POTENTIAL USE OF MODIFIED RICE HUSK FOR REMEDIATION OF WASTEWATER CONTAINING LEAD IONS

A new method has been developed to reduce the concentration of Pb (II) ions present as inorganic impurities in wastewater streams. This method is based on the silica extracted by alkaline treatment of rice husk to prepare modified rice husk (MRH), used as sorbent. Several parameters (contact time, initial lead concentration, sorbent mass, pH and temperature) were examined. Concurrently removals of lead cation from the aqueous medium were found to be not affected by the presence of different concentrations of nitrate or sulfate ion up to 0.1 M. The two-parameters equilibrium models (Langmuir equations) were determined at various temperatures (35, 45 and 55°C). Adsorption isotherm indicates that the monolayer coverage is 124.3, 230.2 and 396.7 mg Pb2+ ions per g sorbent at 35, 45 and 55°C, respectively. Therefore, the developed rice husk adsorbent is considered a proper sorbent for removal of Pb2+ ions due to its low cost and good efficiency. The ion-exchange reaction on the silica surface is the sorption mechanism of lead ions using modified rice husk (MRH).