The coordination core and charge of chromium in Metakaolin-geopolymers as revealed by X-Ray absorption spectroscopy

摘要

Geopolymers obtained by mixing metakaolin powder with tannery wastewater and NaOH pellets are proposed as 3D aluminosilicate network to chemically entrap Cr(III) species. X-ray Absorption Spectroscopy studies show the absence of toxic Cr(VI). The analysis of EXAFS also reveals a Cr(III) first coordination shell formed by 6 oxygens and a second shell of 7/8 Al or Si atoms, indicating strong bonding with the aluminosilicate network. (C) 2020 Elsevier B.V. All rights reserved.