In Situ Remediation of MTBE-Contaminated Aquifers Using Propane Biosparging
Abstract
Methyl tert-butyl ether (MTBE) has been used as a high-octane additive in mid and high-grade gasoline since 1979, and to replace lead and other gasoline additives such as benzene, toluene, ethylbenzene and xylenes (BTEX). The 1990 Clean Air Act Amendments required that in high pollution areas of the country, oxygenates be used in all grades of gasoline. MTBE was selected as the oxygenate of choice to meet the new standards. In 1992, more than 1.8 billion gallons of MTBE went into gasoline, and its use has increased each year since. In 1995, 17.62 billion pounds of MTBE was produced primarily for use in gasoline, and its production and use has continued to increase. The discharge of gasoline from leaky underground storage tanks into soils and groundwater has resulted in the contamination of these media with MTBE. Because MTBE is highly soluble in water (~43,000 mg/L), it is often found as plumes in groundwater near service stations, storage facilities, and filling terminals throughout the United States. More than 300,000 releases from leaking underground tanks have been reported to state regulatory agencies. Historically, the most common treatment technology for groundwater contamination has been a pump and treat approach. Because of its high aqueous solubility, low Henry s Law Constant (low volatility from water), and poor adsorption to carbon, the usual ex situ treatment techniques designed for contaminants such as benzene and trichloroethylene have proven to be ineffective or expensive for removal of MTBE from groundwater. In situ approaches to groundwater remediation include air or nutrient supplementation to stimulate contaminant degradation (e.g., biosparging), addition of compounds such as zero-valent iron for chemical dechlorination, and addition of bacteria capable of contaminant destruction (bioaugmentation).
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 2003
- Accession Number
- ADA607332
Entities
People
- Robert Steffan