Removal of Fe2+ and Pb2+ions from wastewater using rice husks-based adsorbents

Abstract

There is an urgent need that all possible sources of inexpensive adsorbents should be explored and their feasibility for the removal of heavy metals. Thus, this study presents application of low-cost adsorbents agro-based wastes, such as rice husk and their utilization possibilities for elimination of heavy metals; Fe (II) and Pb (II) from wastewater by the adsorption process.The adsorption technique was used for the removal of Fe 2+ and Pb2+ in two drains (Khashaa drain and Tera drain) which are discharged into Burullus Lake. The obtained results showed that, the adsorption of the metal ions was adsorbent dosage, adsorbate concentration, contact time and pH dependent. The optimum contact time, adsorbent dosage, and pH were found to be at 105 min, 8 g and pH 8, respectively, for Fe2+ and at 40 min, 8 g and pH 8, respectively, for Pb2+. Freundlich isotherm model was found to be the best fit most suitable for each of heavy metals at R2= 0.96, 0.91. Kinetic studies showed that pseudo-second-order reaction model best described the adsorption process.The results revealed also a good removal of Fe2+ and Pb2+using rice husk under optimum conditions with removal percentage 91.36% and 94.42% for Fe2+, respectively and Pb2+ in Khashaa drain and 93.56% and 90.93% for Fe2+ and Pb2+, respectively in Tera drain. Therefore, the study showed that rice husk can be efficiently used as low cost alternative for removal of metal ions.