Release of pollutants from hardened pastes containing fly ash

An investigation was made of the release in demineralized water bf heavy me tals, chloride and sulphate ions from cementitious pastes containing fly as h coming from Municipal Solid Wastes. The analytical procedure applied with a periodical changing of the leachant (dynamic test) on the solidified mix tures, characterized by different curing periods, has allowed to evidence a cumulative percent increase of;release even more lower with leaching time. A remarkable decrease of the eluate concentration as regards long cured pa stes was found. The characteristic leaching behaviour of chloride, sodium a nd potassium elements has given useful informations on overall progress of solidification/stabilization processes of cement-fly ash mixtures.