화학공학소재연구정보센터
Journal of Hazardous Materials, Vol.283, 880-887, 2015
Enhanced paramagnetic Cu2+ ions removal by coupling a weak magnetic field with zero valent iron
A weak magnetic field (WMF) was proposed to enhance paramagnetic Cu2+ ions removal by zero valent iron (ZVI). The rate constants of Cu2+ 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 Cu2+ adsorption to the ZVI surface and the transformation of Cu2+ to Cu by ZVI. The enhanced Cu2+ sequestration by ZVI with WMF was accompanied with expedited ZVI corrosion and solution ORP drop. The uneven distribution of paramagnetic Cu2+ along an iron wire in an inhomogeneous MF verified that the magnetic field gradient force would accelerate the paramagnetic Cu2+ transportation toward the ZVI surface due to the WMF-induced sharp decay of magnetic flux intensity from ZVI surface to bulk Cu2+ solution. The paramagnetic Fe'+ 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 Fe2+, and facilitate the local galvanic corrosion of ZVI, and thus, Cu2+ 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. (C) 2014 Elsevier B.V. All rights reserved.