Evaluation of Resource-Based Rural Sewage Treatment System Driven by Clean Energy in Northwest China

Abstract

Rural areas in Northwest China are sparsely populated. Traditional centralized domestic sewage treatment facilities have large-scale investments, high operating costs, and complicated operation and maintenance management, challenging their application in these areas. Given the abundant clean energy and limited agricultural irrigation water in Northwest China, this study constructed a rural domestic sewage treatment system driven by solar-wind power. Effluent quality was suitable for farmland irrigation. The efficiency of complementary solar-wind power generation and the system operating performance and potential application value were assessed. The effluent CODCr concentration met the Water Quality Standard for Farmland Irrigation (GB5084-2021) standard for vegetable crops (70% average removal efficiency). Nitrogen and phosphorus were effectively retained. Using the emission factor method, indirect and direct carbon emissions and the carbon reduction potential were evaluated. Finally, a life-cycle cost evaluation model quantified a 25-year life cycle cost-effectiveness. The application potential was confirmed based on investment costs. This study demonstrates this novel treatment system feasibility in terms of operational performance, carbon emissions, and cost-effectiveness and provides a scientific basis for low-carbon and sustainable resource recycling to rural sewage treatment systems.

Keywords: Complementary solar-wind power, Rural domestic sewage treatment, Carbon emission, Life-cycle cost