Removal of sulfamethoxazole from water by biosurfactant-modified sludge biochar: Properties and mechanism

With industrialization and urbanization accelerating, water pollution, especially from pharmaceuticals like sulfamethoxazole, has become a major global issue. The widespread use of sulfamethoxazole has increased its concentration in water bodies, posing serious threats to ecosystems and human health. Thus, developing efficient and cost-effective removal methods is urgently needed. The aim of this study was to synthesize and evaluate a biosurfactant modified sludge biochar to enhance its ability to remove sulfamethoxazole from wastewater. Sludge was used as raw material and modified sludge biochar was obtained by pyrolysis and biosurfactant modification. The effects of different pH, initial concentration of sulfamethoxazole and the amount of modified sludge biochar on sulfamethoxazole adsorption were investigated by batch adsorption experimental system and the adsorption mechanism was discussed. The modified biochar was characterized using techniques such as Fourier transform infrared spectroscopy. The maximum adsorption capacity of modified sludge biochar on sulfamethoxazole reached 43.61 mg/g. The biosurfactant modification significantly altered the pore structure and surface functional groups of the biochar, which improved the adsorption capacity of sulfamethoxazole. Both physisorption and chemisorption played an important role in the adsorption process. The results of this study provide a potential solution for the treatment of pollutants in water bodies.