Research On Oxidation Degradation Of High Concentration Petroleum Contaminated Soil And Deep Oxidation Guarantee Remediation Technology

This study takes simulated contaminated soil and actual contaminated soil as the research object,and studied three methods of Fenton oxidation,Fenton oxidation pyrolysis-coupling and high temperature oxidation to remediate petroleum contaminated soil.The best conditions were obtained and applied to the actual oilfield contaminated soil.The Fenton system,as an oxidation system for degradation and remediation,oxidatively degrades petroleum hydrocarbon pollutants in petroleum-contaminated soil.The effect of various factors such as the method of oxidant addition,addition sequence,p H,and reaction time on the degradation effect is studied.Studies have shown that the non-aqueous phase reaction is more efficient than the water phase reaction under the same molar ratio of Fenton oxidation.Drying first and then oxidation,the optimal conditions are p H=3,n(H₂O₂/Fe²⁺)=6,and the removal rate of simulated petroleum contaminated soil can reach up to 46%.The removal rate of petroleum hydrocarbons from the actual polluted soil is 27%.In the oxidized oil soil,organic macromolecules are effectively degraded,and the content of asphaltenes and gums is significantly reduced;the hydrogen-carbon atom ratio increases,the degree of unsaturation decreases,the degree of branching decreases,and the aromatic carbon ratio decreases.Fenton oxidative pyrolysis-coupled remediation method is used to repair oil-contaminated soil,and the effects of various factors such as reaction temperature,reaction time,and initial hydrocarbon content on the pyrolysis effect were studied.Studies have shown that Fenton oxidation pyrolysis-coupled repair is better than pyrolysis alone,and the removal rate can reach99.61%at a lower reaction temperature of 370℃;Fenton oxidation pyrolysis-coupled process can be divided into There are three stages of low temperature,medium temperature and high temperature;the content of carbon and hydrogen in the soil after Fenton oxidation pyrolysis-coupling treatment is significantly reduced,the value of carbon to oxygen ratio is small,the degree of carbon reduction is higher,and the difference between carbon and oxygen The bonding mode is mainly carbon-oxygen single bond.Using high temperature oxidation remediation system to remove petroleum hydrocarbon pollutants in petroleum contaminated soil,and the influence of various factors such as reaction temperature,reaction time,and initial hydrocarbon content on the effect of high temperature oxidation treatment was studied,and the thermogravimetric curve was used to Kinetic analysis of two petroleum-contaminated soils.The higher the reaction temperature,the higher the removal rate of petroleum hydrocarbons,and the influence of the initial petroleum hydrocarbon concentration and reaction time on the removal rate of petroleum hydrocarbons is significantly smaller than that of the reaction temperature.The reaction conditions are 400°C temperature,30 minutes reaction time,and the removal rate of petroleum hydrocarbons can reach 99.24%.Studies believe that the high-temperature oxidation reaction is divided into three stages:（1）volatilization of water and a small amount of low-boiling hydrocarbons,（2）rapid weight loss,（3）burning of heavy components and coke.The kinetic analysis results of the high-temperature oxidation process of petroleum-contaminated soil show that both the simulated petroleum-contaminated soil and the actual petroleum-contaminated soil have the activation energy of the low-temperature reaction higher than the high-temperature reaction.The activation energy of the simulated petroleum-contaminated soil in the low-temperature and high-temperature sections is smaller than that of the actual petroleum-contaminated soil...