Experiment research on effect of different additives on degradation process of engine lubricating oil in soil

To seek out ways to rapidly degrade the engine lubricating oil in the soil, the experiment on effect of different soil additives on degeneration process for engine lubricating oil were conducted in laboratory by the soil experimental method. The general soil was mixed with 5% engine lubricating oil to simulate the conditions of polluted soil. The test sample were divided into A B C and D group by different treatment way: A group was simple soil, which did not mixed up with engine lubricating oil and anything else; B group was the admixture of oil and soil, that was called oil soil, which was mixed up with 5% engine lubricating oil in the soil; C group was the admixture of oil soil, urea and calcium phosphate monobasic, which was commixed 12 g urea and 8 g calcium phosphate monobasic in the oil soil; D group was the admixture of oil soil, urea, calcium phosphate monobasic, and bacterium liquid, which was commixed 4 mL bacterium liquid in test sample C. Then, the experiment specimen soil was laid in the same condition, and the amount of degradation was measured timely to get the relationship of the degradation with the time. Results showed that degeneration rate of the engine lubricating oil in the test sample C was 10.6% after 36 days and improved by 35.9% compared with B; the degeneration rate of the test sample D was 13.9% after 27 days, and improved by 77.2% compared with B, and also improved by 31.1% with C. Generally, adding some urea, calcium phosphate monobasic, and suitable bacterium into the oil soil was advantageous in speeding up the degeneration of the engine lubricating oil, but the degeneration rate was little and limited in a given period. This research offers a way for degrading engine lubricating oil rapidly in soil.