Thermal Desorption Unit. Basically it's an oven that bakes the...

Thermal Desorption Unit. Basically it's an oven that bakes the material in it at about 800 deg C or hotter. The nasty bits are driven/evaporated out of the soil solids and extracted as a gas. This gas passes through a filter system. The clean soils are then expelled and the nasty stuff is either destroyed by the heat (most materials) or consolidated. In the case of consolidated PCBs and OCBs (nastiest of nasties) they are send to Qld for destruction in a BCD unit that destroys those chemicals at something like 10,000 deg C in an electric arc furnace.