Removal of Zn(II) from water by adsorption on China clay

Abstract

The efficiency of china clay as an adsorbent for the removal of Zn(II) from water has been determined at different concentrations, temperatures and pH of the solutions. The kinetic studies of adsorption indicate the process to be diffusion controlled and the intraparticle transport of Zn(II) within the pores of china clay is found to be the rate limiting step. Equilibrium data at different temperatures follow Langmuir model of adsorption. Thermodynamic parameters for the present system indicates spontaneous and endothermic nature of adsorption. The maximum removal (95%) is observed at pH 8.0 and temperature 40°C with initial concentration 1.53 × 10^‐4M. The variation in adsorption with pH has been explained on the basis of surface ionisation and complexation.