Biosorption of rare earth metal ion on aerobic granules

Aerobic granules are microbial aggregates possessing excellent settling ability and high-porosity structure. In this study, aerobic granules as a novel type of biosorbent were used for cerium's removal from aqueous solution simulating the polluted industrial wastewater. Batch trials were conducted at different initial cerium ion and granule concentration. Biosorption kinetics was also studied. The biosorption conformed to a first-order kinetics model. The results showed that the biosorption ability of aerobic granules was related to both initial cerium ion and granule concentration. The maximum biosorption capacity of cerium by aerobic granules was 357 mg g(-1) granules. The aerobic granules were settled down by gravity from the aqueous solution in one minute after the biosorption experiments. Thus, the post-separation of the conventional suspended biosorbents from the treated effluent could be ignored in the aerobic granule-based biosorption process. All the results confirmed the technical feasibility of the biosorption process by aerobic granules.