Research Of Rainwater Utilization In Urban Community

As the urban water shortage problem has become increasingly prominent, the rainwater which is one of the most fundamental, direct and economical water resources is more and more attention by people. Rainwater utilization in residential community is not only to provide new water sources for the production of human life, but also to play an important role in supplementing and regulating water resource, preventing floods and improving urban water environment. Raising the rate of rainwater utilization is also an important measure in building water-saving cities. This article is main research on rainwater utilization in urban community. On the basis of referring to large domestic and international literature, this article analyses the relation between urban water resource and urban rainwater utilization, the impact of urbanization on urban rainwater utilization and the main way of rainwater utilization. Through the monitoring of the rainfall in some areas of Tianjin, it discusses the characteristics of the rainfall in this region and the impact of rainwater utilization. It monitors the quality of runoff in typical area, and sums up its characteristics. For treatment of the first runoff, some physical and chemical experiments are made in library and some technical parameters are educed. Finally, the program of rainwater utilization for an actual urban community is made.Based on rainfall monitoring, it is found that most of rainfall is thunderstorm in Tianjin, the early rainfall intensity is greater and rainfall duration is not long. Half of the rainfall which is monitored in rain season of 2007 is thunderstorm. The following conclusions can be drawn from the monitoring of runoff quality:â‘ the major pollutants in runoff is SS and CODcr, and SS is relatively large contribution to CODcr.â‘¡the pollution in early runoff is more serious, the biggest SS load is 2608 mg/L and the biggest CODcr load is 742mg/L in road runoff. As the rain duration is extension, the concentration of road runoff CODcr is about 100mg/L and roof runoff is about 50mg/L. and the concentration of pollutants decline faster in the first 10 min. through coagulation experiment about first runoff it is found that coagulation treatment suffice the load of first runoff pollution, and the pollution removal rate is higher, the water meet some standard requirements after treatment. As the quality of first runoff is different, their best dosing is between 20mg/L and 30mg/L.the effect of coagulation is better if runoff is not precipitation, and the floc sedimentation time is about 10 min. A rainwater utilization program is made for urban community, it collects and recycles runoff of all the underlying surface, and recycle.