MIGRATION LAW OF OIL CONTAMINATION IN SALINE SOIL FROM INSHORE AREA

Oil contamination in soil is instability and easy to migrate again under the action of environment. It then contaminates surrounding soil and even water. Experiments are undertaken on saline soil in inshore area. Variable parameters of pollution intensity, residual time of oil contamination in soil, and soil density are considered. Migration law of two-dimensional space under immediate filter and outdated filter condition are studied. Results indicate the following feature. (ⅰ) In the case of immediate filter condition, the migration depth of oil in saline soil is deeper with the increasing of oil contaminated lever, and the maximum migration depth is 6 cm. Dry density(1.2g·cm^-3-1.4g·cm^-3) has little effect on migration depth, but oil entrapment increases as dry density intensifies. The concentration of oil contamination on same depth is lower with the increasing dry density. As to horizontal direction, the concentration distribution of oil contamination decreases steeply with the increasing of oil contaminated lever and soil density. (ⅱ) In the case of outdated filter condition, the migration law of oil contamination in vertical direction is similar to that of immediate condition, but oil entrapment of soil surface enhances, and the maximum migration depth in saline soil is 4 cm. The maximum oil entrapment rate(0~2 cm) is 99.98%. In the horizontal direction, the concentration distribution of oil contamination decreases largely with the increasing of oil contaminated lever and the decreasing of soil density. Saline soil has good ability to adsorb oil contamination and can be improved by increasing soil density.