title: Evaluation of rural wastewater treatment processes in a county of eastern China.
abstract: With the rapid urbanization and industrialization in China, wastewater treatment in rural areas has become an increasing national concern. The selection of appropriate treatment processes closely based on the actual local status is crucial for the prevention of water quality deterioration in rural areas of China. This study presents a full year survey on the performances of various rural wastewater treatment processes at a county level in eastern China including seven three-chamber septic tanks (ST), five micro-power biological facilities (MP), seven constructed wetlands (CW), three stabilization ponds (SP) and five centralized activated sludge treatment plants (AS). It was found that although ST could remove a notable portion of total suspended solids (TSS) and chemical oxygen demand (COD(Cr)), it was ineffective in reducing nutrients and pathogens. Reliability and stability analyses showed that the centralized AS and decentralized CW processes outperformed the SP and MP processes. There were obvious discrepancies between the mean design concentrations, which ensure that 95% of the effluents meet the discharge standards, and the actual effluent concentrations determined for each process. The expected compliance with the tentatively adopted second-grade discharge standards (GB 18918-2002) was unsatisfactory for most of the water quality parameters examined, indicating an urgent need to design more practical discharge standards for decentralized treatment processes. Based on an overall assessment of reliability, stability and cost-effectiveness, the centralized AS was suitable for densely populated towns while the decentralized CW was suitable for sparsely populated villages.
authors.affiliation: State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.
authors.forename: Hui-Yu
authors.initials: HY
authors.lastname: Dong
authors.forename: Zhi-Min
authors.initials: ZM
authors.lastname: Qiang
authors.forename: Wei-Dong
authors.initials: WD
authors.lastname: Wang
authors.forename: Hui
authors.initials: H
authors.lastname: Jin
mesh_terms: D002681:China; D014865:Waste Disposal, Fluid / Q000379:methods* / Q000592:standards / Q000706:statistics & numerical data; D014874:Water Pollutants, Chemical / Q000032:analysis*; D014877:Water Pollution, Chemical / Q000706:statistics & numerical data*; D060753:Water Quality / Q000592:standards*; D053833:Wetlands
chemical_list: D014874:Water Pollutants, Chemical