Biochar-Based Strategies for Antibiotics Removal: Mechanisms, Factors, and Application

The increasing use of antibiotics induces the spread of antibiotic-resistant genes (ARGs) in the environment, which seriously threatens the natural ecosystem and human health. Reducing antibiotics in the environment is of the utmost importance. Biochar, as a cost-effective, environmentally friendly, and carbon-rich porous material with circular economy prospects, has shown great potential in antibiotic remediation in the environment. The adsorption mechanisms (e.g., electrostatic interaction, hydrogen bonding interaction, hydrophobic interaction, π-π electron donor-acceptor (EDA) interaction, and pore diffusion) and the biotic roles (e.g., biochar as a microbial shelter, carrier, and electron mediator) synergistically promote antibiotic removal from the aqueous phase. This review critically discusses various removal mechanisms based on classes of antibiotics, the efficacy of biochar in antibiotics removal, and the influence of crucial parameters on the removal of antibiotics. Furthermore, the review provides a critical discussion on engineering the application of biochar. Finally, the review highlights the prospects and challenges of biochar application in treating antibiotic-contaminated liquid streams.