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U.S. Department of Energy
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Subsurface contaminant remediation, biodegradation and extraction methods and apparatuses

Patent ·
OSTI ID:6450880

A method of in situ air sparging, vacuum extraction and bioremediation for removal of contaminants from soil and from groundwater present in the soil in the form of a groundwater aquifer, there being a vadose soil zone existing down to a water table defining the upper boundary of the groundwater aquifer, is described comprising the steps of: (a) establishing a plurality of well nests, each well nest comprising one or more injection wells extending through the vadose zone to a depth below the water table and one or more extraction wells in the vadose zone extending to a depth above the water table; (b) injecting oxygen-containing gas into the injection wells; (c) continuously stimulating with the oxygen-containing gas microorganisms present in the vadose zone; (d) increasing the rate of biodegradation of volatile and nonvolatile contaminants by substantially maximizing available oxygen introduced in situ via the injection wells; (e) applying a vacuum to one or more extraction wells at a negative flow which is volumetrically greater than the positive glow of gas injected into the injection wells; and (f) extracting, via the extraction wells, an effluent containing volatile contaminants and biodegradation by-products of both volatile and non-volatile contaminants from the groundwater aquifer and the soil. An apparatus is described for in situ air sparging, vacuum extraction and bioremediation for removal of contaminants from soil and from groundwater present in the soil in the form of a groundwater aquifer, there being a vadose soil zone existing down to a water table defining the upper boundary of the groundwater aquifer.

Assignee:
Environmental Improvement Technologies, Inc., Albuquerque, NM (United States)
Patent Number(s):
US 5221159; A
Application Number:
PPN: US 7-712919
OSTI ID:
6450880
Country of Publication:
United States
Language:
English