Abstract: To quantify the environmental benefits and green low-carbon transformation value of the expansion project of municipal sewage treatment plants, this study takes the Phase II Project of Zhangguizhuang Sewage Treatment Plant in Dongli District, Tianjin as the research object. Based on its construction background of the composite "TOT+BOT" model and the operation data after its official commissioning in 2024, it systematically analyzes the process optimization characteristics, pollutant removal efficiency and resource recycling level of the Phase II Project, and focuses on evaluating its comprehensive improvement effects on the regional water environment, ecosystem and green development. The results show that the Phase II Project innovatively integrates the "five-stage Bardenpho process + MBR membrane separation technology", supported by the nation's first precise aeration system and a 6-megawatt photovoltaic project. After commissioning, the daily sewage treatment capacity of the whole plant has been increased to 450,000 tons, and the daily sludge treatment capacity has reached 600 tons. The effluent quality is stably better than the Class A standard of Discharge Standard of Pollutants for Municipal Wastewater Treatment Plants (DB12/599-2015), with the total nitrogen removal efficiency reaching 90%-95%, and the annual reduction of core pollutants increased by 125% compared with the Phase I Project. The photovoltaic project of the Phase II Project is expected to reduce carbon dioxide emissions by 101,000 tons during the operation period, helping the plant be selected as one of the first batch of "Green and Low-Carbon Benchmark Sewage Treatment Plants" in China in 2025. As a key project for the coordinated development of the Beijing-Tianjin-Hebei region, the commissioning of the Phase II Project has significantly improved the water environment quality of the Dongjian River, Beitang Drainage River and the coastal waters of Dagu Estuary in the Bohai Sea, enhanced the regional flood control, drainage and ecological restoration capabilities, and constructed a new municipal sewage treatment model of "efficient pollution control - resource recycling - low-carbon operation".
邢北辰 et al. (Wed,) studied this question.