In-situ treatment of radioactive mine water using reactive materials - Results of laboratory and field experiments in uranium ore mines in Germany

Flooding of uranium mines causes a release of considerable amounts of urani um, radium-226, and arsenic into rivers and aquifers. Thus treatment is nec essary in some cases. In order to evaluate alternative water treatment meth ods for mine water a research project was carried out by means of both labo ratory experiments and small-scale field tests in abundant mines of the Ore Mountains in East Germany. At two test sites columns filled with Fe-0, Fe/ Mn containing waste sludge, and peat were installed for the duration of one year to investigate geochemical reactions and the fixation processes of re levant radionuclides and arsenic. While Fel is changing the geochemical con ditions from oxidizing to reducing milieu, peat and Fe/Mn-sludge have a sig nificant sorption capacity. In addition, iron hydroxides coprecipitate resi dual contaminants. The fixation capacity of peat was found to be exhausted within half a year. The Fe/Mn-sludge adsorbed 60 % of radium and 70 % of ar senic. The best results for uranium elimination of about 96 % were obtained by means of Fel.