کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5468494 1519038 2017 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Thermoexfoliated and hydrophobized vermiculites for oleic acid removal
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات ژئوشیمی و پترولوژی
پیش نمایش صفحه اول مقاله
Thermoexfoliated and hydrophobized vermiculites for oleic acid removal
چکیده انگلیسی
The aim of the present study was to investigate the removal efficiency of oleic acid from aqueous solutions by thermally expanded and hydrophobized vermiculites. The expansion of the samples was carried out in a furnace at 1000 °C for 2 min. The hydrophobization using polymethyl-hydro-siloxane as hydrophobing derivatizing reagent was performed by immersion and hydrophobizing atmosphere methods. The investigation was started with two vermiculites from Brazil, the Goiás and Piauí states, respectively. After some previous tests the Goiás vermiculite was selected to investigate five effects: 1) Adsorption at different pH. 2) Adsorption at different concentrations of hydrophobizing reactive and different weights of vermiculite. 3) Adsorbent mass. 4) Influence of the number of stages of adsorption. 5) Influence of salinity. Oleic acid uptake was quantitatively evaluated using the Langmuir, Freundlich and Dubinin-Kaganer-Radushkevich (DKR) models. In addition, the adsorption equilibrium was described well by the DKR isotherm model, indicative of a cooperative process. The maximum adsorption capacity obtained with DKR model was of 1.29 mol/g of oleic acid. The hydrophobization Goiás vermiculite and the adsorption of oleic acid were verified using infrared spectroscopy. The findings of this study showed that this thermally expanded and hydrophobized vermiculite: 1) was very suitable for the recovery of oleic acid in water; 2) the adsorption increased with the increase of the salinity of the aqueous medium; 3) it was possible to reuse vermiculite unsaturated to recover more oleic acid.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Applied Clay Science - Volume 150, 15 December 2017, Pages 147-152
نویسندگان
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