Pb(II) Removal from Aqueous Solution by using Chemically Treated Rice Straw

Abstract

Rice straw was used as an adsorbent for the removal of lead ions from aqueous solutions through batch equilibrium technique to find out the effectiveness of lead removal. From the characterization of adsorbents by using FT-IR spectra, untreated rice straw and treated rice straw reveals a number of bands centered at about 791.39, 1039.93, 1318.60, 1623.96, 2918.68 and 3323.01 cm-1.The effect of contact time, adsorbent dosage, initial concentration and pH on adsorbed amount of lead ions were also investigated. Treated rice straw attained equilibrium time at 60 min. The studies also shows the adsorption of lead ions was strongly affected by pH. The treated rice straw exhibited the highest lead removal, 91.90% at pH 8. Meanwhile, untreated rice straw and commercial activated carbon percentage removal is 73.51% and 100% of lead ions at pH 8 respectively. Kinetic for the adsorption of lead on untreated rice straw, treated rice straw and commercial activated carbon were developed using the Pseudo First-order and Pseudo Second-order kinetic model. The equilibrium data from the adsorption of lead fitted well to the Pseudo Secondorder kinetic model. The correlation coefficient, R22 obtained from the kinetic studies gave the value of 0.9987.