Pollution Situation of Nitrogen and Phosphorus in Rural Water Environment in Typical Region of Tai Lake

The pollution situation of nitrogen and phosphorus in rural water environment in typical region of Tai Lake was studied by determining the contents of total-phosphorus,nitrate nitrogen and ammonium nitrogen 6 times during a year in rural water body of Tai-lake typical region(Yixing,Wangzhuang and Xinzhuang).The results showed that the contents of nitrogen and phosphorus during rainy season were higher than other periods obviously.In surface water,ammonium nitrogen was the main contamination and its content was higher than nitrate nitrogen.Nitrate nitrogen was the main pollution resource in groundwater,but the pollution of ammonium nitrogen was worse than nitrate nitrogen in groundwater.The annual average values of ammonium nitrogen in Yixing and Wangzhuang were 1.596 mg·L-1 and 2.103 mg·L-1,and the highest values were 5.782 mg·L-1 and 5.441 mg·L-1 respectively,which exceeded the standard limit of types V of water quality about 10 times.The contents of nitrate nitrogen in groundwater of Xinzhuang from May to September exceeded the limit value(10 mg·L-1) for drinking which prescribed by WHO,and it was not fit for drinking.In the study area of Tai-lake,the annual average content of phosphorus was 0.492 mg·L-1,the pollution of phosphorus was worse than other surface water because of the accumulation trend of total-phosphorus,and in addition,the annual average contents of nitrate nitrogen and ammonium nitrogen were 2.152 mg·L-1 and 2.885 mg·L-1 respectively.Therefore,the water of Tai-lake in researched region is in the situation of eutrophication.