Beseitigung von organischen Stoffen und flüchtigen Metallen aus Böden durch Thermodesorption

摘要

The removal of organics and volatile metals from soils using thermal desorption comprises moving contaminated materials, positioned on a belt conveyor (36), through a chamber (20) under oxygen conditions, temperature conditions, and residence time effective to substantially avoid incineration of the contaminants. The method further comprises heating the contaminated material for volatilizing the contaminants and for producing a processed material that is substantially decontaminated. To carry the volatilized contaminants from the chamber (20), a transport gas may be passed through the chamber (20) countercurrent to the movement of the contaminated material. A gas stream including the volatilized contaminants and the transport gas may be passed through a condenser (70) and through a scrubber (80) for producing a substantially cleaned gas and a contaminated liquid concentrate. The cleaned gas may be recycled back into the chamber (20) as the transport gas or passed through a gas cleaning system (86) prior to discharge into the atmosphere. The liquid concentrate is passed through a water treatment system (90) for producing substantially cleaned water. The water may be passed through an air cooler (92) and recycled back into the quencher (70) or may be passed through a carbon absorption column (94) and recycled as quench water for the processed material.