Application and Mechanisms of Biochar in Wastewater Treatment: A Comprehensive Review

Abstract

With the increasingly serious water pollution problem, traditional wastewater treatment technologies are facing the double challenges of performance and cost. Biochar, as a porous material prepared by pyrolysis of biomass, has gradually become a research hotspot in the field of wastewater treatment due to its rich pore structure and diverse surface functional groups. In this paper, the raw material source, preparation process and physicochemical properties of biochar are systematically reviewed, and its main mechanisms in wastewater treatment are analyzed, including adsorption, surface complexation and ion exchange, microbial carrier function and catalytic redox reaction. Combined with typical application cases, the effects and advantages of biochar in the removal of heavy metals, organic pollutants and nutrient salts are introduced. Finally, the future development trends and research directions are discussed with respect to the problems of insufficient long-term stability and difficulty in scaling up the functionalization in the application of biochar, aiming to provide references for the research and application in the related fields and to promote the sustainable development of biochar technology.