Effect of Oil Pollution on Permeability of the Grey Desert Soil under Freeze-thaw Cycles in Arid Areas of Western China

Abstract

ABSTRACT There are abundant oil resources in Xinjiang, and the exploitation of oil resources could easily pollute the soil. In this paper, the impact of oil pollution on permeability of the gray desert soil affected by freeze-thaw cycles under a dry and cold climate of Karamay region in Xinjiang was studied. First, varying-head infiltration tests were conducted on soil samples with different water contents and pollution intensity without exposing to freeze-thaw cycles. The variability of permeability were analyzed employing the scanning results of the polluted soil samples by an electron microscope. Then several freezing and thawing cycle tests were implemented on the samples. The test results shown that the soil permeability was optiomal and the permeability coefficient was highest when the crude oil pollution intensity was 0.61% and the water content was 15.53%. With the water content in soil samples being the same, the soil permeability coefficient increased in the beginning and then decreased as the pollution intensity increased. When the pollution intensity ranging from 0.5% to 1.75%, the freezing and thawing condition could be the leading factor affecting the soil permeability. However, when the oil content was within the range of 1.81% – 2.41%, the freezing and thawing condition could not be the leading factor affecting the soil permeability. The results provided in this study could serve as a relevant basis for the remediation of soil pollution in oil production plants in arid areas of Western China.