Remediation of PAHs contaminated low permeability soil by hydraulic fracturing/chemical oxidation method
Due to the impediment to oxidant mass transfer in soil,remediation often has poor impact in low permeability contaminated soil.The effects of various hydraulic fracturing process parameters on the permeability coefficient and fracturing result of the soil column were examined using polycyclic aromatic hydrocarbons(PAHs)as the target pollutant(phenanthrene and pyrene as the represents)by hydraulic fracturing/chemical oxidation method.The removal effects of 3 oxidants(H2O2,KMnO4 and activated sodium persulfate)on PAHs were compared.The best permeability coefficient and fracturing result of the soil column were achieved with injection flow rate of fracturing fluid 347.3 L/h,fracturing fluid viscosity 294 mPa·s,water content 20.0％in the soil column,and intermittent injection.Adding 2.5 mmol/g activated sodium persulfate was the most economic and efficient way to remove phenanthrene and pyrene.The removal rates of phenanthrene and pyrene with hydraulic fracturing elevated by 19.2 and 21.2 percentages,respectively after chemical oxidation,in comparison to those without hydraulic fracturing.Therefore,hydraulic fracturing could effectively improve the remediation impact on PAHs contaminated low-permeability soil when using chemical oxidation.
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维普
