In situ treatment technologies

In situ groundwater treatment is an alternative to the conventional pump-and-treat methods. In situ treatment uses biological or chemical agents or physical manipulations that degrade, remove, or immobilize contaminants. In situ treatment technologies can usually treat both contaminated groundwater and soil. In many instances a combination of in situ and aboveground treatment will achieve the most cost-effective treatment at an uncontrolled waste site. 

Natural attenuation, often called intrinsic remediation, intrinsic bioremediation, bioattenuation, or monitored natural attenuation (MNA) is an in situ treatment technology for soil, sediment, or groundwater. The technology has been used for full-scale remediation of sites contaminated with volatile organic compounds (VOCs), total petroleum hydrocarbons (TPH), chlorinated solvents, explosives, inorganics, and metals. 

Mueller, J. G., Pritchard, P. H., Montgomery, M.T. Schultz, W. W. (1994b). In situ treatment technologies for PAH-contaminated sediments. National Research Council s Committee on Contaminated Marine Sediments, Technology Review Workshop, April 21—22, 1994, Chicago 1L. Cincinnati, OH US EPA. 

Permeability and hydraulic conductivity are the controlling factors in the effectiveness of in situ treatment technologies. The ability of soil flushing fluids to contact and remove contaminants can be reduced by low soil permeability. Low permeability can lessen the volatilization of VOCs in soil vapor extraction or limit the effectiveness of in situ vitrification by slowing vapor releases. 

Watson, D. Leavitt, M., Smith, C., Klasson, T., Bostick, B., Liang, L., and Moss, D. (1997). Bear Creek valley characterization area mixed wastes passive in situ treatment technology demonstration project - status report, Proceedings of the 1997 International Containment Technology Conference and Exhibition, St. Petersburg, FL, Feb. 9-12, 1997, 730-736. 

Palmer PL. Reactive walls. In Nyer EK, Kidd DF, Palmer PL, Crossman TL, Fam S, Johns FJ II, Boettcher G, Suthersan SS, eds. In Situ Treatment Technology. Boca Raton, FL CRC, 1996 271-288. 

Vacuum extraction involves aeration followed by vacuum. It represents one of the most commonly used in situ treatment technologies. The technigue is effective when employed under buildings it is relatively cost effective but lengthy, and is not effective in water-saturated soils. 

Nyer, Evan, In Situ Treatment Technology—Second Edition, CRC Press, 2000 NW Corporate Blvd., Boca Raton, FL. 

IN SITU TREATMENT TECHNOLOGIES 23.2.3.1 Product recovery via GCW technology... 

Kelly RT, Guerin TF (1995) Feasibility of using hyperaccumulating plants to bioremediate metal-conteminated soil. In Hinchee RE, Means JL, Burris DR (eds) Bioremediation of inorganics. Battelle, Columbus, OH, pp 25—32 Kidd DF (1996) Fracturing. In Nyer E (ed) In situ treatment technology. Lewis... 

U.S. EPA, Recent Developments for In Situ Treatment of Metal Contaminated Soils, EPA-542-R-97-004, Technology Innovation Office, Washington, 1997. 

U.S. EPA, Recent developments for in-situ treatment of metal contaminated soils, U.S. EPA, Office of Solid Waste and Emergency Response, Technology Innovation Office, EPA Contract No. 68-W5-006, 1997, pp. 1-47. 

For practitioners of in situ technologies, note that U.S. EPA has issued a policy statement that reinjection of contaminated groundwater is allowed under Resource Conservation and Recovery Act (RCRA)35 36 as long as certain conditions are met. This policy is intended to apply to remedies involving in situ bioremediation and other forms of in situ treatment. Under this policy, groundwater may be reinjected if it is treated aboveground prior to reinjection. Treatment may be by a pump-and-treat system or by the addition of amendments meant to facilitate subsurface treatment. Also, the treatment must be intended to substantially reduce hazardous constituents in the groundwater (either before or after reinjection) the cleanup must be protective of human health and the environment and the injection must be part of a response action intended to clean up the environment.37... 

There are a wide range of bioremediation technologies either in use or proposed for use on oil/gasoline-contaminated land [301, 319], and these can be divided into two broad groups. In situ techniques treat the contamination at the site of the pollution event, whereas ex situ techniques remove the contamination from the ground and transfer it to another location for treatment. The use of in situ treatment is often preferable in terms of financial considerations, due to the cost of moving large quantities of soil [20]. Some novel approaches to the problem of hydrocarbon contamination of contaminated aqueous-solid phase environments is the use of (1) gas-liquid foams to enhance in situ bioremediation, and (2) biostimulation, as follows. 

T0293 Enzyme Technologies, Inc., Dissolved Oxygen In Situ Treatment (DO IT)... 

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