[Key Problems and Strategies for Greenhouse Gas Reduction in China's Wastewater Treatment Industry]

The wastewater treatment industry is an energy-intensive industry and one of the main sources of high warming potential greenhouse gases （GHG） such as CH₄ and N₂O. The GHG reduction in this industry is an important part of achieving global climate goals. In 2019, there were 4 359 urban wastewater treatment plants in China, with a total wastewater treatment volume of 63.26 billion m³, ranking first in scale worldwide. From 2009 to 2019, the energy consumption, GHG emissions, and GHG emissions intensity of wastewater treatment in China increased by 161.78%, 193.55%, and 41.54%, respectively. Faced with the new situation, new tasks, and new requirements of the collaborative promotion of carbon reduction, pollution reduction, green expansion, and growth, water pollutant reduction needs to be coordinated with GHG reduction. To this end, the sources and trends of energy consumption and GHG emissions in the wastewater treatment industry were identified, and the situation and challenges to GHG reduction in this industry were analyzed. The results indicated that the wastewater treatment industry in China has been facing problems such as a lack of carbon emission-related standards, insufficient energy self-sufficient technology reserves, lack of coordination between wastewater treatment levels and carbon emissions control, and inadequate infrastructure and operation and maintenance management. Based on this, it is necessary to accelerate the top-level design of GHG reduction in the wastewater treatment industry； strengthen the research and development, verification, demonstration, and integrated application of disruptive technologies； expand the natural-based solution as a technological supplement； innovate refined management in the wastewater treatment industry； and ultimately promote the reconstruction of the wastewater treatment industry.