A Review on Application of Biochar in the Removal of Pharmaceutical Pollutants through Adsorption and Persulfate-Based AOPs

Increasing quantities of pharmaceutical pollutants have been found in aquatic ecosystems. The treatment of pharmaceutical pollutants has been a major task that people have been committed to in recent years. The removal of pharmaceutical pollutants can be achieved by adsorption and advanced oxidation processes (AOPs). Compared with other carbon materials, biochar has a strong adsorption capacity and persulfate activation ability, and more importantly, biochar is cheap and easy to obtain; thus, it has higher economic benefits. This study firstly reviews the application of biochar in the removal of drugs (tetracycline (TC), sulfamethoxazole (SMX), acetaminophen (ACT), cephalexin (CPX), levofloxacin (LEV), etc.) through adsorption and persulfate-based AOPs. In addition, we summarize the adsorption mechanism of biochar for various pharmaceutical pollutants and the main attack sites on different pharmaceutical pollutants in persulfate-based AOPs catalyzed by biochar. Finally, the challenges and prospects of biochar with respect to the removal of pharmaceutical pollutants are put forward.