Evaluation And Selection On Rural Sewage Treatment Technology In Guanzhong Plain

With the increasingly rapid urbanization many problems are brought to our attention, one of them is the domestic water pollution. Theoretically, several ingredients trend to trigger the issue of the environment. On the top of the list is that the most villages don't have sewage collection channels and treatment facilities. A great deal of untreated sewage flow uncontrollably, which leads to environmental pollution and threats to farmers'health. Though, many effective measures were taken by our government, and emerging different kinds of rural domestic sewage treatment. Existing technologies are lack of adjusting measures to local conditions. There is in urgent need of incorporating the evil trend of water pollution situation in our country, considering from the different characteristics of rural conditions, selected different sewage treatment in rural areas. It can provide suggestion to our government making decision.This paper is based on the urgency of rural sewage treatment selection in Guanzhong plain, using the entropy weight method to calculate the weight, estimating the commonly used 12 kinds of rural domestic sewage treatment by fuzzy comprehensive evaluation. According to each item of index evaluation score, and select rural domestic sewage treatment technique suitable for different area in Guanzhong plain. The conclusions from our study can be summarized as follows:(1) The result of rural domestic sewage treatment by fuzzy comprehensive evaluation is: anaerobic-anoxic-oxic (A~2/O) process> constructed wetlands> stabilization ponds and constructed wetlands> oxidation ditch> stabilization ponds> subsurface wastewater infiltration system> biogas digesters> SBR> septic tank> septic tank and constructed wetlands> biogas digesters and constructed wetlands> biological contact oxidation technology.(2) Rural domestic sewage treatment technique use in plain area is:anaerobic-anoxic-oxic (A~2/O) process, constructed wetlands, oxidation ditch, stabilization ponds, SBR and so on; Rural domestic sewage treatment technique under the applicable for the loess district on the Weibei mesa is.-anaerobic-anoxic-oxic (A~2/O) process, constructed wetlands, stabilization ponds and constructed wetlands, oxidation ditch, stabilization ponds, subsurface wastewater infiltration system; Rural domestic sewage treatment technique under the applicable for hilly mountain is:septic tank, biogas digesters, stabilization ponds, constructed wetlands, septic tank and constructed wetlands, subsurface wastewater infiltration system.(3) Rural domestic sewage treatment technique under the applicable for the riverfront is: stabilization ponds and constructed wetlands, biogas digesters and constructed wetlands, constructed wetlands, anaerobic-anoxic-oxic (A~2/O) process, septic tank and constructed wetlands, aerated or facultative lagoons, SBR and biological contact oxidation technology; Rural domestic sewage treatment technique under the applicable for yielding water recycling area:The anaerobic-anoxic-oxic (A~2/O) process, oxidation ditch, SBR and biological contact oxidation technology. Rural domestic sewage treatment technique under the applicable for yielding water used for farmland irrigated area is:stabilization ponds and constructed wetlands, constructed wetlands, anaerobic-anoxic-oxic (A~2/O) process, oxidation ditch, stabilization ponds, subsurface wastewater infiltration system, SBR, septic tank and constructed wetlands, biogas digesters and constructed wetlands, biological contact oxidation technology.(4) Rural domestic sewage treatment technique under the applicable for the source of water protected area and water head area is:stabilization ponds and constructed wetlands, constructed wetlands, anaerobic-anoxic-oxic (A~2/O) process, oxidation ditch, stabilization ponds and so on. But, infiltration filter system is not recommended. Stabilization ponds and constructed wetlands, constructed wetlands, anaerobic-anoxic-oxic (A~2/O) process, stabilization ponds can be selected in nature reserve.