Polynuclear aromatic hydrocarbon (PAH) release from soil during treatment with Fentonʹs reagent

Fentonʹs Reagent was used to treat soil from a wood-treating site in southeastern Ohio which had been contaminated with creosote. Slurries, consisting of 10 g of contaminated soil and 30 mL water were treated with 40 mL of Fentonʹs Reagent (1:1 of 30% H2O2 : 8.84 mM FeSO4). Concentrations of fourteen PAHs were monitored during 24 hours treatment. In preliminary experiments, we observed a significant increase in the extractibility of the PAHs after 1 hour of treatment. Twelve of the fourteen PAHs showed consistent increases (13 to 56%) in extractibility from soil after one hour of contact time with the Reagent. Only acenaphthylene and acenaphthene showed no increase in extractibility. Electron exchange by structural iron in clay mineral and the swelling of clay layers is proposed as the release mechanism of tightly held PAHs. Results obtained in this study suggest that this treatment may enhance soil remediation. The results also indicate that the PAH analytical method employed may provide inaccurate results in some situations.