Thermal desorption is basically a remediation technique heavily used to clean contaminated soils, sludge’s etc. This technique uses heat to vaporize the contaminants, and works only for volatile contaminants. These include typically organic wastes composed of hydrocarbons, such as coal tar wastes, chlorinated solvents, oil refining wastes, fuels, pesticides, and a lot other.
In the process, contaminated soils are heated to temperatures sufficient to cause constituents to volatilize and desorb from the soil. Even though they are not designed to decompose organic constituents, thermal desorption units can, depending upon the specific organics presence and the temperature of the desorption unit, cause some of the constituents to completely or partially decompose. The volatilized contaminants are then either collected or thermally destroyed in secondary treatment units. A thermal desorption system thus has two major components; the unit itself and the off-gas treatment system.