Sorption kinetic study of selenite and selenate onto a high and low pressure aged iron oxide nanomaterial.
ABSTRACT The sorption of selenite (SeO(3)(2-)) and selenate (SeO(4)(2-)) onto Fe(3)O(4) nanomaterials produced by non microwave-assisted or microwave-assisted synthetic techniques was investigated through use of the batch technique. The phase of both synthetic nanomaterials was determined to be magnetite by X-ray diffraction. The average grain sizes of non microwave-assisted and microwave-assisted synthetic Fe(3)O(4) were determined to be 27 and 25 nm, respectively through use of the Scherrer's equation. Sorption of selenite was pH independent in the pH range of 2-6, while sorption of selenate decreased at pH 5 and 6. The addition of Cl(-) had no significant effect on selenite or selenate binding, while the addition of NO(3)(-) only affected selenate binding to the microwave assisted Fe(3)O(4). A decrease of selenate binding to both synthetic particles was observed after the addition of SO(4)(2-) while selenite binding was not affected. The addition of PO(4)(3-) beginning at concentrations of 0.1 ppm had the most prominent effect on the binding of both selenite and selenate. The capacities of binding, determined through the use of Langmuir isotherm, were found to be 1923 and 1428 mg Se/kg of non microwave-assisted Fe(3)O(4) and 2380 and 2369 mg Se/kg of microwave-assisted Fe(3)O(4) for selenite and selenate, respectively.
- SourceAvailable from: Xiaoshan Zhu[show abstract] [hide abstract]
ABSTRACT: Iron oxide nanoparticles have been explored recently for their beneficial applications in many biomedical areas, in environmental remediation, and in various industrial applications. However, potential risks have also been identified with the release of nanoparticles into the environment. To study the ecological effects of iron oxide nanoparticles on aquatic organisms, we used early life stages of the zebrafish (Danio rerio) to examine such effects on embryonic development in this species. The results showed that ≥10 mg/L of iron oxide nanoparticles instigated developmental toxicity in these embryos, causing mortality, hatching delay, and malformation. Moreover, an early life stage test using zebrafish embryos/larvae is also discussed and recommended in this study as an effective protocol for assessing the potential toxicity of nanoparticles. This study is one of the first on developmental toxicity in fish caused by iron oxide nanoparticles in aquatic environments. The results will contribute to the current understanding of the potential ecotoxicological effects of nanoparticles and support the sustainable development of nanotechnology.PLoS ONE 01/2012; 7(9):e46286. · 3.73 Impact Factor