کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
581014 | 1453155 | 2010 | 8 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Removal of hexavalent chromium [Cr(VI)] from aqueous solutions by the diatomite-supported/unsupported magnetite nanoparticles
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی شیمی
بهداشت و امنیت شیمی
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: Removal of hexavalent chromium [Cr(VI)] from aqueous solutions by the diatomite-supported/unsupported magnetite nanoparticles Removal of hexavalent chromium [Cr(VI)] from aqueous solutions by the diatomite-supported/unsupported magnetite nanoparticles](/preview/png/581014.png)
چکیده انگلیسی
Diatomite-supported/unsupported magnetite nanoparticles were prepared by co-precipitation and hydrosol methods, and characterized by X-ray diffraction, nitrogen adsorption, elemental analysis, differential scanning calorimetry, transmission electron microscopy and X-ray photoelectron spectroscopy. The average sizes of the unsupported and supported magnetite nanoparticles are around 25 and 15Â nm, respectively. The supported magnetite nanoparticles exist on the surface or inside the pores of diatom shells, with better dispersing and less coaggregation than the unsupported ones. The uptake of hexavalent chromium [Cr(VI)] on the synthesized magnetite nanoparticles was mainly governed by a physico-chemical process, which included an electrostatic attraction followed by a redox process in which Cr(VI) was reduced into trivalent chromium [Cr(III)]. The adsorption of Cr(VI) was highly pH-dependent and the kinetics of the adsorption followed a pseudo-second-order model. The adsorption data of diatomite-supported/unsupported magnetite fit well with the Langmuir isotherm equation. The supported magnetite showed a better adsorption capacity per unit mass of magnetite than unsupported magnetite, and was more thermally stable than their unsupported counterparts. These results indicate that the diatomite-supported/unsupported magnetite nanoparticles are readily prepared, enabling promising applications for the removal of Cr(VI) from aqueous solution.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Hazardous Materials - Volume 173, Issues 1â3, 15 January 2010, Pages 614-621
Journal: Journal of Hazardous Materials - Volume 173, Issues 1â3, 15 January 2010, Pages 614-621
نویسندگان
Peng Yuan, Dong Liu, Mingde Fan, Dan Yang, Runliang Zhu, Fei Ge, JianXi Zhu, Hongping He,