Kinetic studies on the use of agricultural wastes for the removal of lead, cadmium and nickel ions from aqueous solutions

Onwu F. K., Abii T. A. and Ogb

Abstract

The potential of economically cheap cellulosic materials from two different species of cassava-manihot esculenta cranz (ME) and manihot walkarae (MW) was assessed for Cd(II), Ni(II) and Pb(II) adsorption from aqueous solutions. Batch adsorption experiments were carried out as a function of adsorbent mass and exposure time. Results showed that the percentage removal of the metal ions increased with increasing adsorbent dosage. Kinetic experiments revealed that equilibrium adsorption for the metal ions were reached within 120 min. The pseudo firstorder, pseudo second-order mechanism and Elovich equation were applied to examine the kinetics of the adsorption process. Results showed that kinetic data fitted better into pseudo second-order model than the pseudo first-order and Elovich equations. Results generally showed that the metal ions were considerably adsorbed onto the cassava wastes and this could be considered as an economic method for the removal these metal ions from aqueous solutions.