Abstract:

The Dianshan Lake is an important drinking water source conservation area of Shanghai city.Its water quality safety have been severely threatened by the increasing eutrophication level and the phytoplankton bloom over the last ten years.For controlling the maximum amounts of pollutants permitted into the Dianshan Lake,the amounts of TN,TP,COD and NH3N released into water body from six towns around the Dianshan Lake were parsed and quantified by using the methods related to emission factors.The results are as follows.The amounts of TN,TP,COD and NH3N,which were from the main pollution sources including industrial,agricultural and domestic sewages,as well as surface runoffs of urban,industrial and road construction land and released into near water body,were 84199 t,11968 t,16 776.07 t and 46110 t respectively in 2009.The pollution source with biggest contribution to TN and NH3N was domestic sewages,while the agricultural pollution contributed most to TP and the surface runoffs from the urban,industrial and road land contributed most to COD. Among the six towns, Fenhu Town is the biggest pollutant contributor, whereas Zhouzhuang Town is the smallest