Biochar as green adsorbents for pharmaceutical pollution in aquatic environments: A review

Rapid urbanization and advances in drug manufacturing have led to more pharmaceuticals in aquatic ecosystems, raising environmental concerns. However, conventional wastewater treatment often falls short of removing these emerging contaminants effectively. Biochar and its modified composites have emerged as highly effective and cost-efficient adsorbents in environmental science, particularly for water remediation. Their notable features, including high surface area, diverse functionalities, sustainability, and tunable properties, make them stand out. The choice of feedstock materials and modification methods emerges as a critical factor influencing the sorption capacity of biochar. This review offers an overview of cost-effective biochar derived from various feedstocks for the removal of pharmaceutical pollutants from water. It discusses fundamental aspects of biochar, including preparation, adsorption mechanisms, and modifications. Studies show that biochar effectively eliminates pharmaceutical pollutants, and enhancing its surface characteristics such as area, pore size, functional groups, and magnetic properties can significantly improve removal efficiency. Further research is crucial for the modification of biochar to improve its efficacy and sustainability in adsorbing pharmaceuticals. The article also explores potential adsorption mechanisms, aiming to address limitations, challenges, research gaps, and future directions in utilizing biochar and its modified composites for sustainable water remediation from pharmaceutical pollutants.