Analysis of pollution loading and water environmental capacity of Gan River in Nanchang.

Based on the investigation and analysis of various pollution sources,status quo in Nanchang section of Gan River was analyzed with COD and NH3-N as index of pollution load,and main pollution source was found. Choosing NH3-N and COD as two indicators,water environmental capacity was computed using two dimensional water quality model as well. According to the water environment capacity and recent amount of pollution discharged into the river,remaining environment capacity was obtained. Results indicated that the pollution load discharged into Nanchang section of Gan River was 94,255.47t in 2008,most of which was COD,with major pollution source being from municipal domestic sewage,agricultural runoff and industrial wastewater. The River has good water quality and amply water environmental capacity except southern branch,which doesn’t have residual water environmental capacity.