Investigation And Analysis Of Rural Domestic Wastewater Treatment Feasible Technology In Tongzhou District

The treatment status of rural domestic wastewater in China and the technology modes applied at present were described systematically in this paper. The compositions of the rural domestic wastewater were more complex, and its quality and the quantity have a large volatility. The adopted technology should be considered the following factors such as the social and economical development level, cost-effective, low management costs, easy to operate and maintain. What's more, the reuse of treated rural domestic wastewater is very important, so that an eco-agricultural mode composed of wastewater treatment and recycle can realize harmless and resource of wastewater.Tongzhou district of Beijing is a metropolis suburb and typical water-deficient area in Northern China. Most of rural domestic wastewater are not be treated and reused effectively except that a small part were discharged to the sewage system of Beijing. So it's significant for promoting the development of a metropolis and the new rural infrastructure to spread out treatment and recycle of rural domestic wastewater, effectively. In 2007, according to scale of the village and lifestyle of residents, a mode with combination of decentralized and centralized treatment system was applied in Tongzhou district. And 24 wastewater treatment units for rural domestic wastewater were constructed in 14 villages of Tongzhou district. Three different technologies, BAAS (a micro-power complete biological treatment process), micro-power wastewater treatment technology and anaerobic baffled biological filter composite flow constructed wetlands were used privately.Investigation results showed all these three technologies, focused on the anaerobic treatment technique with the characteristics of cost-effective and easy to run,were feasible. After analysis of key design parameters of these technologies, it was founded that these technologies possessed different creatures.Every year, 523100m3 of rural domestic wastewater was treated as resource of irrigation, and 136.6 ton of COD can be removed It is necessary and feasible for considering economic, social or ecological benefits.60 m3/d plant in Taizifu village was constructed with a combined process of anaerobic baffled biological filter composite flow constructed wetlands. The domestic wastewater treatment system was stabliization of high effeciency and mutative-load resistance. Under the condition of 125-292mg/Lof CODCr, 17-47 mg/L of BOD5, 33-65 mg/L of SS for influent wastewater, CODCr BOD5 SS of effluent were below 60 mg/L,20 mg/L 20 mg/L,respectively. The main quality index of effluent water can meet Discharge Standard of Demostic Wastewater Pollutants in Beijing. And its investment costs and running costs of the plant were $3275 yuan/m3 and $0.374 yuan/m3.d, respectively. It seems this technology is suitble to be spread out in rural district.All in all, it was thought that the modes of rural domestic wastewater treatment were cost-effective and technology feasible through invetigation and analysis, which could be spread in metropolis suburb of North China. The summary of design parameters of different technologies can provided technical support for adopting feasible wastewater treatment technology.