Porous biochar composite assembled with ternary needle-like iron-manganese-sulphur hybrids for high-efficiency lead removal

Hierarchical porous biochar derived from corn straw containing ternary needle-like iron-manganese-sulphur composites ([email protected]) are fabricated, and their physicochemical characteristics and performance for Pb removal were examined in detail. Introduction of Mn (transition metal) into Fe-biochar composites can effectively alter the chemical state of Fe; simultaneous doping with S can enhance cation exchange for Pb removal. High uptake of Pb by [email protected] in a short time period was observed with the adsorption capacity of 181.5 mg g−1 and the pseudo-second-order rate constant of 0.075 g mg-1 h−1. Complexation, reduction, and precipitation were found to be involved in the Pb removal by [email protected] based on the results of HRTEM, XPS, and XRD analyses. This study demonstrated the feasibility of Fe-Mn-S biochar composites for high-efficiency Pb removal from aqueous solution.