Removal of arsenic from aqueous solution by granular modified natural siderite: Characterization and behavior

Iron-based minerals have been the focus of sorbents for arsenic removal due to their low cost and high uptake capacity. Granular Modified Natural Siderite (GMNS) was prepared by siderite power after granulation and calcination in this study. The optimal modified product for arsenic removal was developed under various modified conditions. The sorbents were characterized by powder XRD, BET surface areas measurement, SEM, and Fe K-edge XANES. Results indicated that the optimal GMNS with about seven times larger surface area than natural siderite was amorphous, with the coexistence of iron (Fe-II) and iron (Fe-III) spherical particles on the surface, which were believed to contribute to the high performance of arsenic removal. GMNS appears to be a promising sorbent that is worthy of further studies and practical application for arsenic removal.