Advanced biochar-based materials for specific antibiotics removal from hospital wastewater via adsorption and oxidative degradation

Antibiotics in hospital wastewater has become a critical issue due to their potential risks to human health and ecosystems. Biochar as a cost-effective and environmental-friendly carbon material has been employed for removing antibiotics. This article gives a holistic view of the properties of advanced biochar-based materials and clarifies mechanisms on removal of specific antibiotics from hospital wastewater. The increased pyrolysis temperature prepares the modified biochar with higher porosity and larger specific surface for enhancing adsorption. The metal-modified biochar possesses abundant functional groups, limits the leaching of metal ions, and increases the conductivity for improving activation of advanced oxidation process (AOP). Adsorption is significantly affected by the pyrolysis temperature, solution pH, and properties of modified biochar and antibiotics. The metal-modified biochar-assisted AOP can effectively degrade the pollutants via generating more reactive oxygen species. Weak acidic and/or weak alkaline condition promotes the degradation process in persulfate and peroxymonosulfate systems or during electrochemical oxidation process. Antibiotics removal at a wide pH range (3−11) can be achieved using Fenton-like and photo-Fenton systems with the presence of metal-modified biochar. Future research should focus on development of novel biochar with high reusability and great capability in removing a broad range of specific antibiotics.