Abstract: As one of the low carbon emission resource technologies, anaerobic digestion technology still faces the challenges of low methane production, unstable system operation, and residue refractory pollutants. Biochar had been widely concerned in the application of improving anaerobic digestion due to its excellent characteristics. In this study, CiteSpace software was used to conduct a quantitative analysis of the research trends of biochar application in the field of anaerobic digestion, and to explore the research status, hot spots and development trends in this field. The results showed that from 2010 to 2022, the number of papers published on the application of biochar in the field of anaerobic digestion kept increasing year by year, and China and the United States were the countries with the largest number of papers. The effects of the physical and chemical properties of different biochar on its application in anaerobic digestion, the mechanisms of improving the efficiency of anaerobic digestion by biochar, and the removal of pollutants such as heavy metals, polycyclic aromatic hydrocarbons and resistant genes by biochar in anaerobic digestion have gradually become hot spots. The research frontiers in this field include quantifying the contribution of different mechanisms of biochar in anaerobic digestion, further developing modification methods to improve the removal of refractory pollutants (heavy metals, polycyclic aromatic hydrocarbons, antibiotics, resistant genes, microplastics, etc.) during anaerobic digestion.

Key words: Anaerobic digestion, Biochar, CiteSpace, Visual analysis, Bibliometric