Reductive dehalogenation of trichloroethylene using zero-valent iron

Reductive dehalogenation of hazardous organics using zero-valent metals is a promising technology. The purpose of this study was to examine the effect of feed concentration, initial pH, metal loading and particle size of metal on the degradation of trichloroethylene (TCE), using zero-valent iron. The degradation rate was found to be first order with respect to the organic molecule, thus the conversion was independent of initial TCE concentration. The amount of TCE degraded at any given time was found to be directly proportional to the dissolved iron in solution. The metal surface area plays a crucial role in the process. Twofold increase in the pseudo first order rate constant was obtained when the metal particle size was decreased from 370 μm by factor of 2.5. For iron surface area per unit volume (S/V) of solution < 1000 m^-1, the TCE degradation rate constant increased linearly with S/V ratio.