Abstract: An in-situ thermal desorption system and process is utilized for mobilization and removal of nonvolatile and semi-volatile hydrocarbons from contaminated soil in the vadose zone. Persistent hydrocarbons are thermally desorbed by direct heating of the contaminated zone through combustion of fuel and air in a burner underneath the contaminated soil zone. The generated soil vapors are collected and treated by soil vapor extraction techniques.

Abstract: Combustion is used as a source of heat to remove polluting volatiles from contaminated groundwater and subsurface soil. The combustor is placed in a well, either in or out of an aquifer, to produce steam and combustion product gases and/or hot water which drives off the volatile contaminants which are collected through separate wells or vents depending upon the site. Key elements are the addition of heat in-situ by causing the combustion to occur below the ground or water level, transfer of heat through the aquifer and/or ground through the flow of steam and combustion product gases and/or hot air and/or hot water to regions affected by the contaminants, and by drawing the flow to other well sites by which the contaminants are removed by pumping and subsequent treatment. Some of the contaminants are thermally destroyed. The design of the well casing can be tailored to proportion the quantities of water and steam and gas delivered, with steam and gas pressure driving the vapors at various levels below ground.

Abstract: A method of entombing a nuclear reactor where the reactor with its bio-shield remains intact. An access shaft, several lateral adits, and several chambers below the reactor location are excavated to provide access at underground locations below the reactor. A main cavern is excavated and lined with a lower base, surrounding sidewall, and a roof structure which has thermal plate at its lower surface. Freeze/thaw pipes are erected vertically in the cavern, and these extend through the earth strata below the cavern into a lower operating chamber. The cavern is filled with water which is then frozen, and the earth strata immediately below the reactor and are isolated from the surrounding earth strata and structure. The upper surface of the ice block is melted by the thermal plate in a controlled manner to lower the reactor, after which concrete and other material is used to fill all of the man made cavities and thus entomb the reactor.

Abstract: Apparatus (10) and a method for vitrifying hazardous waste includes a melting vessel (12) in which hazardous waste and any other necessary components for forming a glassy mixture upon heating are introduced for heating by a heater (38), and a metallic containment vessel (46) of the apparatus receives the melting vessel so as to receive and contain any material that exits the melting vessel upon failure. A voltage is applied across spaced electrical connections (72) of the melting vessel (46) to heat material within the melting vessel. Any failure of the melting vessel (12) is detected by a sensor (48). A stirrer (39) can be utilized to mix the material (18) during the heating. The containment vessel (46) is preferably hermetically sealed around the melting vessel (12) to contain gases as well as any melted material received from the failed melting vessel (12).

Abstract: A method and apparatus for optimizing the curing of concrete poured under hostile ambient temperature conditions. The apparatus includes a liquid reservoir and pumping system and a number of spaced-apart tube segments overlaid into the forms for receiving the concrete with respective ends of the tubes positioned outside the concrete forms. A liquid manifold is connected to one set of tube ends and a second liquid manifold is connected to the other set of tube ends. The temperature of the liquid in the reservoir is adjusted for optimum curing of concrete, and the liquid is pumped through the tubes after the concrete has been poured; when the concrete hardens the liquid is disconnected, and the tubes are disconnected from the manifolds without removing the tubes from the hardened concrete.

Abstract: A method of remediating soil contaminated with inorganic and organic pollutants as disclosed. A method comprises treating the soil with a complexing agent capable of chelating the pollutants and a matrix-generating agent for authigenically generating within the soil an alumino-silicate colloid matrix. The matrix has a plurality of reactive sites, which are capable of physically and chemically altering the pollutants into innocuous forms. The matrix-generating material comprises a mixture of a cement, blast furnace slag, fly ash, organophilic clay, and a free radical generator.

Abstract: A thermal barrier is disclosed for surface confinement with active cooling to control subsurface pressures during thermal remediation of shallow (5-20 feet) underground contaminants. If steam injection is used for underground heating, the actively cooled thermal barrier allows the steam to be injected into soil at pressures much higher (20-60 psi) than the confining strength of the soil, while preventing steam breakthrough. The rising steam is condensed to liquid water at the thermal barrier-ground surface interface. The rapid temperature drop forced by the thermal barrier drops the subsurface pressure to below atmospheric pressure. The steam and contaminant vapors are contained by the thermal blanket, which can be made of a variety of materials such as steel plates, concrete slabs, membranes, fabric bags, or rubber bladders.

Abstract: A system for in situ decontamination of contaminated soil in a contaminated zone comprising:a. a metal section placed in the contaminated soil,b. a heating means attached to said metal section for heating said metal section,andc. an extraction system adjacent or near said metal section for withdrawing vapors and condensates generated from heating the contaminated soil.

Abstract: An improved system for remediating soil contaminated with short-chain hydrocarbons, long-chain hydrocarbons and PCB's. The system includes an rotary drum having first and second heat exchanging regions, each containing separated inner and outer regions. The drum in inclined such that soil fed into the system with a sealed auger for remediation is gravitationally urged through the inner regions whereat thermal energy provided by a burner means, including clamshell ducts, remediates the soil by vaporizing and oxidizing the hydrocarbons and PCB's in a stream of hot gases.

Abstract: An apparatus is provided which passively removes contaminated gases from a subsurface. The apparatus includes a riser pipe extending into a subsurface which has an exterior end in fluid communication with a valve. When well pressure is greater than atmospheric pressure, the valve opens to release contaminants into the atmosphere, and when well pressure is less than atmospheric pressure, the valve closes to prevent flow of air into the well. The valve assembly of the invention comprises a lightweight ball which is lifted from its valve seat with a slight pressure drop between the well and the atmosphere.

Abstract: Contaminated material such as soil or sludge is remediated by injecting a suitable remediation fluid into the material during excavation of the contaminated material with a trenching tool. The remediation fluid is injected into the contaminated material through an injection means, preferably a plurality of injection nozzles positioned along the length of the trenching tool. The thusly treated material is backfilled or deposited directly into the trench excavated by trenching tool thereby obviating the need for off-site disposal. The constituent remediation agents in the remediation fluid may be adjusted to adapt to varying site conditions and contaminants. The remediation fluid may also be heated to accomplish volatile stripping of the contaminated material or to activate microbial agents in a low temperature environment.

Abstract: The object of the present invention is to avoid the difficulty of recruiting snow removal personnel by automatically melting snow that has accumulated on roads in areas having cold climates, and protect human life and secure the safety of vehicles and aircraft traveling on such roads and runways.The present invention is comprised of a heating unit wherein a surface heating element, in which an electrically conductive coating is applied onto a cloth, is positioned between metal plates such as aluminum plates above and below and wrapped in a tar-based moisture-proof sheet. Said heating unit is then embedded beneath the surface of road paving. After particularly carefully steam rolling the asphalt and concrete base layer in this case so that it is free of irregularities, the upper surface of said base layer is coated with a primer.

Abstract: A method and apparatus for, decontaminating in-situ soil by use of solar energy is provided. A targeted area of contaminated in-situ soil is covered with a substantially sunlight-transmitting, nonporous covering that allows solar energy to penetrate said covering. A greenhouse effect subsequently occurs in which trapped solar energy heats the interior air within the covering and in-situ soil below the covering. As the in-situ soil is heated, contaminants found within the in-situ soil are vaporized. The structure comprises first and second side panels with attached first and second end panels. An exhaust vent is provided such that vaporized contaminants and air can escape the interior of the covering. An exhaust means can be utilized to further assist in removal of vaporized contaminants and air within the covering. A fresh air intake slot allows replenishment of air that is exhausted or vented with vaporized contaminants.

Abstract: A system and method of preventing groundwater contamination by a plume of liquid born toxic contaminants that includes establishing a dry barrier between a plume of liquid contaminants and the water table to immobilize the toxic contaminants. The dry barrier is formed by transporting dry gas into the barrier region, such as with injector wells, and then removing it and any moisture it has absorbed, such as with extraction wells to create a layer or bowl shaped structure that is so dry that liquid borne contaminants cannot pass therethrough. By maintaining the barrier, the contaminants form an immobile crust above the barrier which assists in prevention of liquid transport of contaminants into the groundwater. The system is particularly effective when radioactive contaminants are involved because the contaminants can remain fixed and undisturbed underground.

Abstract: Ionic contact is established and maintained between electrodes and soil in ohmic heating of a subsurface formation for recovery of volatile and semi-volatile materials, such as hazardous waste, hydrocarbon-like materials, and valuable minerals having thermally responsive properties. A compressed, dry sponge is wrapped around an electrode, which is then inserted into a bore hole. A conductive liquid is added to the bore hole, causing the sponge to swell, creating a stable and substantial interface for the flow of heating currents.

Abstract: The object of the present invention to provide a method for thawing frozen ground for laying concrete primarily at a construction site by use of a continuous length of circulating hose placed on the frozen ground inside and/or adjacent a concrete form where the concrete will be laid, covering the circulating hose with a layer of aggregate material for insulation from cold air caving the ends of the circulating hose protruding from the aggregate connecting the ends of the hose to a source of heated liquid to circulate warm liquid through the circulating hose to thaw the frozen ground, laying the concrete in the concrete form while continuing to circulate heated liquid in the circulating hose to prevent the concrete from freezing, leaving the portion of the hose in the form under the concrete by cutting the ends protruding from the aggregate, removing the remaining portions of the hose.

Abstract: Apparatus (10) and a method for vitrifying hazardous waste includes a melting vessel (12) in which a stirrer (38) mixes hazardous waste and any other necessary components for forming a glassy mixture upon heating while an electrical current is applied across the melting vessel and the stirrer to provide electrical current flow, and a metallic containment vessel (46) of the apparatus receives the melting vessel so as to receive and contain any material that exits the melting vessel upon failure. Any failure of the melting vessel (12) is detected by a sensor (48). The containment vessel (46) is hermetically sealed around the melting vessel (12) to contain gases as well as any melted material received from the failed melting vessel (12). The sensing of the failure can be either by a pressure change in the hermetically sealed chamber (58) or by sensing of the presence of material received by the containment vessel (46) from the failed melting vessel (12) such as by an electrical circuit type detection.

Abstract: An integrated soil warming probe assists soil remediation by heating contaminated soil. A thermal probe is driven into the contaminated soil and fluid injected into the soil proximate the thermal probe for enhancing remediation. Such a soil warming probe includes an elongate tube with permeable walls and a conical cap at one end for assisting soil penetration. Circulating tubes within the hollow region of the elongate tube circulate contained fluid therein while providing thermal coupling between the contained fluid to the permeable walls of the elongate tube. The circulating tubes are disposed within the elongate tube so as to leave an independent channel between the circulating tubes and the permeable walls of the elongate tube for channeling a supplemental fluid within and out the permeable walls of the soil warming probe.

Abstract: The present invention includes a method of treating solid earthen material having volatile, semi-volatile, and non-volatile contaminants that utilizes electrical energy. A plurality of electrodes are inserted into a region of earthen material to be treated in a selected geometric pattern. Varying phase and voltages configurations are applied to corresponding electrodes to achieve heating, physical phase changes, and the placement of substances within the treatment region. Additionally, treatment mediums can be added to either treat the contamination within the soil or to restrict their mobility.

Abstract: Heavy metals contaminants in soils are fixed and rendered non-leachable by the process of heating the metal contaminated soil containing a hydrocarbon liquid, at an elevated temperature sufficient to convert at least a part of the liquid hydrocarbon into solid carbon or coke deposited on the surface of the soil and subjecting the thus heated soil to sufficient microwave radiation to sustain at least a partial fusion or melting process that results in a fixing of the heavy metals in the soil.

Abstract: Apparatus (10) and a method for vitrifying hazardous waste includes a melting vessel (12) in which hazardous waste and any other necessary components for forming a glassy mixture upon heating are introduced for heating by a heater (38), and a metallic containment vessel (46) of the apparatus receives the melting vessel so as to receive and contain any material that exits the melting vessel upon failure. Any failure of the melting vessel (12) is detected by a sensor (48). Different embodiments of the heater (38) provide current flow through molten material (18) being heated, induction heating and electric resistance heating. A stirrer (39) can be utilized to mix the material (18) during the heating. The containment vessel (46) is preferably hermetically sealed around the melting vessel (12) to contain gases as well as any melted material received from the failed melting vessel (12).

Abstract: An in situ waste treatment system for contaminated soil employs a high temperature energy probe which is lowered into a borehole casing that has been inserted into the contaminated soil. The energy probe is activated and then melts surrounding region of the contaminated soil. The probe is raised and continues to melt a cylindrical column of soil that surrounds the borehole casing. Oxygen is introduced into the molten material so that organic and metallic components thereof are oxidized. In basaltic soils superheating and nucleation materials are introduced to enhance formation of a crystalline structure in the contaminated soil as it solidifies. Increased crystallinity makes the resultant solidified basaltic materials more resistant to leaching by ground water. Other types of contaminated soils are treated with waste modifiers to produce optimum leach resistance of the resultant resolidified soil.

Abstract: A technique for in situ decontamination of an earth formation. High gas temperatures can be achieved at subsurface formations by supplying a fuel at a subsurface location, such as at the bottom of a wellbore. Pressurized air or gas preheated to a temperature of about 700.degree. F.-1200.degree. F. is supplied to the wellbore to ignite the fuel. The combustion heat produced by the fuel further heats the preheated gas to temperatures in the range of 1200.degree. F.-4500.degree., which heated gases are forced out of the borehole into the contaminated formation. Contaminants are thereby volatilized or oxidized and removed from the formation to the surface.

Abstract: A process for the in-situ remediation of a contaminated heterogeneous soil region comprising: (a) introducing material for treating contaminants in a contaminated heterogeneous soil region into at least one liquid permeable region within the contaminated heterogeneous soil region to form at least one treating zone within the contaminated heterogeneous soil region, (b) transmitting direct electric current through at least one low permeability soil region within the contaminated heterogeneous soil region between a first electrode and a second electrode having opposite charge, wherein (i) the first electrode is located at a first end of the contaminated heterogeneous soil region and the second electrode is located at the opposite end of the contaminated heterogeneous soil region or (ii) the first electrode is located at a first end of each of the low permeability soil regions and the second electrode is located at the opposite end of each of the low permeability soil regions, (1) to cause an electroosmotic flow

Abstract: A dynamic underground stripping process removes localized underground volatile organic compounds from heterogeneous soils and rock in a relatively short time. This method uses steam injection and electrical resistance heating to heat the contaminated underground area to increase the vapor pressure of the contaminants, thus speeding the process of contaminant removal and making the removal more complete. The injected steam passes through the more permeable sediments, distilling the organic contaminants, which are pumped to the surface. Large electrical currents are also applied to the contaminated area, which heat the impermeable subsurface layers that the steam has not penetrated. The condensed and vaporized contaminants are withdrawn by liquid pumping and vacuum extraction. The steam injection and electrical heating steps are repeated as necessary.

Abstract: The probe for circulating heated water for thawing frozen ground is a portion of a mobile heating system including a plurality of hose sections. The probe includes a T-connection having a fluid inlet section, a first fluid outlet section, and a second fluid outlet section. An elongate outer tube having an ingress port is affixed to the first fluid outlet section. The elongate outer tube includes a closed penetrating end for insertion into a frozen ground surface. An inner tube is positioned inside the T-connection and the outer tube. The inner tube has an inflow end positioned proximate to the closed penetrating end and an elbow having an outflow opening positioned within the T-connection where the outflow opening is positioned proximate to the second fluid outlet section. The probe defines a perpendicular fluid-flow course which depends downwardly between the outer tube and the inner tube for entry into the inner tube proximate to the penetrating end.

Abstract: A process and apparatus is presented for removing contaminants from particulate materials especially earth materials by converting said materials by mixture with water and additives to slurries which are energized to volume boiling conditions thereby dislodging contaminant components from the particulate materials, said dislodging can be enhanced through centrifugal or cyclone apparatus for example, which contains electrodes in direct contact with the slurry along the walls of the cyclone. An electrical current flows through the slurry as the energizing source.

Abstract: A system to exterminate and control subterranean termites and other subterranean pests inhabiting a subterranean area surrounding or in close proximity to a structure having a perimeter near ground level and support pads includes a plurality of first pipes, a plurality of second pipes, a source of steam, a plurality of temperature sensors, a temperature display and a controller. Each pipe has a plurality of holes in its sidewall. The first and second pipes are disposed beneath ground level along the perimeter of the structure and along its support pads, respectively. The source of steam is fluidly coupled to the pipes. Each temperature sensor is disposed adjacent to one of the pipes. The temperature sensors generate temperature signals. The temperature display displays a temperature reading of the temperature adjacent to each pipe in response to the temperature signals. The controller regulates pressure and/or temperature of the source of steam in response to the temperature signals.

Abstract: In-situ decontamination of soil is accomplished by providing electromagnetic energy of relatively short wavelengths from an array of applicators (antennas), inserted into a borehole array that encompasses the contaminated zone. The borehole array geometry is designed according to the soil's thermophysical properties. Electromagnetic energy heating and heat transfer mechanisms are used to raise the temperature of the soil to the desired level for vaporization of contaminants while at the same time avoiding excessive heat loss from the much larger array size. Heating is maintained throughout the contaminated zone after the final temperature has been reached by proper compensation of the envelope heat loss. Contaminants are evaporated by the heating. Contaminant vapors are collected by vapor collection pipes and/or a gas cover over the soil being heated. The contaminant vapors are then reduced in volume to manageably safe levels and then treated and/or disposed of.

Abstract: A subsurface hydronic heat-exchanging apparatus and method are provided for controlling the temperature of a turf field. A temperature-controlling fluid is circulated from a temperature-controlled fluid source through a supply header laterally disposed to the field and coupled to an array of hollow tubular heat-exchanging elements underlying the field. Fluid is recirculated to the fluid source from the tubes through a return header laterally disposed to the field and coupled to the tubes. Temperature sensors are disposed adjacent the turf field which detect the temperature of the field and a temperature control device is provided which is responsive to the detected temperature.

Abstract: A process is disclosed for the reduction of landfill material and biodegradable refuse which comprises the aeration and wetting of the refuse to facilitate anaerobic decomposition processes. Aeration is achieved by mixing and agitating the refuse.

Abstract: The present invention includes a method of treating solid earthen material having volatile, semi-volatile and non-volatile contaminants. Six electrodes are inserted into a region of earthen material to be treated in a substantially equilateral hexagonal arrangement. Six phases of voltages are applied to corresponding electrodes. The voltages are adjusted within a first range of voltages to create multiple current paths between pairs of the electrodes. The current paths are evenly distributed throughout the region defined by the electrodes and therefore uniformly heat the region. The region of earthen material is heated to a temperature sufficient to substantially remove volatile and semi-volatile contaminants. This temperature is less than a melting temperature of the earthen material. The voltages are then increased to a second range of voltages effective to create dry regions around the electrodes.

Abstract: A burn chamber for a recirculating system for remediation of contaminated soil, the burn chamber including a burn chamber housing, the housing having an inlet (152) and an opposing outlet (164). Contaminate-containing vapors moving into the interior of the burn chamber through the inlet (152) are directed through grill members (170 and 172) into flame areas produced by burners (174 and 176), with the vapors then being circulated by a baffle member (198) positioned near the front of the chamber housing and then through grill members (190 and 192), which are oriented to direct the vapors around the ends of the baffle (198) and out the outlet (164) to the remainder of the recirculating system.

Abstract: The present invention includes a method of treating solid earthen material having volatile, semi-volatile, and non-volatile contaminants. Six electrodes are inserted into a region of earthen material to be treated in a substantially equilateral hexagonal arrangement. Six phases of voltages are applied to corresponding electrodes. The voltages are adjusted within a first range of voltages to create multiple current paths between pairs of the electrodes. The current paths are evenly distributed throughout the region defined by the electrodes and therefore uniformly heat the region. The region of earthen material is heated to a temperature sufficient to substantially remove volatile and semi-volatile contaminants by promoting microbial action. This temperature is less than a melting temperature of the earthen material.

Abstract: The in situ process for increasing the capacity of a municipal solid waste landfill involves disturbing the municipal solid waste present within a landfill site, adjusting the moisture content of the waste material, adding a lime reagent, stockpiling the waste material and allowing the temperature to increase so that aerobic biostabilization is facilitated and allowing the temperature of the municipal solid waste material to decrease to a stable point. The process can be practiced with the use of currently available types of earth moving and refuse handling equipment and involves the addition of no other substances to the municipal solid waste except lime and water.

Abstract: An apparatus for decontaminating ground areas where toxic chemicals are buried includes a plurality of spaced electrodes located in the ground and to which a voltage is applied for bringing about current flow. Power delivered to the ground volatilizes the chemicals that are then collected and directed to a gas treatment system. A preferred form of the invention employs high voltage arc discharge between the electrodes for heating a ground region to relatively high temperatures at relatively low power levels. Electrodes according to the present invention are provided with preferentially active lower portions between which current flows for the purpose of soil heating or for soil melting and vitrification. Promoting current flow below ground level avoids predominantly superficial treatment and increases electrode life.

Abstract: A method of killing soil pathogens to improve the agricultural production of a field comprises the steps of moving a plurality of agricultural tools through the soil and during this movement emitting microwave energy into the soil at a frequency within the range of 2GH.sub.z to 12GH.sub.z. The microwave energy heats the soil organisms to levels sufficient to kill the organisms.

Abstract: A method of processing contaminated soil whereby the soil in the form of feed stock is heated in a combustion chamber of a processor with the hydrocarbons being evacuated to a condensing system resulting in a petroleum product while the soil feed stock is detoxified in an afterburner to form clean soil for general use.

Abstract: A method is disclosed in which a plasma arc torch is used to vitrify and remediate a site containing contaminated soils, resulting from a hazardous material deposit or spill, or contaminated buried objects. The contaminated earthen material or subterranean deposit is pyrolyzed, melted or solidified by the plasma torch which is energized at the bottom of a cased, vertical borehole, and then gradually raised to the surface. An array of boreholes, appropriately spaced, will remediate an entire mass of contaminated material. Similarly, buried objects such as metal drums containing contaminants and underground storage tanks may be selectively remediated at their specific buried depth. Similar use is made of the plasma torch in a second embodiment with the additional step of processing at selected underground locations in the borehole array to create a sealed horizontal layer, vertical cutoff walls or a sealed basin as a barrier against further leaching of contaminants into surrounding soil and groundwater.

Abstract: An Enhanced Deep Soil Vapor Extraction Process and Apparatus utilizes heaters placed into the soil at least to the depth of contamination and a vapor/condensate extraction system that withdraws volatilized contaminant vapors from the subsurface and any condensate that collects in the extraction well. Depending on the rate of formation of condensate in the well, a second conduit may be placed inside the well for the collection and removal of condensate by a downhole pump or a suction device located at ground surface. The process is directed towards contaminants trapped in or below the normal groundwater level. Groundwater extraction wells are also employed to create a "cone of depression", or local draw-down of the groundwater to expose those soils that are normally water saturated and thereby permit decontamination of such soils. Conduits may be placed within the groundwater extraction wells for the purpose of extracting groundwater.

Abstract: An in situ, on-the-ground method of cleaning contaminated soil comprises breaking and piling up contaminated soil, placing the broken soil in a substantially enclosed on-the-ground system and circulating air under pressure to promote an increase in temperature which aids the oxidation, vaporization and gasification of the contaminants and substantially harmless metabolic products thereof produced by indigenous microorganisms, extracting any gases or vapors comprising the contaminants and metabolic products thereof from the now substantially decontaminated soil under vacuum, filtering the thus extracted gas- or vapor-containing air to separate clean air from the contaminants, and return it to the environment or recycle it, and returning the decontaminated soil to the environment.

Abstract: A technique for in situ decontamination of an earth formation. High gas temperatures can be achieved at subsurface formations by supplying a fuel at a subsurface location, such as at the bottom of a wellbore. Pressurized air or gas preheated to a temperature of about 700.degree. F.-1200.degree. F. is supplied to the wellbore to ignite the fuel. The combustion heat produced by the fuel further heats the preheated gas to temperatures in the range of 1200.degree. F.-4500.degree., which heated gases are forced out of the borehole into the contaminated formation. Contaminants are thereby volatilized or oxidized and removed from the formation to the surface.

Abstract: An enhanced pressure gradient remediation system (10) for decontaminating a contaminated volume of soil incorporates at least one extraction well (40) operated independently or in conjunction with at least one injection well (12). The injection well (12) is employed to inject steam, or ambient or heated air, into the soil, and extraction probe (40) extracts fluids, contaminants (30,32,34) and possibly groundwater (58) from the soil. The invention further contemplates injection and extraction by means of recoverable extraction and injection probes (14) which obviate the need for permanent wells. The enhanced pressure gradient results from employing extraction in possible conjunction with injection at higher vacuum and pressure than previously known in the art.

Abstract: A process for treating wastes contaminated by toxic metals and/or organic materials is disclosed. The process involves heating the metal-contaminated wastes to a temperature sufficient to volatilize the metals. This temperature is also high enough to destroy or volatilize organic contaminants. The metal vapors are contacted with a sorbent which is reactive with the metals and sequesters them, thereby forming a non-leachable complex which can be disposed as non-hazardous conventional waste.

Abstract: An in-situ soil heating/treatment system consists of a frame to which are attached a plurality of heater spikes and a plurality of tubular, perforated vapor extraction spikes. An insulated shield covers the frame and internal components. The spikes, which are 1-2 feet in length, are driven into the ground and heated to temperatures in excess of 1000.degree. C. The heat generated at the heater spikes is conducted and convected into the soil. As the soil temperature rises and approaches the boiling point of the contaminants, the contaminants volatilize and flow to the vapor collection spikes. A vacuum system connected to the vapor extraction spikes withdraws the contaminant vapors through the perforated, tubular spikes and treats them.

Abstract: A road surface is warmed by means of a two-phase thermosyphon with an easily vaporizable liquid partially filling a sealed container. A portion of the container serves as a condenser and another portion as an evaporator. If at least a portion of the evaporator is above the boiling point of the liquid, the liquid will boil and the vapor will rise into the condenser part of the thermosyphon, and if the condenser part is in an environment below the condensing temperature of the vapor, the vapor will condense, thereby radiating heat and warming the surrounding environment. The condenser is elongated and installed underground so as to lie closely beneath the road surface. A thermally insulating layer is provided below the condenser part so as to more efficiently utilize the radiated heat. The evaporator may be of a double-tube structure such that the liquid can flow through the entire length thereof even if these tubes include rising and falling sections.

Abstract: A method and apparatus for ex situ remediation of hydrocarbon-contaminated soil, comprising the excavation of the soil from its in situ position and forming a covered pile of loosened soil, at the base of which an array of a plurality of hot air inlet conduits are located. At least one array of a plurality of gas take-off conduits are situated at one or more higher level(s) in the pile. Heated air is injected into the inlet conduits at the base of the pile and allowed to percolate up through the soil to remove the hydrocarbons and volatile organic compounds as hydrocarbon vapor entrained process gas. This process gas is drawn off by applying a negative pressure to the take-off conduits. The drawn-off process gases are then passed through a gas burner which thermally oxidizes the hydrocarbons and organic compounds. The heat generated from the gas burner is exchanged with ambient inlet air to provide the hot air used to inject into the base soil pile.

Abstract: The recirculating system includes a soil stack (10), which is formed by sequential layers of contaminated soil from a site and hot air pipes (22, 26, 32, 34). A plurality of vapor collection pipes (40, 46) is laid over the top of the stack, with a sealing member (50) positioned over the entire soil stack (10) and sealed around the base thereof. First and second connecting means (99, 102) connect the hot air pipes and the vapor collection pipes to a heating/vapor destruction system (52), which includes a burn chamber (54), a first air duct (91) extending from the outlet of the burn chamber (54) to a first blower (93), a second air duct (97) extending from the first blower (93) to the first connecting means (99), a third air duct extending from the second connecting means (102) to a second blower (110), and a fourth air duct which extends from the second blower (110) to the inlet (58) of the burn chamber (54).

Abstract: A method is disclosed in which a plasma arc torch is used to vitrify and remediate a site containing contaminated soils, resulting from a hazardous material deposit or spill, or contaminated buried objects. The contaminated earthen material or subterranean deposit is pyrolyzed, melted or solidified by the plasma torch which is energized at the bottom of a cased, vertical borehole, and then gradually raised to the surface. An array of boreholes, appropriately spaced, will remediate an entire mass of contaminated material. Similarly, burled objects such as metal drums containing contaminants and underground storage tanks may be selectively remediated at their specific buried depth. Similar use is made of the plasma torch in a second embodiment with the additional step of processing at selected underground locations in the borehole array to create a sealed horizontal layer, vertical cutoff walls or a sealed basin as a barrier against further leaching of contaminants into surrounding soil and groundwater.

Abstract: The process or the present invention serves to remediate and reduce the volume of waste materials in a landfill site and increases the useful life of the treated landfill. The process steps involve drilling a series of holes into the waste material mass at proper spacing, inserting and operating a plasma arc torch in each drilled hole to pyrolize, remediate and vitrify the waste materials and allowing the melted materials to cool and harden. During the process, a gaseous by-product is produced and collected in a hood which is attached to scrubbing and chemical cleaning apparatus. The resultant gases are commercially useful as fuel gas and the vitrified residue is significantly smaller in volume than the original waste material volume, thus substantially extending the useful life of the landfill site and ultimately providing a firm foundation for construction.