Fenton-like and potassium permanganate oxidations of PAH-contaminated soils: Impact of oxidant doses on PAH and polar PAC (polycyclic aromatic compound) behavior

International audience(C. Biache). HIGHLIGHTS KMnO4 and Fenton-like treatments were applied to PAH contaminated soils. The impact of two oxidant doses on PAC contamination were studied. Treatments were less efficient on soil with low PAC availability. KMnO4 was more efficient to degrade the PAH than Fenton-like. Low dose of KMnO4 induced the formation of toxic oxygenated by-products. Abstract Potassium permanganate and Fenton-like oxidations were applied on two PAH-contaminated soils collected on former coking plant and gas plant sites. The impact of oxidant dose on the polycyclic aromatic compound (PAC) evolution, including 16 US-EPA PAHs, 11 oxygenated-and 4 nitrogen heterocyclic-PACs (O-and N-PACs) was studied for both treatments. The content of extractable organic matter and PACs was determined prior and after oxidation. Overall, permanganate treatment was more efficient than Fenton-like to decrease the PAH content, this latter being limited by the contamination availability. However, permanganate treatment resulted in incomplete PAH degradation, leading to the formation of O-PACs, that was limited with the application of higher dose. It underlines the importance of the dose and the oxidant type in the selection of oxidation parameters for remediation purpose, as improper use of oxidant can lead to the accumulation of oxidation by-products that could be as toxic as the parent compounds