Study Of Sve And Bv Coupled Remediation Of Petroleum Hydrocarbon Contaminated Soil At Gas Station

At present,China has come to the period of the leakage of underground oil storage tanks in gas stations,but because of the late start,there is no more mature solution in our country.In 2016,the State Council issued the plan for the prevention and control of soil pollution.All sectors of society have begun to pay more attention to soil pollution.In the face of this urgent situation,the oil spill pollution problem of underground storage tanks of gas stations was discussed.First,the sampling investigation and analysis of the characteristic pollutants of a gas station were carried out,and then a proposal of SVE and BV coupling was put forward to repair oil hydrocarbon pollution in gas stations.After that,a one-dimensional soil column experiment was used to study the law of SVE treatment of light component petroleum hydrocarbon and BV to deal with the recombined petroleum hydrocarbon.At last,The SVE-BV coupling experiment was carried out under the optimal parameters.The conclusions are as follows:The soil pollution in the gas station mainly comes from the leakage of steam and diesel,in which the gas leakage mainly causes the high light TPH content in the soil and the excess of the MTBE in the groundwater,and the diesel leakage mainly results in the high TPH of the soil recombination(> C15).Field moisture capacity is the best soil moisture content for SVE.In the process of gas extraction,the volatilization process mainly occurs in the soil airfilledpore.The oil phase contaminants in the capillaw pores are first pushed into the airfilledpore,and then participate in the volatilization process,and the closer to the gas source,the earlier it is pushed into the ground.In the direction of air flow,the efficiency of SVE declines,the longer it is from the inlet of airflow,the longer the time it takes to enter the trailing period,and this decline is related to the airflow velocity and the soil porosity,and the higher the airflow velocity or the larger the porosity,the lower the decline.For the contaminated sites with less than half or more petroleum hydrocarbons below C12,the SVE-BV coupling technology,especially the thermal enhanced SVE-BV coupling repair technology,has the advantage of shorter time and higher removal ratio than pure BV.