Thermal remediation can achieve the removal of chlorinated solvents, petroleum hydrocarbons, polyromantic hydrocarbons such as naphthalene and coal tars/creosote, pesticides, PFAS and PCBs to meet stringent soil and groundwater cleanup criteria.
Depending on the contaminant and the remediation goal, the temperature of the system can range between 30 °C to over 350 °C. At the lower temperature ranges the heat will encourage aerobic and anaerobic degradation. As temperatures are increased, depending on the contaminant, it will enter a gaseous phase that can move more easily through the soil. At the higher temperature range, the contaminants will be destroyed.
The three primary technologies for thermal remediation include Thermal Conduction Heating (TCH), Electrical Resistance Heating (ERH), and Steam Enhanced Extraction (SEE). A description of each is provided below. Contact Vadose Remediation for a detailed review of your site to determine if thermal remediation is a good solution for your project.
ERH can be highly effective at sites with relatively uniform soil resistivity, including saturated silts, sandy silts, clayey sands, and some clays. Because ERH relies on soil moisture for conducting electrical current to heat the soil, maximum treatment temperature is limited to approximately 100°C. At this temperature ERH can be used to treat VOCs, CVOCs, LNAPL and DNAPL.
TCH can be applied in-situ or ex-situ, to soil or groundwater and can be used to treat VOCs, SVOCs, PAHs, PCBs, dioxins, LNAPL, DNAPL, PFAS and other contaminants. TCH can reach temperatures 350°C or greater depending on the contaminant type.
SEE is highly effective and efficient in permeable geologies and can be used for recovery of free product and the remediation of VOCs. SEE technology includes treatment through steam injection into wells and extraction of hot fluids. This technology is often used in combination with TCH or ERH.