Evaluación del Tercer Año de Ejecución del Proyecto Alli Allpa

There are many documented examples of field pilot-scale EK remediation of toxic/radioactive metals and hazardous organic chemicals. The individual project descriptions are included in the publicly available reference documents listed below:

U.S. ARMY CORP OF ENGINEERS 1992

Installation Restoration and Hazardous Control Tech- nologies

U.S. EPA 1995 PUBLICATION 542-K-94-007 In-Situ Remediation Technology: Electrokinetics U.S. EPA 1997 PUBLICATION 402-R-97-006 Electrokinetic Laboratory and Field Processes Applica-

ble to Radioactive and Hazardous Mixed Waste in Soil and Groundwater

Electrokinetic Enhanced Soil Bioventing

The conventional application of soil vapor extraction of volatile organic chemicals (VOCs) cannot overcome low permeability soil media to render the successful completion of a project. The electrokinetic process can enhance the desorption of water and contaminants from clay by breaking down the clay layer’s electrically charged bonds. This will make the VOCs available for contact and treatment. The major drawback of soil vapor extraction is air emission which is a physical phase transfer process instead of destruction. The EK enhanced closed loop bioventing process was applied to destroy the VOCs without air emission at sites with clayey soil. The following

122 IN SITUELECTROKINETIC TREATMENT OF MtBE, BENZENE, AND CHLORINATED SOLVENTS is a list of sites where EK enhanced bioventing processes

were successfully implemented:

PepBoys Site, San Diego, California (25) Bioventing of gasoline in clayey soil Bat Rentals Site, Las Vegas, Nevada (29)

Bioventing of gasoline, diesel and kerosene in clayey caliche soil

Evergreen Site, Los Angeles, California (30) Bioventing of gasoline in clayey soil

DBM Oil Site, Long Beach, California (30) Bioventing of diesel and waste oil in clayey soil Cadillac Site, Northridge, California (27) Bioventing of gasoline in clayey soil

Former Texaco Site, Long Beach, California (27) Bioventing of gasoline in silty/clayey soil

Former ARCO Site, Monterey Park, California (27) Bioventing of gasoline in clayey soil

Electrochemical Oxidation

It is difficult to distinguish which electrokinetic process is responsible for destroying petroleum hydrocarbons. The bench test on a soil sample from the PepBoys Site indicated that electrochemical oxidation is responsible for destroying petroleum hydrocarbons.

For all the bioventing projects described in the previous section, the electrochemical oxidation process is responsible for a portion of the destruction of the petroleum hydrocarbons rather than bioventing alone.

Electrobiochemical Oxidation

Electrobiochemical oxidation applies to the aqueous phase biotreatment of petroleum hydrocarbons in soil and groundwater. Electrokinetic processes are responsible for distributing nutrients and oxidants in impacted soil and groundwater. It can be used together with bioventing in the vadose zone. The following is a list of sites where EK enhanced aqueous phase biotreatment processes were successfully implemented:

Westland Site, Hayward, California (26)

Electrobiochemical of gasoline and diesel in Bay Mud clay and water

Bat Rentals Site, Las Vegas, Nevada (29)

Bioventing(wet) of gasoline, diesel and kerosene in clayey caliche soil and shallow groundwater Cadillac Site, Northridge, California (27)

Bioventing(wet) of gasoline in clayey soil and ground- water

Former Texaco Site, Long Beach, California (27) Bioventing(wet) of gasoline in silty/clayey soil and

groundwater

Former ARCO Site, Monterey Park, California (27) Bioventing(wet) of gasoline in clayey soil

At all these sites, food additive nutrients and oxidants were introduced as electrolytes by electrokinetically induced migration through wells (horizontal migration) and infiltration galleries (vertical migration) to penetrate into the clayey matrix of soil and groundwater. Additions of nontoxic and nonhazardous food additives, nutrients, and oxidants into the subsurface are not regulated by underground injection control regulations. Petroleum hydrocarbons like BTEX in soil and groundwater were treated to nondetectable levels at most sites.

Electrolysis of MtBE and Benzene

The two most resistant dissolved petroleum hydrocarbons in the environment are MtBE and benzene due to their higher solubility in water and low cleanup levels which most often cannot be achieved by conventional remedial treatment technologies.

The gasoline additive MtBE is highly soluble in water and usually migrates furthest away downgradient from the spill location. Air stripping of MtBE is not an effective treatment option. There are reports that MtBE in the air were solublized into air-stripper blowdown water. Plus, MtBE is not readily biodegradable in the subsurface. The following is a list of sites where EK induced electrolysis processes were successfully implemented:

Cadillac Site, Northridge, California (27)

Bioventing(wet) of gasoline in clayey soil and ground- water

Former Texaco Site, Long Beach, California (27) Bioventing(wet) of gasoline in silty/clayey soil and

groundwater

MtBE was first treated in groundwater, accidentally (not by design), in 1997 at the Cadillac Site, Northridge, California, while treating dissolved BTEX using the electrobiochemical aqueous phase treatment. It was discovered that MtBE soon ‘‘disappeared’’ after the start- up of the electrokinetic enhanced biotreatment. The MtBE in groundwater was treated to nondetectable levels in less than 3 months of treatment. It also appeared that benzene concentration was decreasing at a slower rate at various monitoring wells. The electrolysis of MtBE and benzene cannot actually be confirmed. It was a surprise to document the MtBE disappearance at the Cadillac Site while at the time the oil company sponsored numerous seminars that pointed to no effective remedy for MtBE in the environment.

The same electrobiochemical treatment technique was applied to MtBE and BTEX at the former Texaco Site in Long Beach, California, in 1997. The dissolved benzene

IN SITUELECTROKINETIC TREATMENT OF MtBE, BENZENE, AND CHLORINATED SOLVENTS 123 and MtBE in groundwater were treated to nondetectable

levels in two monitoring wells outside of the zone of influence of the electrobiochemical treatment area which was focused on the former underground storage tank pit area. This indicated that the only thing that can influence these peripheral monitoring wells is the DC flow field. This is the first confirmation of the electrolytic breakdown of dissolved MtBE and benzene in groundwater. The nondetectable MtBE and benzene performance in the vadose zone soil in the tank pit area is also a first. Chlorinated Solvents

The conventional remedial treatment technology of chlo- rinated solvent in soil is soil vapor extraction. The newer and innovative remedial treatment of chlorinated solvents in groundwater is cometabolic biotreatment. None of the above will be effective when treating clayey material. Electrokinetic processes excel in des- orbing the contaminants from clay and distributing nutrient, oxidants and cosubstrates in the soil and groundwater.

The following is a list of sites where the EK enhanced chlorinated solvent treatment processes were successfully implemented:

Northrop ESD Site, Anaheim, California (31)

EK enhanced soil vapor extraction of chlorinated sol- vents in clayey soil

The Good Guys Site, Emeryville, California (8,20,28, 30,32) EK enhanced cometabolic biotreatment of chlorinated solvents in clayey soil and groundwater BIBLIOGRAPHY

1. Loo, W.W. (2001). Bioremediation & electrokinetic treatment of hazardous wastes. Standard Handbook of Environmental Health, Science and Technology. J.H. Lehr (Ed.). McGraw- Hill, New York, Chapters 14.4 & 14.6.

2. Roberts, P. et al. (1990). Biostimulation of Methanotrophic Bacteria to Transform Halogenated Alkene for Aquifer Restoration. Conference Proceedings of Petroleum Hydrocar- bons and Organic Chemicals in Groundwater, Houston, TX, pp. 203–217.

3. Garnier, P., Auria, R., Magana, M., and Revah, S. (1999). Co- metabolic Bio-treatment of MTBE by a Soil Consortium. Proceedings of The Fifth International In situ and On-Site Bio-remediation Symposium, Battelle Press, San Diego, CA, Vol. 5(3), pp. 31–35.

4. Battelle Press. (1999). Engineered Approaches for In situ Bio-remediation of Chlorinated Solvents. Proceedings of The Fifth International In Situ and On-Site Bio-remediation Symposium, San Diego, CA, Vol. 5(2).

5. Gaudy, A.F. and Gaudy, E.T. (1980). Microbiology for Envi- ronmental Scientists and Engineers. McGraw-Hill, New York. 6. Wilson, J.T. and Wilson, B.H. (1985). Biotransformation of trichloroethylene in soil. Applied and Environmental Microbiology 49(1): 242–243.

7. Nelson, M.J.K. et al. (1987). Bio-treatment of trichloroethy- lene and involvement of an Aromatic Biodegradative pathway. Applied and Environmental Microbiology 53(5): 949–954.

8. Loo, W. W. (1991). Heat Enhanced Bio-remediation of Chlo- rinated Solvents and Toluene in Soil. Conference Proceedings of R&D 1991, Anaheim, CA, pp. 133–136.

9. Loo, W.W. et al. (1993). Field Bio-treatment of Chlorinated Solvents: A Co-Metabolic Process Utilizing Glucose as Co- Substrate. Proceedings of HAZMACON 1993, Association of Bay Area Government(ABAG), Santa Clara, CA.

10. Casagrande, L. (1947). The Application of Electro-Osmosis to Practical Problems, in Foundations and Earthworks. Building Technical Paper No. 30, H. M. Stationary Office, London. 11. Casagrande, L. (1948). Electro-Osmosis. Proc. 2nd Int. Conf.

on Soil Mech. and Found. Eng., vol. 1, pp. 218–222. 12. Casagrande, L. (1952). Electro-Osmotic Stabilization of Soils.

Boston Soc. Civ. Eng. 39(1): 51.

13. Chilingar, G.V. et al. (1963). Possible use of electric current for increasing volumetric rate of flow of oil and water during primary and secondary recovery. Chem. Chron. 28(1): 1–4. 14. Chilingar, G.V. et al. (1964). Use of direct electrical current

for increasing the flow rate of reservoir fluids during petroleum recovery. J. Canadian Pet. Tech. 3(1): 8–14. 15. Chilingar, G.V. et al. (1968). Possible use of direct current for

augmenting reservoir energy during petroleum production. Compass of Sigma Gamma Epsilon 45(4): 272–285.

16. Chilingar, G.V. et al. (1970). Effect of direct electrical current on permeability of sandstone cores. J. Pet. Tech. 22(7): 830–836.

17. US EPA. (1997). Electrokinetic Laboratory and Field Processes Applicable to Radioactive and Hazardous Mixed Waste in Soil and Groundwater. US EPA publication 402- R-97-006, Center for Remediation Technology and Tools, Washington, DC.

18. Van Doren, E.P. and Bruell, C.J. (1987). Electro-Osmotic Removal of Benzene from a Water Saturated Clay. Proc. of Petroleum Hydrocarbons and Organic Chemicals in Ground Water: Prevention, Detection and Restoration, Nov. 17–19, 1987, Houston, TX, pp. 107–126.

19. U.S. Army Corps of Engineers. (1992). Installation Restora- tion and Hazardous Control Technologies. Prepared for US Air Force, US Navy, US Army, and US EPA, pp. 45–46. 20. Loo, W.W. (1995). Electrokinetic Treatment of Hazardous

Wastes in Soil and Groundwater, HAZMACON’95 Award Winning Paper. Proceedings of HAZMACON’95, sponsored by the Association of Bay Area Governments, San Jose Convention Center, San Jose, CA, pp. 147–158.

21. US EPA. (1995). In-Situ Remediation Technology: Electroki- netics. US EPA publication 542-K-94-007, Office of Solid Waste and Emergency Response, Office of Technology Inno- vation Office, Washington, DC.

22. Hinchee, R.E. et al. (1989). Enhancing Bio-treatment of Petroleum Hydrocarbon Fuels Through Soil Venting. Con- ference Proceedings of Petroleum Hydrocarbons and Organic Chemicals in Groundwater, Houston, TX, pp. 235–248. 23. Hinchee, R.E. et al. (1990). Enhanced Bioreclamation Soil

Venting and Groundwater Extraction: A Cost-Effectiveness and Feasibility Comparison. Conference Proceedings of Petroleum Hydrocarbons and Organic Chemicals in Ground- water, Houston, TX, pp. 147–164.

24. Miller, R.N. et al. (1990). A Field Investigation of Enhanced Petroleum Hydrocarbon Bio-treatment in the Vadose Zone at Tyndall AFB, Florida. Conference Proceedings of Petroleum Hydrocarbons and Organic Chemicals in Groundwater, Houston, TX, pp. 339–351.

25. Loo, W.W., Wang, I.S., and Fan, K.T. (1994). Electrokinetic Enhanced Bioventing of Gasoline in Clayey Soil: A Case