Remediation techniques for Hg-contaminated sites

Abstract

Mercury-polluted soil is a very serious problem, which we have to face not only in the highly industrialized regions, but also in developing countries. Although the production and use of mercury has decreased in the Western World since the late 1970s (in the USA from 1632 t Hg in 1972 to ca. 411 t Hg in 1990), in some developing countries the import and use is increasing, e.g. in 1972 Brazil imported 115 t and in 1990 240 t Hg (Hasse 1994; Jasinski 1995). The sources and uses of mercury with respect to its chemical form are listed. At places of mercury production or use, we often face problems of environmental contamination. Mercury is generally considered one of the most toxic elements found in the environment. Especially the organic compounds are characterized by high toxicity and gentoxicity. Ahtough mercury is often emitted in the elemental or inorganic form, highly toxic organic compounds can be formed by biological activity or chemical reaction (Hintelmann et al. 1993). In contrast to most of the heavy metal compounds, mercury in the elemental form and also in some of the organic forms is volatile at room temperature. These chemophysical properties must be taken into account during risk assessment. Managing sites contaminated with mercury requires the assessment of the remediation alternatives which may be applied. This chapter shows remediation techniques either already applied, emerging on the laboratory scale, or just invented and published. It reviews techniques aimed to immobilize or isolate the pollutant and focus on cleanup methods which attempt to clean the soil or at least part of the soil. (orig.)Available from TIB Hannover: RA 3251(98/E/52) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman