New and effective multi-element alpha-hematite systems for reduction of trichloroethylene

Abstract

The reactivity of different -hematite (-Fe2O3) systems for dechlorination of trichloroethylene (TCE) in the presence of Fe(II) and CaO was investigated. Initially different experiments were conducted to investigate the reactivity of pure and doped -Fe2O3. It was found that the presence of elements such as Si, Cu, and Mn in -Fe2O3 had a significant effect on TCE reduction potential of -Fe2O3; however, the reduction potential was less than that of -Fe2O3 (Bayferrox((R))-110M, used in a previous study). Further studies were carried out and -Fe2O3 was synthesized in a manner similar to that of Bayferrox((R))-110M. This synthetic -Fe2O3 showed improved reactivity and was found to follow pseudo-first-order kinetics when used in TCE reduction experiments. The preliminary end products analysis showed that TCE degradation was probably via -elimination pathway. Detailed investigations of -Fe2O3 systems were carried out using X-ray diffraction, X-ray fluorescence, and scanning electron microscopy with energy-dispersive spectrometry. The results demonstrated that the TCE reduction capacity of -Fe2O3 was strongly dependent on the other elements present in iron powder used to synthesize -Fe2O3. It was suspected that these multi-elements in -Fe2O3 helped to improve its conduction property. Current findings suggest that -Fe2O3 not in the pure but combined with other elements could be thought as a potential system for TCE reduction.