Kinetic and Equilibrium Studies for Zn (II) and Cu (II) Metal Ions Removal Using Biomass (Rice Husk) Ash

Abstract

Heavy metal ions have the severe hazardous effects on human health even were present in traces in waste water. Conventional methods are not economical for the removal of low level concentration of these ions. The present research reports the adsorption of Cu and Zn ions from aqueous solutions at low concentration range (5-100 mg/L) in batch systems using Rice Husk Ash as an adsorbent, which is abundantly available as agricultural waste. The present study emphasizes on the experimental development of the optimum parameters such as equilibrium time, pH and initial concentration. Equilibrium data obtained have been fitted to the Langmuir, Freundlich, Tempkin and Dubinin - Radushekevich (DR) adsorption isotherms. Freundlich isotherm best fits the experimental results. Kinetic modeling of first order and pseudo-second order showed that the pseudo-second order equation was the most appropriate for the description of Zn (II) and Cu (II) adsorption by Rice Husk Ash.