Study On The Release Law Of Guanzhong Waterlogging Pollutants From Substrate Sludge To Water Body

The Waterlogging sediment in the rural areas of the northern arid regions,as a carrier of pollutants,can not only absorb various pollutants in the overlying water,but also release various pollutants into the water.The paper conducted a preliminary study on the sediment release from rural Waterlogging Lake.At the same time,among the 18 Waterlogging Lakes in the Guanzhong area of Shaanxi Province,three representative target Waterlogging Lakes were selected and experienced eight months of summer,autumn and winter.By monitoring and analyzing the changes of organic carbon,total phosphorus,ammonia nitrogen and nitrate nitrogen in sediment and water,and adjusting the ratio of overlying water to muddy water in the experiment,the release law of main pollutants in the sediment of Waterlogging Lake was explored.Pre-drainage sediments from the Waterlogging Lake release large amounts of pollutants into the water body,which significantly increased the content of COD,total phosphorus,ammonia nitrogen and nitrate nitrogen in the overlying water.The release rate of ammonia nitrogen was the highest,reaching 90%,and the lowest total phosphorus was 14 Between%and 30%.After 2 months,the sediment release rate decreased.The wave balance is reached until around December of winter.In the final state,the final release rates of the four pollutants,organic carbon,total phosphorus,ammonia nitrogen and nitrate nitrogen,were between 19.18%to 49.21%,8.10%to 12.50%,9.71%to 25.57%,and 4.7%to 47%,respectively..The final release rate from large to small is:organic carbon,nitrate nitrogen,ammonia nitrogen,total phosphorus.The process of releasing the sediment to the water body is largely affected by the temperature change.It is in the high temperature phase from July and the temperature is kept above 30?.The enhancement of microbial activity and intermolecular force in the process promoted the release of the sediment from the Waterlogging Lake to the water body,resulting in an increase in the content of four pollutants.The temperature is around 20? between September and November.The release rate of pollutants in the sediment is slowed down or in a reverse adsorption state.By December,the temperature was around 5?,and the ecosystem within the test device gradually reached a state of wave balance.Therefore,in the treatment of Waterlogging Lake,more research is needed on the release of high temperature in summer,and certain chemical,biological reaction or plant matching methods can be adopted to control the release of sediment pollutants.The process of releasing pollutants from the sediment of the Waterlogging Lake to the water body is simultaneously affected by the concentration gradient between the solid and liquid phases.The greater the concentration gradient,the faster the release rate of each pollutant in the sediment to the overlying water body,thus causing secondary pollution to the water body.At the same time,Under three different mud to water ratios,the greater the sediment concentration,the higher the contaminant content in the water.In summary,in the governance process of Waterlogging,it is not only necessary to control the water body treatment in Waterlogging Lake,and the control of the sediment release process is also essential.It is necessary to comprehensively consider the gradient relationship between the sediment concentration and the concentration of pollutants in the water body.At the same time,when the sediment concentration is too high,it will also affect the release of pollutants.Therefore,the control of the mud-water ratio is also indispensable.When the sediment deposits accumulate to a certain extent,it can be partially cleaned and other engineering measures.