Trailer Mounted DTFO Unit for Soil Remediation by US Military
Executive Summary
Epcon delivered a self-contained, trailer-mounted direct-fired thermal/oxidation (DTFO) system to a U.S. military environmental-remediation project — designed to remediate contaminated soil by thermally desorbing hazardous volatile and semi-volatile substances and thermally oxidizing off-gas. This mobile unit allows safe, on-site soil cleanup with high contaminant destruction efficiency (VOC/HAP elimination), minimal secondary waste, and flexible deployment. It supports military remediation requirements by providing a turnkey, relocatable solution for contaminated-soil treatment.
Project Overview
In this project, the mission was to decontaminate soil potentially impacted by fuel, solvents, or other hazardous chemicals at a military site. The soil needed to be treated on-site (or near-site) rather than shipped elsewhere, to minimize handling risk and disposal logistics. Traditional fixed facilities were impractical due to site restrictions and mobility needs.
Epcon was commissioned to supply a mobile trailer-mounted DTFO unit, combining soil-thermal treatment (thermal desorption) with a high-temperature oxidizer for off-gas destruction. The system allows for excavation (or stockpiled contaminated soils), feed into the trailer unit, thermal treatment to vaporize contaminants, and destruction of volatiles — all within a portable, self-contained package.
The Challenge
Several critical challenges needed to be addressed:
- Varied soil contamination and unpredictable volatilized contaminant load: Soils could contain a mix of VOCs, semi-volatile organics, perhaps residues from fuels, solvents, or other hazardous materials. The remediation system must handle variable contaminant concentrations and unpredictable off-gas composition.
- Need for on-site, mobile remediation: Military or restricted sites often lack infrastructure for permanent soil-remediation plants; logistics of transporting contaminated soil off-site are costly, risky, or restricted. A mobile, trailer-mounted solution is required.
- Effective destruction of volatile and semi-volatile contaminants: Thermal desorption alone volatilizes contaminants but does not destroy them; an efficient oxidation step is required to avoid merely transferring contamination to air emissions. According to accepted practice, thermal oxidizers destroy VOCs/HAPs by combustion at high temperature, achieving conversion to benign byproducts (CO₂, H₂O) under proper residence time and turbulence.
- Regulatory compliance and environmental safety: The process must comply with air-quality regulations, avoid generation of secondary hazardous waste streams, and safely treat all off-gases (including any particulate, acid-gas potential, or toxic byproducts).
- Flexibility, ease of deployment, and minimal installation overhead: The unit must be easy to transport, deploy, operate, and demobilize — no heavy civil works, minimal site preparation, and ability to handle varying soil volumes and treatment durations.
The Solution
Epcon delivered a turnkey Trailer-Mounted DTFO Soil Remediation System, featuring:
- Thermal Desorption Unit (TDU) — soil (or excavated contaminated material) is fed into the unit, then heated (direct- or indirect-firing depending on configuration) to volatilize water and organic contaminants (VOCs/SVOCs) from the soil matrix, following established remediation practice for ex-situ soil cleanup.
- Off-Gas Treatment via Thermal Oxidizer — the volatilized contaminants and vapors are drawn into an attached oxidizer chamber where high temperature, sufficient residence time, and turbulence combine with oxygen to oxidize VOCs/HAPs into CO₂ and H₂O, preventing release of untreated contaminants. Thermal oxidizers are widely used for VOC/HAP abatement in industrial exhaust and remediation contexts.
- Mobile, Self-Contained Trailer Configuration — all required components: soil inlet/feed, heating system, combustion/oxidation chamber, exhaust controls, power/ fuel supply, instrumentation and safety systems — are mounted on a trailer, enabling transport, deployment, and operation on-site or near-site without need for fixed infrastructure.
- Flexible Load Handling / Wide Turn-Down Ratio — the design accommodates variable soil feed rates, contaminant concentrations and off-gas loads; it handles small batch operations or larger remediation volumes as required.
- Complete Turnkey Delivery — including design, fabrication, commissioning, and operator training — minimizing site-preparation needs and speeding up mobilization for military-environmental projects.
Technical Specifications
System Type: Trailer-mounted Direct-Fired Thermal Desorption + Thermal Oxidizer (DTFO) Soil Remediation Unit
Soil Treatment Method: Thermal desorption — heating contaminated soil to volatilize organics / water / solvents (temperature depending on contaminant/soil type)
Off-Gas Treatment: Thermal oxidizer — high-temperature combustion of vapors (VOCs, organics) ensuring destruction rather than simple volatilization; uses combustion principles (Temperature, Residence Time, Turbulence + Oxygen) for efficient VOC/HAP removal.
Mobility & Deployment: Self-contained trailer-mounted design — rapid deployment, minimal civil works, suitable for on-site or remote location remediation
Load Flexibility: Able to handle variable soil feed rates, contaminant loads and vapor flows (wide turn-down ratio) — suitable for batch or continuous remediation work
Environmental Compliance & Safety: Off-gas combustion to destroy contaminants, no residual contaminated soil off-gas discharge; ensures proper emissions control to meet regulatory standards; containment & control minimize risk of fugitive emissions or soil transport hazards
Operational Scope: Soil remediation for military or industrial contaminated sites — soil excavated, treated on-site, potentially allowing re-use where permissible
The Results
After deployment, the trailer-mounted DTFO system delivered:
- Effective destruction of hazardous contaminants — VOCs, semi-volatile organics and other hazardous constituents in soil are thermally desorbed and destroyed, reducing environmental hazard and exposure risk.
- On-site remediation with reduced liability & transport risk — contaminated soils need not be transported off-site, minimizing handling risk, regulatory complications, and logistic cost.
- Flexible, scalable soil-cleanup capacity — suits small-scale cleanup jobs as well as larger volume remediations, by adjusting feed rate and operating hour.
- Reduced secondary waste streams — unlike solvent-washing or excavation + landfill disposal, this method avoids generation of chemical-waste or large contaminated water volumes; off-gas is treated, solids are stabilized/cleaned.
- Cost-effective and rapid deployment for military / defense contexts — with mobile, self-contained design, the unit can be deployed quickly, operated remotely, and demobilized, offering efficient remediation with minimal infrastructure investment.
- Compliance with emissions and environmental regulations — by using proven thermal oxidation for gas-treatment, system provides controlled exhaust, reducing risk of fugitive emissions, vapor & odor Control, or regulatory non-compliance.
