Assessment And Adaptability Of Prevention And Control Technology For Non-point Source Pollution In Agriculture And Rural Areas Of China In Recent 10 Years

The contribution of COD,TP and TN from rural agriculture in the total discharge of various pollutants in key river basins is enormous.The non-point source pollution has become the main source of pollution affecting water environment from agricultural and rural areas in China.In view of the fact that non-point source pollution has the characteristics of high spatial dispersion,high spatial and temporal variation of transportation,and Involving thousands of households,it is an international problem in the field of environmental protection.In the past 10 years,China has carried out a layout study on the research of non-point source pollution of major rivers by the National Major Scientific and Technological Water Projects,thus has formed a series of various non-point source pollution prevention and control technologies.However,due to different regions,different land use patterns,different economic levels and production conditions,the source of output and their control methods vary widely of agricultural and rural areas.It is necessary to sort and classify existing technologies so that the technical select for appointment and assembly in the non-point source pollution control can according to the map,targeted.This research collects and sorts out the non-point source pollution prevention and control technologies involved in agricultural and rural areas in the past ten years of paper publications,public patents,and open technical reports about 100 items.The technical data is sorted and summarized,and representative single technology and comprehensive technology are selected.Using Analytic Hierarchy Process to analyze the characteristics of technical achievements,technical elements and implementation Conditions.Main conclusions showed as follows:(1)The research and development of agricultural and rural non-point source pollution prevention and control technology is mainly carried out in the important river basins where the eutrophication pollution in China is more serious,and the different control links are applied around the source,flow,sink and trinity.Focus on the management of farmland,agriculture(including aquaculture farming),rural comprehensive non-point source(including decentralized rural life,production sewage),and the types of technologies used are mainly bio-ecological technology and chemical technology.The management of rural comprehensive sources is mainly concentrated in the end-of-pipe technology,and the source-flow-sink trinity technology is biased towards the reduction of agricultural sources.From the point of view of the reduction effect of pollutants,the use of the three-in-one combined process is the best than the end-of-pipe treatment technology.Secondly,the in-situ ecological restoration engineering technology based on the end treatment has better effect on the reduction of non-point source pollution compared with other end treatment technologies.(2)Using the analytic hierarchy process(AHP),this paper optimizes and evaluates the existing agricultural and rural non-point source pollution prevention and control technology.The results of four kinds of technology optimization are as follows:in the technical system of rural comprehensive non-point source treatment,the optimization results of the existing technology are as follows:Small-area water source non-point source pollution remediation interception-cultivation control system,rural comprehensive non-point source pollution ecological control technology,control source-sewage-resource-recycling(BMPS)technology system,microbial composite medium-ditch-canal-tang ecological control technology,etc.Has a good application development potential.In agricultural integrated surface source treatment technology,the preferred result of the prior art is:Rain and sewage diversion technology,constructed wetland technology,multi-stage percolation pond technology,combined source-sewage-resource-resource technology,facility agricultural water and fertilizer integration technology have good application development potential.The soil treatment system and biofilter technology in the rural decentralized sewage treatment process have obvious advantages compared with other technologies and have good application development potential.In the farmland non-point source treatment technology,the optimization results of the prior art show that the industrial optimization layout-balanced fertilization combined application technology,constructed wetland,and ecological pond system technology have good application development potential.(3)Based on the comparative analysis of the prevention and control mechanism,the results show that the selection of governance techniques for agricultural non-point sources should focus on the governance of the Trinity and source pollution control.(4)The discussion believes that for the prevention and control of rural non-point source pollution in the plateau lake basin,the technical scheme adopted should pay more attention to the application of source technology and the source-flow-sink joint technology.It is hoped that through the research and comparison of different types of agricultural and rural non-point source pollution control technologies and their application cases,the adaptability of existing technologies and the conditions for future application will be summarized.’So as to provide a basis for the prevention,control and treatment of agricultural and rural non-point source pollution in relevant regions of China.