Ion-imprinted silica gel and its dynamic membrane for nickel ion removal from wastewaters

An ion-imprinted sorbent (IIP) was prepared by using Ni²⁺ as template, 3-2-(2-aminoethylamino) ethylamino] propyl-trimethoxysilane as functional monomer, and silica gel as carrier. The adsorption performance of IIP towards Ni²⁺ was investigated. IIP showed a higher adsorption capacity than that of non-imprinted sorbent, and it also exhibited high selectivity for Ni²⁺ in the presence of Cu²⁺ and Zn²⁺ ions. Then, IIP was used to form a dynamic membrane onto the surface of ceramic membrane for treatment of electroplating wastewater containing Ni²⁺. Compared with ceramic membrane, IIP dynamic membrane had much higher steady membrane flux, and also rejected Ni²⁺ to obtain a lower concentration of Ni²⁺ in the permeate fluid. Perhaps it is suitable for future practice applications.