Sustainable remediation of antibiotic contaminants using engineered biochar and composite materials

Antibiotic contamination is a growing global crisis due to widespread use and unregulated disposal, contributing to the proliferation of antibiotic-resistant microbes and ecological risks. This review critically evaluates antibiotic contamination and its impact on the environment and human health. Biochar and modified biochar modulate antibiotic resistance gene (ARG) dynamics and the destruction of ARG transfer. Optimization of biochar properties includes surface chemistry, structure, synthesis process, and surface engineering to enhance antibiotic adsorption and degradation. Therefore, a comprehensive evaluation of biochar and modified biochar for the adsorption and degradation of different antibiotics under diverse water and soil chemistry conditions is needed. The key factors influencing biochar/engineered biochar performance include pyrolysis temperature, chemical modifications, pH, contact time, and initial antibiotic concentration. Also, machine learning can be used to evaluate the binding mechanism of antibiotic molecules to biochar/artificial biochar surfaces and predict their use in pilot-scale wastewater treatment. The adsorption mechanism of antibiotics on biochar/artificial biochar surfaces has been deliberated. Other antibiotic degradation mechanisms, different degradation pathways, and developed intermediates are explored. Thus, the studies have indicated that the adsorption capacity of the designed biochar could reach 552 mg g⁻¹, and the removal efficiency could reach ∼100%. The challenges of biochar and biochar-based materials have been considered and exemplified with recommendations and future prospects for the remediation of antibiotics in the environment.