Vol.23, Special Issue, 2023, pp. S19–S24
UDC:

Natural zeolite and bentonite were used as mineral additions to create cement-based building materials that are safe for the environment. This research focuses on the adsorptive qualities of these two clay raw materials, i.e., their propensity to immobilize heavy metal ions like Cd²⁺. The acquired results were examined using kinetic models of pseudo-first and pseudo-second order. The isotherms of Langmuir and Freundlich were examined. Zeolite and bentonite had different adsorption affinities for Cd²⁺ cations. Seven cement binders with various mineral additions (fly ash, zeolite, bentonite) underwent a leaching test. The adsorption and hydration mechanisms that immobilized heavy metals within cementitious composites caused leachates obtained on cement samples with the addition of fly ash and clay (either zeolite or bentonite) to contain lower concentrations of Cd²⁺ ions than leachates obtained on cement samples with fly ash alone.

Keywords: mineral additives, construction materials, recycling, ion immobilization, leaching control