Research Of Ectopic Joint In-situ Bioremediation Technology For High Concentrations Of Petroleum Contaminated Soil

On the basis of laboratory research and field research, soil of island region which belongs todongying city in Shandong was taken as the research object, and we carried out engineeringresearch and repair engineering design parameters in-situ associated with ectopic bioremediationfor high concentrations of petroleum contaminated soil. First, take ectopic biological for the highconcentration of petroleum contaminated soil (ectopic repair), greatly reducing the concentrationof petroleum hydrocarbon in the soil. And then send piled up according to the amount back to thefield, making the field of petroleum hydrocarbons in the soil after concentration below2000mg/kg, to meet the requirements of in-situ repair. The last part in situ after repair, ultimately meetthe requirements of repair. Its purpose is to put ectopic bioremediation and in situ bioremediationinto organic union, achieving efficient and economic repair for high concentrations of petroleumcontaminated soil. During the study, by biological stacking test, biological reactor was optimizedway of ventilation, initiator and C/N and other process parameters, by monitoring the stackingprocess of the change in temperature, the degradation of petroleum pollutants in soil and thechange of microbial indicators, to evaluate the different stacking in the pile body under theconditions of oil degradation of pollutants. On the basis of calculation of theory and actual massof tailings which should be sent back to the field, by ploughing, adding biological bacteriumagent and soil conditionerand planting the alkaline, we put the contaminated soil in the field toreceive the in-situ bioremediation, aiming to achieve the ideal repair effect. The main researchconclusions are as follows:(1) The grid method was used to the research on regional soil investigation, found that themost of oil pollutants exposed to the surface and assumed in zonal distribution, which made thedegree of petroleum contaminated soil in the area be of a larger difference. This tells us to takedifferent restoration measures respectively according to actual situation.(2) The optimum ventilation of biological stacking technique is: forced ventilation,ventilation once every three days, no less than two hours at a time, the ventilation intensity of 0.6m3/h, every time sampling for an artificial plough. When the pile body was adopt naturalventilation and oil degradation rate is only36.82%, compared with compulsory ventilation ofpile body of oil degradation rate of53.02%, increased by16.2%.(3) Early biological piled up, adding5%of fresh pig manure as initiator into pile body canstrengthen the effect of biological stacking technique in repairing high concentration ofpetroleum contaminated soils. The measures of adding initiator can make the pile body oildegradation rate of55.47%, compared with the pile body without pig manure, increased by2.45%.(4) Early biological piled up, adding fertilizer such as urea into the pile body to regulate soilC/N to10:1measures more conducive to biological stacking technique for restoration of highconcentration of petroleum contaminated soils. Regulating C/N of the pile body can make the oildegradation rate be as high as63.14%, and while compared with no treatment (53.70%) itincreased by9.44%.(5) In the application of biological stacking technique to repair oil pollution of soil, paymore attention to adjust the way of ventilation, the initiator and C/N at the same time. On thebasis of the measures of forced ventilation, adding initiator and regulating C/N to10:1, oildegradation rate increased by10.12%compared with forced ventilation measures only; inaddition, its oil degradation rate increased by7.67%compared with no C/N regulation measures.(6) After an ectopic repair on oil pollution of soil, the soil oil couldn’t approach thestandard, and it would be sent back to the field to accept an in-situ repair, in the perspective ofachieving ideal repair effect and cost savings at the same time. When sent the stacked tailingsback to the field, calculate the theory mass of tailings on the basis of previous research. Thetheory mass of tailings which could be sent back (m) must meet [m/(1.5×105﹣m)≤(2000﹣CB)/CA](m-theory mass of tailings which could be sent back, kg;1.5×105-field surface soilquality, kg; CA-oil concentration of tailings, mg·kg-1; CB-oil concentration of soilbackground, mg·kg-1), the actual mass needing sending back is0.9m.