Fenton-like soil remediation catalyzed by naturally occurring iron minerals

The ability of the iron minerals hematite and magnetite to catalyze the decomposition of hydrogen peroxide (H2O2) and initiate the Fenton-like oxidation of pentachlorophenol (PCP) was investigated in batch, bench-scale systems in which PCP was spiked onto silica sand. Pentachlorophenol degradation was documented in silica sand-mineral-H2O2 systems by the release of chloride and the loss of total organic carbon. The most efficient oxidation stoichiometry was the magnetite-catalyzed reaction over the first 8 h with 490 mel H2O2 consumed/mol PCP degraded. After 8 h, the peroxide efficiency decreased significantly; amorphous iron hydroxide formation on the magnetite surface may have catalyzed the decomposition of H2O2 to oxygen species other than hydroxyl radicals, Mineral-catalyzed Fenton-like treatment in two natural soils was demonstrated after spiking the soils with PCP; the contaminant was degraded with no iron addition, The oxidation stoichiometry in the two soils was 1,100 and 2,930 mol H2O2 consumed/mol PCP degraded.