Effects of Gamma(γ)-Irradiation on the Physicochemical Properties and Bioavailability of Iron Oxyhydroxides Coprecipitated with Varying Concentrations of Na-Alginate

Description

This study investigated the impacts of γ-radiation at a dose of 25 kGy on the physicochemical properties of a range of wet iron oxyhydroxides (2-line ferrihydrite, lepidocrocite, and goethite) synthesized in the presence of varying concentrations of the polysaccharide Na-alginate (C/Fe ratio of 0, 0.5, 1.0, and 1.5). This dataset contains data that appears in the article and supplementary material in numerical, text-based format. The data includes characterization techniques used to determine the extent of impact of irradiation on the physicochemical properties of the studied samples. The data includes XRD, FTIR-ATR, chemical properties, chemical extractions, specific surface area, mesopore, micropore, and total pore volumes, Zeta-potential and Z-average radius, electron micrographs, chemical composition of the supernatants, and kinetic Fe(III) bioreduction data for the native and post-irradiated iron oxyhydroxides. The data also includes Mössbauer spectroscopy of the native and post-irradiated ferrihydrite samples taken at 77 and 5 K. Our data shows a substantial dissolution of Fe and the concomitant release of Fe(II) and alginate into solution, whereas XRD and FTIR-ATR showed no change in the bulk mineralogy and crystallinity of the studied iron oxyhydroxides. Mössbauer spectroscopy (77 and 5 K), however, showed a change in the crystallinity of the 2-line ferrihydrites studied post irradiation. Moreover, among the minerals studied, the specific surface area and porosity decreased for only the post-irradiated 2-line ferrihydrite coprecipitates with a C/Fe ratio of 0.5 or 1.0. The bioreduction rates of studied minerals and their irradiated counterparts did not significantly differ, whereas the extent of bioreduction of post-irradiated 2-line ferrihydrite coprecipitates (C/Fe 0.5, 1.0, and 1.5) exhibited a significant increase of up to 28%. In contrast, the extent of Fe reduction for select post-irradiated lepidocrocite (C/Fe 0.5) and goethite (C/Fe 1.5) coprecipitates was slightly higher than determined for their corresponding native controls. The observed disparities in bioavailability between the native and irradiated coprecipitates were linked to alterations induced by irradiation to the aggregation and coagulation status of the particles as determined by particle size analyses and visual observations.

Institutions

Categories

Funding

Licence