Sustainable Development Evaluation Of Rural Sewage Treatment In The Progress Of New Urbanization

The special of rural sewage included wide coverage, heavy pollution, large amount, high value; hard to management and large fluctuations. The rural water environment problem is an important part of sustainable development, and an inevitable requirement of building a harmonious rural society. A proper application of processing technology, a strong coordination between operation and management and the promotion of relevant incentive mechanism seemed to be significant to the process of urbanization and rapid propulsion of rural sewage works, which were important guarantee for the sustainable development of rural sewage treatment simultaneously.Based on the above, this paper carried out the researches in the sustainability of treatment process and studied the operation management and incentive mechanism. The specific research contents and results showed as follows:(1)The researches on the methods of sustainable evaluation:Discuss the advantages and disadvantages of typical sustainable evaluation method, and especially compare and analyze the Life cycle method and Emergy analysis method. Life cycle method was a promising way to comprehensively consider factors of products from "born" to "die" and assess the life cycle, but its application in the rural sewage sustainability evaluation still had a lot of problems. Emergy analysis method was simple, intuitive, easy to realize and had certain reliability, chosen as the core method of this study evaluation. The emergy analysis method worked through the "channel" of emergy, which can connect various forms of energy and provide a platform for their comparisons. Combining the particularity of sewage treatment system, adding the waste fluids of solid, liquid and gas input or output of energy waste to the traditional energy analysis while the system running, Emergy analysis was chosen as the core method, construct the evaluation system based on SEYR, SELR, SESI, SEBR, ECPT,EPI, EEF, EAR, and evaluate the sustainability, ecological and economic benefits and sustainable development of system mainly by three evaluation indicators: SESI, SEBR and EAR.(2) The sustainable evaluation of typical treatment process:Considering the sewage treatment process of sensitive region characteristic and the particularity of the rural sewage treatment, analysis of typical process sustainability and its adaptability to regional differences. Reference existing typical area sewage disposal technology application research, decided to take artificial wetland, MBR, SBR as typical process evaluation. In order to guarantee the reliability of the data, chose regions that better developed, like Beijing, Guangzhou, Jiangsu region as cases. Specific case as follows:: 1# Constructed Wetland(Changzhou)、2# Constructed Wetland(Beijing)、3# Constructed Wetland(Guangzhou)、4#MBR(Changshu)、5#SBR(Changshu).Take the value indicators of each system studyed in the second chapter, analysis the system sustainability showed that: SESI1#> SEBI3#> SEBI5#> SEBI2#> SEBI4#;SEBR1#> SEBR3#> SEBR5#> SEBR2#> SEBR4#;EAR4#>1> EAR 5#> EAR2#> EAR3#> EAR 1#. Analysis of the sustainability of each system showed that the sustainability, ecological and economic benefits and sustainable development of 1#system were both the strongest. 4# system did not have the sustainable development; whose environmental sustainability and ecological environment benefit were both the weakest.Researches compared the sustainability of different regions found that the 1# Constructed Wetland treatment system in Changzhou had the strongest sustainability while the 2# was the worst. Analysis of different process in the same area of sustainability showed that: Constructed Wetland >SBR> MBR; The application and dissemination of the sustainable development of rural sewage treatment, especially the Constructed Wetland technology, was helpful to the sustainable development of rural sewage treatment. And increasing the products reuse of processing system was favorable to improve sustainability.(3) The researches on adaptability of typical process:Supposed that case processes can be normally operated all around, we conducted the emergy analysis again and found that the system emergy flow changing only when the local renewable energy flows change due to regional differences. Studies of regional technology processing system adaptability and process adaptability were conducted from the perspective of sustainable development. Studies on the regional characteristics showed that local energy density(P, sej/m2·yr): PBeijing > PChangzhou> PChangshu> PGuangzhou, Solar energy was the dominant in the process of energy density change.Calculate the value indicators with the same method, analysis region process adaptation and adaptability. In Changzhou, 2 # system needed increase value if want to normal operation, 3 #, 4 # and 5 # system reduced; 5 # system performance was stable, strong adaptability. In Beijing, 1 #, 3 #, 4 # and 5 # system all needs to reduce the energy inputs if want to normal operation, contrastly, 3 # worst performance of the system stability, 5# best performance of the system stability. All system needed to increase investment value in Guangzhou if want to normal operation, 1 # was relatively stability. In Changshu, 3 # system needed to reduce energy inputs if want to normal operation, 1 # and 2 # system increased, 1 # system was strong adaptability. Adaptive process area, according to research the processing system in different regions characterized by sustainable development were as follows: Beijing strongest, Changzhou(Changshu) second, Guangzhou weakest. Studies on the adaptability of process areas showed that sustainable development performance enhanced from south to north, which might be related with local energy density.(4)Study the United States, Germany, Japan and Australia rural sewage disposal mechanism, and analyze their operation management, ways of cost burden, and the characteristics of the maintenance and management. Summarizes the domestic and foreign typical management mode and cost burden, and the short of maintenance and management, put forward the opinion from the Angle of sustainable development for the rural sewage disposal mechanism, pouring standards specialization, capital market diversification, processing cost internalization, environmental awareness, responsibility main body explicit universalization, capital stimulation co-ordinated, management main body on the local.