The Effect Of Soil Organic Matter On Solid-Phase Iron Fenton To Oxidize The Crude Oil In Soil

Although the modified Fenton method is widely used to remediate contaminated soil,hydroxyl radical?OH^·?is mainly produced in the aqueous phase and only exists for a short time,it would be disappeared before oil desorbed from the soil solid phase to the aqueous phase.Our previous study have found that functional groups such as alcohols,ethers or C-O in humic acids in soil organic matter?SOM?can adsorb or complex soluble iron to form the solid-phase?Fe-SOM?and include the organic bound iron?Organic Fe-SOM?and organic bound iron oxides?Fe-SOM oxides?,respectively.The Fe-SOM can combine with the crude oil to form the complex?Fe-SOM-crude oil?and the Fe-SOM can catalyze H₂O₂ to produce OH^·to oxidze directly the crude oil.This paper studied that the effects of chitosan?Cs?and humic acid?HA?on the formation of Fe-SOM and the characteristics of OH^·,H₂O₂ decomposition and crude oil oxidation were studied in Fenton system.Providing theoretical basis for the in situ remediation of oil contaminated soil by solid-phase iron Fenton system.The experiment of conclusions as below:?1?Cs mainly promote the formation of Fe-SOM oxides,and HA mainly promotes the formation of organic Fe-SOM;?2?The instantaneous intensity of OH^·?I_t?and production of O₂ were high and less in Organic Fe-SOM Fenton system but the instantaneous strength and production were low and more in Fe-SOM oxide Fenton system;?3?The ability of Organic Fe-SOM catalyzes H₂O₂to oxidize crude oil is stronger than Fe-SOM oxides,in which the oxidation amount of the chain hydrocarbon C₁₈-C₂₇is significantly higher than Fe-SOM oxides;?4?The higher instantaneous?I_t?and total?I?intensity of OH^·in solid phase,the higher removal efficiency of crude oil in solid phase;?5?By adjusting the contents of Cs and HA to obtain the highest content of Fe-SOM,so as to get the highest instantaneous?I_t?and total?I?intensity of OH^·in solid phase;?6?This study shows that the population of residual indigenous bacteria is negatively correlated with the concentration of Fenton reagent,and the released nutrient level is positively correlated with the concentration of Fenton reagent.Study has shown that matching the population of residual petroleum bacteria and nutrient levels will promote oil biodegradation.