Bioremediation process using liquefied petroleum gas
A method is provided for stimulating anaerobic degradation of a subsurface contaminant, comprising the steps of vaporizing liquefied petroleum gas (LPG) to form a treating gas and directing the treating gas to at least one subsurface injection site that includes the subsurface contaminant; wherein the treating gas stimulates anaerobic degradation of at least a portion of the subsurface contaminant.
1. A method of stimulating anaerobic degradation of a subsurface perchlorate contaminant, comprising the steps of:
a) vaporizing liquefied petroleum gas (LPG);
b) mixing the vaporized LPG with one or more supplemental gaseous electron donors to form a treating gas having an LPG component; and
c) directing the treating gas to a subsurface injection site that includes at least one perchlorate contaminant; wherein the treating gas stimulates anaerobic degradation of at least a portion of the perchlorate contaminant.
2. The method of claim 1 , wherein the treating gas includes about 50% to about 99.9% vaporized LPG by volume.
3. The method of claim 1 , wherein the treating gas includes about 80% to about 99.8% vaporized LPG by volume.
4. The method of claim 1 , wherein the vaporized LPG and the one or more supplemental gaseous electron donors are further mixed with a carrier gas to form a treating gas having an LPG component.
5. The method of claim 4 , wherein the treating gas includes about 1% to about 50% vaporized LPG by volume.
6. The method of claim 4 , wherein the treating gas includes about 5% to about 30% vaporized LPG by volume.
7. The method of claim 4 , wherein subsurface injection site includes groundwater.
8. The method of claim 4 , wherein the subsurface injection site includes soil.
9. The method of claim 8 , wherein the soil is in a vadose zone.
10. The method of claim 4 , wherein the subsurface injection site is at least 5 feet below ground surface.
11. The method of claim 4 , wherein the subsurface injection site is at least 20 feet below ground surface.
12. The method of claim 4 , wherein the treating gas is directed to more than one subsurface injection site.
13. The method of claim 4 , wherein at least one nutrient is injected with the LPG.
14. The method of claim 4 , wherein the carrier gas includes at least one member of the group consisting of steam, air, carbon dioxide, nitrogen, argon, and gas extracted from the subsurface.
15. The method of claim 4 , wherein the carrier gas is substantially devoid of oxygen.
16. The method of claim 4 , wherein the carrier gas includes water vapor.
17. The method of claim 1 , further including a step of directing water vapor to the subsurface site.
18. The method of claim 1 , wherein the supplemental gaseous electron donor is present at a concentration of at least about 0.2% by volume.
19. The method of claim 18 , wherein the supplemental gaseous electron donor is hydrogen.
20. A method of stimulating anaerobic degradation of a subsurface perchlorate contaminant, comprising the steps of:
a) vaporizing liquefied petroleum gas (LPG);
b) mixing the vaporized LPG with a carrier gas and one or more supplemental gaseous electron donors to form a treating gas having an LPG component; and
c) directing the treating gas to a subsurface injection site that includes at least one perchlorate contaminant; wherein the treating gas stimulates anaerobic degradation of at least a portion of the perchlorate contaminant.
21. The method of claim 20 , wherein the supplemental gaseous electron donor is present at a concentration of at least about 0.2% by volume.
22. The method of claim 21 , wherein the supplemental gaseous electron donor is hydrogen.