title: Activating persulfate by Fe⁰ coupling with weak magnetic field: performance and mechanism.
abstract: Weak magnetic field (WMF) and Fe(0) were proposed to activate PS synergistically (WMF-Fe(0)/PS) to degrade dyes and aromatic contaminants. The removal rates of orange G (OG) by WMF-Fe(0)/PS generally decreased with increasing initial pH (3.0-10.0) and increased with increasing Fe(0) (0.5-3.0 mM) or PS dosages (0.5-3.0 mM). Compared to its counterpart without WMF, the WMF-Fe(0)/PS process could induce a 5.4-28.2 fold enhancement in the removal rate of OG under different conditions. Moreover, the application of WMF significantly enhanced the decolorization rate and the mineralization of OG. The degradation rates of caffeine, 4-nitrophenol, benzotriazole and diuron by Fe(0)/PS were improved by 2.1-11.1 fold due to the superimposed WMF. Compared to many other sulfate radical-based advanced oxidation technologies under similar reaction conditions, WMF-Fe(0)/PS technology could degrade selected organic contaminants with much greater rates. Sulfate radical was identified to be the primary radical species responsible for the OG degradation at pH 7.0 in WMF-Fe(0)/PS process. This study unraveled that the presence of WMF accelerated the corrosion rate of Fe(0) and thus promoted the release of Fe(2+), which induced the increased production of sulfate radicals from PS and promoted the degradation of organic contaminants. Employing WMF to enhance oxidation capacity of Fe(0)/PS is a novel, efficient, promising and environmental-friendly method since it does not need extra energy and costly reagents.
authors.affiliation: State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Department of Civil Engineering of Jiujiang College, Jiujiang 332005, Jiangxi, PR China.
authors.forename: Xinmei
authors.initials: X
authors.lastname: Xiong
authors.affiliation: State Key Lab of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, PR China.
authors.forename: Bo
authors.initials: B
authors.lastname: Sun
authors.affiliation: State Key Lab of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, PR China.
authors.forename: Jing
authors.initials: J
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China.
authors.forename: Naiyun
authors.initials: N
authors.lastname: Gao
authors.affiliation: State Key Lab of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, PR China.
authors.forename: Jimin
authors.initials: J
authors.lastname: Shen
authors.affiliation: State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China.
authors.forename: Jialing
authors.initials: J
authors.lastname: Li
authors.affiliation: State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China. Electronic address: guanxh@tongji.edu.cn.
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Guan
mesh_terms: D001391:Azo Compounds / Q000302:isolation & purification; D002110:Caffeine / Q000302:isolation & purification; D003116:Color; D004237:Diuron / Q000302:isolation & purification; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000737:chemistry*; D007700:Kinetics; D060526:Magnetic Fields; D008903:Minerals / Q000737:chemistry; D009596:Nitrophenols / Q000302:isolation & purification; D013431:Sulfates / Q000737:chemistry*; D014230:Triazoles / Q000302:isolation & purification; D014874:Water Pollutants, Chemical / Q000302:isolation & purification
chemical_list: D001391:Azo Compounds; D008903:Minerals; D009596:Nitrophenols; D013431:Sulfates; D014230:Triazoles; D014874:Water Pollutants, Chemical; C008710:Orange G; D002110:Caffeine; C012771:benzotriazole; D004237:Diuron; D007501:Iron; C024836:4-nitrophenol
keywords: Emerging contaminants; Orange G; Phenolic compounds; Sulfate radicals; Weak magnetic field