Study On Surface Runoff Pollution Control In Typical Urban Villages

In the process of rapid development in China,water ecosystem control is a serious challenge,especially to the urban villages with relatively backward urbanization and slow development process,the water pollution is more obvious,the need of control is more urgent,and should be paid attention to by the society.Relevant studies have shown that there is a high pollution load on the surface of urban villages,and the environmental pollution of urban villages is caused by the following two reasons.First,there are a large number of village enterprises and small workshops with backward management level and obsolete equipment in urban villages,and the gaseous,liquid and solid pollutants produced by "run and drip" in the production process are distributed throughout urban villages.Second,villagers have poor awareness of environmental protection,and it is also very common for domestic sewage and catering wastewater to be discharged and garbage to be discarded at will.At the early stage of rainfall,rainwater carries pollutant particles in the air to the ground,forming runoff and discharging a large amount of surface pollutants into the surrounding water bodies,causing great damage to the surrounding water bodies,Something must be done about itIn this paper,a typical urban village of Sikouzhen community as an example,on the basis of the study area complete diversion system reform,analysis of the road runoff changes and runoff pollution characteristics,and the construction of SWMM model,the regulation and storage efficiency of four different distribution degrees of regulation and storage pool layout scheme comparative analysis.First of all,the current situation of the study area is investigated on the spot,and according to the complete shunt drainage system,the reconstruction focus is determined and the reconstruction plan is proposed.Secondly,sampling sites were selected to determine sampling and water quality detection methods and water quality evaluation standards.Based on sampling data,it was found that the changes of pavement runoff in the study area were mainly affected by average rainfall intensity,average rainfall intensity before runoff,peak rainfall intensity and rainfall type,and the rainfall and cumulative runoff were positively correlated through linear fitting analysis.Then,SS,COD,TN and TP were selected as the analysis indexes of runoff pollution.By analyzing the change process of the concentration of each pollutant,the results showed that the concentration of other three pollutants except TP far exceeded the discharge standard in the early sampling period.Through the linear fitting analysis of SS and the other three pollutants,The results show that there is a high correlation between the other three pollutants and SS.Therefore,SS can be treated specifically in the later optimization design of storage tank to reduce other pollutants.In addition,when drawing the dimensionless curve of M(V),it is found that the four pollutants all have the initial scour effect,which mainly occurs in the top 35% of the runoff volume ratio.Therefore,the first 35% of the runoff volume can be considered in the design of the storage tank volume.According to the terrain elevation and pipe network data of the study area,the SWMM model was built for the study area,and the statistics of the determined parameters were made,and the sensitivity analysis of the uncertain parameters was made.After the final parameter calibration,the simulation results of the model were compared with the measured water quality and quantity data,and the results showed that the simulation results were more accurate.Finally,combined with the actual situation of the study area,four kinds of storage pond layout schemes with different concentration and distribution degrees were proposed,and the rainfall data of four different recurrence periods(P=0.1a,P=0.5a,P=1.0a,P=3.0a)were obtained by combining the Xiamen rainstorm intensity formula with the Chicago rain pattern as the parameters of the rainfall module of the model.Combined with the SWMM model,the total runoff at the port of the regulating pond was simulated,and the volume of each regulating pond was calculated according to the35% interception ratio.Then,the peak runoff and the total pollutant amount at the outlet were simulated,and these were taken as the important reference standards to evaluate the regulating and storage efficiency of different regulating pond distribution schemes.The results showed that under the condition that the total volume of regulating pond was basically the same,with the increase of the dispersion degree of regulating pond,The peak value of runoff and the reduction rate of total pollutants also increased,indicating that the greater the dispersion degree of storage tank,the better the overall storage efficiency.