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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.


Schematic representation of the procedure of the metal extraction experiments.
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membranes-05-00168-f003: Schematic representation of the procedure of the metal extraction experiments.

Mentions: The external phase was prepared through dissolving the chromium salt in distilled, deionized or tap-water, and the pH was adjusted with hydrochloric acid (point 2a, Figure 3). The internal phase containing the desired concentration of the stripping agent was prepared with the same type of water as the external phase. The diluent was mixed with emulsifier, co-surfactant, and carrier, while the emulsification of the internal and the membrane phase was conducted using a high speed homogenizer (IKA T25 Digital ULTRA-TURRAX) with an agitation of 3200–3400 rpm (point 2b, Figure 3). The external phase and the ELM phase were contacted using an agitator stirred by twisted impellors, with varying agitation speed (point 3, Figure 3). Samples were taken periodically during each run using syringes left undisturbed for the short time required for the ELM and external phase to separate, and the concentration of chromium in the feed phase was detected (point 4, Figure 3). The concentration of chromium left in the external phase was determined using ICP-OES (point 5, Figure 3).


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)

Schematic representation of the procedure of the metal extraction experiments.
© Copyright Policy
Related In: Results  -  Collection

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

membranes-05-00168-f003: Schematic representation of the procedure of the metal extraction experiments.
Mentions: The external phase was prepared through dissolving the chromium salt in distilled, deionized or tap-water, and the pH was adjusted with hydrochloric acid (point 2a, Figure 3). The internal phase containing the desired concentration of the stripping agent was prepared with the same type of water as the external phase. The diluent was mixed with emulsifier, co-surfactant, and carrier, while the emulsification of the internal and the membrane phase was conducted using a high speed homogenizer (IKA T25 Digital ULTRA-TURRAX) with an agitation of 3200–3400 rpm (point 2b, Figure 3). The external phase and the ELM phase were contacted using an agitator stirred by twisted impellors, with varying agitation speed (point 3, Figure 3). Samples were taken periodically during each run using syringes left undisturbed for the short time required for the ELM and external phase to separate, and the concentration of chromium in the feed phase was detected (point 4, Figure 3). The concentration of chromium left in the external phase was determined using ICP-OES (point 5, Figure 3).

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.