Treatment of petroleum-contaminated soils using iron mineral catalyzed hydrogen peroxide

Naturally-occurring iron minerals, goethite and magnetite, were used to catalyze hydrogen peroxide and initiate Fenton-like reaction of silica sand contaminated with diesel and/or kerosene in batch system. Optimum reaction conditions were investigated by varying H2O2 concentrations (0, 1, 7, 15, and 35 wt%) and iron mineral contents (0, 1, 5 and 10 wt%). Contaminant degradation in silica sand-iron mineral-H2O2 system was identified by determining total petroleum hydrocarbon (TPH) concentration with gas chromatography. Iron mineral system was less aggressive in contaminant degradation but it was more efficient than FeSO4 system. Magnetite system provided more strong oxidation condition than goethite system due to coexistence of Fe+2 and Fe+3 and dissolution of iron. The results indicate that iron mineral catalyzed H2O2 system would have a promising application to site remediation since natural soils generally contain 0.5-5 wt% of iron minerals. (C) 1998 Elsevier Science Ltd. All rights reserved.