Alkali-activated cementitious materials: Alternative matrices for the immobilisation of hazardous wastes Part II. Stabilisation of chromium and lead

摘要

This research focuses on the study of the stabilisation/solidification capacity of a cementing matrix, which has been made using alkali activation of fly ash, in the presence of toxic elements chromium and lead. Such capacity has been compared with that of Portland cement. Leaching tests carried out proved that this new matrix is able to stabilise and solidify lead in a very efficient way (analysed lead concentrations from leaching are in parts per billion). However, it does not present itself as efficient concerning chromium fixation since this element strongly disturbs the alkali-activation mechanism of the ash.