Adsorption of perchlorate using cationic modified rice husk

Perchlorates are highly soluble anions and are used as ingredients in solid rocket fuels, fireworks, missiles, batteries etc. The potential human risk of perchlorate exposures includes effects on nervous system, inhibition of thyroid activity and mental retardation in infants. Various materials and techniques have been used to remove perchlorate from drinking water. For light polluted water of perchlorate, adsorption seems to be one of the most attractive, easiest, safest and cost effective physio-chemical treatment methods especially for drinking water. Rice husk, one of the major bi-products of rice milling industry can be used as a low cost adsorbent for perchlorate removal. Present study deals with adsorption of perchlorate using cationic modified rice husk by optimizing various parameters like pH, adsorbent mass, adsorbate concentration, temperature and time of adsorption. The surface charge is the major governing factor for perchlorate removal compared to surface area. To enhance the adsorption capacities, modifications with cationic surfactants were made. Powdered rice husk was surface modified with Cetyl Trimethyl Ammonium Bromide (CTAB). The adsorption of perchlorate was studied experimentally after surface modifications and the different parameters including pH, adsorbent mass, adsorbate concentration, temperature and time were optimized. The performance of adsorption was found at different conditions and it has been observed that more than 97% adsorption efficiency was achieved in the perchlorate removal.