Removal of heavy metals from aqueous solution using porous (Styrene-divinylbenzene)/CuNi bimetallic nanocomposite microspheres

Abstract

The existence of elevated heavy metals concentrations in aqueous resources raised a problem of worldwide concern because of their toxic, bio-accumulating and non-biodegradable character. The presence of these heavy metals beyond the allowable limit can cause serious health hazards to humans and animals. Recent advances in nanotechnology have explored the use of bimetallic nanoparticles as an adsorbent in drinking water treatment systems and have received increasing interest. In the present study, a novel Porous(Styrene-divinylbenzene)/CuNi bimetallic nanocomposite microsphere was synthesised and a series of batch scale adsorption experiments were conducted to investigate the adsorption characteristics of Pb2+, Cd2+, Mn2+ and Zn2+. The effects of contact time, pH, adsorbent mass and initial metal concentration on the adsorption characteristics of adsorbent was explored. The results revealed that the removal efficiency of adsorbent increased with increase in contact time and adsorbent mass, and decreased with increase in initial metal concentration. Significant variations in adsorption were observed for different heavy metals and the highest adsorption was achieved for zinc and manganese. With increasing pH of the solution from 3 to 7, the removal percentage of all heavy metals were increased and the experimental maximum adsorption capacity of adsorbent was 15.60 mg Pb(II)/g, 5.28 mg Cd(II)/g, 22.42 mg Mn(II)/g and 20.57 mg Zn(II)/g respectively. Batch experiments indicate that the pseudo-first-order kinetic model is more appropriate to explain the adsorption kinetics and the Langmuir adsorption isotherm was closely fits to experimental data than the Freundlich model. It can be concluded therefore that Porous(Styrene-divinylbenzene)/CuNi bimetallic nanocomposite microspheres have great potential for removing heavy metals from water.