35.  Vitrification

Vitrification is the transformation of soil (the part not saturated with water) by heat into a molten material which, after cooling, becomes a glass encapsulating the pollutants (figure 35 ). The technique is functional but not widely used, as it is costly due to the energy consumption of the process. Vitrification has interesting applications in the case of soils contaminated by metals or certain radio-nuclides. In the end, however, the metals remain in the soil but are immobilized.

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