Application of modified biochar in constructed wetlands for efficient livestock wastewater treatment

Livestock wastewater contains high concentrations of organic contaminants, heavy metals, and antibiotic residues. If it is inadequately treated, its discharge can lead to water eutrophication, ecosystem degradation, biodiversity loss, and the spread of antibiotic resistance genes, posing a significant threat to global public health. Therefore, the development of efficient wastewater treatment technologies holds substantial environmental and societal significance. Due to its exceptional adsorption capacity and stability, modified biochar (MBC) has been widely applied in constructed wetlands (CWs), substantially enhancing pollutant removal efficiency. However, comprehensive reviews on the synergistic application of MBC and CWs for livestock wastewater treatment remain limited. This review provides a comprehensive summary of the preparation methods of MBC and its current applications in CWs. It discusses the effects of various modification techniques on the removal of key pollutants in livestock wastewater and examines the regulatory impact of MBC on wetland substrates, microbial communities, and plant growth. Finally, the review outlines the prospects and challenges associated with the combined application of MBC and CWs, offering valuable insights for optimizing and scaling up its use in livestock wastewater treatment.