Molecular imprinting functionalization of magnetic biochar to adsorb sulfamethoxazole: Mechanism, regeneration and targeted adsorption

Sulfamethoxazole (SMX), a typical medical antibiotic, is regarded as a major risk in the surface hydrosphere because of its harmful biological reaction and potential to trigger bacterial resistance. Ameliorating the hydro-sphere will become more convenient if the challenging adsorption and separation of SMX in hydrosphere are achieved. To reveal the mechanism, regeneration and targeted adsorption of SMX on a novel surface-imprinted polymer (MIP-MBC) and batch experiments were carried out in this study. MIP-MBC was prepared in organic solution using a Fe-Mn-modified biochar to selectively adsorb SMX in a water solution. Owing to the mesopores and oxygen-containing functional groups of MIP-MBC, imprinted cavities in pores are found to lead to a remarkable adsorption efficiency for SMX. The maximum adsorption capacity for SMX reaches up to 25.65 mg g-1 process matches well with the second-order kinetics and Freundlich thermodynamic model, which indicates that hydrogen bonds and electrostatic interactions are simultaneously involved in the adsorption process. After five cycles, the adsorption rate for MIP-MBC reaches 88.34%. Furthermore, MIP-MBC is applied to the binary system to remove SMX, and it can be used to accurately identify and adsorb SMX due to K`> 1 and being independent of the ion concentration. The high affinity site plays a major role in the imprinting process for SMX. This study furnishes a novel perspective for promoting the practical application and economic benefits of targeted biochar material to capture SMX in sewage purification. , which is 1.34 times that of the non-molecularly imprinted magnetic biochar (NIP-MBC). The adsorption