Investigation And Governance Research On Sewage Treatment In Dalian Rural Areas

While the rural area covers a large amount of water source, rural sewage disposal directly relates to the safety of drinking water thus becomes important link which influences the social and economic sustainable development. Presently, rural sewage disposal in our country is in groping stage that some areas have constructed rural sewage disposal demonstration projects. Due to lack of laws and regulations as well as guidance, however, rural sewage disposal demonstrates diverse situations, which results in the treatment effects with big differences and the inconspicuous economic benefit.In order to look for the way suitable for rural sewage treatment in Dalian, this study starts to investigate the existing sewage treatment facilities in Dalian rural areas thoroughly, to know the current situation regarding rural sewage treatment in Dalian. Then,10typical wastewater treatment projects were chosen as the research object after screening the surveyed projects. The construction and operation situations are summarized and compared, and assess them economically to determine the suitability of the existing rural sewage treatment in Dalian. And finally, based on two results above, this paper discusses the development direction of the rural sewage treatment in Dalian.The results show that the existing sewage treatment facilities can be divided into three categories:large fully functioning sewage plant (above2000t/d), medium town-suitable sewage station (500-2000t/d) and small town on-site sewage station (500t/d below), and the daily processing power concentrated in the range of2000t below. It can be divided into two processing mode, distributed and centralized, based on the service population and the center distance between the service area and town. Technology also is divided into three categories including small buried integrating membrane bioreactor, the traditional town wastewater treatment technology (active sludge method or biological membrane method) and land treatment system. Different processing in different economic evaluation shows different advantages. Since the whole advantage is unknown, it therefore can not simply judge which way obtains higher efficiency. Overall, rural sewage projects are with low land use, high investment as well as high energy consumption with per ton of water, and large pipe network investment. Through the analysis of evaluation results above, and combined with actual situation in rural areas in Dalian, this paper puts forward the following suggestions:It should construct large scale and fully functional sewage treatment plant in the transition zones between urban and rural areas. At the same time, in the situation of separation of sewage treatment plant, pipe network and sewage pumping station, operation mode of the franchise sewage can be adopted. Agricultural districts should strengthen the concept of community, with its emphasis on integrity. In the finished countryside, medium concentrated sewage treatment facilities can be constructed, while renovating toilet to become ecological healthy one in the unfinished areas. For some remote villages combination and ecological relocation can be implemented. And island districts have to pay attention to the waste problem, which means the islands need to reserve garbage disposal facilities in the planning stage to manage sewage and junk integrated without ignoring water reuse.