Distribution Characteristics And Potential Risks Of Phenols In Schistosomiasis Epidemic Areas Of Dongting Lake Surface Water

This study selected the typical Schistosome-endemic Areas as the research object, and taking the Three Gorges Reservoir as the contrast area. in order to investigate the pollution characteristics of a variety of phenolic compounds from81surface water samples collected from Dongting lake research area. and the47surface water samples collected from the Three Gorges Reservoir were also investigated. the high sensitive tandem mass spectrometry (ms) quantitative analysis method of the phenolic compounds was established and optimized.the control conditions of derivatization reaction were optimized.and the phenolic compounds were simultaneous determined by using PFBBr derivatization and GC-MS.this analysis and determination method was established in this study.the128surface water samples were dealed by SPE extraction. PFBBr derivatization, qualitative and quantitative analysis by GC-MS, and the data was dealed by SPSS17.0. combining with phenolic compounds migration-degradation rule and environmental chemical, hydrology, geology, and climate knowledge. and roundly discussing the distribution characteristics and potential risks of the pollutants from the research area.so as to provide important reference for evaluating the pollution situation of phenolic compounds in surface water from the local area. the main research results are as follows:(1) Establishing and optimizing the method of analysis and determination, the best derivative condition was ascertained, the water bath temperature is30℃, the water bath time is25min, potash adding amount is0.2g. the LOD (≤218.18pg/L) of this method is much lower than lμg/L, through the recovery repeatability tests of the seven high concentration and seven low concentration samples, the test results in the low level of concentration show that the recovery is72%~123.7%, the relative standard deviation is8.0%~27.6%.and the recovery is72.3%~119%, the relative standard deviation is7%~12.8%in the low level of concentration, the experimental results show that the improved the method of analysis and determination is easier to implement, reagents and material are easy to access, test conditions are also easy to control, the recovery and test repeatability is acceptable.it contents the detection requirements of a variety of phenolic constituent from Nature water. (2) The first study of phenolic compounds pollution from the most typical lake-swamp type epidemic areas and three gorges reservoir area have been done. donging the system research on the variety of phenolic compounds existed simultaneously in surface water samples. the results from Dongting lake research area show that the highest total concentrations of the14phenolic compounds in the three rivers were from the medium water period. the total concentration are1362.64-2436.53ng·L-1(geometric mean), there is significant difference between the concentrations of phenols in these samples from one river in different period (P <0.05,T test). there is no significant difference between the concentrations of phenols in different rivers in same period (P>0.05,T test, and the pollution level is in the same order of magnitude. the concentration of Phenol,2,6-Dichlorophenol,2-Nitrophenol and PCP detected from these three rivers in different periods are the highest, the concentrations are separately ND～1783.89ng·L-1,0.01～362.72ng·L-1,0.02～11908.22ng·L-1,ND～6057.37ng·L-1, which respectively accounted for13.8%,1%,54.7%%,26.9%in total content of phenols, they are the most predominant phenolic compounds. The results from the Three Gorges Reservoir show that the concentrations of phenolic compounds in the samples from the main stream and tributaries were52.47ng·L-1and87.99ng·L-1, respectively. The concentrations of non-chlorinated phenols were higher than those of chlorinated phenols in the main stream and tributaries, and so the non-chlorinated phenols were the predominant compounds in these surface water samples. Phenol, o-cresol and2-nitrophenol were the predominant compounds accounted for79.1%,3.7%,and3.6%in the samples from the main stream, respectively. Phenol, o-cresol,2,6-dichlorophenol and2-nitrophenol were the main compounds accounted for77.5%,5.4%,3.8%and2.2%in the samples from the tributaries, respectively.(3) Analyzing the potential risks of phenolic pollution from the Dong Ting lake research area. as compared the concentrations of phenol2,6-Dichlorophenol2-Nitrophenol and PCP with the standard limits in National Environmental Health Risk List, GB3838-2002and GB5749-2006, the levels of these compounds were much lower than the standard limits, suggesting negligible risk of these four predominant phenolic compounds in these samples. Comparing the concentration of PCP in different period with the results reported in the other schistosome-endemic areas, the levels of PCP reported in this study were in the moderate levels order of magnitude in these schistosome-endemic areas, the pollution of PCP, and it's derivatives will lead to the potential risk of local water environment, comparing the concentrations of phenol and2-nitrophenol from the Three Gorges Reservoir research area with the standard limits in The National Environmental Health Risk List, the levels of phenol and2-nitrophenol were much lower than the standard limits, suggesting negligible risk of phenol and2-nitrophenol in these samples.