Removal of hazardous metal ions from wastewater by radiation synthesized silica-graft-dimethylaminoethyl methacrylate adsorbent

Silica-based adsorbent was prepared by radiation-induced grafting of dimethylaminoethyl methacrylate (DMAEMA) onto silanized silica (SS). The SS was pre-irradiated by electron beam (EB) and then reacted with DMAEMA solution at various conditions. The FTIR and TG-DTA spectra manifested that DMAEMA was successfully grafted onto the SS surface. Three kinds of typical hazardous metal ions (Cr (VI), As (V) and Hg (II)) were used to evaluate the adsorption properties of the resultant silica-based adsorbent. The adsorbent possessed sound Cr (VI) and As (V) adsorption ability as anion ion-exchange resin, and a particular selective adsorption for Hg (II) ions was found among other divalent cationic metal ions. The adsorptions of Cr (VI), As (V) and Hg (II) fitted with Langmuir mode, and their adsorption kinetics fitted well with pseudo-second-order model. These results suggested that SS-g-DMAEMA adsorbent has potential application for the removal of hazardous metal pollutants from wastewater. (C) 2011 Elsevier B.V. All rights reserved.