Characterization Of Heavy Metal Pollution Of Stormwater Runoff In Rapid Urbanization Areas

With the acceleration of urbanization,water pollution has become the focus ofissues domestic and foreign scholars discussed.Water pollution in urban environmenthas become an important part of city sustainable development,rapidly increasingurban construction impervious surface,resulting in rainwater runoff process producesa qualitative change.In the rainy season,via accumulation of atmosphericdeposition,dust and harmful gas emissions of industrial zone,road traffic caused bydust and vehicle exhaust mode of surface contaminants through rainfall runofftransmission pathway in the surface migration,thus bring negative effect to the citywater environment.In this paper,taking Urumqi city as an example,select three different levels ofroad surface runoff of Pb,Cu,Zn,Cd4sampling elements were monitored duringrainfall runoff events occurred.The pavement runoff concentration of heavymetals,mean concentration of heavy metals,and the correlation among heavy metalswere analyzed.It was concluded that3sampling points of heavy metalconcentrations were5to15minutes to reach the peak,with the reduction of runoff,concentration is reduced gradually,3sampling points of concentrations of elementsZn,Cu,Pb was the highest,while the concentrations of elements Cd wasminimum;Heavy metals in road runoff in the strong correlation between eachother.Different road grade heavy metal concentration,urban traffic area road runoffconcentration of heavy metals is higher than the road inside of community.Urumqiroad runoff pollution levels of heavy metals than other cities,which reflected therewas a wide gap between Urumqi and other cities on the environment maintenanceand management of the roads.The heavy metal concentrations of Cu,Pb,Zn,Cd and Ni were analyzed during therainfall runoff occurred on different impermeable surface,the results showed that thefirst flush phenomenon was quite obvious on different impervious.In the initial stageof runoff,the concentrations of heavy metal elements with changes in rainfall andrunoff will peak,and then continued to decline,in the sampling the end of thestage,the concentrations of heavy metal elements increase or balance.The averagerainfall,rainfall intensity,rainfall duration and sunny accumulation has certaininfluence on impervious surface changes of heavy metal concentration.Comparisonof surface water environmental quality state,not through the heavy metal elements Pb,Cu,Zn in the water have exceed the standard in different degree,3different typesof impervious surfaces,heavy metal pollution of road was the highest the number ofparking.The correlation between rainfall and runoff in Urumqi heavy metal elementsand heavy metal pollutants significantly,the homology with a certainrelationship;through the artificial experiment,obtained heavy metal pollution andurbanization in frequent traffic activity and deposition of pollutants in surfaceimpervious surfaces have a great relationship.Given the analysis results,the management of urban non-point source pollutioncontrol gives improved clean urban transport rate,control stormwater runoffcoefficient,the use of low-polluting water proof material,to enhance awareness ofenvironmental protection countermeasures in order for the urban surface runoffcontrol and improvement of urban water environment pollutants provide some help.