Carbon emission reduction in China’s wastewater treatment plants: challenges and future pathways

Green and low-carbon development has emerged as a pivotal direction in the global development agenda. In alignment with this trend, China has established a significant roadmap with its “3060” carbon peak and carbon neutrality goals. Under this strategic framework, various industries in China have initiated comprehensive carbon emission reduction efforts. Notably, the wastewater treatment sector has been a focal point, as China has consistently prioritized significant investments in this are a. While the country boasts a vast network of sewage systems, including extensive sewage discharge volumes, an extensive pipeline network, and a large number of wastewater treatment plants, these achievements come with substantial carbon emissions. This is primarily due to both the indirect carbon emissions resulting from energy consumption in the wastewater treatment process and the direct generation of greenhouse gases during treatment operations. To address these challenges and advance carbon emission reduction in the wastewater treatment industry, this study provides a comprehensive analysis of the current state of China’s wastewater treatment sector. By examining multiple pathways for carbon emission reduction in Chinese wastewater treatment plants—such as the utilization of sewage heat energy, innovative wastewater treatment processes, smart water applications, photovoltaic technology integration, and sludge resource recovery —this paper identifies actionable strategies for achieving low-carbon operation.