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Removal of PAHs from Creosote Oil Contaminated Soil by Addition of Concentrated H2O2 and Biodegradation

Abstract This study describes the combined chemical, i.e. modified Fenton’s reaction, and aerobic biological removal of polycyclic aromatic hydrocarbons (PAHs) in creosote oil contaminated soil. The initial concentration of eight selected PAHs (acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benz(a)anthracene and chrysene) was 4 g/kg soil. The soil was rich in iron (16.4 g Fe/kg soil) and slightly acidic (pH 5-6). Therefore, no pH adjustment or iron addition was performed. Aged contaminated soil was treated with 30% H2O2 in laboratory-scale, packed soil columns. The chemical treatment removed up to 52% of the total PAHs in the soil. The effect of the chemical treatment on indigenous PAH-degrading bacteria was studied by incubating untreated and H2O2 treated soil. Biodegradation of untreated soil removed up to 36% of the total PAHs. The indigenous PAH-degrading bacteria were able to survive aggressive chemical soil treatment with concentrated H2O2 and the combined chemical-biological treatment decreased the PAH-concentration by 55%.