کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
607843 1454605 2013 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Temperature impact on the sorption of selenium(VI) onto anatase
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی شیمی کلوئیدی و سطحی
پیش نمایش صفحه اول مقاله
Temperature impact on the sorption of selenium(VI) onto anatase
چکیده انگلیسی

The impact of temperature (298 K, 313 K, and 333 K) on the sorption of selenium(VI) onto anatase was investigated for the first time. At a macroscopic level, batch experiments showed a decrease of selenium(VI) retention with both increasing pH (3.5–7.0) and temperature. The thermodynamic parameters of the sorption reaction, i.e. the enthalpy ΔRH, entropy ΔRS, and the Gibbs free energy ΔRG, were determined from the temperature dependence sorption data using the van’t Hoff equation. The sorption process was found to be exothermic. Neither significant phase transformation nor a significant increase of anatase solubility could be detected with increasing temperature by XRD and ICP-MS. However, electrophoretic mobility measurements showed that both the zeta potential as well as the isoelectric point (pHIEP) of anatase were shifted to lower values with increasing temperature, leading to a decreased selenium(VI) sorption. At a microscopic level, the sorption mechanism of selenium(VI) onto anatase was elucidated at the three investigated temperatures by means of in situ Attenuated Total Reflection Fourier-Transform Infrared spectroscopy (ATR FT-IR). Results evidenced the formation of outer-sphere surface complexes, with no significant structural changes within the investigated temperature range.

Figure optionsDownload high-quality image (128 K)Download as PowerPoint slideHighlights
► Increasing temperature (298–333 K) decreases Se(VI) sorption onto anatase.
► Sorption of Se(VI) onto anatase is an exothermic process.
► Increasing temperature (298–333 K) decreases the pHIEP of anatase.
► Sorption of Se(VI) onto anatase proceeds via outer-sphere complexation.
► Increasing temperature (298–333 K) does not impact the sorption mechanism of Se(VI) onto anatase.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Colloid and Interface Science - Volume 390, Issue 1, 15 January 2013, Pages 170–175
نویسندگان
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