Degradation of organic pollutants by a Co_3O_4 -graphite composite electrode in an electro-Fenton-like system  

作　　者：LIU Shuan GU Yan WANG ShuLian ZHANG Yu FANG YanFen JOHNSON David M HUANG YingPing 

机构地区：[1]Engineering Research Center of Eco-environment in Three Gorges Reservoir Region,Ministry of Education,China Three Gorges University [2]Institute of Oceanology,Chinese Academy of Sciences [3]School of Natural Science & Mathematics,Ferrum College

出　　处：《Chinese Science Bulletin》2013年第19期2340-2346,共7页

基　　金：supported by the National Natural Science Foundation of China (21177072, 21207079);the Educational Commission for Distinguished Group of Hubei Province, China (T200703);the Natural Science Foundation for Innovation Group of Hubei Province, China(2009CDA020)

摘　　要：A novel composite electrode was constructed by pressing together Co3O4 and graphite and it was used as the cathode in an electro-Fenton-like (EFL) system. The poor electron transport characteristic of Co3O4 was overcome by incorporating graphite. In situ electro-catalytic generation of hydroxyl radicals (·OH) occurred at high current efficiencies from pH 2-10, extending the traditional Fenton reaction pH range. Cyclic voltammetry and AC impedance spectrometry were used to characterize the composite electrode. The ability of the EFL system to degrade organic compounds was investigated using sulforhodamine B (SRB) and 2,4-dichlorophenol (2,4-DCP) as probes. Decoloration of SRB (1.0×10-5 mol/L) was complete (100%) in 150 min and SRB was effectively degraded from pH 2-10. The decomposition of SRB was studied using Fourier transform infrared spectroscopy (FT-IR) and total organic carbon (TOC) analysis and results indicated that the final degradation products were carbon dioxide, carboxylic acids and amines. The EFL system also decomposed 2,4-DCP and the degradation was 98.6% in 240 min. Electro-catalytic degradation of SRB occurs by a ·OH mechanism. After 5 times reused, the degradation rate of SRB did not significantly slow down. The electrode shows excellent potential for use in advanced oxidation processes (AOPs) used to treat persistent organic pollutants (POPs) in wastewater.A novel composite electrode was constructed by pressing together Co3O4 and graphite and it was used as the cathode in an electro-Fenton-like （EFL） system. The poor electron transport characteristic of Co3O4 was overcome by incorporating graphite. In situ electro-catalytic generation of hydroxyl radicals （·OH） occurred at high current efficiencies from pH 2-10, extending the traditional Fenton reaction pH range. Cyclic voltammetry and AC impedance spectrometry were used to characterize the composite electrode. The ability of the EFL system to degrade organic compounds was investigated using sulforhodamine B （SRB） and 2,4-dichlorophenol （2,4-DCP） as probes. Decoloration of SRB （1.0×10-5 mol/L） was complete （100%） in 150 min and SRB was effectively degraded from pH 2-10. The decomposition of SRB was studied using Fourier transform infrared spectroscopy （FT-IR） and total organic carbon （TOC） analysis and results indicated that the final degradation products were carbon dioxide, carboxylic acids and amines. The EFL system also decomposed 2,4-DCP and the degradation was 98.6% in 240 min. Electro-catalytic degradation of SRB occurs by a ·OH mechanism. After 5 times reused, the degradation rate of SRB did not significantly slow down. The electrode shows excellent potential for use in advanced oxidation processes （AOPs） used to treat persistent organic pollutants （POPs） in wastewater.

关 键 词：污染物降解 复合电极 L系统 石墨 傅里叶变换红外光谱 FENTON反应 持久性有机污染物 硫酸盐还原菌 

分 类 号：X5[环境科学与工程—环境工程] O643.32[理学—物理化学]