Research Trends and Future Prospects of Constructed Wetland Treatment Technology in China

With the intensification of water pollution problems worldwide, constructed wetlands, as a green, efficient, and energy-saving wastewater treatment technology, have gradually attracted the wide attention of scholars at home and abroad. In order to better understand and master the research trends of constructed wetland treatment technology in China and promote its development, the literature from 2000 to 2023 in the CNKI database and the Web of Science (WoS) database (located in China) were selected as research objects. Then, CiteSpace software (6.2.R4) was used to visualize and analyze the literature, revealing the research trends and hot areas of constructed wetland treatment technology in China. Then, the optimized way of operation effect of constructed wetland was discussed to provide a theoretical and technical basis for the wide application of constructed wetland technology in our country. The results indicate that the annual publication volume of research on constructed wetlands in China is showing a rapid upward trend. Among them, the Chinese literature mainly focuses on how to improve the application effect of constructed wetlands on nitrogen and phosphorus removal of rural domestic wastewater by matching different wetland plants or developing combined processes. The English literature from the Web of Science (WoS) database mainly focuses on how to remove emerging pollutants, such as heavy metals and resistance genes in wastewater in China, by changing the filling matrix and microbial community structure or developing new processes, and the related mechanisms have been discussed. One of the hot spots for the future research of constructed wetlands in China is to vigorously develop microbial fuel cells, and try to overcome the problem of poor purification efficiency of constructed wetlands under complex conditions such as low temperature, low carbon-nitrogen ratio, and high pollution load. In order to strengthen its application, the specific optimization methods can be divided into two categories: self-optimization strategies such as increasing oxygen supply and transfer, providing electron donor matrix, preventing matrix blockage, and combination processes coupled with anaerobic treatment and other technologies.