Study On Healthy Conditions Of Urban Storm Sewer System

Urban sewer system has its own carrying capacity. Urban is considered as a whole organism. All of its apparatus have the limit of carrying capacity. So does the sewer system. If the sewer system works under overloading, it will damage the urban organism healthy conditions, it is the source of urban illnesses such as storm flood and non-pointed source pollution. This paper has studied and modeled hydrodynamic and water quality transport in urban storm sewer aimed at the problem. This paper has also made some urban storm sewer healthy condition evaluations primarily.This paper is parted into two main sections for the study on sewer healthy conditions. The first one is hydrodynamic modeling, the other one is pollution transport modeling. In the hydrodynamic modeling section this paper has used hydrodynamic modules of SWMM model. The paper has modeled invariable and variable flow in many types of river network and pipe network to test the applicability of the model. The results of calculation are well agreed with the data of measured. The applicability of the hydrodynamic model is proved. In the water quality modeling section, this paper has used cumulate model and storm crush model to model the pollution which is crushed into urban sewer system. CSTR method (Continuously Stirred Tank Reactor) is used to model the pollution transport in the pipe network. The results of modeling are well agreed with academic and measured values.This paper has set up a storm sewer system in Dalian University of Technology based on the model up said. The system can calculate the carrying capability and pollution wiping off ability of the drainage network in different rainfall conditions of DUT. It can perfectly forecast the quantity and quality of discharged water in each rainfall when the storm sewer network is well set up in DUT.Finally, the paper has made healthy evaluation used the results of calculation and observation. From the analysis of the carrying capability of sewer system and pollution concentration of discharged water of DUT, the sewer system is unhealthy now. The paper has given out some advice to improve this condition from the using of rain water resource, optimizing of drainage pipe network and wiping off pollutions facets.