Abstract: The present invention provides a method and gaseous composition for the in situ bioremediation of soil and groundwater contaminated with organic compounds, including halogenated hydrocarbons. The gaseous composition, which readily permeates a subsurface region, comprises hydrogen (H2) and one or more volatile phosphates, such as triethylphosphate (TEP) and tributylphosphate (TBP). The volatile phosphates serve as nutrients that stimulate the growth and activity of indigenous microbes that are capable of degrading the contaminants. The addition of hydrogen facilitates the direct reductive dehalogenation of highly halogenated contaminants. The gaseous composition may optionally contain one or more of a volatile alkane and nitrous oxide as additional supports for microbial growth, and carbon dioxide to lower the pH of remediation sites that are highly alkaline.

Abstract: The present invention provides a method and a gaseous composition for bioremediation of soil and groundwater contaminated with organic compounds, including halogenated organic compounds and explosives. The gaseous composition contains (a) at least one gaseous microbial metabolic inducer and (b) a carrier gas. The gaseous composition may also optionally include one or more of a gas phase nutrient, a gaseous carbon source, a gas phase reductant, and a moisture source.