Removal of Arsenic in Aqueous Solutions by Adsorption onto Waste Rice Husk

Abstract

Rice husk has tremendous potential as a remediation material for the removal of arsenic from groundwater. The present work investigates the possibility of the use of rice husk adsorption technology without any pretreatment in the removal of arsenic from aqueous media. Various conditions that affect the adsorption/desorption of arsenic are investigated. Adsorption column methods show the complete removal of both As(III) and As(V) under the following conditions: initial As concentration, 100 μg/L; rice husk amount, 6 g; average particle size, 780 and 510 μm; treatment flow rate, 6.7 and 1.7 mL/min; and pH, 6.5 and 6.0, respectively. The desorption efficiencies with 1 M of KOH after the treatment of groundwater were in the range of 71−96%. The present study might provide new avenues to achieve the arsenic concentrations required for drinking water recommended by Bangladesh and the World Health Organization (WHO).