Study On The Characteristics Of Rapid Bioremediation Of Petroleum Hydrocarbons And Biological Communities

The experiment of biological stimulation was carried out on oil-contaminated soil by means of adding nutrition to stimulate the reproduction of indigenous bacteria in the soil.To explore the relationship between the nutrient components and the growth of oil-degrading bacteria.By adjusting the nutrient level of organic matter in the nutrient solution,the effects of different nutrient ratios on the bioremediation of oil-contaminated soil were studied,and the effects of different stages of nutrient solution addition on the nutrient utilization and petroleum hydrocarbon(TPH)remediation efficiency in each period of bioremediation were discussed.The effects of each experiment on the degradation of medium and long chain hydrocarbons in crude oil with high initial concentration were analyzed.The research results are as follows:(1)The nutrient components after fermentation can provide sufficient nutrition for petroleum degrading bacteria.The TPH degradation rate of the experimental group with fermentation supernatant on S1 and S2 reached 58% and 52%,respectively,while the degradation of large amounts of crude oil reached 7471mg/kg and 8715mg/kg,respectively.(2)The carbon source and nitrogen source in the component reactor after fermentation can consume more than 90%,thereby promoting the proliferation of petroleum-degrading bacteria.For the reactor added with fermentation supernatant,most of the ammonia nitrogen and DOC in the two soils were consumed in the first 20 days,so the early stage of bioremediation is the best period for the use of nutrients by petroleum-degrading bacteria.(3)The fermentation supernatant can effectively stimulate the use of nutrients by indigenous oil-degrading bacteria in the soil to reproduce,and rapidly degrade petroleum hydrocarbons in the early stage of bioremediation.S1 reproduces faster than S2 in petroleum degrading bacteria.(4)In low-oil-concentration soil S1,the degradation of medium and long-chain hydrocarbons by adding medium-level nutrient solution reached 67% and 62%,respectively.Most of the nutrient consumption is concentrated in the first 40 days.The addition of medium-level nutrient solution and the stimulation of a small amount of phosphorus make the use of nutrients by the petroleum-degrading bacteria faster,and the respiration activity of the early microorganisms is higher.(5)The first addition of 5m L of nutrient solution can increase the respiratory activity of the microorganisms in S1 and S2 to 1.03mol/kg and 0.91mol/kg,respectively,and the initial addition of petroleum degrading bacteria grows faster.With the addition of multi-nutrient solution,other microorganisms in S1 compete with petroleum-degrading bacteria.Therefore,for S1,the amount of nutrient solution should be controlled,while S2 needs more nutrient solution.