Removal of Sulfamethoxazole from Water by Erbium-doped Biological Activated Carbon

Adsorption technology has attracted significant attention in the treatment of antibiotic-containing wastewater due to its advantages of high efficiency and cost-effectiveness. However, how to further enhance the performance of adsorbents and apply them to low-concentration aqueous environments remains a significant research challenge. In this study, a rare earth metal erbium-doped bioactive carbon Er-BC was prepared by molten alkali roasting. By leveraging the unique electronic orbital structure of erbium, the internal pore microenvironment of the material can be effectively regulated, introducing more active sites. Compared with undoped materials, the specific surface area of Er-BC is enhanced by 40.8%, leading to the formation of a multi-level pore structure. This results in a removal efficiency of sulfamethoxazole (SMX) in water as high as 99.6%, with an increase in adsorption capacity by 190.3%. During long-term stable operation, Er-BC was able to reduce trace levels of SMX (1 μg/L) in water to below 0.05 μg/L, demonstrating excellent trace antibiotic removal performance. This study provides a new design strategy for the removal of low-concentration antibiotics from real water bodies using rare-earth-doped modified biological activated carbon.