An Integrated Analysis & Evaluation On The Water Pollution Character Of The Tongyang River At The Chaohu Lake

The into-lake rivers were the main ways for the municipal sewage and agricultural pollution entered into the Chaohu Lake. A research on the pollution of the into-like rivers' water and sediments is very important to trace back the pollution sources and to control pollutants.The water and sediment quality of the Tongyang River, one of the into-lake rivers of the Chaohu Lake, was analyzed on the basis of the data that came from the field investigation and experiments in the summer of 2007. The main results are as follows:1) From analysis of the physical and chemical properties of the Tongyang River's water, it showed weak acidic and contained rich nutrient. So it was beneficial for aquatic plants' growing.2) The result of the fuzzy assessment showed that the water quality in the upper Tongyang River was subject to the fifth grade, and in the middle of the river to the third grade. But in the lower part of the river, the water quality was decreased to the fourth grade because of the effected of the ChaoHu Lake.3) In the upper part of the Tongyang River's sediment, the pollutants showed higher contents and greater change, and it tended to be stable in the lower. But at the horizontal direction, the pollutants in the sediment had no remarkable changes law.4) From the principal component analysis, the main pollution factors in the TongYang River's water body consisted of nitride, biological activities and ionic attribute. And the bottom sediment was mainly controlled by the organic compounds, acid base properties and re suspension ability.5) The analysis of the rations of nutrients showed that the organic pollutants in the Tongyang River's sediment was from the farmland around, and the utility of phosphorus was very low. From the fertility analysis, it showed a higher organic index and a severe pollution in the sediment.On the basis of the analysis & evaluation above, the author finds that all of the endogenous and exogenous pollution must be controlled to improve the water environment of the Tongyang River: 1) The main method to control the exogenous pollution is to decrease the living pollution and using pesticide,chemical fertilizer in the scientific way; 2) Dredging is proposed to treat with the endogenous pollution of the river, and the sludge could be used for agricultural production to avoid secondary pollution.