Sorption Of Petroleum Hydrocarbons On Soil And Sorption Of Selected Organic Pollutants On Petroleum-Contaminated Soil

Sorption of organic pollutants by soils plays an important role in their transport,fate and bioavailability in natural environment.Petroleum hydrocarbons is a typical organic pollutants in Northeast of China but its sorption and potential effects on sorption of other organic pollutants are still unclear.The further understanding of the interaction mechanism between organic pollutants and oil will help us to evaluate and predict the distribution,transport, transformation,and fate of organic pollutants in the environment,and will provide scientific basis for regulation,control,and remediation of organic pollutants in the Northeast of China where oil often co-existed with other organic pollutants.Based on the sorption of petroleum hydrocarbons to soil,the sorption among multimedia including oil-soil-water-organic pollutant was investigated.Sorption of petroleum hydrocarbons by black carbon and dissolved organic carbon in soil was investigated.In addition,sorption of polar,apolar organic pollutants and PFOS on oil-contaminated soil was discussed detailedly.Besides,sorption of PFOS on oil-derived black carbon and its influential factors in solution were studied.The main conclusions of this dissertation are as follows:(1) Soil organic matter is response to the sorption of petroleum hydrocarbons on soils. Sorption coefficients for petroleum hydrocarbons are linear with soil organic carbon content rather than the clay content.Soil-solution ratio(SSR) is an important parameter for sorption of petroleum hydrocarbons.Sorption coefficients normalized by organic carbon content decreased and the desorption hysterisis increased with the increase of SSR.(2) Log-linear cosolvency model is operative for oil.Then,a model was developed to extrapolate the sorption coefficient.An average of log K_DOC was estimated by comparing the difference of sorption coefficients by extrapolation and direct measurement.Through the measurement of sorption of petroleum hydrocarbons by original and combusted soil.K_F,BC^env was calculated which can be used as a generic starting points for environmental modeling purposes.(3) It is observed that sorption of polar and apolar organic pollutants by oil are different. For phenanthrene and butylate,apparent sorption coefficients(K_d) increased with the increase of oil concentrations when oil as a separate phase while little or no change of K_d was observed. Oil-water distribution coefficients(log K_oil) for phenanthrene and bury late were 5.03±0.16 and 3.94±0.10 L/kg,respectively.Specific interactions are responsible for the sorption of polar organic pollutants.(4) Oil is a strong and nonlinear sorbent for PFOS,together with the independence of oil-water distribution coefficient(K_oil) on solution pH and[Ca²⁺],suggesting that hydrophobic interactions of the hydrophobic moieties of PFOS with oil at the water-oil interfaces played a dominant role.(5) BC sorption for PFOS is not stronger and more nonlinear than other natural forms of organic carbon from solution at pH of 5.05 and[Ca²⁺]of 0.5 mM,indicating that specific adsorption sites on BC was probably not fit for PFOS.However,both sorption capacity and nonlinearity of PFOS increased significantly with decreasing solution pH and increasing [Ca²⁺],resulting in the probable importance of BC to sorption of PFOS at environmentally low level,from solution at high[Ca²⁺]or low pH values.It indicated both of the hydrophobic interactions and electrostatic interactions were important to sorption of PFOS on BC.The above results provide data to predict and model the transport,distribution and fate of petroleum hydrocarbons,and offer a theoretical gist for the sorption of organic pollutants in oil-contaminated soil.