Three-dimensional composite hydrogel based on polyamine zirconium oxide, alginate and tannic acid with high performance for Pb(II), Hg(II) and Cr(VI) trapping

In this study, preparation of multifunctional polymer hydrogels (Zr-DETA/TS) was achieved via organic inorganic crosslinking to form three-dimensional network structure for application of Pb2+, Hg2+ and CrO42- extraction. The equilibrium data of Pb2+, Hg2+ and CrO42- were best described by the Langmuir isotherm, and the kinetic data were found to follow the pseudo-second-order kinetic model. It was notable that ionic exchange and complexation were the main adsorption mechanism for Pb2+ and Hg2+ while electrostatic attraction, inner-sphere complex and esterification played an important role in CrO42- adsorption. Thus, Zr-DETA/TS hydrogels could be used as a promising biomaterial for Pb2+, Hg2+ and CrO42- removal from wastewaters. (C) 2016 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.