Rice Polish: An Alternative to Conventional Adsorbents for Treating Arsenic Bearing Water by Up-Flow Column Method

Abstract

“Rice polish”, an agrowaste from rice milling industries, was utilized as potential biosorbent for removal of arsenic from water in a continuous up-flow fixed bed column system. The experiments were conducted to study the effect of important design parameters such as bed height, flow rate, and initial metal ion concentration. At a bed height of 25 cm, flow rate 1.66 mL/min, and initial metal ion concentration 1000 μg/L, the metal uptake capacity of rice polish for As(III) and As(V) was found to be 66.95 and 78.95 μg/g, respectively. The bed depth service time (BDST) model was used to analyze the experimental data. The computed sorption capacity (No) was 28776 and 28248 μg/L for As(III) and As(V), respectively. The rate constant (Ka) was recorded as 0.117 × 10−3 and 0.26 × 10−4 (L/μg)/min for As(III) and As(V), respectively. The column regeneration studies were carried out using 10% NaOH as eluant for three sorption−desorption cycles. The high arsenic removal ability and regeneration efficiency of this bio...