비완충상태에서 0가 철을 이용한 Trichloroethylene의 처리

Abstract

Batch experiments were performed to examine the reaction rate constant, pH exchanges and mineral precipitates during reductive dechlorination of trichloroethylene using zero-valent iron in unbuffered system. The effect of pre-treatment of iron particles with acid and NaCl solutions on the degradation of trichloroethylene was investigated, too. The degradation rate was found to be pseudo first order with respect to trichloroethylene concentration, with the observed reaction rate constant kobs, 0.0385hr-1. The pH of solution increased to 8.5 at first and then decreased gradually with reaction time. In the experiment, the greenish suspended particles were identified as green rusts, which in known as potential reducing agents and then were oxidized to magnetite(Fe3O4) with dark gray color. The NaCl-washed iron had a strong enhancement effect whereas effect of iron pre-treatment with H2SO4 on the reductive dechlorination of trichloroethylene was negligible. These results confirm the rate-increasing effect of chloride, which accelerated dechlorination rates probably because of pitting corrosion and autocatalytic nature.