO-HO), electro-Fenton (EF) and photoelectro-Fenton (PEF). Experiments were performed in either a 0.050M NaSO solution or a real OOMW at pH 3.
View Article and Find Full Text PDFSolutions of 100 mL with 1.20 mM of salicylic acid (SA), 4-aminosalicylic acid (4-ASA) or 5-aminosalicylic acid (5-ASA) have been comparatively degraded by anodic oxidation with electrogenerated H2O2 (AO-H2O2), electro-Fenton (EF) and photoelectro-Fenton (PEF). Trials were carried out with a stirred tank reactor with a BDD anode and an air-diffusion cathode for continuous H2O2 production.
View Article and Find Full Text PDFAcidic solutions of trans-cinnamic acid at pH 3.0 have been comparatively treated by anodic oxidation with electrogenerated HO (AO-HO), electro-Fenton (EF), and photoelectro-Fenton (PEF). The electrolytic experiments were carried out with a boron-doped diamond (BDD)/air-diffusion cell.
View Article and Find Full Text PDFSolutions of pH 3.0 containing trans-ferulic acid, a phenolic compound in olive oil mill wastewater, have been comparatively degraded by anodic oxidation with electrogenerated H2O2 (AO-H2O2), electro-Fenton (EF) and photoelectro-Fenton (PEF). Trials were performed with a BDD/air-diffusion cell, where oxidizing OH was produced from water discharge at the BDD anode and/or in the solution bulk from Fenton's reaction between cathodically generated H2O2 and added catalytic Fe(2+).
View Article and Find Full Text PDFThe degradation of 2.5L of Allura Red AC solutions in sulfate medium containing 0.50mM Fe(2+) has been studied by solar photoelectro-Fenton (SPEF) using a flow plant equipped with a Pt/air-diffusion cell and a solar photoreactor.
View Article and Find Full Text PDFThe mineralization of sulfanilamide solutions at pH 3.0 was comparatively studied by electro-Fenton (EF) and solar photoelectro-Fenton (SPEF) using a 2.5 L pre-pilot plant containing a Pt/air-diffusion cell coupled with a solar photoreactor.
View Article and Find Full Text PDFThe electrochemical incineration of omeprazole, a widely prescribed gastrointestinal drug which is detected in natural waters, has been studied in a phosphate buffer of pH 7.0 by anodic oxidation with electrogenerated H(2)O(2) (AO-H(2)O(2)) operating at constant current density (j). The experiments were carried out in a cell equipped with either a Pt or a boron-doped diamond (BDD) anode and an air-diffusion cathode to continuously produce H(2)O(2).
View Article and Find Full Text PDFThe mineralization of sulfanilic acid has been studied by electro-Fenton (EF) and photoelectro-Fenton (PEF) reaction with UVA light using an undivided electrochemical cell with a boron-doped diamond (BDD) anode and an air diffusion cathode able to generate H(2)O(2). Organics were then oxidized by hydroxyl radicals formed at the anode surface from water oxidation and in the bulk from Fenton's reaction between generated H(2)O(2) and added Fe(2+). The UVA irradiation in PEF enhanced the production of hydroxyl radicals in the bulk, accelerating the removal of organics and photodecomposed intermediates like Fe(III)-carboxylate complexes.
View Article and Find Full Text PDFThe anodic oxidation of sulfanilic acid solutions has been studied in acidic medium using a divided cell with a boron-doped diamond (BDD) anode and a stainless steel cathode. Overall mineralization was achieved under all experimental conditions tested due to the efficient destruction of sulfanilic acid and all its by-products with hydroxyl radicals generated at the BDD anode from water oxidation. The alternative use of an undivided cell with the same electrodes gave rise to the coating of the cathode with polymeric compounds, thus preventing the complete electrochemical incineration of sulfanilic acid.
View Article and Find Full Text PDFThe mineralization of flumequine, an antimicrobial agent belonging to the first generation of synthetic fluoroquinolones which is detected in natural waters, has been studied by electrochemical advanced oxidation processes (EAOPs) like electro-Fenton (EF) and photoelectro-Fenton (PEF) with UVA light. The experiments were performed in a cell containing a boron-doped diamond (BDD) anode and an air-diffusion cathode to generate H(2)O(2) at constant current. The Fe(2+) ion added to the medium increased the solubility of the drug by the formation of a complex of intense orange colour and also reacted with electrogenerated H(2)O(2) to form hydroxyl radical from Fenton reaction.
View Article and Find Full Text PDFThe degradation of the beta-blockers atenolol, metoprolol tartrate and propranolol hydrochloride was studied by electro-Fenton (EF) and solar photoelectro-Fenton (SPEF). Solutions of 10 L of 100 mg L⁻¹ of total organic carbon of each drug in 0.1 M Na₂SO₄ with 0.
View Article and Find Full Text PDFSolutions of about 0.25 mM of the β-blocker metoprolol tartrate (100 mg L(-1) total organic carbon) with 0.5 mM Fe(2+) in the presence and absence of 0.
View Article and Find Full Text PDFThe beta-blocker propranolol hydrochloride has been degraded by electrochemical advanced oxidation processes like electro-Fenton (EF) and photoelectro-Fenton (PEF) using a single cell with a Pt anode and an air diffusion cathode (ADE) for H(2)O(2) electrogeneration and a combined system containing the above Pt/ADE pair coupled in parallel to a Pt/carbon-felt (CF) cell. Organics are mainly oxidized with hydroxyl radical (OH) formed from Fenton's reaction between added Fe(2+) and electrogenerated H(2)O(2). The PEF treatment in Pt/ADE-Pt/CF system yields almost total mineralization because OH production is enhanced by Fe(2+) regeneration from Fe(3+) reduction at the CF cathode and Fe(III) complexes with generated carboxylic acids are rapidly photodecarboxylated under UVA irradiation.
View Article and Find Full Text PDFThe treatment of enrofloxacin synthetic wastewaters using conductive-diamond electrochemical oxidation (CDEO), ozonation and Fenton oxidation has been studied. Results show that the three technologies can reduce the organic content of enrofloxacin synthetic wastewaters but with different performances. CDEO was the most efficient technology in terms of mineralization but not on COD removal, which was more efficiently achieved by ozonation.
View Article and Find Full Text PDFElectrochemical advanced oxidation processes (EAOPs) are environmentally friendly methods based on the destruction of organic pollutants in wastewaters with in situ electrogenerated hydroxyl radical. This species is formed in anodic oxidation (AO) from water oxidation at the anode and in indirect electro-oxidation methods like electro-Fenton (EF) and photoelectro-Fenton (PEF) also from reaction between catalytic Fe2+ and H2O2 continuously produced at the O2-diffusion cathode. The PEF method involves the irradiation of the treated solution with UVA light to enhance the photolysis of organics including Fe(III) complexes.
View Article and Find Full Text PDFWater Res
January 2008
Solutions containing 164 mg L(-1) salicylic acid of pH 3.0 have been degraded by electrochemical advanced oxidation processes such as anodic oxidation, anodic oxidation with electrogenerated H(2)O(2), electro-Fenton, photoelectro-Fenton and solar photoelectro-Fenton at constant current density. Their oxidation power has been comparatively studied in a one-compartment cell with a Pt or boron-doped diamond (BDD) anode and a graphite or O(2)-diffusion cathode.
View Article and Find Full Text PDFAcidic aqueous solutions of clofibric acid (2-(4-chlorophenoxy)-2-methylpropionic acid), the bioactive metabolite of various lipid-regulating drugs, have been degraded by indirect electrooxidation methods such as electro-Fenton and photoelectro-Fenton with Fe(2+) as catalyst using an undivided electrolytic cell with a Pt anode and an O(2)-diffusion cathode able to electrogenerate H(2)O(2). At pH 3.0 about 80% of mineralization is achieved with the electro-Fenton method due to the efficient production of oxidant hydroxyl radical from Fenton's reaction between Fe(2+) and H(2)O(2), but stable Fe(3+) complexes are formed.
View Article and Find Full Text PDFThe anodic oxidation of 1.8l of solutions with mecoprop (2-(4-chloro-2-methylphenoxy)-propionic acid or MCPP) up to 0.64 g l(-1) in Na2SO4 as background electrolyte within the pH range 2.
View Article and Find Full Text PDFThe degradation of 100ml of solutions with paracetamol (N-(4-hydroxyphenyl)acetamide) up to 1 g l(-1) in the pH range 2.0-12.0 has been studied by anodic oxidation in a cell with a boron-doped diamond (BDD) anode and a graphite cathode, both of 3-cm2 area, by applying a current of 100, 300 and 450 mA between 25 and 45 degrees C.
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