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Degradation of clofibric acid in acidic aqueous medium by electro-Fenton and photoelectro-Fenton.
Chemosphere. 2007 Jan; 66(9):1660-9.C

Abstract

Acidic 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. The photoelectro-Fenton method favors the photodecomposition of these species under UVA irradiation, reaching more than 96% of decontamination. The mineralization current efficiency increases with rising metabolite concentration up to saturation and with decreasing current density. The photoelectro-Fenton method is then viable for treating acidic wastewaters containing this pollutant. Comparative degradation by anodic oxidation (without Fe(2+)) yields poor decontamination. Chloride ion is released during all degradation processes. The decay kinetics of clofibric acid always follows a pseudo-first-order reaction, with a similar rate constant in electro-Fenton and photoelectro-Fenton that increases with rising current density, but decreases at greater metabolite concentration. 4-Chlorophenol, 4-chlorocatechol, 4-chlororesorcinol, hydroquinone, p-benzoquinone and 1,2,4-benzenetriol, along with carboxylic acids such as 2-hydroxyisobutyric, tartronic, maleic, fumaric, formic and oxalic, are detected as intermediates. The ultimate product is oxalic acid, which forms very stable Fe(3+)-oxalato complexes under electro-Fenton conditions. These complexes are efficiently photodecarboxylated in photoelectro-Fenton under the action of UVA light.

Authors+Show Affiliations

Laboratori d'Electroquímica dels Materials i del Medi Ambient, Departament de Química Física, Facultat de Química, Universitat de Barcelona, Martí i Franquès 1-11, 08028 Barcelona, Spain.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Comparative Study
Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

16938340

Citation

Sirés, Ignasi, et al. "Degradation of Clofibric Acid in Acidic Aqueous Medium By electro-Fenton and Photoelectro-Fenton." Chemosphere, vol. 66, no. 9, 2007, pp. 1660-9.
Sirés I, Arias C, Cabot PL, et al. Degradation of clofibric acid in acidic aqueous medium by electro-Fenton and photoelectro-Fenton. Chemosphere. 2007;66(9):1660-9.
Sirés, I., Arias, C., Cabot, P. L., Centellas, F., Garrido, J. A., Rodríguez, R. M., & Brillas, E. (2007). Degradation of clofibric acid in acidic aqueous medium by electro-Fenton and photoelectro-Fenton. Chemosphere, 66(9), 1660-9.
Sirés I, et al. Degradation of Clofibric Acid in Acidic Aqueous Medium By electro-Fenton and Photoelectro-Fenton. Chemosphere. 2007;66(9):1660-9. PubMed PMID: 16938340.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Degradation of clofibric acid in acidic aqueous medium by electro-Fenton and photoelectro-Fenton. AU - Sirés,Ignasi, AU - Arias,Conchita, AU - Cabot,Pere Lluís, AU - Centellas,Francesc, AU - Garrido,José Antonio, AU - Rodríguez,Rosa María, AU - Brillas,Enric, Y1 - 2006/08/30/ PY - 2006/04/28/received PY - 2006/07/17/revised PY - 2006/07/18/accepted PY - 2006/8/30/pubmed PY - 2007/3/16/medline PY - 2006/8/30/entrez SP - 1660 EP - 9 JF - Chemosphere JO - Chemosphere VL - 66 IS - 9 N2 - Acidic 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. The photoelectro-Fenton method favors the photodecomposition of these species under UVA irradiation, reaching more than 96% of decontamination. The mineralization current efficiency increases with rising metabolite concentration up to saturation and with decreasing current density. The photoelectro-Fenton method is then viable for treating acidic wastewaters containing this pollutant. Comparative degradation by anodic oxidation (without Fe(2+)) yields poor decontamination. Chloride ion is released during all degradation processes. The decay kinetics of clofibric acid always follows a pseudo-first-order reaction, with a similar rate constant in electro-Fenton and photoelectro-Fenton that increases with rising current density, but decreases at greater metabolite concentration. 4-Chlorophenol, 4-chlorocatechol, 4-chlororesorcinol, hydroquinone, p-benzoquinone and 1,2,4-benzenetriol, along with carboxylic acids such as 2-hydroxyisobutyric, tartronic, maleic, fumaric, formic and oxalic, are detected as intermediates. The ultimate product is oxalic acid, which forms very stable Fe(3+)-oxalato complexes under electro-Fenton conditions. These complexes are efficiently photodecarboxylated in photoelectro-Fenton under the action of UVA light. SN - 0045-6535 UR - https://www.unboundmedicine.com/medline/citation/16938340/Degradation_of_clofibric_acid_in_acidic_aqueous_medium_by_electro_Fenton_and_photoelectro_Fenton_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0045-6535(06)00974-X DB - PRIME DP - Unbound Medicine ER -