Separation of heavy metals from water samples using anion exchange polymers by adsorption process

Abstract

The present study focuses the efficiency of an anion exchange polymer for the adsorption of different heavy metal ions from water samples. Solutions with different concentrations of the heavy metals were prepared and the efficiency of the ionomer in separation of the metals was evaluated by adsorption technique. Quaternized poly styrene ethylene butylene poly styrene (QAPSEBS) was used as the ionomer and it was prepared by two step method, viz. chloromethylation and amination. The membrane was prepared by solution casting method using an appropriate solvent. There are various factors affecting the metal ion adsorption on the polymer membrane such as metal ion concentration, pH, treatment time and temperature were studied. From the results obtained, it was found that the percentage adsorption increased with (a) increase in the metal ion concentration, (b) increase in the treatment time up to 2 h after which it levels off, (c) decrease in temperature from 75 °C to 35 °C. In addition to that, the effect of extent of amination of the polymer membrane was also examined. The polymer membrane was characterized using FT-IR, 1H-NMR, DSC, TGA, XRD and SEM. The results revealed that the polymer membrane showed high efficiency in adsorption for Cr(VI) ion rather than removal of Cu(II) and Ni(II) ions.