Emerging antibiotic pollution and its remedy by waste based biochar adsorbents: a review

One of the pollutants of emerging concern, antibiotics, have been reported in soil, water, sediment, animal manure, food, and even drinking water. Their partially metabolized forms reach wastewater treatment plants (WWTPs) and natural waters wherein the development of antibiotic resistant bacteria (ARB) and dissemination of antibiotic resistance genes (ARGs) have been reported to occur. Antimicrobial resistance (AMR) is projected to cause 10 million deaths annually across the world by 2050 in case stringent measures are not taken. In this study, various methods of adsorptive removal of antibiotics with their critical analysis and emphasis on the application of biochar (BC) and modified biochar derived from waste biomass have been comprehensively reviewed. Also, the antibiotic toxicity, preparation of biomass waste-derived BC adsorbents from cost-effective precursors to ensure sustainability, the adsorption kinetics, isotherm models and thermodynamic parameters have been discussed. It was inferred that biochars are quite efficient in terms of antibiotic removal in water owing to their large surface area, excellent surface characteristics and functionality, facile synthesis and the potential to be regenerated, while being cost-effective and sustainable in nature. This review aims to guide the expansion of research in the aforementioned area of interest and to provide a progressive push towards the development of a circular economy.