Thermal Methods Developed in the Netherlands for the Cleaning of Contaminated Soil

Abstract

Four different processes for the thermal decontamination of soil have been developed in The Netherlands. Three processes make use of rotary tube furnaces with different combinations of direct and indirect heating, followed by an incineration of the volatilized products. In the direct heating processes the flames are in direct contact with the contaminated soil, while in the indirect heating process the soil is in contact with the heated wall of the furnace only. The indirect heating process uses an inert gas atmosphere. The fourth process uses a fluidized bed furnace with a temperature of 800–900 C and a freeboard for the incineration of the residual volatilized products.

Three processes have been shown to be effective for the decontamination of polluted soils from gaswork sites (polycyclic aromatic hydrocarbons + complex cyanides), while all processes are capable of treating soils contaminated with hydrocarbons (oil type pollution) or aromatic compounds.

The treatment of soils contaminated with organochlorine compounds is still under investigation. In view of the danger of the emission of toxic chlorinated dibenzodioxins, special provisions such as high temperature incineration and completely gas tight installations may prove to be necessary.

ArticleNote

This article was prepared in cooperation with H. van Driel (ATM), R. Haverkamp Begamann/S. Dijkstra (Boskalis-Esdex), L.C. de Leur (NBM), and C. Schuler (Ecotechniek), who provided the details about the technical realization and potential of the different processes.