Fenton-like soil remediation catalyzed by naturally occurring iron minerals

The ability of the iron minerals hematite and magnetite to catalyze the dec omposition of hydrogen peroxide (H2O2) and initiate the Fenton-like oxidati on of pentachlorophenol (PCP) was investigated in batch, bench-scale system s in which PCP was spiked onto silica sand. Pentachlorophenol degradation w as documented in silica sand-mineral-H2O2 systems by the release of chlorid e and the loss of total organic carbon. The most efficient oxidation stoich iometry was the magnetite-catalyzed reaction over the first 8 h with 490 me l H2O2 consumed/mol PCP degraded. After 8 h, the peroxide efficiency decrea sed significantly; amorphous iron hydroxide formation on the magnetite surf ace may have catalyzed the decomposition of H2O2 to oxygen species other th an hydroxyl radicals, Mineral-catalyzed Fenton-like treatment in two natura l 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.