In Situ EXAFS Study of Sr Adsorption on TiO2(110) under High Ionic Strength Wastewater Conditions

In order to provide important details concerning the adsorption reactions of Sr, batch and a set both ex situ in Grazing Incidence X-ray Absorption Fine Structure (GIXAFS) experiments were completed on powdered TiO2 rutile(110), reacted with either SrCl2 or SrCO3 solutions. sorption capacity for strontium (Sr) ranges from 550 ppm (SrCl2 solutions, second kinetics) 1400 (SrCO3 first kinetics), respectively, is rapid. Sr decreased as function chloride concentration but significantly increased carbonate concentrations increased. presence carbonate, ability remove solution increases by factor ~4 due rapid epitaxial surface precipitation an thin film, which registers itself rutile(110) strontianite-like phase (d-spacing 2.8 Å). Extended (EXAFS) results suggest initial attachment via tetradental inner-sphere adsorption. Moreover, adsorbates concentrated solutions contain hydroxyl species, inner- outer-sphere explains reduced these systems. These not only new insights into kinetics also valuable information potential improvements effluent water treatment models are pertinent developing methods rutile-coated structural materials within nuclear power plants.