Eutrophication Evaluation And Distribution With Source Of PAHs In Taihu Lake

Taihu Lake is located in China's most economically developed Yangtze River Delta,is the important freshwater resources.With the rapid economic development,,water pollution and eutrophication of Taihu is becoming increasingly serious from the early 80s of the 20th century.Therefore,it is necessary to study the trend and spatial distribution of water environment in typical areas of Taihu Lake Basin,and to evaluate the degree of eutrophication and the distribution and traceability analysis of Polycyclic Aromatic Hydrocarbons(PAHs).In this study,the monitoring data of Taihu Lake water environment and the sampling data of typical water sources in 2015 were selected.The Spearman rank correlation coefficient method was used to analyze the trend of water environment pollution.The principal component analysis method was used to analyze water environment pollution in Taihu Lake.Multidimensional normal cloud model was used to analyze eutrophication degree in the lake.The characteristics of polycyclic aromatic hydrocarbons(PAHs)in Taihu Lake drinking water source were studied,and the characteristic compound method and principal component method were used to study the waterlogging characteristics of Taihu Lake water source.Concluded as follow:(1)From 2000 to 2006,most of the indicators showed an upward trend.The results showed that the indexes were WT,pH,DO,NH3-N,NO3-N,TN,TP,PHE and Chla.Taihu Lake water pollution sources are mostly acid and alkali biochemical pollution,thermal pollution and oil,sediment pollution.Compared with other lakes,Wuli Lake was polluted more seriously.(2)From 2000 to 2006,the eutrophication degree of the nine lakes in Taihu Lake was in the middle of the nutrient and above,and could be divided into three groups.The first group is Meiliang Bay,Wuli Lake,Zhu Shan Lake and the western coastal area,the four lake water body nutrition degree to re-rich nutrition;the second group for the Gonghu Lake area,the eastern coastal area and the southern In the coastal area,the water quality of the four lake areas is mainly nutritious.The third group is the eastern Taihu Lake and the eastern part is the eutrophication degree of the East Taihu Lake.(3)A total of 11 PAHs were detected in four typical drinking water sources in Taihu Lake and the surface sediments of Wangyu River in Wuxi,with a maximum content of 280ng/g and an average of 114ng/g.PAHs pollution in drinking water sources in Taihu Lake is at a low level.4 typical drinking water sources were Wuxi Gonghu water source,Suzhou Jinshu port water source,Suzhou Temple port water source and Suzhou Yuyangshan water source,Wuxi Wangyu River for the water channel into the lake.(4)PAHs in the surface sediments were mainly composed of 4 rings and 5-6 rings PAHs,accounting for 43.86%and 50.88%,respectively.The PAHs of 2-3 rings were relatively low,accounting for only 5.26%.(5)The surface sediments PAHs Mainly for the fossil fuels(including gasoline,diesel,coal,wood,etc.)burning,but also with oil pollution.