太湖水质现状与主要污染物分析

Assessment of water quality and the main pollutions of Taihu Lake

2007年11月至2008年8月，按季度对太湖进行水化学及水生生物学分析采样，并采用水质污染指数评价法和综合富营养化指数法对太湖水质现状和主要污染物进行评价与分析。水质污染评价指数法分析结果显示，太湖的主要污染物为氮（N）、磷（P）和有机耗氧量（CODMn）。总磷（TP）所占的污染负荷指数最大（34．34％～54．34％），平均污染指数为48．36％。叶绿素a（Chl—a）与TN、TP和CODMn之间呈显著正相关，Pearson相关系数分别为0．715（P〈0．01）、0．666（P〈0．01）和0．740（P〈0．01）。采用综合营养状态指数法评价太湖的水质状态，发现太湖4个季节的综合营养状态指数TLI（∑）值均在60～70之间，平均值为65．54，各季节的水质状态差异较小。太湖水质整体上已处于中度富营养状态，部分区域已呈严重富营养化。

The analysis samples of water chemistry and aquatic biology were collected quarterly in Taihu Lake from November 2007 to August 2008. We evaluate the actual condition of water quality and the main pollution sources of Taihu Lake by ways of water pollution index and comprehensive analysis of eutrophication. Evaluation of water pollution index analysis revealed that the main pollutants in Taihu Lake were nitrogen （N）, phosphorus（P） and organic oxygen consumption （CODMn）. Total phosphorus （TP） shared the largest pollution load index（34.34% -54.34% ）, with the average pollution index of 48.36%. TN, TP and CODMn had a significant positive correlations with Chlorophyll a（ Chl-a）, Pearson correlation coefficients were 0. 715 （P 〈 0.01 ）, 0. 666 （ P 〈 0.01 ） and 0. 740 （ P 〈 0.01 ） respectively. According to comprehensive analysis of nutritional status indicators, it also showed that TLI（Y,） values of Taihu Lake were between 60 and 70 in four seasons, with a mean value of 65.54. The seasonal changes of water quality were small. In a word, Taihu Lake was in a moderately eutrophication, and some of the region had shown a serious eutrophication.