| Abstrakt: |
Soil hydrocarbons can affect the physical, chemical and biological characteristics. Soil samples were prepared from the oil-rich area of Kermanshah province, which have been under oil pollution for a long time. 120 soil samples were collected from a depth of 0-15 cm with three pollution levels of low (L), moderate (M) and high (H) and the physicochemical characteristics were measured. Then bacteria were counted in NA and CFMM media and a positive and significant correlation was observed between bacterial population and oil concentration. The mean of oil measured by Soxhlet method was 4.03%, 9.95% and 22.50% for L, M and H levels, respectively. With the increase of oil in soil samples, ACP and ALP increased. In all samples, ACP was lower than ALP. The highest ACP and ALP were obtained 45.78 and 84.90 (gPNP.g-1.h-1µ) respectively in soil with high pollution level. Regression analysis showed that the oil percentage, sand percentage and EC with an regression coefficient of 0.71 were effective variables on the ACP, and the oil and sand percentage were also effective variables on the activity of ALP with an regression coefficient of 0.43. PCA analysis was also performed and the results showed that the first two components explained 68% of the variance between the samples. Based on the results, it was observed that natural and long-term oil pollution, with the passage of time led to the adaptation of microbial communities resistant to pollution and the number of these microorganisms and the activity of phosphatase enzyme increased. [ABSTRACT FROM AUTHOR] |
