Analysis of the Pollution Status of Water Quality in Bai Lianjing River and the Coutermeasures

Bailianjing River is an important tributary of Huangpu River; 1000 meters upstream its influx to Huangpu River will be set as a landscape river in Expo Site. So the water quality there is of great importance. History reference demonstrated that the river quality was heavily polluted by organic matters and nutrient salts, So the indicators of CODcr, BOD₅, NH₄ ⁺-N, NO₃ ^--N, NO₂ ^--N, total nitrogen (TN), total phosphorous (TP) were analyzed in six sites during the period of May, 2008 to April, 2009. The spatial distribution of the value of CODcr explicated that the pollution level of organic matters alleviated since November, 2008. Until April, 2009, it reached category IV surface water body according to CODcr value. Trough analyzing the biodegradability index of the water it could conclude that organic matters were mainly came from the domestic waste water. Nitrogen and phosphorous pollution made the river reach category V surface water. Analyzing the nitrogen indicators in different month it was found that ammonia accounted 82 percent for total inorganic nitrogen while total inorganic nitrogen occupied 65 percent for total nitrogen, so it was critical to control ammonia input for relieving nitrogen pollution. Nitrogen was polluted more seriously in dry seasons, but phosphorous was polluted worse in wet seasons indicated point source and diffuse source pollution, respectively.