Study On Uptake Of Petroleum Hydrocarbon Pollutants By Suaeda Salsa

Petroleum hydrocarbon pollutants entering the environment through different channels not only cause pollution on the ecological environment such as water and soil,but also pose a serious threat to human health.In addition,petroleum hydrocarbon pollutants could remain in the environment for a long time due to the faint degradability.Therefore,petroleum hydrocarbon pollution has become an urgent ecological and environmental problem.In recent years,Suaeda salsa has great application potential in phytoremediation of petroleum hydrocarbon contaminated soil.The current research mainly focus on the remediation of heavy metal and improvement of soil salinity.However,there is no systematic report on the uptake and transport of petroleum hydrocarbons in saline alkali soil.In order to provide technical support and theoretical basis for the in-situ remediation of oil contaminated sites,in this paper,the uptake of phenanthrene（PHE）,fluoranthene（FLA）,n-Eicosane（C20）,n-Tetradecane（C24）and n-Octacosane（C28）by Suaeda salsa was systematically investigated,and the influence mechanism of typical environmental factors（concentration,p H value and salinity）on uptake was also investigated.The main contents and results are as follows:Firstly,in this work,the uptake of five petroleum hydrocarbon pollutants（PHs）by Suaeda salsa were investigated in solution culture system.The results showed that petroleum hydrocarbon pollutants could be absorbed by Suaeda salsa.Under the experimental conditions,the content of five target pollutants（PHE,FLA,C20,C24,C28）in Suaeda salsa increased rapidly and then tended to decrease,and reached the peak value（148-521μg/g）in approximate3-4 days.According to the fitting of the uptake law of PHs in the Suaeda salsa,the absorption rate of the five PHs in the root was 76.9-133 d^-1,and the absorption rate in the shoot was 7.78-11.5 d^-1.The root is the main enrichment part,all the petroleum hydrocarbon pollutants could be translocated from root to shoot.Petroleum hydrocarbon pollutants with relatively high hydrophobicity were more easily uptaken by roots,and had a relatively tough translocation,as a result,the migration of petroleum hydrocarbon pollutants depended on their physicochemical properties.Secondly,the influence of typical environmental factors（exposure concentration,p H value and salinity）on the uptake of petroleum hydrocarbon pollutants by Suaeda salsa were systematically studied.The results showed that the uptake increased gradually with the increase of PHs concentration.The order of root absorption is C28>C24>C20>FLA>PHE,and the order of shoot is PHE>FLA>C20>C24>C28.Neutral environment is the most favorable for Suaeda salsa to uptake five petroleum hydrocarbon pollutants.When the p H value is 6-8,the absorption of five PHs is higher.When p H=7,the root absorption is C28>C24>C20>fla>PHE.With the increase of salinity,the absorption of PHs by Suaeda salsa increased linearly.When the salinity is 5.445 psu,the maximum absorption of root and shoot is 514μg/g and 52.2μg/g,respectively.