Development of nano-composite adsorbent for removal of heavy metals from industrial effluent and synthetic mixtures; its conducting behavior

Abstract

A semi-crystalline stable composite cation exchange adsorbent for the treatment of heavy metal ions has been synthesized at pH 1.0 by sol–gel method which was characterized by FTIR, XRD, SEM, TGA and TEM analysis. Ion exchange capacity, pH titration, elution behavior and distribution studies were also carried out to determine the primary ion-exchange characteristics of the material. The material shows exchange capacity of 1.47meqg−1 (for Na+ ions). The composite material exhibits improved ion-exchange capacity, chemical and thermal stability. It can be used up to 200°C with 88% retention of initial ion-exchange capacity. pH titration data reveal its bifunctional behavior. The distribution coefficient values (Kd) of metal ions have been determined in various solvent systems. On the basis of Kd values the material was selective for Ba(II), Hg(II), and Pb(II) ions. The limit of detection (LOD) and the limit of quantification (LOQ) for Pb(II) was found to be 0.97 and 2.93μgL−1, respectively. A number of important and analytically difficult quantitative separations of metal ions have been achieved using columns packed with this exchanger. The composite cation exchanger is applied for the treatment of sewage water and synthetic mixture successfully and can be used as a conducting material.