Study On The Optimal Method Of Controlling Sources Of Typical River Channels In Southern Jiangsu Province

This study takes the typical river Xiangtougang in southern Jiangsu as the research object,based on the near-term goal of the project control project of the Xiangtougang,through the investigation of the current situation and the collection and analysis of the data,the water quality of Xiangtou Port was evaluated and the source of pollution in the basin was analyzed.Two kinds of pollutant total amount control schemes were formulated and combined with individual technical measures,six kinds of source-controlled interception implementation schemes were constructed based on the optimization of individual technical measures.The main conclusions of the paper are as follows:(1)Analysis of water quality at the end of Xiangtougang by single factor index method.It was determined that the main pollution factor of Xiangtougang was total nitrogen,followed by COD and ammonia nitrogen.Based on the on-site investigation and data collection,the pollution sources in the Xiangtougang were analyzed and estimated.The COD in the basin mainly comes from urban direct discharge sewage,and the amount of river inflow accounts for 81%.Ammonia nitrogen and total nitrogen are mainly derived from non-point source pollution in rural areas,accounting for 57% and 56% respectively.Combined with the distribution characteristics of Xiangtougang pollution sources,urban life point source pollution is the primary reduction target.(2)Based on the survey results,and the recent goals of the project control project of the Xiangtougang,the hydrodynamic and water quality model of Xiangtougang was constructed using the MIKE21 model.Based on the control of the water quality at the end section,the total amount of pollutant control plan for Xiangtou gang was formulated.Taking into account the overall water quality of the project,the two total pollutant control schemes were selected.Based on these two schemes,six specific schemes for total pollutant control were developed.(3)Selecting a representative single pollution technical measure of each pollution source and combining it with six specific pollutants control specific schemes,and six implementations of controlled source interception were obtained and used as an alternative to the near-term goal of the project to control the sewage interception project.Using the analytic hierarchy process and multi-objective decision analysis model,construct a comprehensive evaluation system for the source and interception schemes from the aspects of environmental benefits and economic benefits.Simulating the water quality improvement effect of six control source interception schemes using the established hydrodynamic water quality model.The results are used as the basis for the evaluation of environmental benefits,and the construction and operation costs of each program are used as the basis for economic benefit evaluation.And comprehensive evaluation of six implementation schemes using the source-source interception scheme evaluation system.The final evaluation scores for each program are: Scheme 6(0.457)> Scheme 1(0.455)> Scheme 5(0.452)> Scheme 3(0.445)> Scheme 2(0.412)> Scheme 4(0.393).Preferably,Scheme 6 is the best solution that combines environmental and economic benefits,and as an implementation plan to realize the short-term goal of the project to control the sewage interception project of Xiangtougang.(4)According to the preferred control source interception scheme,combined with the situation in the field,the scheme is designed.