Research on Carbon Accounting for a Water Supply Plant: A Case Study of the S Plant in Urumqi

In response to the “dual carbon” goals, this study focuses on carbon emissions during the operational phase of the S Water Supply Plant in Urumqi. The plant is equipped with two treatment lines. Line 1 adopts the process route of raw water processed by pretreatment and high-density clarifier, then filtration and disinfection. The Line 2 replaces the high-density clarification process with conventional coagulation-sedimentation, with all other treatment units remaining identical. Using the emission factor method, this study accounted for the plant’s carbon emissions from 2024 to 2025, and systematically quantified indirect emissions (from electricity consumption) and extended responsibility carbon emissions (from chemical consumption and transportation). Results showed that Line 1 not only had higher production capacity but also exhibited a significantly lower carbon emission intensity (0.0598 kgCO2-eq/m3), when compared to Line 2 (0.0813 kgCO2-eq/m3). This is primarily attributed to its higher equipment efficiency and integrated control technology, which minimizes energy waste. To address the high carbon emissions of Line 2, specific measures are proposed, including optimizing high-energy-consuming equipment, implementing intelligent upgrades, and constructing energy recovery devices. Water supply plants can achieve both carbon reduction and efficiency improvement through process optimization and technological innovation, providing empirical support for the green and low-carbon development of the water industry.