title: Electrochemical enhanced heterogeneous activation of peroxydisulfate by Fe-Co/SBA-15 catalyst for the degradation of Orange II in water.
abstract: Mesoporous silica SBA-15 supported iron and cobalt catalysts (Fe-Co/SBA-15) were prepared and used in the electrochemical (EC) enhanced heterogeneous activation of peroxydisulfate (PDS, S2O8(2-)) process for the removal of Orange II. The effects of some important reaction parameters such as initial pH, current density, PDS concentration and dosage of Fe-Co/SBA-15 catalysts were investigated. The results showed that the decolorization efficiency was not significantly affected by the initial pH value, and it did increase with the higher PDS concentration, current density and Fe-Co/SBA-15 dosage. Both the sulfate radical (SO4(·-)) and the hydroxyl radical (OH) are considered as the primary reactive oxidants for the Orange II decolorization. The Fe-Co/SBA-15 catalyst maintained its high activity during repeated batch experiments. The intermediate products were identified by GC-MS analysis and a plausible degradation pathway is proposed accordingly. The removal efficiencies of chemical oxygen demand (COD) and total organic carbon (TOC) were 52.1% and 31.9%, respectively after 60 min of reaction time but reached 82.9% and 51.5%, respectively when the reaction time was extended to 24 h. Toxicity tests with activated sludge indicated that the toxicity of the solution increased during the first 30 min and then decreased as the oxidation proceeded.
authors.affiliation: Department of Environmental Engineering, Hubei Biomass-Resource Chemistry and Environmental Biotechnology Key Laboratory, Wuhan University, Wuhan 430079, China.
authors.forename: Chun
authors.initials: C
authors.lastname: Cai
authors.affiliation: Department of Environmental Engineering, Hubei Biomass-Resource Chemistry and Environmental Biotechnology Key Laboratory, Wuhan University, Wuhan 430079, China. Electronic address: eeng@whu.edu.cn.
authors.forename: Hui
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Department of Environmental Engineering, Hubei Biomass-Resource Chemistry and Environmental Biotechnology Key Laboratory, Wuhan University, Wuhan 430079, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Zhong
authors.affiliation: Department of Environmental Engineering, Hubei Biomass-Resource Chemistry and Environmental Biotechnology Key Laboratory, Wuhan University, Wuhan 430079, China.
authors.forename: Liwei
authors.initials: L
authors.lastname: Hou
mesh_terms: D001391:Azo Compounds / Q000737:chemistry*; D001557:Benzenesulfonates / Q000737:chemistry*; D001673:Biodegradation, Environmental; D057919:Biological Oxygen Demand Analysis; D002384:Catalysis; D003035:Cobalt / Q000737:chemistry*; D004396:Coloring Agents / Q000737:chemistry; D004563:Electrochemistry / Q000379:methods*; D008401:Gas Chromatography-Mass Spectrometry; D006863:Hydrogen-Ion Concentration; D017665:Hydroxyl Radical; D007501:Iron / Q000737:chemistry*; D008956:Models, Chemical; D010100:Oxygen / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry*; D013431:Sulfates / Q000737:chemistry*; D014867:Water; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification / Q000379:methods
chemical_list: D001391:Azo Compounds; D001557:Benzenesulfonates; D004396:Coloring Agents; C509969:SBA-15; D013431:Sulfates; D014874:Water Pollutants, Chemical; C069025:sulfate radical; D014867:Water; D017665:Hydroxyl Radical; D003035:Cobalt; D012822:Silicon Dioxide; D007501:Iron; C014722:2-naphthol orange; D010100:Oxygen
keywords: Electrochemical; Fe-Co/SBA-15; Mineralization; Peroxydisulfate; Sulfate radicals