Microbial Eco-system of the Contaminated Soil with Petrochemical Hydrocarbons in the Oilfields of Northern China

摘要

The investigations of the microbial eco-system of oil contaminate soil, such as the pollutant content and properties, the environmental elements of soil, the soil microbe community and enzyme activity have been carried out in several oilfields in northern China recent years. The results present that the petrochemical content in polluted soil the is very high soil, and the alkyl and aromatic compounds are accounted for more than 50% of the total hydrocarbon concentrations, pH value is above 7.8, and average nutrient level was lower than normal soil, effective nitrogen < 30 mg/kg dry soil and phosphorus <10 mg/kg dry soil. Based on the evaluation of nitrogen and phosphorus levels, the effective N and P only are accounted for about 5% of total nitrogen and phosphorus, which means most parts of N and P in polluted soil cannot be used by degrading microbes during the biodegradation of the petrochemicals. The biological analysis results showed that degrading microbes reached 108 ceils/g dry soil, and the FDAabs about 1.5 in the soil. It can be concluded from the field investigation and indoor experiment results that concentrations and properties of the contaminants in polluted soil in different oilfields in Northern China are available for the bioremediafion, and adjusting the nutrient level and optimizing the abiotic factors of the microbial eco-system can be effective to increasing the microbial numbers and improving the enzyme activity of the degrading bacteria, and effectively enhancing the biodegradation rates.