Bibliometric Analysis of Research Trends Related to Carbon Sources for Nitrogen Removal in Wastewater Treatment

The low organic carbon content of municipal wastewater reduces the effectiveness of biological nitrogen removal. Herein, we reviewed recent trends in carbon sources for nitrogen removal during wastewater treatment. A bibliometric analysis using the Science Citation Index Expanded database from the Web of Science was performed to analyze articles published in this field from 2000 to 2022. The major conclusions are as follows: (1) publications from China ranked 1st, followed by those from the USA and India during the statistical period. Regarding research institutions, the Chinese Academy of Sciences was the largest contributor with the most publications. (2) Based on the trend analysis of keywords, further research hotspots were discussed, showing related research on external carbon sources. Research on traditional carbon sources (e.g., methanol and ethanol) has decreased, whereas that on alternative carbon sources, such as sludge hydrolytic acidification liquid, fermentation liquid of food waste, agricultural waste, and biodegradable polymers, has increased. (3) New nitrogen removal technologies, particularly anammox, are becoming increasingly popular. (4) In the study on nitrogen removal, increasing attention is paid to changes in the microbial community, and the biological mechanism of nitrogen removal is discussed from a microscopic perspective.

Automated summary

This article reviews recent trends in carbon sources for nitrogen removal during wastewater treatment. A bibliometric analysis of articles published from 2000 to 2022 was conducted. The major conclusions are as follows: (1) China has the highest number of publications, followed by the USA and India. The Chinese Academy of Sciences is the largest contributor. (2) Research on traditional carbon sources has decreased, while alternative carbon sources such as sludge hydrolytic acidification liquid, fermentation liquid of food waste, agricultural waste, and biodegradable polymers have seen an increase. (3) New nitrogen removal technologies, particularly anammox, are gaining popularity. (4) There is an increasing focus on changes in microbial communities and the microscopic biological mechanism of nitrogen removal.