A review on utilization potential of functionalized biochar for the removal of antibiotics from water

Abstract

Globally, water resources are facing serious threat owing to the increasing concentration of various emerging contaminants. Indiscriminately discarded and/or excreted antibiotics and their residues are one such emerging contaminants. Since long-term persistence of these residues in environment is responsible for developing antimicrobial (antibacterial) resistance in the organisms, their removal from water / wastewater is essential. Hence, scientists are attempting to evolve novel methods to encounter antibiotics and their residues in water. One such method is the adsorption of antibiotics onto a suitable matrix thereby reducing their concentration in water. Biochar has been proven to act as a suitable adsorbent for various contaminants; however, their removal efficiency remains a concern. Therefore, functionalization of biochar using various physical and chemical modifications, was developed as a technique that can help in efficient removal of antibiotics. Functionalization has been seen to improve the physical and chemical properties of biochar; such as, pore volume, pore diameter, surface morphology, surface functional groups, polarity, porosity etc. In this review, functionalized biochars have been explored to understand their efficacy and mechanism for the removal of antibiotics and their residues. The discussion includes biochar functionalization methods, impact of property modifications on the removal of antibiotic residues, and their removal mechanism. In addition, cost-effectiveness, economy of the adsorption process, and its environmental effects have also been dealt with.