Arsenate Removal from Aqueous Solutions Using Modified Red Mud (MRM) and Pillared Clay (PILC) Complex

Red mud (RM), a waste tailing from alumina production, (as an important environmental problem), can be used as a strong absorbent pollutant. In this study, the modified red mud (MRM) and pillared clay (PILC) were used for the removal of arsenate from water. The modified red mud (MRM) and PILC complex were characterized using XRD, SEM and XRF microanalysis. The adsorption of arsenate on modified red mud (MRM) and PILC complex was studied as a function of pH, time, and temperature by AAS method. The maximum adsorption efficiency reached 98.86% when the pH was 3.5 at 40°C. The uptake of arsenate ions as a function of time and the results clearly indicated that the adsorption of arsenate ions reached equilibrium within 60 min. Langmuir and Freundlich isotherms equation were used to fit the adsorption isotherms. The Langmuir isotherm was the best-fit adsorption isotherm model for the experimental data. It is evident from this study that red mud and pillared clay complex has been found to be efficient for the removal of various aquatic pollutants, especially arsenic and its compounds.