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A new emulsion liquid membrane based on a palm oil for the extraction of heavy metals.

Björkegren S, Karimi RF, Martinelli A, Jayakumar NS, Hashim MA - Membranes (Basel) (2015)

Bottom Line: Span 80 is used as surfactant and butanol as co-surfactant.This result was achieved with an optimal concentration of 0.1 M NaOH as stripping agent and an external phase pH of 0.5.Different water qualities have also been investigated showing that the type of water (deionized, distilled, or tap water) does not significantly influence the extraction rate.

View Article: PubMed Central - PubMed

Affiliation: Applied Surface Chemistry, Chemical and Biological Engineering, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden. sanna.bjorkegren@chalmers.se.

ABSTRACT
The extraction efficiency of hexavalent chromium, Cr(VI), from water has been investigated using a vegetable oil based emulsion liquid membrane (ELM) technique. The main purpose of this study was to create a novel ELM formulation by choosing a more environmentally friendly and non-toxic diluent such as palm oil. The membrane phase so formulated includes the mobile carrier tri-n-octylmethylammonium chloride (TOMAC), to facilitate the metal transport, and the hydrophilic surfactant Tween 80 to facilitate the dispersion of the ELM phase in the aqueous solution. Span 80 is used as surfactant and butanol as co-surfactant. Our results demonstrate that this novel ELM formulation, using the vegetable palm oil as diluent, is useful for the removal of hexavalent chromium with an efficiency of over 99% and is thus competitive with the already existing, yet less environmentally friendly, ELM formulations. This result was achieved with an optimal concentration of 0.1 M NaOH as stripping agent and an external phase pH of 0.5. Different water qualities have also been investigated showing that the type of water (deionized, distilled, or tap water) does not significantly influence the extraction rate.

No MeSH data available.


Extraction of chromium as a function of time. Data are plotted for ELM formulations containing 3 wt% Span 80, 1 wt% butanol and 0.35 wt% TOMAC, without Tween 80 (hollow symbols) and with 1 wt% Tween 80 (filled symbols) prepared in distilled water (DW; ■) and tap-water (Tap; ▲). The initial concentration of chromium was 95 ppm (DW) and 104 ppm (Tap).
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membranes-05-00168-f006: Extraction of chromium as a function of time. Data are plotted for ELM formulations containing 3 wt% Span 80, 1 wt% butanol and 0.35 wt% TOMAC, without Tween 80 (hollow symbols) and with 1 wt% Tween 80 (filled symbols) prepared in distilled water (DW; ■) and tap-water (Tap; ▲). The initial concentration of chromium was 95 ppm (DW) and 104 ppm (Tap).

Mentions: The effect of Tween 80. As a novel approach, the hydrophilic surfactant Tween 80 was included in the emulsion phase. Tween 80 reduces the viscosity of the emulsion and in addition facilitates the creation of a double emulsion during the extraction process. We believe that Tween 80 stabilizes the multiple emulsion, resulting in a more homogeneous solution when contacting the emulsion phase and the external phase, giving a positive effect on the overall chromium removal efficiency, as can be deduced from Figure 6. The use of butanol as a co-surfactant was also applied in some cases since it increased the stability of the emulsion, however it had no significant effect on the extraction rate.


A new emulsion liquid membrane based on a palm oil for the extraction of heavy metals.

Björkegren S, Karimi RF, Martinelli A, Jayakumar NS, Hashim MA - Membranes (Basel) (2015)

Extraction of chromium as a function of time. Data are plotted for ELM formulations containing 3 wt% Span 80, 1 wt% butanol and 0.35 wt% TOMAC, without Tween 80 (hollow symbols) and with 1 wt% Tween 80 (filled symbols) prepared in distilled water (DW; ■) and tap-water (Tap; ▲). The initial concentration of chromium was 95 ppm (DW) and 104 ppm (Tap).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4496638&req=5

membranes-05-00168-f006: Extraction of chromium as a function of time. Data are plotted for ELM formulations containing 3 wt% Span 80, 1 wt% butanol and 0.35 wt% TOMAC, without Tween 80 (hollow symbols) and with 1 wt% Tween 80 (filled symbols) prepared in distilled water (DW; ■) and tap-water (Tap; ▲). The initial concentration of chromium was 95 ppm (DW) and 104 ppm (Tap).
Mentions: The effect of Tween 80. As a novel approach, the hydrophilic surfactant Tween 80 was included in the emulsion phase. Tween 80 reduces the viscosity of the emulsion and in addition facilitates the creation of a double emulsion during the extraction process. We believe that Tween 80 stabilizes the multiple emulsion, resulting in a more homogeneous solution when contacting the emulsion phase and the external phase, giving a positive effect on the overall chromium removal efficiency, as can be deduced from Figure 6. The use of butanol as a co-surfactant was also applied in some cases since it increased the stability of the emulsion, however it had no significant effect on the extraction rate.

Bottom Line: Span 80 is used as surfactant and butanol as co-surfactant.This result was achieved with an optimal concentration of 0.1 M NaOH as stripping agent and an external phase pH of 0.5.Different water qualities have also been investigated showing that the type of water (deionized, distilled, or tap water) does not significantly influence the extraction rate.

View Article: PubMed Central - PubMed

Affiliation: Applied Surface Chemistry, Chemical and Biological Engineering, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden. sanna.bjorkegren@chalmers.se.

ABSTRACT
The extraction efficiency of hexavalent chromium, Cr(VI), from water has been investigated using a vegetable oil based emulsion liquid membrane (ELM) technique. The main purpose of this study was to create a novel ELM formulation by choosing a more environmentally friendly and non-toxic diluent such as palm oil. The membrane phase so formulated includes the mobile carrier tri-n-octylmethylammonium chloride (TOMAC), to facilitate the metal transport, and the hydrophilic surfactant Tween 80 to facilitate the dispersion of the ELM phase in the aqueous solution. Span 80 is used as surfactant and butanol as co-surfactant. Our results demonstrate that this novel ELM formulation, using the vegetable palm oil as diluent, is useful for the removal of hexavalent chromium with an efficiency of over 99% and is thus competitive with the already existing, yet less environmentally friendly, ELM formulations. This result was achieved with an optimal concentration of 0.1 M NaOH as stripping agent and an external phase pH of 0.5. Different water qualities have also been investigated showing that the type of water (deionized, distilled, or tap water) does not significantly influence the extraction rate.

No MeSH data available.