Temperature effect on tert-butyl alcohol (TBA) biodegradation kinetics in hyporheic zone soils.
BACKGROUND
Remediation of tert-butyl alcohol (TBA) in subsurface waters should be taken into consideration at reformulated gasoline contaminated sites since it is a biodegradation intermediate of methyl tert-butyl ether (MTBE), ethyl tert-butyl ether (ETBE), and tert-butyl formate (TBF). The effect of temperature on TBA biodegradation has not been not been published in the literature.


METHODS
Biodegradation of [U 14C] TBA was determined using hyporheic zone soil microcosms.


RESULTS
First order mineralization rate constants of TBA at 5 degrees C, 15 degrees C and 25 degrees C were 7.84 +/- 0.14 x 10-3, 9.07 +/- 0.09 x 10-3, and 15.3 +/- 0.3 x 10-3 days-1, respectively (or 2.86 +/- 0.05, 3.31 +/- 0.03, 5.60 +/- 0.14 years-1, respectively). Temperature had a statistically significant effect on the mineralization rates and was modelled using the Arrhenius equation with frequency factor (A) and activation energy (Ea) of 154 day-1 and 23,006 mol/J, respectively.


CONCLUSIONS
Results of this study are the first to determine mineralization rates of TBA for different temperatures. The kinetic rates determined in this study can be used in groundwater fate and transport modelling of TBA at the Ronan, MT site and provide an estimate for TBA removal at other similar shallow aquifer sites and hyporheic zones as a function of seasonal change in temperature.
Greenwood
Mark H
MH
Utah Water Research Laboratory, Utah State University, Logan, Utah 84321, USA. markgreen@cc.usu.edu
Sims
Ronald C
RC
McLean
Joan E
JE
Doucette
William J
WJ
D001673:Biodegradation, Environmental; D002245:Carbon Dioxide / Q000737:chemistry; D002273:Carcinogens / Q000737:chemistry; D005742:Gasoline; D007700:Kinetics; D008956:Models, Chemical; D015233:Models, Statistical; D008962:Models, Theoretical; D009009:Montana; D010100:Oxygen / Q000737:chemistry; D012987:Soil; D013696:Temperature; D014867:Water / Q000737:chemistry; D020002:tert-Butyl Alcohol / Q000737:chemistry*
D002273:Carcinogens; D005742:Gasoline; D012987:Soil; D014867:Water; D002245:Carbon Dioxide; D020002:tert-Butyl Alcohol; D010100:Oxygen