Degradation of trichloroethylene using iron, bimetals and trimetals.
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.
Department of Occupational Safety & Health, China Medical University, Taichung, Taiwan. kpchao@mail.cmu.edu.tw
Keh-Ping
KP
Chao
Say Kee
SK
Ong
Todd
T
Fryzek
Wanchun
W
Yuan
Washington
W
Braida
D003300:Copper / Q000737:chemistry; D005410:Flame Ionization; D007501:Iron / Q000737:chemistry; D009532:Nickel / Q000737:chemistry; D014241:Trichloroethylene / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification / Q000379:methods*
D014874:Water Pollutants, Chemical; D014241:Trichloroethylene; D003300:Copper; D009532:Nickel; D007501:Iron