Research On The Device Of Urban Rainwater Filtration Based On The Concept Of ‘Sponge City'

In recent years,China has suffered from a severe waterlogging disaster because of the rainstorm,and the shortage of water resource has been one of the difficulties faced by our country for a long time.To solve these problems,our country put forward a concept of construction of sponge city.This article is to design a kind of water filter device based on this concept,and we optimized and transformed the device from hydraulic power and water quality,then we built an engineering demonstration area of sponge city in the Tianjin airport economic zone which is our research object.Firstly,we got the basic information of the target area such as the climate,geographical position and so on,through actual investigation and research.We collected the natural rain,roofing rainwater runoff and road rainwater runoff in the target area,and detected six water quality indexes of these water samples,including pH,turbidity,SS,COD_Cr,BOD₅ and DO.According to the results,we could find out the relationship between the pollutants'concentration and the rainfall duration,and also analysis the correlation between several pollutants which had the similar change rule.The second task is to design the device of rainwater filter.The content is divided into two parts,which are hydraulic and water quality.One part is to design the general structure of rainwater filter according to the basic requirements,and by using FLUENT software we could simulate the internal flow of the device,then find out the defects and optimize them.The other part is to choose the most adaptable filtering material.After building the actual model in the laboratory and making up the rainwater runoff according to the main pollutants and their concentration in the target area,the best filtering material can be decided by changing the water turbidity,the flow rate and the thickness of filter.At last,through researching the present situation,existing problems,and the actual rainwater utilization of the target area,we applied the device of rainwater filter into the practical project.We took Tianjin airport economic zone city management center as an engineering demonstration area,and proposed a new planning scheme about sponge city and finished the project design of the rainwater utilization system in this area.