Study On Migration And Penetrating Law Of Petroleum Pollutant In Soil

The article investigated the problem pollution in soil of Shengli oil field; It designdeindoor soil column leaching experiment and adsorption experiment to study the migration ruleand sorption rule of oil pollutant in the soil; It studied biodegradation rule of petroleumsubstances in soils through field experimental, and studies the composition of petroleumfractions in the process. It studied the petroleum migration model in soil, and updated theexisting model.The investigation and indoor experiment meant that interception effect of soil on oil wasvery strong.10cm thick layer could hold back more than99%oil in soil. Effect of adsorptionof petroleum substances in soil were influenced by temperature, liquid-solid ratio.Theincreasing temperature can lead to the decrease of adsorption capacity of soil. When theliquid-solid ratio is less than5, the increasing ratio of liquid to solid leads to the decrease ofadsorption of petroleum in soil; When the liquid-solid ratio is greater than5, the adsorption ofpetroleum in soil rate tends to stabilize. The oil pollutant total adsorption constant anddesorption constant can be calculated by mapping:K a=25.0L kg-1、Kd=1156.3L kg-1.The biodegradation of different substance of petroleum is different in soil. The process ofbiological degradation of alkanes in the soil is accord with the first-order reaction ofMichaelis-Menten equation. The process of biological degradation of total hydrocarbon in thesoil of was similar to zero-level reaction of the Michaelis-Menten equation. Aromatichydrocarbon was between the above two. The curves of biodegradation of aromatichydrocarbons in the soil were obviously divided into two stages. Put forward the hypothesis:the biodegradation process of aromatic hydrocarbons can be divided into two steps. The firststep: aromatic ring were broken two parts, one aromatic hydrocarbons were broken into twoor more alkane molecules. The second step, the new alkane molecules reacted according to afirst-order reaction of Michaelis-Menten equation. The first step of the reaction was restrictedby aromatic toxicity.In the existing migration model of petroleum substances in soil, it was assumed that thedegradation process of petroleum accords with the first order kinetic equation. It can notdescribe the biodegradation process of the petroleum in the soil completely. The article proposed that the Kcc of the existing oil pollutant migration mode can be replaced by It can describe the biodegradation process of oil content in soil more accurately.