Study On The Characteristics Of Runoff Wastewater And Their Treatability Evaluation

The purpose of this study is identification and characterization of concentration variation of pollutants of runoff, as well as their collection. Samples were collected in 4 rain fall events in Xi'an in 2010.The purpose of this study is concentration variation of pollutants in it and to evaluate it's flush effect. The study aslo try to make sure the collection of rainfall runoff in order to lessen the pollution. We stiill investigated the effeets of watertreatment units on pollutant removal.Study results show that event mean concentrations (EMC) of pollutants didn't meet requirement. The concentrations of COD,NH3-N,TP were requirement's 8.65,3.85,6.65 times.In the same rainfall COD,SS,NH3-N,TP in pavement were that in roofing runoff 5.84,20.53,3.53,15.71 times.Flush effects and FFE are not found in this area,and affected by several factors. Flush effects of roofing is obvise than that of pavement.Finally we choose 12mm to be our collection.In the study of treatbility evaluation we studied the charaeteristies of pollutants and their distribution in rainfall,and investigated the effeets of watertreatment units on pollutant removal. There are more soluble COD in roofing runoff than that in pavement. 27.55% of COD is soluble of roofing runoff and that in pavement is 36.77%. 41.34% of NH3-N is soluble of pavemen runoff and that in roofing is 72.55%.38.35% of TP is soluble of pavemen runoff and that in roofing is 16.73%.The method of fuzzy analysis was applied to evaluate the weight of the main pollutants in the rainwater. regarding 3 kinds of watertreatment proeess such as sedimentation,,CRI, research on activity of microorganism. Removal rates of COD,SS, NH₃-N,TP by sedimentation were 56.3%,40.2%,19.8%,21.6%. Removal rates of COD,SS,NH3-N,TP by CRI were 68.20%,49.95%,22.90%,53.86%. Water quality matrix and water quality conversion matrix was introduced into the analysis for treatbility evaluation.The methods adopted in this paper are applieable in the filed of rainfallwatertreament. The result of the study can provide the theoretical basis for the selection of rainwater treatmentmethod.