Kinetic Isotherms Study of Copper Adsorption from Solutions by a Low-cost Adsorbent

The disposal of industrial pollutants particularly heavy metals into water resources causes damage to the aquatic environment. Copper is a toxic element present in many industrial wastewaters. At high concentrations, it causes severe physiological and health effects for human and other organisms. Adsorption is one of the most widely used processes for wastewater treatment containing heavy metals, because it is an economical, simple, effective and environmental friendly method. Various organic and inorganic low-cost adsorbents have been used for the removal of toxic metals from water and wastewater. The objective of this research is to develop an inexpensive and effective sorbents prepared from compost. The raw and thermal modified compost were examined for copper sorption using batch experiments. Some of physical and chemical properties of adsorbents were determined. The sorption experiments were carried out to investigate the effect of equilibrium time on the copper adsorption. The results showed that the heat treatment of compost increased the removal efficiency of copper. The kinetics of copper adsorption was evaluated using four kinetic models including the pseudo-first-order, the pseudo-second-order, Elvoich equations and intra-particle diffusion. Based on the obtained correlation coefficient (R2), the adsorption of copper ions by the adsorbents was fitted well by the pseudo-second order kinetic model.