Thermal remediation

Machines. A machine is a device which is capable of manufactuting a product or completing a task such as removing hydrocarbon contaminants from siUca and dirt. Examples of machines iaclude an extmsion apparatus, a book biader, and a tractor. The U.S. Patent No. 5,020,462 tided "Thermal Remediation Apparatus and Method" (3) discloses both a machine and a process. 

Udell, K. (1998). Application of In Situ Thermal Remediation Technologies for DNAPL Removal, in Ground Water Quality and Protection - Proceedings of the Ground Water Quality 98 Conference, Universitaet Tuebingen, German, September 1998, IAHS Publication 250, 367-374. 

For hydrocarbons, data on solubility at the temperatures attained during in situ thermal remediation are scarce. The aqueous solubilities of TCE and PCE as functions of temperature are presented in Figure 24.5. While the solubilities of the two compounds depicted increase exponentially with temperature, they do so only at temperatures above the conventional boiling point of water. The solubility actually achieves a minimum value around 30-50 °C as observed in experimental studies for both TCE and PCE (Imhoff, Frizzel, and Miller, 1997 Heron, Christensen, and Enfield, 1998 Heron et al, 1998 Knauss et al, 2000). 

The performance of in situ thermal remediation systems are strongly affected by the simultaneous flow of two (gas and water) or three (gas, water, and NAPE)... 

Further studies have also demonstrated that thermophilic degradation of PAHs and nonvolatile hydrocarbons increased at temperatures likely to occur adjacent to the active treatment zone of an in situ thermal remediation site (Huesemann et aL, 2002). This observation is likely the result of shifts in the population of microorganisms from predominantly mesophUic to predominantly thermophilic. This type of community shift is usually associated with a reduction in the diversity of microorganisms. As subsurface temperatures cool after active thermal treatment, the consortia within the heated zone will again shift as conditions become less favorable for thermophUes and return to the optimum temperatures for mesophiles. The EPA Technology Innovation Office has pubhshed a more detailed review of this topic, available at the website www.clu-in.org. 

U.S. EPA. (2002a). Final Design Analysis, Thermal Remediation Pilot Stndy, PN C1871, Soil and Groundwater Operable Units. Wyckoff/Eagle Harbor Snperfnnd Site, Bainbridge Island, WA. Report to EPA by U.S. Army Corps of Engineers. 

U.S. EPA. (2002b). A Discussion of the Effects of Thermal Remediation Treatments on Microbial Degradation Processes. Office of Solid Waste and Emergency Response, Technology Innovation Office, Washington, DC. www.clu-in.org. 

Installation of bearings and pulleys Important checks at the time of commissioning Maintenance of electric motors and their checks Maintenance of bearings General problems in electric motors and their remedy Winding temperature measurement at site Analysis of insulation failures of an HT motor at a thermal power station... 

Remediation activities at American Thermostat included the excavation and thermal treatment of over 13,000 cubic yards of soil and sediments contaminated primarily with perchloroethylene, trichloroethylene, and solvents. The soil was excavated and treated using a thermal treatment unit called the low-temperature enhanced volatilization facility (LTEVF). The performance test for the site s thermal unit had just been completed at the time of the inspection, so there was limited activity. 

Remediation aetivities ineluded site mobilization (i.e., installation of trailers, utilities, and equipment elearing and grubbing grading roads and eonstruetion of deeontamination faeilities, drainage pump stations, and a water treatment system), soil exeavation, thermal proeessing of 7,700 eubie yards of soil, baekfilling and regrading the exeavated area, and site demobilization. 

Iben lET et al. (1996) Thermal blanket for in-situ remediation of surficial contamination a pilot test. Environ Sci Technol 30 3144-3154. 

Tse KKC, S-L Lo, JWH Wang (2001) Pilot study of in-situ thermal treatment for the remediation of pentachlorophenol-contaminated aquifers. Environ Sci Technol 35 4910-4915. 

In situ soil remediation with physical methods includes the in situ heating (in situ thermal treatment), ground-freezing, hydraulic fracturing, immobilization/stabilization, flushing, chemical detoxification, vapor extraction, steam extraction, biodegradation/bioremediation, electroosmosis/ electrokinetic processes, etc. 

This alternative includes components of Alternatives 3 and 4 and introduces a thermal destruction component to address the TCE-contaminated soil. For the site remediation case shown in Figure 16.21, the lead-contaminated soil in Area 1 would be fixed and covered with a soil/clay cap, as described in Alternative 4. The groundwater would be addressed through pumping and treating, via an air stripper, as described in Alternatives 3 and 4. The TCE-contaminated soil in Area 2 would be excavated and treated on site by a thermal destruction unit comprisng a mobilized rotary kiln. 

Since 1995, the sparks solvent/fuel site located in Sparks, Nevada, a remediation system consisting of MPE, air sparging, and SVE, has been operational. The treatment system consists of 29 MPE wells, an oil-water separator, and a fluidized bed bioreactor, with an influent flow rate of 23.3 L/s (370 gpm) and a retention time of 8 min. Vapors are sent through a condenser, followed by a thermal oxidizer, before its release to the atmosphere. Condensate is sent back through the oil-water separator. Performance data, available for the first 650 days of site operation, showed a reduction in MTBE concentration across the bioreactor from 2400 to 55 pg/L. No data were provided for reduction of MTBE concentrations in the aquifer.51... 

NON-THERMAL PLASMA-ASSISTED CATALYTIC NO REMEDIATION, FOR SUBSTITUTING FUNCTIONS 1 AND 2 OF THE MODEL. ACTIVATION OF THE LOW-TEMPERATURE DeNO -FUNCTION 3 OF ALUMINA [32-38]... 

The preceding results suggest an advantageous plasma-catalyst coupling effect on the NO remediation, in full accordance with the proposed mechanism [38], The C H Oz and RNO compounds, produced by the non-thermal plasma before the catalytic reactor... 

Khacef, A., Cormier, J.M. and Pouvesle, J.M. (2002) NOx remediation in oxygen-rich exhaust gas using atmospheric pressure non-thermal plasma generated by a pulsed nanosecond dielectric barrier discharge, J. Phys. D Appl. Phys. 35, 1491-8. 

Adams, T. V. and Smith, G. J., 1998, DNAPL Remediation in Clay Till Using Steam-Enhanced Extraction In Physical, Chemical, and Thermal Technologies — Remediation of Chlorinated and Recalcitrant Compounds (edited by G. B. Wickramanayake and R. E. Hinchee), Battelle Press, Columbus, OH, pp. 103-108. 

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