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Indexed by:期刊论文

Date of Publication:2010-07-01

Journal:JOURNAL OF ENVIRONMENTAL SCIENCES

Included Journals:SCIE、EI、PubMed、ISTIC、CSCD

Volume:22

Issue:4

Page Number:500-506

ISSN No.:1001-0742

Key Words:degradation; cathodic reduction; anodic oxidation; sequential electrolysis

Abstract:The electrochemical degradation of p-nitrophenol (PNP) under different conditions was investigated. The electrochemical behavior of PNP and its reduction product p-aminophenol (PAP) on stainless steel cathode and Ti/Pt anode through cyclic voltammetry were observed. Electrochemical. degradation process was performed in an undivided cell and 92% PNP was removed corresponding to a 22% total organic carbon removal. A divided cell was also used and it was found that PNP degradation was mainly attributed to cathodic reduction, while anodic oxidation was responsible for PNP removal due to the reaction with hydroxyl radicals and surface oxide generated on the anode. The sequential electrolytic processes, reduction-oxidation and oxidation-reduction, were compared in the divided cell. In the case of reduction-oxidation process, the total organic carbon removal reached 40%, but PNP removal was the same with the undivided cell. A black deposit was found in the effluent and identified by Fourier transform infrared spectroscopy as a polymer of PAP produced by the 1,4-addition reaction of quinoneimine. Intermediates left in the solution such as hydroquinone, p-benzoquinone and PAP were determined by high performance liquid chromatography. Whereas, the oxidation-reduction process proved unsatisfying.