Removal of tetracycline from water by adsorption with biochar: A review

The efficient removal of antibiotics such as tetracycline (TC), which are frequently detected in multiple environments, has attracted widespread attention due to the potential risks to human health and the environment. Biochar (BC), with its low cost, effective adsorption properties, and excellent regeneration performance, has been widely used for antibiotic removal by adsorption in recent years. However, the limited antibiotic adsorption capacity of BC affects its practical application. Thus, there is a need to modify BC to enhance its practicability in the treatment of wastewater. This review describes the raw materials and preparation methods, including pyrolysis, hydrothermal liquefaction and microwave pyrolysis, of BC. Furthermore, the effects of biological, physical and chemical modification methods on the physicochemical properties of BC were analyzed and discussed. Moreover, the influencing factors and adsorption mechanism of TC and regeneration methods of BC and the removal of TC from real wastewater by BC were also reviewed. Finally, there is a lack of research on the use of BC for treating TC-polluted water, and analyses and ideas for the future growth of BC adsorption to TC are provided. The contents of this article are intended to help scholars gain a comprehensive and in-depth understanding of the latest progress in this field.