Fe(ii) and Mn(ii) removal by Ca(ii)–manganite (γ-MnOOH)-modified red mud granules in water

Abstract

In this study, a material (DLRMG) was synthesized by modifying Ca²⁺ and manganite (γ-MnOOH) on red mud granules (RMG), which were the main raw materials derived from industrial alumina. Moreover, a series of experiments were conducted on the adsorption of Fe²⁺ and Mn²⁺ in underground water. The prepared samples were analyzed by X-ray diffraction (XRD), thermogravimetric analysis-differential thermal analysis (TG-DTA), zeta potential analysis, BET and scanning electron microscopy (SEM); the concentration of the effluent was found to be of acceptable standard after the treatment. DLRMG continued to treat fluoride wastewater even after the saturated adsorption of Fe²⁺ and Mn²⁺, and the results clearly showed that the treatment was effective. Overall, the problems of red mud stockpile and pollution in China would be effectively controlled by DLRMG.