Analysis and prediction of the dynamics of Polycyclic aromatic hydrocarbons in the coastal environment polluted by heavy oil.

事故发生7年后，纳霍德卡漏油重污染现场的海岸沙子等介质中多环芳烃(PAHs)的浓度被发现与本底浓度一样低。仅在岩石的空洞和空洞中发现了石油残留物，这些残留物中的多环芳烃含量在两年内下降到原值的三分之一，但在此之后，多环芳烃的含量保持在相同的水平，这表明多环芳烃将随着石油残留物的存在而长期存在。基于有机物的分配系数Koc与辛醇-水分配系数有很好的相关性，可以用线性自由能假设来描述。表层沉积物和河水之间的多环芳烃交换足够快，使得我们可以认为沉积物和水之间的分配是近似平衡的。在实验室实验中，我们考察了溶解有机物(DOM)对多环芳烃在沉积物和水之间分配的影响，发现随着芳环数量的增加，DOM的影响增加，还发现为了准确描述这种现象，DOM的影响也增加了。我们必须考虑DOM对沉积物颗粒的吸附。如上所述，在沿海环境中，水和海岸颗粒介质之间的交换速度足够快，在几年内就能从污染地点清除污染物，在河口，这种速度如此之快，以至于我们可以假设一个近似的平衡。多环芳烃对颗粒物的吸附主要是对有机物的吸附，分配系数随芳环数目的增加而增大，可用线性自由能假设进行粗略估算。

The concentration of polycyclic aromatic hydrocarbons (PAHs) in the coastal sands and other media of a heavily polluted site of the Nakhodka oil spill were found to be as low as the background after the 7 years of the accident. Oil residues were found only in the hollows and cavities of the rocks, and PAH contents in those residues decreased to one thirds of the original value in two years, but after that, PAHs contents remained at the same level, suggesting that PAHs will remain long as oil residues.Two years of monitoring of PAHs in the river water, SS and sediments revealed that the main sorbent of the PAHs in the sediments was organic matter. Organic matter based partition coefficient Koc was found to be well correlated to octanol-water partition coeffient, and can be described by using liner free-energy assumption.The exchange of PAHs between surface sediments and river water was sufficiently fast for allowing us to consider that the partition between the sediments and water is approximately in equilibrium.In the laboratory experiments, we investigated the effect of dissolved organic matter (DOM) on the partition of PAHs between sediments and water, and found that as the number of aromatic rings increases, the effect of DOM increases, and also found that for the precise description of the phenomena, we have to take into account the adsorption of DOM to the sediment particles.As described above, in the coastal environment, exchange between water and coastal particulate media is sufficiently fast to remove the pollutants from the polluted sites in several years, and at the mouth of the river, that is so fast that we can assume an approximate equilibrium. Sorption of PAHs to particulate matter is mainly to organic matter, and the partition coefficient is larger as the number of aromatic rings increases, and can be roughly estimated by using linear free energy assumptions.