Investigation on the Adsorption Behaviour of lead (Ii) onto Rice Husk Powder

Abstract

The application of low-cost adsorbents obtained from agricultural wastes as analternate to the conventional methods of removing heavy metalions from waste water has been investigated. Present study deals with the adsorption of lead (II) from aqueous solution on rice husk and it’s chemically modified form. Rice Husk is a by-product generally obtained from rice mill.The Chemically Modified Rice Husk (CMRH) is obtained by treating raw ricehusk with 4M sulfuric acid. Batch studies were performed at an initial concentration of 25 mg/L to evaluate the influence of various parameters like pH,equilibrium time, amount of adsorbent and concentration of adsorbate. Studies showed that pH of aqueous solution affected lead (II)adsorption as a result the removal efficiency increased with increasing pH of the solution.The maximum efficiency was achieved at pH 5.Kinetics and isotherm modeling studies demonstrated that the experimental data best fit a pseudo-second order and Langmuir isotherm model, respectively. The maximum Langmuiradsorption capacity was found to be 143.25 mg/g &133.81 for CMRH and RRH, respectively. Furthermore, the studies showed CMRH was more favorable than RRH for the adsorption of lead (II)from aqueous solution.In summary, biosorption onto rice husk is a low cost, effective and simple process for treating Pb(II) loaded waste water.