A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Thermoexfoliated and hydrophobized vermiculites for oleic acid removal
https://orcid.org/0000-0002-3208-1912
AbstractThe 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 2min. 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 1.29mol/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.
HighlightsVermiculite thermoexfoliated and hydrophobized was suitable for oleic acid removal.The oleic acid adsorption increased with the increase of the salinity of the medium.Vermiculite unsaturated of adsorbate can be reused to recover more oleic acid.
Thermoexfoliated and hydrophobized vermiculites for oleic acid removal
https://orcid.org/0000-0002-3208-1912
AbstractThe 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 2min. 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 1.29mol/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.
HighlightsVermiculite thermoexfoliated and hydrophobized was suitable for oleic acid removal.The oleic acid adsorption increased with the increase of the salinity of the medium.Vermiculite unsaturated of adsorbate can be reused to recover more oleic acid.
Thermoexfoliated and hydrophobized vermiculites for oleic acid removal
https://orcid.org/0000-0002-3208-1912
AbstractThe 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 2min. 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 1.29mol/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.
HighlightsVermiculite thermoexfoliated and hydrophobized was suitable for oleic acid removal.The oleic acid adsorption increased with the increase of the salinity of the medium.Vermiculite unsaturated of adsorbate can be reused to recover more oleic acid.
Thermoexfoliated and hydrophobized vermiculites for oleic acid removal
Marcos, Celia (author) / Menéndez, Roberto (author) / Rodríguez, Irene (author)
Applied Clay Science ; 150 ; 147-152
2017-09-20
6 pages
Article (Journal)
Electronic Resource
English
Thermoexfoliated commercial vermiculites for Ni2+ removal
| Online Contents | 2016
Thermoexfoliated commercial vermiculites for Ni2+ removal
| Elsevier | 2016
Vermiculites irradiated with ultraviolet radiation
| Online Contents | 2015
Vermiculites irradiated with ultraviolet radiation
| Elsevier | 2015
Acid-leached mixed vermiculites obtained by treatment with nitric acid
| Online Contents | 2015