Water Environment Effect And Regulation Of The Proposed Wetland In The Construction Of Sponge City In Hunnan District

Hunnan District,Shenyang City is the third batch of pilot areas for ecological civilization construction in the country.Over the years,in order to ensure the safety of the Hunnan water system,a number of comprehensive renovation projects have been implemented,and the ecological environment in the region has been greatly improved.In recent years,with the frequent waterlogging in urbanization construction,runoff pollution,and massive loss of rain water resources,it has caused a certain impact on the ecological environment of Hunnan District.Sponge city construction combines natural approaches with manual measures,and on the premise of ensuring the safety of urban drainage and waterlogging prevention,maximizes the accumulation,penetration and purification of rainwater in urban areas,and promotes the use of rainwater resources and ecological environmental protection.The rivers and lakes system in Hunnan District plays a vital role in the water system pattern in Shenyang City.In the planning and construction of the sponge city in Hunnan District,it is planned to solve the problems of waterlogging,rainwater resources utilization,etc.through the construction of new wetlands.This study takes the proposed wetland in the construction of the sponge city of Hunnan District as the research object,and provides a certain science for the wetland planning of the Hunnan District through the study of the water environment effects of the main pollutants in the water body of the proposed wetland during the storage and infiltration process in accordance with.The main results obtained in this study are as follows:(1)Analysis of water environment characteristics in Hunnan District.By collecting the natural profile data of Hunnan District of Shenyang City,the geological landforms,meteorology,and hydrological characteristics of the study area are analyzed;the monitoring of the distribution points in Hunnan District obtains the monitoring data of surface water and groundwater,and the water quality of the water environment is analyzed using appropriate mathematical methods Evaluation.Use the comprehensive mark index method to determine the surface water quality of the surface water,and use the fuzzy comprehensive evaluation method to determine the groundwater quality for the groundwater in the study area.It is Class II or Class III water quality.The water quality in the wet season is better than that in the dry season.Among the pollutants monitored,ammonia nitrogen pollution is more serious,so this study selected ammonia nitrogen as the main pollutant.(2)Analysis of soil biogeochemical properties of the proposed wetland.According to the measured physical properties of soil bulk density,porosity,water content,lithological composition,etc.,the lithology of the proposed wetland soil is silty clay.According to highthroughput sequencing,the abundance and diversity of bacterial communities in each sampling area are obtained.There is no significant difference.According to the sequencing results of the bacterial community structure composition,the Proteobacteria,Acidobacteria,Bacteroidetes,Chloroflexi in the community composition at the phylum level 1.Actinobacteria is an advantage,and its relative abundance is greater than 10%;and Proteobacteria is the largest proportion.Some bacteria in the Proteobacteria have denitrification functions,such as ammonia-oxidizing bacteria or anti-bacteria.Nitrifying bacteria,etc.;Actinomycetes bacteria can also play a role in the nitrogen cycle in nature.(3)The static absorption and desorption test of pollutants in the proposed wetland soil.Through the static adsorption and desorption test,understand the static adsorption and desorption process of ammonia nitrogen in water pollutants in the proposed wetland soil,and determine the adsorption and desorption effects and characteristics of pollutants in the soil.According to the adsorption kinetic experiment of ammonia nitrogen,the soil The adsorption capacity of ammonia nitrogen is very strong,and it basically tends to adsorption equilibrium in about 4 hours,and the equilibrium adsorption rate reaches more than 90%.The quasi-secondorder kinetic equation has a high fitting degree to the measured curve of soil nitrogen adsorption by the test soil,and can be used to describe the process of soil nitrogen adsorption by the experimental area under this experimental condition.(4)Study on the migration and transformation of ammonia nitrogen in the proposed wetland soil.First,determine the soil seepage coefficient,dispersion and other hydrodynamic parameters through soil column experiments;secondly,conduct indoor soil column experiments under different p H,different redox potentials and different hardness conditions to understand the migration and transformation of ammonia nitrogen in the proposed wetland soil law.The results show that the greater the PH,the greater the removal amount;the higher the redox potential,the more favorable the ammonia nitrogen nitrification reaction;the higher the hardness,the weaker the ability of the proposed wetland soil to intercept ammonia nitrogen.(5)Study on the water environment effect and regulation of the proposed wetland.In this study,the QUAL2 K water quality model was used to simulate and predict the impact on the ecological environment of the main river-Baitabao River after the proposed wetland operation.The results show that the proposed wetland will not affect the water quality of the Baitabao River ecological environment.It can also meet the standards of its water function area.After the effluent flows into the Hunhe River,it will not affect the water quality of the Hunhe River.By establishing a numerical model of the groundwater environment system,the effects on the groundwater quality and water level under different conditions are separately predicted: Under the existing groundwater source exploitation conditions,after the proposed wetland has been in operation for ten years,the groundwater level is basically the same as that of the unbuilt wetland,which will not affect the groundwater level.After all the municipal water source wells in Hunnan District are shut down,the groundwater There will be some recovery,and the groundwater quality meets Class III standards,indicating no impact on groundwater quality.In this study,in view of the geological and geomorphological characteristics and water system pattern of Hunnan District,we have constructed a variety of technical approaches such as "seepage,stagnation,storage,net,use,drainage" of wetlands and artificial lakes and the implementation of river and lake connection projects to achieve sponge cities.Construction,to realize the benign hydrological cycle of the city,to maintain and restore the sponge function of the city,this is also a new attempt on the concept of sponge city construction.This study has important guiding significance for the planning and construction of the sponge city of Hunnan District.