The Distribution And Source Analysis Of PAHs In The Typical Wetlands Of Sanjiang Plain

Polycyclic aromatic hydrocarbons(PAHs) are a group of persistent organicpollutants(POPs) which are carcinogenic, teratogenic and mutagenic and also havegreat threat to human health and environment. PAHs are common in variousenvironmental media at home and abroad, therefore, the problem of PAHs pollutionhas caused a great attention of environmental researchers around the world. SanjiangPlain wetlands in northeast China is the largest marshes areal, which has a wealth ofnatural and mineral resources. Recent decades, due to the large-scale agriculturaldevelopment many times, it has become the important commodity grain base in ourcountry. With the large area of vegetation burned for agricultural reclamation andindustrial production process, a great number of PAHs pollutants have beenproduced that have a great impact on the environment quality of the Sanjiang Plainwetlands. Studies of PAHs,which are limited to the distribution and sources insurface sediments, on the historical change with depth in sediment profile arerelatively few.Adopting gas chromatography-mass spectrometer(GC-MS), this paper hascarried on the detailed analysis on the composition and contents of PAHs in bothsurface sediment and profiles(50cm) of the samples in Dongfanghong, Heixiaziisland wetlands and Shenjiadian peatland-three important wetlands in SanjiangPlain. This study also determined the PAHs pollution level and mastered thehistorical change of PAHs with depth in three sample profiles. Combinating theratioes of PAHs compounds and the main human activities in different historicalperiod of Sanjiang Plain, we can reveal the sources and impact of PAHs on thewetland environment from the human development processes.It provided a scientificbasis to ensure the degree of human disturbance to the environment, regionalenvironmental change and the quality evaluation of ecological environment.The result revealed that all16EPA priority control PAHs were detected insurface sediment of three samples, the total concentrations are3784ng/g,5645ng/g, 2909ng/g respective in Dongfanghong, Heixiazi island wetlands and Shenjiadianpeatland, which are greater than the average contents in other wetlands at home andabroad and far more than the American EPA standard, belong to the seriouspollution levels.Low rings PAHs were given priority in surface sediments of three samples,however, the sediment of Shenjiadian peatland has more high rings PAHs than Dongfanghong and Heixiazi island samples.According to the ratioes of PAHs compounds, plants and coal combustion fromthe agricultural development and the industrial production processes are thedominant sources of PAHs in Dong fanghong and Heixiazi island wetlands. MostPAHs migrate to the wetlands with the river current, another are through theatmospheric deposition. PAHs in Shenjiadian sediment are both from petroleum andcombustion sources, followed by the human activities and migrate to the peatlandthrough the process of atmospheric deposition.The study of PAHs in three sample profiles implied that total concentration andingredients of PAHs decrease with the increase of depth in Dongfanghong andHeixiazi island sample profiles. The concentration of PAHs in layer0~15cm ishigher than16~30cm and31~50cm, and low rings PAHs play a leading role,which come from natural plants and coal combustion. However, total concentrationand ingredients of PAHs in Shenjiadian sample profile change little, both low andhigh rings PAHs occupy a large proportion. The mixture of petroleum andcombustion are the sources of PAHs in Shenjiadian.peatland.