Calcium aluminate cement as an alternative to ordinary Portland cement for the remediation of heavy metals contaminated soil: mechanisms and performance

Abstract Purpose This work deals with the application of a solidification/stabilization process aim to obtain safe and reusable granular materials from polluted soil elucidate mechanisms involved in retention several heavy metals. Materials methods The High Performance Solidification/Stabilization (HPSS®) was applied selected contaminated by using both ordinary Portland cement calcium aluminate cement, as well binders prepared combining these two types different proportions. Leaching mechanical tests were carried out evaluate performances proposed pellets produced HPSS® process, while XRD analysis SEM/EDX imaging used investigate phase composition internal microstructure treated samples. Result discussion examination obtained revealed that immobilization Sb mainly related its inclusion within silicate hydrates’ structure; Cr, Pb, Ni, Co, Zn Tl associated eluate pH their incorporation ettringite structure, for Se, Cu, Ba V, main mechanism physical encapsulation. In addition, wet conditioning improved materials’ performance, leading granules always satisfying Italian regulatory requirements reuse. Conclusions findings this study useful better metals binders, contributing development sustainable management strategies soils sediments through transformation into materials. Graphical abstract