Trichloroethylene batch degradation

Mars AE, J Houwing, J Dfolfing, DB Janssen (1996) Degradation of toluene and trichloroethylene by Burk-holderia cepacia G4 in growth-limited fed-batch culture. Appl Environ Microbiol 62 886-891. 

In batch kinetic tests, Yan and Schwartz (1999) investigated the oxidative treatment of chlorinated ethylenes in groundwater using potassium permanganate. 1,1-Dichloroethylene reacted more quickly than cis- and /ra/ 5-l, 2-dichloroethylene, trichloroethylene, and tetrachloroethylene. The reaction rate decreased with an increasing number of chlorine substituents. The pseudo-first-order rate constant and half-life for oxidative degradation (mineralization) of 1,1-dichloroethyene were 2.38 x 10 Vsec and 4.9 min, respectively. 

In a similar study, Zhang and Wang (1997) studied the reaction of zero-valent iron powder and palladium-coated iron particles with trichloroethylene and PCBs. In the batch scale experiments, 50 mL of 20 mg/L trichloroethylene solution and 1.0 g of iron or palladium-coated iron were placed into a 50 mL vial. The vial was placed on a rotary shaker (30 rpm) at room temperature. Trichloroethylene was completely degraded by palladium/commercial iron powders (<2 h), by nanoscale iron powder (<1.7 h), and nanoscale palladium/iron bimetallic powders (<30 min). Degradation products included ethane, ethylene, propane, propene, butane, butene, and pentane. The investigators concluded that nanoscale iron powder was more reactive than commercial iron powders due to the high specific surface area and less surface area of the iron oxide layer. In addition, air-dried nanoscale iron powder was not effective in the dechlorination process because of the formation of iron oxide. 

In laboratory studies, Ravikumar and Gurol [46] monitored the Fenton degradation of pentachlorophenol (PCP) and trichloroethylene (TCE) from sand. In both column and batch studies, they observed the degradation of PCP and TCE with the addition of hydrogen peroxide only. They concluded that iron naturally present in the sand was an effective catalyst for the formation of hydroxyl radical from the added peroxide. However, addition of soluble ferrous salts caused a more rapid degradation of the pollutants, indicating that either insufficient iron was present in the sand or the nature of the iron in the sand made it a poor catalyst. 

Mars, A.E, Houwing, I, Dolfing, J. Janssen, D.B. 1996. Fed-Batch Culture by Burkholderia cepacia G4 in growth-Umited degradation of toluene and trichloroethylene. Appl Environ. Microbiol. 62(3) 886. 

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