On the Research of adsorption of Polycyclic Aromatic Hydrocarbons (Phenanthrene) in Soil-Groundwater in Zhangshi Irrigation District

The thesis mainly studies the dynamic variation features of absorption of polycyclic aromatic hydrocarbons (PAHs) in soil and groundwater of Zhangshi irrigation district in southwest part of Shengyang City of China. On the basis of the field inspection on hydrogeochemistry of Zhangshi irrigation district, we choose four typical sites, taking samples from surface soil layer, sub-vadose zone and acquifer to do experiment of dynamic successive absorption on phenanthrene as the typical pollutant. And we also study the absorptional dynamics characteristics of phenanthrene in soil and groundwater. Linear models and Freundlich models are also used to simulate the absorption isotherm. The results show two outstanding phases of phenanthrene adsorption in underground environment: the quick linear partition phase and the slow nonlinear adsorption phase. Phenanthrene adsorption is in positive correlation with the organic contents in soil. Whereas the balance time of adsorption is in negative correlation with the organic contents in soil. Since the adsorption curve is a typical “S” type in the organic-rich top soil, the tendency shows the likeliness of multilayer adsorption. The partition function of solid phase and liquid phase of phenanthrene in the relatively poor organic lower vadose zone shows certain linear relationship. The adsorption of phenanthrine in organic-poor acquifer soil particles belongs to linear adsorption. The relevant factors R are all above 0.9627.