Immobilization of Pb2+ and Cr3+ using bentonite-sulfoaluminate cement composites

Abstract The contamination of Pb and Cr to the environment cannot be ignored. It is an urgent task to explore an efficient and cheap technique to treat Pb and Cr. Bentonite-sulfoaluminate cement composites (Bent-CSA) was prepared to solidify Pb2+ and Cr3+, and their leachability, setting time, and compressive strength were researched in this study. Then the hydration products were analyzed via XRD and SEM. The results show that Bent-CSA immobilized Pb2+ and Cr3+ efficiently, the compressive strength was slightly affected by Pb2+ and Cr3+, but that gradually decreased as bentonite content increased. Bent-CSA could be reused as foundation cushion and roadbed materials after solidifying Pb2+ and Cr3+.