کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
150616 456453 2011 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Synthesis, characterization and kinetics of bentonite supported nZVI for the removal of Cr(VI) from aqueous solution
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی مهندسی شیمی (عمومی)
پیش نمایش صفحه اول مقاله
Synthesis, characterization and kinetics of bentonite supported nZVI for the removal of Cr(VI) from aqueous solution
چکیده انگلیسی

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.

Figure optionsDownload as PowerPoint slideHighlights
► 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.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Chemical Engineering Journal - Volume 171, Issue 2, 1 July 2011, Pages 612–617
نویسندگان
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