Removal of Hexavalent Chromium from Aqueous Solution Using Activated Taro Residue Carbon as an Adsorbent

Abstract

Hexavalent chromium, Cr (VI) is one of the major heavy metals of great concern in aqueous solution. Its removal from aqueous solution is crucial for environmental protection. In this study, the adsorption of Cr (VI) from an aqueous solution by preparing Activated Taro Residue Carbon (ATRC) was investigated. ATRC was characterized in terms of moisture content, ash content, volatile matter, x-ray diffraction, and FTIR. Batch adsorption experiments were used to study the efficiency of the adsorbent for the removal of Cr (VI). Different parameters as batch studies with different contact times, pH, adsorbent dose, and initial metal ion concentration were studied and the optimal conditions were established. The established optimal conditions include 180 min contact time, 5 g/L adsorbent dose, 5 mg/L initial metal concentration and pH 2. The percentage removal of Cr(VI) increased with increasing adsorbent dose from 1 to 10 g/L and contact time from 10 to 420 min and also decreased when the initial metal concentration increased from 1 to 50 mg/L. Freundlich isotherm model showed a better fit to the equilibrium data than the Langmuir model. The kinetics of adsorption for Cr(VI) was well represented by the pseudo-second order kinetic model. In the batch experiment the adsorption capacity Cr(VI) from aqueous solution using activated taro residue carbon as an adsorbent was around 8.93 mg/g and also the desorption studies of the adsorbent was examined. ATRC can be employed as an effective adsorbent and substitute for commercially available activated carbon for the removal of Cr(VI) from an aqueous solutions.