2026-04-17T13:53:38Zhttps://riubu.ubu.es/oai/request

oai:riubu.ubu.es:10259/108602025-09-12T00:05:34Zcom_10259_4249com_10259_5086com_10259_2604col_10259_4250

00925njm 22002777a 4500 dc Russo, Raffaele Emanuele author Santoni, Elisa author Fattobene, Martina author Giovini, Mattia author Genua, Francesco author Leonelli, Cristina author Lancellotti, Isabella author Herrero Gutiérrez, Ana author Berrettoni, Mario author 2025-08 Alkali-activated aluminosilicate matrices are increasingly studied for their ability to stabilize hazardous metal contaminants via alkali activation at room temperature. In this study, metakaolin-based geopolymers were used to immobilize chromium and nickel salts, with systematic variation of key synthesis parameters, Na/Al molar ratio, metal concentration, anion type, and alkaline solution aging time, which have not been previously studied. A Design of Experiments approach was employed to study the effect of factors on metal leaching behavior and to better understand the underlying immobilization mechanisms. The analysis revealed that higher Na/Al ratios significantly enhance geopolymerization and reduce metal release, as supported by FTIR spectral shifts and decreased shoulder intensity. Notably, aging time had an influence on chromium behavior due to its effect on early silicate network formation, which can hinder the incorporation of chromium species. All tested formulations achieved metal immobilization rates of 98.8% or higher for both chromium and nickel. Overall, this study advances our understanding of geopolymer-based heavy metal immobilization. 1420-3049 https://hdl.handle.net/10259/10860 10.3390/molecules30153235 1420-3049 Alkali activation Metakaolin-based geopolymer Chromium salts Nickel salts Heavy metal stabilization Multivariate approach Design of experiments Principal component analysis Design of Experiments Approach for Efficient Heavy Metals Stabilization Using Metakaolin-Based Geopolymers