Study on combined flow system retrofitting measures based on stormwater interception rate
The control of combined sewer overflow pollution was an urgent and challenging task faced by urban drainage systems in China,especially in densely populated and difficult-to-renovate old city areas.It was crucial to establish an economically feasible set of measures for retrofitting combined sewer systems to reduce overflow pollution and fully utilize the regulating capacity of existing infrastructure.Based on the water's environmental capacity,stormwater interception rate was used as a pollution control indicator,and equivalent rainfall intensity was combined to determine the total interception and storage capacity.A hydraulic and water quality model of the drainage system in a large old city area was constructed using the time-area model of MIKE Urban.Feasibility and economic analyses were conducted for the retrofitting of interception and storage,resulting in the development of a retrofit scheme that maintaining the existing interception facilities,installing flow restriction devices on the pumps,and constructing a 4 mm rainfall storage tank.After simulation,the stormwater interception rate increased from 58.9％to 85.3％,simplifying the calculation of retrofitting interception and storage,enhancing its applicability and further improving the linkage between interception and storage.This approach not only satisfied pollution control requirements but also more intuitively demonstrated the effectiveness of overflow pollution control,guiding a more rational and efficient implementation of combined sewer retrofitting in old city areas.
NETL
NSTL
万方数据
