SOME CONSIDERATION REGARDING Cr AND Mo IMMOBILIZATION IN HYDRAULIC MATRIX

摘要

The paper presents experimental results regarding lixiviation properties of hydraulic matrix with sludge or electroplating waste - after the removal of some heavy metals, both with Cr (Ⅲ) and Mo (Ⅵ) content. Different solidification/stabilization matrixes with different water/binder ratio were studied. Binders contain different amounts of ordinary Portland cement, blastfurnace slag, puzzolans and carbidic sludge. Mo, Cr, Pb, Zn and Ni concentrations in the leachate was determined. Molibdenum (and less important Cromium) releases at a high rate into solutions with high pH. But, the Mo release into basic aqueous solution is limited by the matrix compactity. In the paper are presented too the experimental methods used to investigate the properties of matrices and leachates in order to understand the weak capacity of Mo immobilization.