Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
4980082 | Journal of Hazardous Materials | 2017 | 10 Pages |
Abstract
The degradation of 4-hydroxyphenylacetic acid, a ubiquitous component of olive oil mill wastewater (OOMW), has been studied by anodic oxidation with electrogenerated H2O2 (AO-H2O2), electro-Fenton (EF) and photoelectro-Fenton (PEF). Experiments were performed in either a 0.050Â M Na2SO4 solution or a real OOMW at pH 3.0, using a cell with a boron-doped diamond (BDD) anode and an air-diffusion cathode for H2O2 generation. Hydroxyl radicals formed at the BDD surface from water oxidation in all processes and/or in the bulk from Fenton's reaction between added Fe2+ and generated H2O2 in EF and PEF were the main oxidants. In both matrices, the oxidation ability of the processes increased in the order AO-H2O2Â <Â EFÂ <Â PEF. The superiority of PEF was due to the photolytic action of UVA radiation on photosensitive by-products, as deduced from the quick removal of Fe(III)-oxalate complexes. The effect of current density and organic content on the performance of all treatments was examined. 4-Hydroxyphenylacetic acid decay obeyed a pseudo-first-order kinetics. The PEF treatment of 1.03Â mM 4-hydroxyphenylacetic acid in 0.050Â M Na2SO4 allowed 98% mineralization at 360Â min even at low current density, whereas 80% mineralization and a significant enhancement of biodegradability were achieved with the real OOMW.
Keywords
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Physical Sciences and Engineering
Chemical Engineering
Chemical Health and Safety
Authors
Nelly Flores, Pere LluÃs Cabot, Francesc Centellas, José Antonio Garrido, Rosa MarÃa RodrÃguez, Enric Brillas, Ignasi Sirés,