title: Weak magnetic field significantly enhances selenite removal kinetics by zero valent iron.
abstract: The effect of weak magnetic field (WMF) on Se(IV) removal by zero valent iron (ZVI) was investigated as functions of pH and initial Se(IV) concentrations. The presence of WMF significantly accelerated Se(IV) removal and extended the working pH range of ZVI from 4.0-6.0 to 4.0-7.2. The WMF induced greater enhancement in Se(IV) removal by ZVI at lower initial Se(IV) concentrations. The influence of WMF on Se(IV) removal by ZVI was associated with a more dramatic drop in ORP and a more rapid release of Fe(2+) compared to the case without WMF. SEM and XRD analysis revealed that WMF accelerated the corrosion of ZVI and the transformation of amorphous iron (hdyr)oxides to lepidocrocite. XANES analyses showed that WMF expedited the reduction of Se(IV) to Se(0) by ZVI at pH 6.0 when its initial concentration was ≤20.0 mg L(-1). Se(IV) dosed at 40.0 mg L(-1) was removed by ZVI via adsorption followed by reduction to Se(0) at pH 7.0 but via adsorption at 7.2 in the presence of WMF. Regardless of WMF, Se(IV) applied at 40.0 mg L(-1) was removed by reduction at pH 4.0-6.0. The WMF-induced improvement in Se(IV) removal by ZVI may be mainly attributable to the Lorentz force and magnetic field gradient force. Employing WMF to enhance Se(IV) removal by ZVI is a 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, PR China; State Key Lab of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, PR China.
authors.forename: Liping
authors.initials: L
authors.lastname: Liang
authors.affiliation: State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, PR China.
authors.forename: Wu
authors.initials: W
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, PR China; State Key Lab of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, PR China. Electronic address: guanxh@tongji.edu.cn.
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Guan
authors.affiliation: Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, PR China.
authors.forename: Yuying
authors.initials: Y
authors.lastname: Huang
authors.affiliation: School of Environmental Science & Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Republic of Korea.
authors.forename: Wonyong
authors.initials: W
authors.lastname: Choi
authors.affiliation: Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, PR China.
authors.forename: Hongliang
authors.initials: H
authors.lastname: Bao
authors.affiliation: Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, PR China.
authors.forename: Lina
authors.initials: L
authors.lastname: Li
authors.affiliation: Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, PR China.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Jiang
mesh_terms: D003343:Corrosion; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000737:chemistry*; D007700:Kinetics; D060526:Magnetic Fields; D010084:Oxidation-Reduction; D020887:Selenious Acid / Q000737:chemistry / Q000302:isolation & purification*; D056928:X-Ray Absorption Spectroscopy; D014961:X-Ray Diffraction
chemical_list: D007501:Iron; D020887:Selenious Acid
keywords: Adsorption; Corrosion; Lepidocrocite; Reduction; Selenium