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SITE TECHNOLOGY CAPSULE: IITRI RADIO FREQUENCY HEATING TECHNOLOGY
Citation:
Science Applications International Corporation. SITE TECHNOLOGY CAPSULE: IITRI RADIO FREQUENCY HEATING TECHNOLOGY. EPA/540/R-94/527a (NTIS 95-231254), 1995.
Impact/Purpose:
present information
Description:
Radio frequency heating (RFH) technologies use electromagnetic energy in the radio frequency (RF) band to heat soil in situ, thereby potentially enhancing the performance of standard soil vapor extraction (SVE) technologies. Contaminants are removed from in situ soils and transferred to collection or treatment facilities. The Illinois Institute of Technology Research Institute (IITRI) RFH process was evaluated under the U.S. Environmental Protection Agency (EPA) Superfund Innovative Technology Evaluation (SITE) Program at a site containing various organic contaminants in a heterogeneous soil matrix. Due to changes in the original design and operational problems experienced during the demonstration, the treatment area was evaluated as two separate zones: the "revised" design treatment zone and the "heated" zone. The revised design treatment zone reflects both changes made to the design of the RFH system and operational problems associated with shallow groundwater at the test site. The heated zone consists of the area that achieved the target temperature of 15O°C. Concentration changes were calculated from paired pre- and post-demonstration soil samples; these concentration changes were evaluated for statistical significance. Conclusions have been drawn based only on data that were statistically significant at greater than or equal to the 90 percent confidence level. Within the revised design treatment zone the estimated mean concentration decrease for Total Recoverable Petroleum Hydrocarbons (TRPH) was 60 percent. Estimated mean concentration decreases for two semivolatile organic compounds (SVOCs), pyrene and bis(2-ethylhexyl)phthalate were 87 and 48 percent respectively. There were statistically significant increases in the concentrations of four volatile organic compounds (VOCs); the estimated mean concentration increases were 457 percent for 2-hexanone; 263 percent for 4- methyl-2-pentanone; 1,073 percent for acetone; and 683 percent for methyl ethyl ketone. Outside of the revised design treatment zone, only TRPH showed a statistically significant change with an estimated 88 percent increase in the mean concentration. Within the heated zone the estimated mean concentration decrease was 95 percent for TRPH. Outside the heated zone, the estimated mean concentration decrease was 37 percent for bis(2-ethylhexyl) phthalate; estimated mean concentration increases were 423 percent for 2-hexanone: 249 percent for 4-methyl - 2-pentanone; 1,347 percent for acetone: and 1,049 percent for methyl ethyl ketone. Several possible reasons exist for changes In concentration observed. They include inward contaminant migration, low extraction rates, widely varying soil temperatures, low pretreatment contaminant concentrations in the soil, and the potential degradation of TRPH and SVOCs. The estimated cost to treat 10,152 tons of contaminated soil based on a scaleup of the revised design treatment zone is $619 per ton; the estimated cost to treat 8,640 tons of contaminated soil based on IITRI’s theoretical system design is $340 per ton. The IITRI RFH technology was evaluated based on the nine criteria used for decision making in the Superfund feasibility study (FS) process. Results of the evaluation are summarized in Table 1. This evaluation was based on information from the SITE demonstration conducted at Kelly Air Force Base (AFB).
URLs/Downloads:
SITE TECHNOLOGY CAPSULE: IITRI RADIO FREQUENCY HEATING TECHNOLOGY504_R-94_527A.PDF (PDF, NA pp, 1 KB, about PDF)