Experimental Study On The Adsorption/desorption Law And Biodegradation On Shengli Oilfield

Because of the exploitation of Shengli oilfield, soil and water were polluted seriously in the later 50 years, especially local pollution. As the material basis of life, if the pollution of soil is beyond its self-purification capability, the ability of soil living will decrease, even die away, which is harmful for human's health, social economy and ecosystem. For this hazard, this task studied the Adsorption/Desorption Law and Biodegradation through the laboratory static and simulates experiment, and discussing its feasibility for protecting soil encironment during the development of oilfields.The adsorption and description law of oil contaminants in the soil and its influence factors were studied by laboratory experiments. A group of predominant strains for decomposing oil have been isolated from the oil-pulluted soil, which can be cultivated only with the petroleum as the sole carbon source. One of them and a group of mixed strains were selected for further study. Experiments have been taken to abtain the best conditions for petroleum degradation in the laboratory. Also the tentative experiments for remediation of the oil-poulluted soil have been carried out. The main contents and results are following:1. The adsorption of petroleum pollutants on soil at static stateThe kinrtics and main influencing factors and adsorption of petroleum pollutants on soil at static state were studied. The results show that the speed of adsorption is rapid; homeostasis can be got in almost 4h. The adsorption isotherm accords with Langmuir adsorption models, R~2 is equal to 0.99 respectively. Temperature, pH and salt can effect the adsorption.2. The desorption of petroleum pollutants on soilThe kinrtics and main influencing factors and desorption of petroleum pollutants on soil were studied. The results show that the speed of desorption is raid, homeostasis can be got in almost 6h. The desorption isotherm accords with Langmuir desorption models, R~2 is equal to 0.99 respectively. Temperature, pH, salt and surfactant can effect the desorption. The microorganisms which have been cultivated with the petroleum as the sole carbon source were added. The results show that adding petroleum degrading bacteria can increase oil bioremesiation effectively. Also adding nutrients can increase oil bioremesiation effectively, and the optimal N/P ratio is 10:1. 3. Simulate experiments for removing of the petroleum pollutants by bioremesiationThe removal of petroleum pollutants from oil-polluted soil by bioremesiation were studied by simulates experiments in the latter part of experiment. The petroleum removal rate of the naturally mixed strains, comparison and predominant strains inoculated is 42.6%, 31.1% and 58.7%, respectively, which is run after 55 days at 30℃. While the petroleum removal rate of the naturally mixed strains, comparison and predominant strains inoculated at room temperature are 41.2%, 28.3% and 57.1%, respectively.The results of the experiment show that the predominant strains have good effects on the removal of petrolenm-pollutants in the appropriate conditions.