The Study Of Urban Stormwater Runoff Pollution Control Theory And Technology

The initial rainwater runoff model of Tianjin drainage system is established in order to study the property and control process of non-point pollution and the comprehensive operation mode of initial rainwater management is proposed. The main outcomes are:(1) Applying the measured runoff data of Tianjin and the experience of the relevant research at home and abroad, the non-point rainwater runoff pollution model is established. And the results of model are validated by the existing experiments.(2) The non-point source pollution load is analysed under different return periods and rainfall patterns. As the increases rainfall return period and intensity, the action of washing ground is enhanced and the peak concentration of pollutants at the outlet is increased. For the same return period, the time of peak concentration of pollutants is different corresponding to the peak time of rainfall curve. For this reason, the concentration control principle is suggested to allow only the initial rainwater of high concentration to reservoir for making full use of storage volume and increasing interception rate of reservoir.(3) By analyzing the status of initial rainwater runoff pollution in Tianjin and summarizing the control technologies home and abroad, the comprehensive operation mode of initial rainwater is proposed. The key points are making full use of methods of source control (increase of ground sweep, green space and permeable surface), reservoir, sewage network, the surplus capacity of sewage treatment plant and self-purification capacity of river to reduce the effect of initial rainwater runoff pollution.(4) 18 regulation and storage solutions are designed by using orthogonal design method. Based on the results of environmental and economic impact assessment, the optimal solution is selected for different return periods. The results of range analysis show the regulating effects of sewage treatment plant and sewage network are small compared to the other regulation measures. Therefore, the measures of sewage treatment plant and sewage network are not suggested to use in practice. The priority selections are reservoir and the increases green space and permeable surface area and ground sweep.(5) Based on the optimal solutions, the proposals of initial rainwater runoff pollution control for the study area and Tianjin are proposed. It provides theoretical and technical support for runoff pollution control and the best management model for Tianjin.