Rotten sugarcane bagasse derived biochars with rich mineral residues for effective Pb (II) removal in wastewater and the tech-economic analysis

Background: Bio-waste derived biochars represent a group of low-cost and effective materials to achieve the removal of the heavy metal ions from polluted water bodies. Methods: Rotten sugarcane bagasse was firstly adopted as raw material to prepare low cost biochars based on a molten salt method for the heavy metal ion removal. Significant findings: The optimized rotten sugarcane bagasse derived biochars (RB-C) demonstrates maximum Pb2+ adsorption capacity of 339 mg g(-1), which is greatly enhanced from the bio-chars prepared from fresh bagasse (172 mg g(-1)). In addition, the RB-C shows high efficiency for the treatment of the simulated wastewater with multiple metal ions. Based on the mechanism studies, these improved absorption performances are possibly derived from the surface physical sorption and static electron interaction due to the enhanced specific surface area (391.9 m 2 g(-1)), increased pore diameter (20.9 nm) and well-developed hierarchical porous structure. Moreover, the RB-C exhibits rich mineral contents, which could further enhance the adsorption performances taking advantage of the ion exchange. In addition, the tech-economic assessment indicated the cost of RB-C ($ 2.39 kg(-1)) is comparable with the commercial active carbon, which endows rotten bagasse a abundant raw material to prepare low cost adsorbent with high performance to remove heavy metal ions from aquatic environment. (C) 2022 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.