Abstract: Improving the adsorption stability of petroleum pollutants in soil is the premise and key to the engineering reuse of contaminated soil. Relying on the disposal needs of oil contaminated saline soil in coastal areas, lime and fly ash that have solidification and adsorption function, were selected as solidifying materials. Solidification effect, contamination intensity and soil density were taken as variable parameters. The external environment was simulated with the help of pressure leaching. The control effect of solidification on the migration of pollutants in soil was evaluated by the residual oil content and oil seepage of soil. Results show that solidification can improve the adsorption stability of pollutants and control its migration. Under the action of pressure leaching, the change rate of oil contents in the solidified contaminated soil is only 1.52%−2.27%, and the oil seepage is 7.15−14.92 mg/L, which meet the class III standard of Integrated Wastewater Discharge Standard (GB 8978－1996) of China. Solidification can solve the large-scale migration problem of pollutants caused by the change of soil density and pollution intensity in unsolidified contaminated soil, and the oil content after leaching is close to the initial oil content. Solidification of lime and fly ash has a stable control effect on pollutants and has universal applicability in the disposal of petroleum contaminated soil.

Key words: petroleum-contaminated soil, migration control, solidification and reuse, lime and fly ash, pressure leaching