Enrichment Of Petroleum-degrading Consortium And The Bioremediation Of Petroleum-contaminated Soil

Petroleum has been widely applied in the Industry, and consequently caused serious soil and water pollution worldwidely. Petroleum is a mixture of chemical compounds and thus being hardly degraded. The physical and chemical approaches are dominant crude oil pollution remediation technologies. However, the biological method gained extensive attention because of its high efficiency and cost effectivfe. The main research goal of the biological remediation technology is to obtain highly effcient petroleum hydrocarbon-degradign consortium, and the apply by combining with physical/chemical approaches.We enriched an microbial consortium capable of degrading petroleum hydrocarbon degradation from the collected soil from Shandong Shengli oilfield, named as PWW culture. The culture’s able to degrade crude oil at a rate of 5.7 mg/L-d in mineral medium. The PWW culture has an optimal pH of 7.0, and preferable carbon source of yeast extract or peptone. The culture has a wide nitrogen source requirement. The degradation rates of petroleum by PWW were significantly improved after adding surfactant Tw-80, LAS, and SDS individually or in combination. The microbial consortium was dominated by Chryseobacteriumet al.The PWW culture was able to remove petroleum in heavily oil-contaminated soil, for instance, degraded 59% of petroleum in soil at a contamination level of 3% in 150 days. The culture was able to remove 46% of petroleum in soil at a contamination level of 32% after adding 26.3 mg/L of Tw-80+ 173.7 mg/L of SDS, or 22.3 mg/L of Tw-80+ 177.7 mg/L of LAS. However,5.0 g/L surfactant significantly suppressed the microbial activities.We prepared the microbial agent using adsorption and embedding methods. The 1:1 bran and lime mixed agent could degrade petroleum at a rate of 1.30 g/kg-d, while the agent made by embedding rate of 1:10 of SA and PVA had highest crude oil degradation rate of 1.89 k/kg-d.