An activated carbon fiber cathode for the degradation of glyphosate in aqueous solutions by the Electro-Fenton mode: Optimal operational conditions and the deposition of iron on cathode on electrode reusability.
An activated carbon fiber (ACF) cathode was fabricated and used to treat glyphosate containing wastewater by the Electro-Fenton (EF) process. The results showed that glyphosate was rapidly and efficiently degraded and the BOD5/COD ratio was increased to >0.3 implying the feasibility of subsequent treatment of the treated wastewater by biological methods. The results of ion chromatography and HPLC measurements indicated that glyphosate was completely decomposed. Effective OH generation and rapid recycling/recovery of the Fe2+ions at the cathode were responsible primarily for the high performance of the ACF-EF process. Factors such as inlet oxygen gas flow rate, Fe2+dosage, initial glyphosate concentration, applied current intensity, and solution pH that may affect the efficiency of the ACF-EF process were further studied and the optimum operation condition was established. Results of SEM/EDX, BET and XPS analysis showed the deposition of highly dispersed fine Fe2O3particles on the ACF surface during the EF reaction. The possibility of using the Fe2O3-ACF as iron source in the EF process was assessed. Results showed that the Fe2O3-ACF electrode was effective in degrading glyphosate in the EF process. The deposition of Fe2O3particles on the ACF electrode had no adverse effect on the reusability of the ACF cathode.
Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Science, Beijing 100085, China.
Huachun
H
Lan
Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Science, Beijing 100085, China.
Wenjing
W
He
Department of Municipal & Environmental Engineering, School of Civil Engineering, Beijing Jiaotong University, China.
Aimin
A
Wang
Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Science, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China. Electronic address: liuruiping@rcees.ac.cn.
Ruiping
R
Liu
State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Huijuan
H
Liu
Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Science, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Jiuhui
J
Qu
Department of Civil and Environmental Engineering, University of Delaware, 352 Du Pont Hall, Newark, DE 19716, USA. Electronic address: huang@udel.edu.
C P
CP
Huang
D002606:Charcoal; D004566:Electrodes; D006861:Hydrogen Peroxide / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D010084:Oxidation-Reduction; D014874:Water Pollutants, Chemical / Q000737:chemistry
D014874:Water Pollutants, Chemical; D002606:Charcoal; D006861:Hydrogen Peroxide; D007501:Iron
Activated carbon fiber (ACF); Electro-Fenton; Electrode reusability; Glyphosate