Study On The Control Of Surface Runoff Pollution By The Source Control Of Northern Sponge Cities

The construction of"sponge city"is an important measure to promote the development of new type of urbanization in the country,which plays an important role in alleviating urban waterlogging,reducing the pollution load of surface runoff and improving urban water environment.But mostly to water control in our country as the goal,to the urban surface runoff pollution has not been given enough attention,in this study is less,but the lack of study of regional engineering field monitoring.Taking changchun city experimental base for pilot,sponge combined with cold in the north to factors such as peculiar climate type,hydrological characteristics,based on practical engineering field monitoring,the cold is suitable for our country were characteristic of the permeable brick and subsided green sponge technical measures,and use of SWMM model,to explore the combination in the actual system infrastructure for the removal of surface runoff pollutants,so cold in the north were the more reasonable application of sponge technical measures of the city,under different engineering requirements for sponge facilities provide reference for the popularization and application in the north in our country,developing rainwater utilization potential at the same time,to provide basic data for rainwater to use,also provides the assessment of construction project,regional project monitoring method,provide relevant departments with sponge reference of city construction project assessment services.First,analyzed the hydrogeological characteristics of the study area,according to the characteristics of special cold northern applicability wide aperture type permeable brick,using its freeze-thaw cycle can ring up to 50 times above,real-time monitoring of the situation of rainfall from April to September 19 times,choose 7 times valid data,discuss its effect on surface runoff pollution control,analyze its of SS,COD,nitrogen and phosphorus runoff pollutants such as the mechanism of purification of water sample value index can reach the standard water recycle,the experimental results show that the crack permeable brick structure of SS,NH₃-N removal effect is good,the removal rate of SS,COD and NH₃-N is respectively 48.60%,36.26%,56.19%,and TP removal effect of the worst,only 8.41%.At the same time,the effect of rainfall（or rainfall intensity）on the removal efficiency of the crack permeable brick was studied,and the removal rate of each index was the best when the rainfall was 24.5mm.Secondly,as the representative of typical green space,it has obvious effect on the surface runoff.The removal rate of SS,COD,NH₃-N and TP was 59.81%,39.01%,37.53%and 30.49%respectively,which had a good effect on SS removal,while the removal efficiency of COD and NH₃-N was not significant,and the removal effect of TP was the worst.There is an obvious initial effect of rainfall runoff pollution.Rain early within 1 h of SS,COD and NH₃-N and TP water and there exists a good linear relationship between feed concentration and level of significance,the correlation coefficient were 0.699,0.791,0.864,0.699 in line with the first order kinetics model;The correlation coefficients of SS,COD,NH₃-Nand TP were 0.842,0.813,0.883and 0.938,respectively,in the later period of rainfall,with the continuous extension of hydraulic retention time.Water index basically met rainwater recycling reference standard,subsided green space on the removal efficiency of pollutants in surface runoff from rainfall（or rainfall intensity）significantly,when the rainfall is about 32mm of SS,COD removal effect is best,during the period of 9 mm to 15 mm on NH₃-N,TP removal effect is best.Finally,the use of SWMM model,to simulate the effect of the quality of the water in the pilot area area using crack permeable brick,subsided after sponge measures such as green,without using results show that the technology control under the condition of water content is higher and the combination of facilities,technology can effectively reduce runoff pollutants in green space accounted for 9%,the biggest characteristic width 14.6m;permeable pavement rate is 25%,the biggest characteristic width 44.4m facilities under control technology for pollutant removal efficiency of SS>COD>NH₃-N>TP,removal rate reached 42.7%,42%,40.1%and 42%,respectively,effluent water quality meet the water reuse reference standard and standard of sewage comprehensive discharge level 3.