CHEMICAL LEACHING OF CONTAMINATED SOIL – CASE STUDY

Abstract

This study presents results of chemical leaching of contaminated soil from several metallurgically loaded locality of Richnava in Slovakia, applying two chelants – Na2EDTA and Na3EDDS of different molar concentration, done at different leaching conditions. The lower molar concentration (2 mM) of chelants showed comparable effect on Mn, Ni, As, Sb and Co leaching. Higher extraction was revealed at application of 10 mM chelants, especially for Cu and Cd release. Repeated washing of soil by 10 mM chelant without the media regeneration was more effective at the toxic elements removal than washing by smaller volumes of media or leaching of soil in static conditions. Final experiments focused on obtained leachates treatment showed that electrolysis and precipitation should represent a perspective way of the washing media regeneration.