Distribution Of Polycyclic Aromatic Hydrocarbonsand Dynamic Changes Of Microbial Community In Sediment Of Hunhe River In Shenyang Section

As a serious pollutant,polycyclic aromatic hydrocarbons(PAHs)pollution has attracted more and more attention.According to the characteristics of PAHs,PAHs tend to accumulate in the sediment with water flow and further affect the composition of microbial communities in the sediment.In order to reveal PAHs distribution,the relationship between the PAHs and microbial community variation,eight sediments samples were collected in Shenyang arear along Hunhe River(from Dongzhou to Hunhe sluice)from April 2018 to October 2018.The effects of accumulation of different PAHs on community composition and microbial succession in Hunhe River at different stages.The main results are as follows:The pH value of each section of Hunhe River is basically in a relatively stable state.The pH value of Dahuofang Reservoir varies slightly in one year,while that of downstream Fushun,Hunhe sluice and Changqing Bridge varies greatly.The TN of each river reach is the highest in October(autumn),followed by summer(June),and the lowest in spring(April).It is speculated that the reason may be related to the time lag of upstream nutrient input.In addition,the fluctuation of PAHs also affects the variation of organic matter concentration in each river section.The accumulation of TP is similar to that of TN,but the change is relatively low.Among them,Shenfu Irrigation Channel has the most serious pollution.The pollution situation of the whole Hunhe River is closely related to the activities of the surrounding people,with the least pollution in April,the least pollutants produced,and the least accumulation in the sediment.In June,the accumulation of PAHs in sediments of each river reach changed the most.Fushun is the most polluted river section,followed by Hunhe Bridge.As there are no factories and industrial sewage outlets in both places,it can be determined that they are caused by the daily life of the population.As the downstream of Dahuofang Reservoir,Hunhe Bridge often exceeds the standard of PAHs,which has to be paid attention to.Although the water quality of Dahuofang Reservoir has been good,it is speculated that the change of water quality of Hunhe Bridge may be caused by the influx of tributaries.At the phylum level,the communities in sediments of different reaches of Hunhe River are basically similar,mainly Proteobacteria,Bacteroidetes,Firmicutes and Actinobacteria,while at the generic level,Acinetobacter,Lactococcus and Kaistobacter are dominant.Arthrobacter is the most common species.