کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
150616 | 456453 | 2011 | 6 صفحه PDF | دانلود رایگان |

Bentonite supported nanoscale zero-valent iron (B-nZVI) was synthesized by the sodium borohydride reduction method, characterized with SEM, and used for aqueous Cr(VI) removal. Bentonite decreased nano-Fe0 aggregation and thus increase Cr(VI) removal efficiency. At 35 °C and 250 r min−1, 99% Cr(VI) removal was achieved from aqueous solution containing 50 mg L−1 of Cr(VI) by B-nZVI, while only 66% removal was achieved with unsupported nZVI after an experimental duration of 3 h when the Fe0 loadings were 1.5 g L−1. XRD indicated the existence of iron oxide and iron-chromium hydroxide coprecipitation on the surface of B-nZVI after exposure to an aqueous solution of Cr(VI). Kinetics studies under a series of different conditions showed that reduction of Cr(VI) to Cr(III) could be expressed by pseudo first-order reaction kinetics, with initial Cr(VI) and B-nZVI concentrations, pH and temperature as variables. The apparent activation energy of Cr(VI) remediation by B-nZVI was 21 kJ mol−1, which was characteristic of a chemically controlled reaction. These results demonstrated that B-nZVI could potentially be used as a new material for use in situ remediation.
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► Bentonite supported nanoscale zero-valent iron (B-nZVI) for the removal of Cr(VI).
► More than 99% Cr(VI) from solution was removed by K-nZVI.
► Characterizations of B-nZVI were by SEM and XRD.
► The formation of a hydroxylated Cr(OH)3 and coprecipitation of CrxFe1−x(OH)3.
Journal: Chemical Engineering Journal - Volume 171, Issue 2, 1 July 2011, Pages 612–617