Ex situ thermal desorption

The System 64MT low-temperature thermal desorption (LTTD) system is a commercially available ex situ thermal desorption technology. This system uses a countercurrent flow rotary drier to heat soils contaminated with volatile organic compounds (VOCs) to temperatures sufficient to cause contaminants to volatilize and physically separate from the soU. Filter bags remove particulate matter and afterbumers/oxidizers are used to destroy organic constituents that remain in the filtered airstream. 

The mobile retort unit is an ex situ thermal desorption technology that, in the absence of air, can remove hydrocarbons from contaminated soil or other media. The term retort means that the material is heated in the absence of air to vaporize the hydrocarbons, which are then transported to a condenser and collected, all in a closed system. 

The HRUBOUT process is a mobile in situ or ex situ thermal desorption process designed to remediate soils contaminated with volatile organic compounds (VOCs) and semivolatile organic compounds (SVOCs). For the ex situ process, excavated soil is treated in a soil pile or in a specially designed container. Heated compressed air is injected into the soil, evaporating soil moisture and removing volatile and semivolatUe contaminants. Heavier hydrocarbons are oxidized as the soil temperature is increased to higher levels over an extended period of time. The vapor is collected and transferred to a thermal oxidizer (incinerator) for destruction. 

For ex situ thermal desorption in general, 15 to 30 per ton ( 20 to 35 per metric ton) is required for direct operating costs including utilities and repairs. Unit transportation and setup costs typically range from 3 to 5 per ton ( 3.30 to 5.50 per metric ton). Excavation of contaminated soils and replacement of treated soils costs about 5 to 10 per ton ( 6 to 11 per metric ton) (D18527, p. 4)... 

VAC TRAX is an ex situ thermal desorption process that separates contaminants such as volatile organic compounds (VOCs), semivolatile organic compounds (SVOCs), polychlorinated biphenyls (PCBs), and radioactive materials from soils, sludges, and solid trash. This process can be applied to mixed and unmixed waste streams. Because the nitrogen atmosphere in which the process occurs is inert, no combustion of organic material takes place. 

Thermal desorption technology is commercially available from numerous vendors. While ex situ thermal desorption technologies are the most common, several in situ techniques have been field tested and are commercially available. 

Several vendors have experience in the operation of ex situ thermal desorption systems and have documented processing costs per ton of soil or waste material treated. The overall range varies from approximately 100 to 400 (1993 dollars) per ton of material treated. Costs are also highly variable due to the following factors ... 

ESTD, ex situ thermal desorption VOCs, volatile organic compounds TPH, total petroleum hydrocarbons BTEX, benzene, toluene, ethylbenzene, xylene PCBs, polychlorinated biphenyls PAHs, polycyclic aromatic hydrocarbons ISTD, in situ thermal desorption. 

Similarly, cost estimates should include such items as preparation of work plans, permitting, excavation, processing, quality assurance/quality control verification of treatment performance, and reporting of data (D15673U, p. 7). For more specific cost estimates for ex situ thermal desorption techniques, refer to the individual technologies in the RIMS 2000 library/database. 

The thermal heating blanket is an in situ thermal desorption system that combines thermal desorption and vacuum extraction to separate organic compounds from in-place contaminated soil. It can be used on soils in situ or ex situ. 

The treatment methods for remediation of energetic materials from soils are divided on in situ and ex situ biological (bioremediation, phytoremediation, composting), in situ and ex situ physico-chemical (adsorption, oxidation, electrokinetic separation, extraction, solidification, reduction, soil washing), in situ and ex situ thermal (pyrolysis, desorption) [1]. Among the above described... 

Other Techniques. Other methods, more conventional in type, are employed for ex-situ treatment. These include solvent extraction and thermal desorption, which are detailed under the "Physical/Chemical Treatment" and "Thermal Treatment" sections, respectively. 

The thermal desorption process could be an excellent first step in soil treatment if used in conjunction with another ex situ treatment. Thermal desorption can remove TCE, most diesel fuel, and perhaps organically bound lead. Chemical Waste Management, Inc., has claimed that thermal desorption can reduce volatile organics to less than 1 mg/L and inorganics to less than 10 mg/L (sometimes even to less than 1 mg/L), and has shown a removal of 96 to 99+% of PCBs from soils containing 120 to 6000 mg/L of initial PCBs.17-91... 

The recently developed ex situ analysis of electrode ad-layers by thermal desorption mass spectroscopy has been demonstrated to be a powerful tool for the study of adsorbates [13, 14],... 

STRATEX, or the stratified temperature extractor technology, is an integrated ex situ soil treatment technology that uses solidification/stabilization, thermal desorption, and steam stripping. 

Ariel Industries, Inc. (Ariel), has designed and manufactured the Ariel SST low-temperature thermal desorber for the ex situ treatment of soil contaminated with volatile organic compounds (VOCs) and hydrocarbons. The system is portable and is used to heat sediment to approximately 900°F, removing moisture and contaminants from the soil. The technology had been offered by Ariel industries on the commercial level, but the company is no longer in the thermal desorption business. 

ASTEC/SPFs low-temperature thermal desorption technology is an ex situ process that treats soil contaminated with petroleum hydrocarbons including gasoline, diesel fuel, jet fuel, lubricating oils, and fuel oils by heating the soil to evaporate the contaminants. 

Enco-Tec Environmental Technology Systems, Ltd. (Enco-Tec), offers the Enco-Tec RS30 thermal desorption system. The system is mobile and is used for the ex situ treatment of soils contaminated with petroleum hydrocarbons. The RS30 thermal desorption system is commercially... 

Enviro-Klean Technologies Inc s (EKTI) KLEAN-MACHINE is a patented ex situ, low-temperature thermal desorption technology used to treat petroleum-contaminated soils. The KLEAN-MACHINE treats soil contaminated with hydrocarbons, volatile organic compounds (VOCs), and petroleum hydrocarbons (with a carbon chain length of 45 carbons or less). The technology also cleans baghouse fines. 

Therm-O-Detox is an ex situ system designed to remove contaminants from soils, sediments, and sludges, using a nonoxidative, medium-temperature thermal desorption process. The mobile Therm-O-Detox system heats the contaminated medium indirectly to desorb contaminants, which are later recovered from sweep gases. 

The HRUBOUT technology is a mobile thermal desorption process that can be used in situ or ex situ. HRUBOUT is designed to remediate soils contaminated with volatile organic compounds... 

IT Corporation s thermal desorption system is a commercially available, ex situ technology for the treatment of soils and sludges contaminated with organics. The process drives volatile and semivolatile organic compounds (VOCs and SVOCs) from the soil by heating the soil to temperatures greater than the boiling point temperature of the contaminants. Volatized vapors are oxidized in a secondary combustion chamber or collected for physical/chemical treatment. 

The KAL CON Environmental Services (a division of Kalkaska Constrnction Services, Inc.) thermal desorption process is an ex situ treatment technology that removes hydrocarbon contamination from soil. This process has been used to treat soils contaminated with gasoline, jet fuel, diesel fuel, kerosene, crude oil, and crude condensate. 

The McLaren/Hart Environmental Engineering Corporation s (McLaren/Hart s) IRV-100 is a mobile, ex situ, low-temperature thermal desorption unit. The IRV-100 treats volatile organic compounds (VOCs) and semivolatUe organic compounds (SVOCs) in contaminated soil by using an infrared heating carriage. The IRV-150 and the IRHV-200 are enhanced versions of the IRV-100. The major enhancement is that both the IRV-150 and IRHV-200 operate under increased vacuum pressure. 

Mercury Recovery Services, Inc. (MRS), has developed the Mercury Removal/Recovery Process (MRRP) to treat media contaminated with mercury. The ex situ process uses medium-temperature thermal desorption to remove the mercury from contaminated wastes. Process wastes are heated in a two-step process to recover metallic mercury in a 99% pure form. MRS claims MRRP can be applied to soils, activated carbon, mixed waste, catalysts, electrical equipment, batteries, lamps, fluorescent bulbs, mercurous and mercuric compounds, mercury-contaminated waste liquids, and debris. 

The GEiM-lOOO low-temperature thermal desorption unit is an ex situ technology that treats soils contaminated with volatile organic compounds (VOCs). This process involves a countercurrent drum, pulse-jet baghouse, and a catalytic oxidizer mounted on a single portable trailer. As the soil is heated in the GEM-1000 unit, contaminants are vaporized. The contaminants are then directed to the system s catalytic oxidizer, which is designed to convert virtually all of the VOCs to carbon dioxide and water vapor. The oxidizer contains approximately 4.9 ft of noble metal catalyst and can destroy between 95 and 99% of the hydrocarbons when operating between 600 and 1250°F. 

On-Site Thermal Services Division of Soil Restoration and Recycling, L.L.C. s (SR2 s) Low-temperature thermal desorption (LTTD) plant is an ex situ technology for treating soil contaminated with petroleum and chlorinated hydrocarbons. 

The thermal recycling system (TRS) is a thermal desorption unit designed for the on-site, ex situ remediation of mercury from contaminated soils. The system volatilizes and then condenses mercury for recovery. The TRS processes contaminants in a nonreactive atmosphere. It uses indirect heat sources to desorb contaminants and recovers 90% of the contaminants. 

The Anaerobic Thermal Desorption Unit (ATDU), also known as the Indirect Heated Unit, is an ex situ technology suitable for treating contaminated soil, sludges, and sediments. It desorbs... 

Thermal desorption is a technology that physically separates volatile and some semivolatile contaminants from contaminated media. In thermal desorption, heated air is used to volatilize contaminants at temperatures below those used for incineration. There are both in situ and ex situ applications of the technology. Ex situ treatments typically are used to remediate soil, sediments, sludges, and filter cakes. In situ applications of the technology use injected steam, thermal blankets, or heat supplied by electrodes to volatilize contaminants, which are then removed using extraction wells. 

The Remediation Technologies, Inc. (RETEC), Thermatek thermal desorption system is an ex situ high-temperature treatment technology that treats soils, sediments, and sludges contaminated with volatile organic compounds (VOCs) and polychlorinated biphenyls (PCBs). The process uses a conventional Holo-Flite thermal desorption unit with RETEC s proprietary modifications, using an indirect heating source. 

TPS Technologies operates several stationary site thermal desorption units exclusively for the ex situ remediation of petroleum-contaminated soil. After processing, the soil is tested by an independent laboratory and reused in commercial construction projects. According to the vendor, over 6000 projects have been completed. TPS has eight soil remediation facilities across the United States. 

The X TRAX technology is an ex situ low-temperature thermal desorption technology that removes organic contaminants from soils, pond sludges, filter cakes, and other solid media. This... 

The WRS Infrastructure Environment, Inc. (WRS), thermal desorption unit (TDU) is an ex situ contaminant separation and concentration technology that primarily treats contaminated soil. The contaminant is vaporized from the soil, collected, condensed, and placed into drums... 

For facilities treating groundwater, the predominant technology chosen has been pump and treat. The innovative technologies selected include in situ bioremediation, ex situ bioremediation, thermal desorption, and chemical treatment. The facilities requiring soil treatment are selected based on established technologies, such as off-site disposal and incineration. The innovative technology most often selected has been SVE. 

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