Analysis Of Water Environment Impact Of Limin River In Wucheng Based On Water Quality Simulation

Under the background of rapid social and economic development in my country,especially after the integration of urban and rural water supply projects in various places,the water problem of urban and rural areas has been greatly improved,and the amount of wastewater has also increased.The treatment scale of most sewage treatment plants can no longer meet the current requirements.The existing sewage treatment plants have been upgraded and renovated all over the country,so that the treatment scale of sewage treatment plants has been improved.However,the treated wastewater usually does not meet the standard of Class V surface water in my country,which makes the tail water discharge still have a certain impact on the receiving river.In this paper,COD,ammonia nitrogen,total nitrogen,total phosphorus,etc.are used as water quality indicators,and the QUAL2K and WAPS models of Limin River are established.Based on this,the impact of tail water discharge from a sewage treatment plant in Wucheng on the water environment of the Limin River,which is accepted by the river,is analyzed.And the accuracy and reliability of the QUAL2K and WAPS models are verified by comparing the actual monitoring values with the simulated values.The main research results are as follows:(1)The monitoring section of Niujiaoyu Gate under the QUAL2K model:the average error between the simulated value of TN and the measured value is 7.2%;the average error of TP is 8.5%;the average error of COD is 2.3%;the average error of ammonia nitrogen is 7.5%.The monitoring section of Sinu Temple Bridge:the average error of TN simulation value and measured value is 6%;the average error of TP is 8.3%;the average error of COD is 3.1%;the average error of ammonia nitrogen is 3.3%.(2)The monitoring section of Niujiaoyu Gate under the WASP model:the average error between the simulated value of TN and the measured value is 11%;the average error of TP is 28.4%;the average error of COD is 4.9%;the average error of ammonia nitrogen is 16.1%.Four female temple bridge monitoring fault:the average error of TN simulation value and measured value is 14.6%;the average error of TP is 13.7%;the average error of COD is 6.1%;the average error of ammonia nitrogen is 7%.(3)The pollutant holding capacity of COD and NH3-N in this water functional area is 2037.69 t/a and 64.97 t/a,respectively.The pollutant concentrations of COD and NH3-N at the discharge of the sewage treatment plant into the river are 33.13 mg/L and 1.52 mg/L,respectively,which meet the discharge standard.According to the sewage discharge volume of 9.0502 million m3 in 2020,the discharge volume of COD and NH3-N into the Limin River was 299.83 t/a and 13.76 t/a respectively,which met the sewage capacity of the Limin River.(4)The tail water discharge from the sewage treatment plant has little impact on the water quality,water ecology and water function areas of the Limin River.In the process of tail water discharge,if strict and effective anti-seepage and anti-leakage measures are taken and the sewage can be discharged stably up to the standard,the tail water discharge will not have a great impact on the groundwater quality in the short term.