Catalytic Degradation of Dichloroethane Using Cu Nanoparticles Under Reducing Conditions

Dichloroethane is a raw material used for the manufacture of vinyl chloride monomer (VCM) and therefore has very often been detected as a contaminant in the groundwater nearby the VCM manufacturing plant. Zero-valent iron is capable of degrading a wide array of chlorinated contaminants in groundwater such as trichloroethylene, vinyl chloride, carbon tetrachloride, and tetrachloroethane. However, it has no reaction with dichloroethane, which has been categorized as a very recalcitrant groundwater contaminant. In this study, zero-valent copper nanoparticles have been synthesized for effective dechlorination of 1,2-dichloroethane under reducing conditions. Cu nanoparticles have the surface areas of about 19.0 m/g and an average diameter of 70 nm. Batch experiments were conducted to test the effectiveness of Cu nanoparticles for 1,2-dichloroethane degradation using sodium borohydride as electron donors where the ORP was measured at -1000 mV. It was found that more than 80% of 1,2-dichloroethane (initial concentration of 30 mg/L) was rapidly degraded within 2 hours in the presence of both Cu nanoparticles (2.5 g/L) and NaBH4 (1 g/L). No reaction was observed when the system contained either Cu nanoparticles alone or NaBH4 alone. The degradation intermediates included ethane and ethylene accounting for 79% and ~1.5% of the 1,2-dichloroethane lost, respectively.