title: Abiotic degradation of trichloroethylene under thermal remediation conditions.
abstract: The degradation of trichloroethylene (TCE) to carbon dioxide (CO2) and chloride (Cl-) has been reported to occur during thermal remediation of subsurface environments. The effects of solid-phase composition and oxygen content on the chemical reactivity of TCE were evaluated in sealed ampules that were incubated at 22 and 120 degrees C for periods ranging from 4 to 40 days. For all treatments, no more than 15% of the initial amount of TCE was degraded, resulting in the formation of several non-chlorinated products including Cl-, CO2, carbon monoxide, glycolate, and formate. First-order rate coefficients for TCE disappearance ranged from 1.2 to 6.2 x 10(-3) day(-1) at 120 degrees C and were not dependent upon oxygen content orthe presence of Ottawa sand. However, the rate of TCE disappearance at 120 degrees C increased by more than 1 order-of-magnitude (1.6 to 5.3 x 10(-2) day(-1)), corresponding to a half-life of 13-44 days in ampules containing 1% (wt) goethite and Ottawa sand. These results indicate that the rate of TCE degradation in heated, three-phase systems is relatively insensitive to oxygen content, but may increase substantially in the presence of iron bearing minerals.
authors.affiliation: School of Civil and Environmental Engineering, Georgia Institute of Technology, 311 Ferst Drive, Atlanta, Georgia 30332-0512, USA.
authors.forename: Jed
authors.initials: J
authors.lastname: Costanza
authors.forename: Eva L
authors.initials: EL
authors.lastname: Davis
authors.forename: James A
authors.initials: JA
authors.lastname: Mulholland
authors.forename: Kurt D
authors.initials: KD
authors.lastname: Pennell
mesh_terms: D000327:Adsorption; D000332:Aerobiosis; D001673:Biodegradation, Environmental; D007501:Iron / Q000737:chemistry; D007700:Kinetics; D008903:Minerals / Q000737:chemistry; D010100:Oxygen / Q000737:chemistry; D013696:Temperature; D014241:Trichloroethylene / Q000302:isolation & purification / Q000378:metabolism*; D014874:Water Pollutants, Chemical / Q000378:metabolism*; D018508:Water Purification / Q000379:methods*
chemical_list: D008903:Minerals; D014874:Water Pollutants, Chemical; D014241:Trichloroethylene; D007501:Iron; D010100:Oxygen