Use of iron minerals in optimizing the peroxide treatment of contaminated soils

The treatment of silica sand contaminated with pentachlorophenol (PCP) using the standard Fenton's reagent procedure, sequential addition of iron (II) and H 2 O 2 , and a goethite (α-FeOOH)-H 2 O 2 system was investigated. The standard Fenton's procedure oxidized 10 mg/L soluble PCP, but was ineffective in degrading 10 mg/kg or 250 mg/kg particulate and sorbed PCP in silica sand. Sequential addition of excess reagents (480 mg/L iron (II) and 7% H 2 O 2 ) degraded particulate and sorbed PCP, but with high stoichiometric H 2 O 2 requirements. The most efficient system for PCP degradation was the H 2 O 2 -goethite system