Nanoscale Iron-Manganese Binary Oxide for As(III) Removal in Synthesized Groundwater

Cost-effective technologies to remove arsenic from high arsenic groundwater are urgently needed for safe water supply in many countries. In this study, a new sorbent of nanoscale iron-manganese binary oxides (NIM) was prepared by an improved co-precipitation method. The as-synthesized adsorbent is amorphous with 280 m2/g surface area and particle size of 10-20nm. For the adsorption of 2 mg/L As(III), the aqueous concentration quickly decreases to less than 10 μg/L within 30 min. During the adsorption of As(III), low concentration of As(V) is measured in aqueous solution in the initial stage and disappeared afterwards, whereas the fraction of As(V) on NIM surface gradually proving the oxidative transformation of As(III) to As(V). Its batch experiment data followed pseudo-second-order kinetics.