Study On Pollution Control Of Combined Sewer Overflow And Optimization Scheduling Solution

The combined sewer overflow pollution of Jizhuangzi drainage system is studied.By collecting the data of the drainage pipelines and pumping stations, combined withthe specific characteristics of rainfall in Tianjin, the combined sewer system ofJizhuangzi is estabilished. The influence factors of overflow and the control measuresto prevent overflow pollution are discussed and the comprehensive optimizationscheduling solution is proposed.The main conclusions are as the following.(1) By applying the ArcGIS (Geographic Information System) platform, RS(Remote sensing) technology is integrated with the Infoworks software and thecombined sewer system model is established. Based on the measured data of rainfalland experimental data of Tianjin, the parameters of model are calibrated.(2) Different conditions of underlaying surface, rainfall, pipe network state of thecombined sewer system are simulated. It is shown that the increase of green space andreduction of the runoff coefficient can effectively reduce the overflow. With theincrease of rainfall return period, the overflows are increased obviously. The time ofrainfall on peak time of sewage will cause more overflow. Continuous rainfall is animportant factor to the increase of overflow. Emptying the pipe network and cleaningthe network before rainfall are verynecessary.(3) Sources of combined sewer overflow pollutants are analyzed. The differenttypes of the underlying surface overflow pollution is simulated on the conditions ofdifferent rainfall intensity and the production process of the pollutants, the change ruleof concentration and the overflow pollution are obtained. The control strategy ofoverflow pollution is discussed.(4) On the basis of the analysis to the factors of overflow and the measures toprevent overflow pollution, a comprehensive optimization scheduling solution isproposed to reduce the overflow pollutants. The closure tube scheduling in Shanghairoad pump station, the concentration control in the end of pipeline networks andtreatment of wastewater plant are applied. The results show that the optimizationscheduling solution reduces effectivelythe overflow pollution.