Degradation of chlorinated organic compounds by mixed particles of iron/iron sulfide or iron/iron disulfide

Abstract

Kinetic study was carried out in order to clear a mixing effect of Fe-Fe-S or Fe-Fe-S2 particles on increase in degradation rate of chlorinated organic compounds. Trichloroethylene (TCE) contained solution was used for dechlorination in 30mL of vial bottle and mixed by rotary device. Estimating that TCE concentration in solution was proportional to TCE gas concentration in head space of vial bottle, gas was obtained from the head space with syringe and measured by GC-FID. TCE degradation occurred on Fe, Fe-S, Fe-Fe-S and Fe-Fe-S2 particles except Fe-S2. TCE degradation of mixed particles of Fe-Fe-S or Fe-Fe-S2 was explained by anode (Fe)cathode (Fe-S or Fe-S2) reaction. TCE degradation rates of Fe-Fe-S and Fe-Fe-S2 caused by anode/cathode reaction were 2.81 x 10-6 and 1.37 x 10-5 (m/h), respectively, which were larger than those of pure Fe and Fe-S. There was no difference in TCE degradation rate of mixed particles of Fe-Fe-S or Fe-Fe-S2 between aerobic and anaerobic solutions. TCE degradation rate of mixed particles of Fe-Fe-S or Fe-Fe-S 2 increased in decrease in size of Fe-S or Fe-S2. TCE degradation rate of mixed particles of Fe-Fe-S or Fe-Fe-S2 increased with increase in decomposition temperature. © 2014 The Japan Institute of Metals and Materials.