Soil Washing and Thermal Desorption: Reliable Techniques for Remediating Materials Contaminted with Mercury

The 'OSPARCOM-decision 90/3' from 14 June, 1990 recommends that all chlorine-alkali electrolysis facilities in Western Europe using the amalgam process shall be decommissioned for reasons of environmental protection at the latest by 2010. Owing to ongoing decommissioning and numerous demolition activities with regard to chlorine-alkali electrolysis plants and acetaldehyde factories worldwide, reliable treatment technologies for mercury-contaminated soil and rubble are in particular soil washing and thermal desorption as an alternative to underground repository. In this article can be shown, that soil washing plants upgraded by froth flotation allow a treatment of soils contaminated in a range of Hg ≥ 1,000 mg/kg. Thermal desorption is a reliable technology in a range of about 10,000 mg/kg in order to reach the Z2 LAGA threshold value Hg ≤ 10 mg/kg.