title: Enhanced paramagnetic Cu²⁺ ions removal by coupling a weak magnetic field with zero valent iron.
abstract: A weak magnetic field (WMF) was proposed to enhance paramagnetic Cu(2+) ions removal by zero valent iron (ZVI). The rate constants of Cu(2+) removal by ZVI with WMF at pH 3.0-6.0 were -10.8 to -383.7 fold greater than those without WMF. XRD and XPS analyses revealed that applying a WMF enhanced both the Cu(2+) adsorption to the ZVI surface and the transformation of Cu(2+) to Cu(0) by ZVI. The enhanced Cu(2+) sequestration by ZVI with WMF was accompanied with expedited ZVI corrosion and solution ORP drop. The uneven distribution of paramagnetic Cu(2+) along an iron wire in an inhomogeneous MF verified that the magnetic field gradient force would accelerate the paramagnetic Cu(2+) transportation toward the ZVI surface due to the WMF-induced sharp decay of magnetic flux intensity from ZVI surface to bulk Cu(2+) solution. The paramagnetic Fe(2+) ions generated by ZVI corrosion would also accumulate at the position with the highest magnetic flux intensity on the ZVI surface, causing uneven distribution of Fe(2+), and facilitate the local galvanic corrosion of ZVI, and thus, Cu(2+) reduction by ZVI. The electrochemical analysis verified that the accelerated ZVI corrosion in the presence of WMF partly arose from the Lorentz force-enhanced mass transfer.
authors.affiliation: State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, PR China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Jiang
authors.affiliation: State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, PR China.
authors.forename: Junlian
authors.initials: J
authors.lastname: Qiao
authors.affiliation: Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong, China.
authors.forename: Irene M C
authors.initials: IM
authors.lastname: Lo
authors.affiliation: State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, PR China.
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, PR China. Electronic address: guanxh@tongji.edu.cn.
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Guan
authors.affiliation: Institute of Materials Science, School of Material Science and Engineering, Shanghai University, Shanghai, PR China.
authors.forename: Zhanpeng
authors.initials: Z
authors.lastname: Lu
authors.affiliation: State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, PR China.
authors.forename: Gongming
authors.initials: G
authors.lastname: Zhou
authors.affiliation: School of Environmental Science and Engineering, Shandong University, Jinan, Shandong, PR China.
authors.forename: Chunhua
authors.initials: C
authors.lastname: Xu
mesh_terms: D000327:Adsorption; D003300:Copper / Q000737:chemistry*; D003343:Corrosion; D007501:Iron / Q000737:chemistry*; D060526:Magnetic Fields; D012996:Solutions; D014874:Water Pollutants, Chemical / Q000737:chemistry
chemical_list: D012996:Solutions; D014874:Water Pollutants, Chemical; D003300:Copper; D007501:Iron
keywords: Adsorption; Heavy metal; Mass transfer; Reduction; Zero valent iron