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Mineralization of cefoperazone in acid medium by the microwave discharge electrodeless lamp irradiated photoelectro-Fenton using a RuO2/Ti or boron-doped diamond anode

Author:
Wen, Zhenjun, Wang, Aimin, Zhang, Yanyu, Ren, Songyu, Tian, Xiujun, Li, Jiuyi
Source:
Journal of hazardous materials 2019 v.374 pp. 186-194
ISSN:
0304-3894
Subject:
activated carbon, ammonium, anodes, carbon fibers, carboxylic acids, cathodes, cefoperazone, electrochemistry, hydrogen peroxide, hydroxyl radicals, iron, mineralization, nitrates, oxidation, pH
Abstract:
The mineralization of 125 mL of 50–300 mg L−1 cefoperazone (CFPZ) has been comparatively studied by electrochemical advanced oxidation processes (EAOPs) like anodic oxidation (AO), electro-Fenton (EF) and photoelectro-Fenton (PEF) with a RuO2/Ti or boron-doped diamond (BDD) anode and an activated carbon fiber (ACF) cathode. A microwave discharge electrodeless lamp (MDEL) was used as the UV source in PEF process. CFPZ decays always followed pseudo-first-order kinetics and their constant rates increased in the order: AO < EF < MDEL-PEF, regardless of anode types. Higher mineralization was achieved in all methods using BDD instead of RuO2/Ti, while the most potent BDD-MDEL-PEF gave 88% mineralization under its optimum conditions of 0.36 A, pH 3.0 and 1.0 mmol L−1 Fe2+. The synergistic mechanisms were explored by quantifying the electrogenerated H2O2 and formed •OH, in which 2.27 and 2.58 mmol L-1 H2O2 were accumulated in AO-H2O2 with RuO2/Ti or BDD anode, respectively, while 92.0 and 263.5 μmol L-1 •OH were generated in EF with RuO2/Ti or BDD anode, respectively. The oxidation power of EAOPs with different anodes was also compared by measuring the evolutions of NO3− and NH4+ as well as four generated carboxylic acids including oxalic, oxamic, formic and fumaric acids.
Agid:
6358790