Preparation of a novel MnO2/red mud composites to enhance arsenic removal.

Red mud (RM), an industrial solid waste generated by the alumina industry, is rich in Fe 2 O 3 , Al 2 O 3 , and SiO 2 , and has excellent potential for use as a cheap and economical support and as an adsorbent. In this work, a co-precipitation method was used to load MnO 2 on RM as an adsorbent (MnRM) to remove As(V) and As(III) from water. The aim was to fully utilize the oxidative properties of MnO 2 and the adsorption capacity of Fe-Al oxides/hydroxides in RM to enhance the As(V) and As(III) capacity in water. The experimental data proved that the adsorption performance of MnRM was much better with adsorption capacities of 31.57 mg/g and 39.32 mg/g for As(V) and As(III), which were 11.29 and 5.71 times higher than that of the raw RM, respectively. Meanwhile, the adsorption capacities of MnRM were also much higher than that of MnO 2 for As(V) (18.90 mg/g) and As(III) (27.97 mg/g). The excellent adsorption performance of MnRM makes it ideal for the treatment of As(V) and As(III) contaminated wastewater. [Display omitted] [ABSTRACT FROM AUTHOR]