title: Enhancement effects of chelating agents on the degradation of tetrachloroethene in Fe(III) catalyzed percarbonate system.
abstract: The performance of Fe(III)-based catalyzed sodium percarbonate (SPC) for stimulating the oxidation of tetrachloroethene (PCE) for groundwater remediation applications was investigated. The chelating agents citric acid monohydrate (CIT), oxalic acid (OA), and Glutamic acid (Glu) significantly enhanced the degradation of PCE. Conversely, ethylenediaminetetraacetic acid (EDTA) had a negative impact on PCE degradation, which may due to its strong Fe chelation and HO•scavenging abilities. However, excessive SPC or chelating agent will retard PCE degradation. In addition, investigations using free radical probe compounds and radical scavengers revealed that PCE was primarily degraded by HO•radical oxidation in both the chelated and non-chelated systems, while O2•-also participated in the non-chelated system and the OA and Glu modified systems. According to the electron paramagnetic resonance (EPR) studies, the presence of HO•in the Fe(III)/SPC system was maintained much longer than that in the Fe(II)/SPC system. The results indicated that the addition of CIT, OA or Glu indeed enhanced the generation of HO•in the first 10 min and promoted degradation efficiency by increasing the amount of Fe(III) and maintaining the concentration of HO•radicals in solution. In conclusion, chelated Fe(III)-based catalyzed SPC oxidation is a promising method for the remediation of PCE-contaminated groundwater.
authors.affiliation: State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, East China University of Science and Technology, Shanghai 200237, China ; Soil, Water and Environmental Science Department, School of Earth and Environmental Sciences, The University of Arizona, 429 Shantz Bldg., Tucson, AZ 85721.
authors.forename: Zhouwei
authors.initials: Z
authors.lastname: Miao
authors.affiliation: State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, East China University of Science and Technology, Shanghai 200237, China.
authors.forename: Xiaogang
authors.initials: X
authors.lastname: Gu
authors.affiliation: State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, East China University of Science and Technology, Shanghai 200237, China.
authors.forename: Shuguang
authors.initials: S
authors.lastname: Lu
authors.affiliation: Soil, Water and Environmental Science Department, School of Earth and Environmental Sciences, The University of Arizona, 429 Shantz Bldg., Tucson, AZ 85721.
authors.forename: Mark L
authors.initials: ML
authors.lastname: Brusseau
authors.affiliation: State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, East China University of Science and Technology, Shanghai 200237, China.
authors.forename: Xiang
authors.initials: X
authors.lastname: Zhang
authors.affiliation: State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, East China University of Science and Technology, Shanghai 200237, China.
authors.forename: Xiaori
authors.initials: X
authors.lastname: Fu
authors.affiliation: State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, East China University of Science and Technology, Shanghai 200237, China.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Danish
authors.affiliation: State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, East China University of Science and Technology, Shanghai 200237, China.
authors.forename: Zhaofu
authors.initials: Z
authors.lastname: Qiu
authors.affiliation: State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, East China University of Science and Technology, Shanghai 200237, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Sui
keywords: Chelating agents (CAs); Groundwater remediation; Hydroxyl radical (HO•); Sodium percarbonate (SPC); Tetrachloroethene (PCE)