Degradation of trichloroethylene using iron, bimetals and trimetals

• Published in: Journal of environmental science and health. Part A, Toxic/hazardous substances & environmental engineering Vol. 47; no. 11; pp. 1536 - 1542
• Main Authors: Chao, Keh-Ping, Ong, Say Kee, Fryzek, Todd, Yuan, Wanchun, Braida, Washington
• Format: Journal Article
• Language: English
• Published: Philadelphia, PA Taylor & Francis Group 01.09.2012; Taylor & Francis; Taylor & Francis Ltd
• Subjects: Applied sciences; bimetal; Bimetals; Biodegradation; Biological and physicochemical phenomena; Carbon; cold; Copper; Copper - chemistry; Degradation; ethylene; Exact sciences and technology; Flame Ionization; Heavy metals; Hydrocarbons; Iron; Iron - chemistry; Leaching; Natural water pollution; Nickel; Nickel - chemistry; Pollution; Rate constants; Trichloroethylene; Trichloroethylene - chemistry; trimetal iron; Water Pollutants, Chemical - chemistry; water pollution; Water Purification - methods; Water treatment; Water treatment and pollution; zero-valent iron (ZVI); nickel; Trichloroethylene; Zerovalent metal; Reaction rate; zero-valent iron (ZVI); First order; copper; Water pollution; Kinetics; Rate constant; trimetal iron; Ethylene(trichloro); bimetal
• ISSN: 1532-4117; 1093-4529; 1532-4117
• DOI: 10.1080/10934529.2012.680397

A cold, electrodeless method was used to prepare bimetals (Fe/Cu, Fe/Ni) and trimetals (Fe/Cu/Ni) for the treatment of trichloroethylene (TCE). With Fe/Cu, the degradation of TCE was observed to increase with increasing copper content up to 9.26 % (w/w) with a first-order degradation rate constant approximately 10 times faster than that of zero-valent iron (ZVI) alone. For copper content greater than 9.26 %, the TCE degradation rate decreased. Dechlorinated compounds were initially observed but they were transitory and accounted for no more than 9 % of initial TCE mass on a carbon molar basis. Ethylene was the primary end product of TCE reduction. Similarly for Fe/Ni, increasing rates of degradation were observed with increasing amounts of nickel with a maximum degradation rate constant of about 30 times higher than that of ZVI alone. However, the amount of nickel needed to reach the maximum rate was only 0.25 %. When copper and nickel were plated onto iron, the maximum reaction rate constant was approximately 50 times higher than that of ZVI. The maximum degradation of TCE was observed for a copper and nickel content of 4.17 % and 0.40 %, respectively. The experimental results indicated that TCE degradation was enhanced by more than one order of magnitude when copper and/or nickel was plated onto the zero-valent iron. However, copper or nickel plated onto iron by the elctrodeless process was found to leach out during the reaction which may, in turn, impact the contaminated water.