title: The role of open and closed curing conditions on the leaching properties of fly ash-slag-based geopolymers.
abstract: This study deals with the synthesis of geopolymers from co-fired fly ash and blast furnace slags. Geopolymer bodies were simultaneously synthesized in open and closed curing conditions in order to elucidate the role of this parameter on their resultant properties. Open curing conditions produce solid bodies characterized by high porosity, low compressive strength and exacerbated leaching of certain oxyanionic metalloids. By contrast, protected curing promotes the binder development, giving rise to higher strength and less porous systems. This imposes physical restrictions to leaching which decreases and/or retards releases of oxyanionic metalloids in comparison to open curing conditions. Fly ash-slag-based geopolymers may immobilize a number of trace pollutants such as Be, Bi, Cd, Co, Cr, Cu, Nb, Ni, Pb, REE, Sn, Th, U, Y and Zr, regardless of the curing conditions. Due to geopolymers displaying weak assimilation capacity for oxyanionic species, their successful regarding oxyanionic retention is strongly dependent on porosity and therefore on curing conditions applied.
authors.affiliation: Institute of Environmental Assessment and Water Research, Jordi Girona 18, 08034-Barcelona, Spain. maria.izquierdo@ul.ie
authors.forename: Maria
authors.initials: M
authors.lastname: Izquierdo
authors.forename: Xavier
authors.initials: X
authors.lastname: Querol
authors.forename: Charles
authors.initials: C
authors.lastname: Phillipart
authors.forename: Diano
authors.initials: D
authors.lastname: Antenucci
authors.forename: Mark
authors.initials: M
authors.lastname: Towler
mesh_terms: D002244:Carbon / Q000737:chemistry*; D060729:Coal Ash; D019245:Compressive Strength; D003247:Conservation of Natural Resources / Q000379:methods; D019216:Metals, Heavy; D052638:Particulate Matter / Q000737:chemistry*; D011108:Polymers / Q000138:chemical synthesis*; D016062:Porosity
chemical_list: D060729:Coal Ash; D019216:Metals, Heavy; D052638:Particulate Matter; D011108:Polymers; D002244:Carbon