Water quality variation process in Nanjing reach of Qinhuai River and pollution control measures

Based on water function zoning of the Nanjing reach of the Qinhuai River,we used the pollution index method to analyze and evaluate the water quality variation process in the reach from 2001 to 2010. We found that the pollution sources of the Nanjing reach of the Qinhuai River were in the following order of descending significance: NH 3-N,BOD,COD Mn,and oil,of which the main contaminant was NH 3-N. The water quality of the new Qinhuai River was much better than that of other river reaches,and the inner Qinhuai River was still seriously polluted. In this paper,we summarize the influences of ten-year pollution control on the water quality of the Qinhuai River and point out that the urban sewage connection rate,pollution sources,and hydrodynamic conditions are the main factors affecting the water environment of the Qinhuai River. To control the pollution,we propose several measures and engineering solutions,including integrated pollution remediation,river dredging,ecological restoration,policy support.