Removal of heavy metals from water using polyvinylamine by polymer-enhanced ultrafiltration and flocculation

This study deals with the removal of heavy metals (i.e., Co (II), Cu (II), Ni (II), Pb (II), Fe (III), Cd (II), Zn (II) and Mn (II)) from water with polymer-enhanced ultrafiltration using polyvinylamine (PVAm) as a complexing agent. At a PVAm dosage of 0.1 wt%, metal rejections as high as over 99% were achieved for Pb (II), Cu (H) and Fe (III). The coordination interactions between PVAm and the heavy metals were investigated using UV-vis spectral and conductometric analyses. It was shown that the performance of PEUF for metal rejection was related to the coordination interactions between PVAm and the heavy metals. It was also found that when divalent sulfate anions were present, the PVAm-metal complexes precipitated out of the solution at high metal concentrations. Thus PVAm could also be used as a flocculant for metal removal by flocculation. (C) 2015 Elsevier B.V. All rights reserved.