Distribution Characters Of PAHs In Aquatic Environment And The Isolation Of PAHs-degrading Bacteria From The Middle And Lower Reaches Of The Huaihe River

PAHs in the samples of water, suspended particulate matters and sedimentss of Huaihe River(from ZhangYangguan to ShuangGou)were analyzed in the paper for distribution characteristics, sources and ecological risk assessment. In addition, PAHs-degrading bacteria is screened from the sample of sediments in the study area, lay the foundation for the bioremediation of PAHs.Using solid phase extraction for the samples of water, soxhlet extraction for suspended particulate matters and sedimentss, the samples were extracted promptly. Then all the samples separated by the C18-SPE, analysed by GC-MS. The results indicate that:In the study, the total PAHs of water is ranged slightly form0.19to2.18μg/L. Compared with the dry season (1.70～5.02μg/L), the total PAHs in wet period is roughly the same trend along the river. And the total PAHs in wet period was slightly lower, may be affected by the suspended particulate matter content and so on. Distribution of molecular weight of the PAHs shows that dissolved PAHs in the study area is mainly due to the high temperature combustion of fossil fuels, as well as direct input of a small amount of oil products. Compared PAHs in water to evaluation criteria, we found that the density of Anthracene、Benzo(b)fluoranthene、 Benzo(k)fluoranthene and Benzo(a)pyrenene have surpassed the standard, measures must be taken to control the pollution.The total PAHs in suspended particulate matters samples of wet and dry seasons are2.72～10.22μg/L and4.85～9.85μg/L. The results of source analysis indicates that the high temperature burning of fossil fuels is the main source of suspended photocatalyst PAHs.The total PAHs in sedimentss along the river vary considerably. The highest is1007.62ng/g in the site of Luohe and948.77ng/g of Pingwei, ZhengYangguan is the lowest (432.30ng/g). Compared the sediments PAHs concentration in the paper with the ecological risk assessment standards. Benzo(b)fluoranthene and Benzo(k)fluoranthene are detected in all samples, may be consistent with a adverse biological effects in sedimentss of the study area. Molecular weight composition and the ratios of PAHs are consistent with a dominant combustion PAHs source and a small amount of oil.PAHs-degrading bacteria was isolated from the sediments of Huaihe River:Q7, By biochemical identification and identification of16S rRNA, Q7was identified as Bacillus sp. After10d, the degradation rate of Benzo(a)pyrenene(at levels of3mg/L) by Q7was64%under conditions of35℃, pH7,150rpm. Besides, Q7shows a strong ability to grow from pH6to pH9, as well as in wide temperature.