Recently, based on the big data analysis of the operation and carbon emissions of municipal sewage treatment facilities in China, the research group from SIAR, USTC, led by Prof. Li Wenwei has comprehensively evaluated the characteristics of greenhouse gas (GHG) emissions in the sewage industry and discussed its future emission reduction potential and technical path. The study provides an important reference to achieve carbon neutrality in the sewage industry. The results were published in Nature Water (doi: 10.1038/s44221-022-00021-0) on January 26, 2023, entitled “Spatiotemporal Pattern of Greenhouse Gas Emissions in China's Wastewater Sector and Pathways towards Carbon Neutrality”.

Sewage treatment plants are not only large consumers of electricity and chemicals, but also produce and directly emit GHG such as CH4 and N2O in large quantities during the degradation and transformation of pollutants. In order to achieve our “dual carbon” goals, carbon neutrality in the sewage treatment industry has become the focus of attention of the whole society. However, there is currently a lack of global, national-scale, detailed spatiotemporal emission data, which restricts the formulation and implementation of carbon emission reduction strategies in various countries. China’s current total carbon emissions and the scale of the sewage treatment industry rank first in the world. Therefore, a comprehensive assessment of the current status of carbon emissions and future development trends of China’s sewage industry will not only provide a useful reference for the planning of the sewage industry development, but also contribute to carbon assessment and carbon emissions reduction.

In this study researchers led by Prof. Li Wenwei elaborated dynamic plant-resolved emission factor values based on the case-specific operating parameters of each municipal wastewater treatment plant (WWTP) and the associated sewers and sludge disposal utilities in China, contrasting with previous estimations that typically focused on WWTP operation without differentiating their spatiotemporal discrepancies. Due to improved wastewater treatment, the national average wastewater GHG intensity grew by 17.2% between 2009 and 2019. A net-zero emission by the entire sector may be achieved as early as 2044 with continually increasing decarbonized energy and a progressive shift to resource-oriented operations. Joint efforts at the scientific, economic and policy level will be required to make this happen. This study may serve as a roadmap for developing carbon-neutral wastewater management policies and technologies in China and the rest of the globe. This research was supported by Prof. Wang Yang from SIAR, USTC, in terms of data analysis.

Paper link: https://www.nature.com/articles/s44221-022-00021-0