Life Cycle Carbon Emission Analysis of a Sludge Dewatering Facility: A South-to-North Water Diversion Case Study

To mitigate the impact of global climate change, countries worldwide must take necessary measures to address this environmental issue. China’s goals of carbon peaking and carbon neutrality and the “1 + N” policy framework have provided guidance for various industries and enterprises in advancing carbon accounting, carbon reduction, and green transformation. This study focuses on the sludge dewatering facility of a typical water treatment plant, which uses water from the South-to-North Water Diversion Project as its water source. Based on its construction and operational data, the carbon emissions at different phases were calculated with the emission factor method in the study, and the composition of these emissions was analyzed. The results show that during the three-year construction period, the sludge dewatering facility emitted a total of 1385.57 tons of CO 2 -eq, with materials being the main source of carbon emissions. While in the one-year operation period, the facility generated 19.38 tons of CO 2 -eq only, with electricity consumption being the primary contributor, followed by chemicals consumption. In conclusion, both the short-term intensive emissions during the construction phase and the long-term cumulative emissions during the operation phase should be considered, so that an integrated mitigation effect can be achieved across the construction and operation stages. This highlights the necessity of adopting a life-cycle perspective in carbon reduction strategies within the defined system boundary, while also supporting the sustainable planning and management of water treatment infrastructure.