Study On Process Selection Of Urbon Night Soil Treatment Scheme

With the increase of city population, urban night soil grows with each passing day. The selection of urban night soil treatment scheme should not only from the point of view of technology to analyze the reliability, but also from the point of view of the economic and social environmental to analyze its feasibility. The environmental problems caused by urban night soil have not been effectively resolved, and seriously affect human living space and quality. So the choice of urban night soil disposal schemes is very important in the decision making of urban infrastructure construction, and solving the problem of harmless and resource of urban night soil is imminent.In this study, we set treatment process as the research object, and we take the establishment of technical, economic and social environment, comprehensive benefits assessment methods as the goal, based on the analysis of economic indicators, we established evaluation index system which is composed of technical factors, economic factors and social factors comprehensive benefit. We use AHP to evaluate urban faeces processing technology.Analysis results of economic indicators: total investment yield index, the highest is composting process, reached 25.76%; the secondary treatment process yields the lowest total investment. Financial net present value index, secondary treatment processes, composting technology, combined composting and water treatment processes, compost and biogas bonding process four processes, the composting process financial highest net present value. Dynamic investment recovery period after tax indicators, composting process has the shortest payback time.On the basis of quantitative evaluation of economic indicators, using analytic hierarchy process modeling, from technical factors, economic factors, social and environmental factors, using quantitative and qualitative analysis, through expert questionnaires, calculate a target layer weights value. Through expert scoring method for scoring all treatment options, we finally arrive at a final score of each program, and then we perform scheme comparison. Analytic Hierarchy Process evaluation results show that the composting process is superior to the other three processes.The Economic Evaluation and proposal comparison has high reference value in the manure treatment plant construction feasibility study stage, with a good theoretical and practical significance. This study will be to a certain extent a strong theoretical basis for the investment and construction of treatment plants, in order to better serve the investment decision.