Remediation of PAH spiked soils: concentrated H2O2 treatment/continuous hot water extraction-oxidation.

Artificially contaminated soil with four different polynuclear aromatic hydrocarbons (acenaphthene, phenathrene, anthracene and fluoranthene) has been separately treated by two different processes: (A) concentrated hydrogen peroxide at mild conditions of temperature (343-393 K) and pressure (0.5 MPa) and (B) hot water extraction at relatively high temperature (523-657 K) and pressure (10 MPa). Both methods achieve acceptable PAH removal percentages from soil. Acenaphthene (the most soluble PAH) is completely removed with treatment A regardless of the operating conditions used. Under optimum conditions, the rest of PAHs are also eliminated to a high extent with both technologies. Temperature and hydrogen peroxide amount seem to play a major role in process A. Similarly, temperature and water flowrate are the most influencing parameters in process B. In the latter case, a post-stage for the extracting water cleaning is required.