Oxygen in groundwater

State Cleanup Levels for Fuel Oxygenates in Groundwater... 

Due to the difficulties involved in maintaining an adequate microbial mass applied to low concentrations of MTBE or other oxygenates in groundwater, treatability studies are often performed to confirm that extracted groundwater can be adequately treated in a bioreactor. 

J.F. Barker, R.W. Gillham, L. Lemon, C.I. Mayfield, M. Poulsen andE.A. Sudicky, Chemical Fate and Impact of Oxygenates in Groundwater Solubility of BTEX from Gasoline-Oxygenate Compounds, API Publication No. 4531, American Petroleum... 

Water circulation systems, where groundwater is pumped, oxygenated in surface installations and reinjected in the contaminated aquifer... 

The treatment performance data for 123 projects show that air sparging (either alone or in combination with other technologies) has been used to reduce MTBE in groundwater from concentrations >1,000,000 to <50 pg/L. The median project duration for the 19 completed sites ranged from 1 to 5 years. Although two of the 123 projects listed TBA as a cocontaminant, neither of these projects reported TBA concentrations before or after treatment no data for other fuel oxygenates were reported. 

From the 323 projects in U.S. EPA s MTBE Treatment Profiles dataset, 85 projects were identified where MTBE in groundwater was remediated using pump-and-treat along with 15 additional projects that treated MTBE in drinking water (collectively referred to as pump-and-treat projects). Information on the treatment of other oxygenates was reported for 20 of these 100 projects 16 projects reported TBA, 6 projects reported TAME, 2 projects reported ethanol, and 1 project reported DIPE as a contaminant in addition to MTBE. 

Because of their water solubility and low partition coefficients, MTBE and other oxygenates are difficult to adsorb on GAC. Other, more preferentially adsorbed, contaminants in groundwater may also reduce the capacity of GAC to remove MTBE and other oxygenates. 

Halden, R.U., Happel, A.M., and Schoen, S.R., Evaluation of standard methods for the analysis of methyl ferf-butyl ether and related oxygenates in gasoline-contaminated groundwater, Environmental Science Technology, 35 (7), 1469-1474, 2001. 

Mysona, E. S. and Hughes, W. D., 1999, Remediation of BTEX in Groundwater with LNAPL Using Oxygen Releasing Materials (ORM) In In Situ Bioremediation of Petroleum Hydrocarbons and Other Organic Compounds (edited by B. C. Alleman and A. Leeson), Battelle Press, Columbus, OH, Vol. 5, No. 3, pp. 283-288. 

---