Study On The Laws Of The Distribution Of Six Kinds Of Typical Polycyclic Aromatic Hydrocarbons In The Ice Phase With Melt Water

In low latitudes of human activity area,many organic pollutants,released by Human,is found out in the high-latitude ice zone now.The accumulation of organic pollutants in high latitudes is fuelled by snow.During Seasonal snowmelt,large amounts of organic pollutants are washed out into the environment in a short time.And it is not enough to understand that the partitioning and transport of organic chemicals between snow pack and the melt water phase during melting.Up to now,there is only little research on the laws of distribution and release of polycyclic aromatic hydrocarbons in ice.But research on this aspect will help us to know actual distribution of polycyclic aromatic hydrocarbons in the ice,and how polycyclic aromatic hydrocarbons entering into ice during ice formation;research on the release law of polycyclic aromatic hydrocarbons from ice has actual significance for infering its impact on ecological environment.And it also can further verificate the differences of their characteristics and their influence on the ecological environment through the comparison of different PAHs.Phenanthrene,Anthracene,Pyrene,Fluoranthene,Benzo（a）anthracene,Chrysene,as polycyclic aromatic hydrocarbons with low relative molecular mass and 2-3 rings,has obvious toxicity on biology.These three groups of isomers in the ice have different changes with the changes of time and temperature.Studying the distribution of these organic pollutants（pops）between ice and other facies plays an important role for us to predict the pollution of organic pollutants.This paper focuses on the distribution of three groups of isomers in the ice phase,the partition coefficient ice and the melt water and transport of them under the different conditions.Specific studies have shown that:（1）The distribution of six kinds of polycyclic aromatic hydrocarbons in different concentration systems is basically consistent.Six kinds of polycyclic aromatic hydrocarbon content in the interior is higher,and their content in the exterior is the lowest;Systems of different concentrations（1.0μg/L,10μg/L,50μg/L）for the six kinds of polycyclic aromatic hydrocarbons in the ice phase had no effect on the distribution.Among this three isomers,Phenanthrene is more inclined to exist in the exterior.The change trend of Anthracene,Benzo（a）anthracene,Chrysene from the interior to the exterior is very obvious in the ice phase,and the content of Fluoranthene,Byrene from the exterior to the interior is increasing.Temperature factor has an important effect on the distribution of the six kinds of PAHs in the ice phase.At the beginning of the decreasing of temperature,the innermost content of the six kinds of polycyclic aromatic hydrocarbons increased obviously.When the temperature is reduced to a certain degree,specifically in-20℃environment in this experiment,the increasing trend of the innermost content of the six kinds of polycyclic aromatic hydrocarbons is reduced,and the change trend of these isomers affected by the temperature change also have bigger difference among them.（2）The distribution coefficient of the six kinds of polycyclic aromatic hydrocarbons between water and ice is different.The distribution coefficient of Phenanthrene is among 1.03—1.17.The distribution coefficient of Anthracene is among 0.75—0.86.The distribution coefficient of Fluoranthene is among 0.95—1.09.The distribution coefficient of Pyrene is among 0.72—0.95.The distribution coefficient of Benzo（a）anthracene is among 0.81—0.93.And in the end,The distribution coefficient of Chrysene is among 0.69—0.79.In addition,PAHs have a certain temperature dependence between 5°C to 25°C.The temperature dependence of K_W/Sweakens in turn,with the increase in the number of PAHs,rings The experimental results show that the ambient temperature indirectly influence the partition coefficient of the PAHs between the two phase by delivering heat in ice.This influence on Phenanthrene Anthracene and Pyrene is obvious.（3）At the beginning of the release in the initial melting,compared with the other five kinds of polycyclic aromatic hydrocarbons,more Phenanthrene were released quickly.During the initial release,the release of Anthracene is very low.With the further release,the release of Anthracene increase gradually.And the release trends of Benzo（a）anthracene,Chrysene are similar with the release trend of Anthracene.In the initial release,the percentage of the amount of release is very low.And in the whole process,the amount of Benzo（a）anthracene,Chrysene get a larger release peak in the late,after a long process with flat trend and the low amount of release.The release of the initial process of Fluoranthene and pyrene have some similarities with the release of Phenanthrene,however,the peak is lower.In the situation of different concentrations,the release trends of these six kinds of polycyclic aromatic hydrocarbons are roughly constant.With the increasing of concentration,the releasing amount of six kinds of substances from the ice phase including the release of the release of the peak changes a lot.Under the conditions of two kinds of temperature with large difference,compared with the amount of the release in high temperature,the amount of the release in low temperature has a certain increasing in the initial melting.With the change of the time,in the whole process of ice melting,most of the six kinds of polycyclic aromatic hydrocarbons in the process of the release in high temperature environment increase comparing with low peak temperature.This phenomenon is especially obvious in the release process of Phenanthrene and Pyrene.The appearance time of the peak value is shortened.