Targeting sorbed PAHs in historically contaminated soil - Can laccase mediator systems or Fenton's reagent remove inaccessible PAHs?

This laboratory study investigates the potential of two innovative laccase-mediator systems for removing PAHs from historically contaminated field soil and focuses on the treatment effect on the accessible and desorption resistant PAH fraction. Laccase degraded accessible PAHs when applied in combination with the mediator TEMPO (up to 24 % within 48 h). The mediator HBT did not induce degradation but mobilized desorption resistant PAHs from high affinity sorption sites via a competitive sorption mechanism.

Enhanced Accessibility of Polycyclic Aromatic Hydrocarbons (PAHs) and Heterocyclic PAHs in Industrially Contaminated Soil after Passive Dosing of a Competitive Sorbate.

To assess the exposure to polycyclic aromatic hydrocarbons (PAHs) it is important to understand the binding mechanisms between specific soil constituents and the organic pollutant. In this study, sorptive bioaccessibility extraction (SBE) was applied to quantify the accessible PAH fraction in industrially contaminated soil with and without passive dosing of a competitive sorbate. SBE experiments revealed an accessible PAH fraction of 41 ± 1% (∑16 US EPA PAHs + 5 further PAHs).