کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
10730497 1042560 2009 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Sorption of Ni(II) on GMZ bentonite: Effects of pH, ionic strength, foreign ions, humic acid and temperature
موضوعات مرتبط
مهندسی و علوم پایه فیزیک و نجوم تشعشع
پیش نمایش صفحه اول مقاله
Sorption of Ni(II) on GMZ bentonite: Effects of pH, ionic strength, foreign ions, humic acid and temperature
چکیده انگلیسی
Bentonite has been widely studied in nuclear waste management because of its special physicochemical properties. In this work, the sorption of Ni(II) from aqueous solution onto GMZ bentonite as a function of contact time, pH, ionic strength, foreign ions, humic acid (HA) and temperature was investigated under ambient conditions. The results indicated that the pseudo-second-order rate equation simulated the kinetic sorption process well. The sorption of Ni(II) on GMZ bentonite was strongly dependent on pH and on ionic strength. At low pH, the sorption of Ni(II) was dominated by outer-sphere surface complexation and ion exchange with Na+/H+ on GMZ bentonite surfaces, whereas inner-sphere surface complexation was the main sorption mechanism at high pH. A positive effect of HA on Ni(II) sorption was found at pH<8, whereas a negative effect was observed at pH>8. The Langmuir, Freundlich, and D-R models were used to simulate the sorption isotherms of Ni(II) at three different temperatures: 303.15, 318.15 and 333.15 K. The thermodynamic parameters (ΔH0, ΔS0 and ΔG0) of Ni(II) sorption on GMZ bentonite at the three different temperatures were calculated from the temperature-dependent sorption isotherms. The results indicated that the sorption process of Ni(II) on GMZ bentonite was endothermic and spontaneous. Experimental results indicate that GMZ bentonite is a suitable sorbent for pre-concentration and solidification of Ni(II) from large volume solutions.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Applied Radiation and Isotopes - Volume 67, Issue 9, September 2009, Pages 1600-1608
نویسندگان
, , , , ,