Antimony is an emerging toxic element released during mining activities and brake pad emissions from vehicles, as a constituent in bullets and from antimony-based catalysts. In this research project nZVI particles were synthesized with a coating of kaolinite (K-nZVI), and characterized with XRD, FTIR, UV/Visible spectroscopy, and investigated the antimony adsorption onto K-nZVI particles in aqueous and porous soil media. Using model Sb(III) and Sb(V) aqueous solutions, ability to adsorb both Sb species with over 98% removal efficiency under acidic to neutral pH conditions was demonstrated. Ion chromatography(IC)-ICP-MS chromatograms revealed that the reduced Sb(III) was not present with the Sb(V) in aqueous phase, indicating that the reduction was preceded by adsorption on to nanoparticles. Adsorption experiments with Sb(III) and Sb(V) solutions and K-nZVI revealed Sb(III) followed the Freundlich isotherm while Sb(V) sorption fit well with the Langmuir model, indicating multilayer and monolayer sorption mechanisms, respectively. The reaction kinetics of Sb(III) and Sb(V) followed pseudo-second order kinetics. Laser ablation(LA)-ICP-MS of Sb sorbed K-nZVI showed a significant increase in the <sup>121</sup>Sb/<sup>57</sup>Fe ratio with the increased Sb concentration indicating Sb is clearly adsorbed onto K-nZVI. Using a series of soil column experiments, the ability to successfully sequester Sb from contaminated shooting range soils and mine tailings by K-nZVI will be presented.

Adsorption properties of Sb onto kaolin coated nano zero valent iron (K-nZVI) and its remediation capabilities of Sb contaminated soils

2019 Spring National Meeting

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.