Research On The Operating Effects And Main Factors Of Xinxue River Wetland

Due to years of reclamation and polder disturbance of human disorder activities and basin pollutant emissions, the Nansi Lake area was seriously structurally polluted and the lake water quality was seriously polluted. Non-point pollution make the Nansi Lake natural ecological environment suffered serious damage, the lake wetland area greatly reduced and the ecological function degradated. Along with the date of diversion of south-to-north water transfer project, the Nasi Lake faced severe and urgent task for the water conveyance project of water security, State of south-to-north water transfer project quality requirement is all water lines in 2010 meetⅢclass quality standard of the surface water environment stable quality standard (GB3838-2002).After several years of comprehensive harness, the Nansi Lake water quality has been improved, but there is still a certain distance from the water requirement of national transferring water quality.This topic is derived from the national mayor project on the control of water pollution"Technology and demonstrations about the ecological restoration and water quality improvement of the degraded wetland in Nansi Lake"(No. 2009ZX07210-009). Taking the Xinxue River artificial wetland as the research object, and through nearly a year of field investigation and experiment, the article studied treatment effect on water pollutant in the river and the treatment effect of factor changes, since the construction of the Xinxue River artificial wetland,and through the construction of artificial wetland model , optimizing the operating parameters, lay the foundation of the optimization for artificial wetland to achieve better effluent quality.The research results are as follows:1. Through nearly a year of the Xinxue River artificial wetland investigation and experiment ,the article analysized the monitoring data of the Weishan county environmental protection agency and the experimental data monitored. Analysis results show that the Xinxue River artificial wetland has good purifying effect in the polluted water of Xinxue River, COD (except May) and ammonia nitrogen (except November and October) effluent concentration in the system basically meet the surficeⅢtype water quality standard;The concentration of pollutant gradually lowered along the process, due to phosphorus releasing of the substrate, the effluent concentration of total phosphorus category of five wetlands was higher than that of the four wetlands; With the rise of temperature, COD removal rate fluctuates greatly, ammonia nitrogen removal rate is obviously improved, total nitrogen removal rate rises slowly, the total phosphorus removal has the slow enhancement tendency, with the increase of the influent concentration, COD removal rate increases, the ammonia nitrogen removal has the tendency of increase,and the total nitrogen removal displays the small range decrease after smooth tendency; The COD and the ammonia nitrogen influent concentration in the artificial wetland reduce year by year, with the pollutant removal also reducing year by year.DO changed not obviously along the technical process change, with its value quite stable, and pH of water body in the wetland system is neutral slightly leaning alkalinity.2. Artificial wetland pollutant removal rate is affected by many factors, Using regression analysis theory model to simulate the process of artificial wetland decontamination, to determine the relationship between the pollutant concentration and temperature , water inflow ,the removal rate and wetland area. Research results show that ammonia nitrogen removal has a significant positive correlation with water temperature, and a significant negative correlation with water flow, total nitrogen removal has a significant positive correlation with water temperature ,COD removal has a significant positive correlation with COD influent concentration, the regression relation between removal of COD, ammonia nitrogen, total nitrogen and area of wetland respectively accords with conic section relation. That is comparing with the spring and winter seasons with low temperature, the artificial wetland in summer and autumn seasons is more suitable for the treatment of polluted river with higher ammonia nitrogen and total nitrogen, proper water inflow reduce of the wetland is an effective method to improve the ammonia nitrogen removal, reduce in artificial wetland influent COD concentration is an effective method to reduce effluent COD concentration. To adopt the regression equations obtained from this article, and through simple calculation, purifying effect of given conditions of artificial wetland system can be predicted.3. According to the inlet and outlet data of the Xinxue River artificial wetland the wetland of artificial neural network model was established, using a three-layer neural network with an input layer, a hidden layer and an output layer, the hidden layer including seventeen nodes, the input layer chooses five representative parameters of influent water, the output layer consists of three major effluent quality index. After the establishment of the model, the former sixteen groups of filtered data were brought into the model to be trained, and four latter groups of network data was verified.The results indicate that the artificial wetland mathematical model based on artificial neural network can reflect the characteristics of artificial wetland technology of pollutant removal , the simulation results and the measured effluent error are small, neural network model has good generalization ability.