A new emulsion liquid membrane based on a palm oil for the extraction of heavy metals.
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.
Applied Surface Chemistry, Chemical and Biological Engineering, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden. sanna.bjorkegren@chalmers.se.
Sanna
S
Björkegren
Applied Surface Chemistry, Chemical and Biological Engineering, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden. fassihi.rose@gmail.com.
Rose Fassihi
RF
Karimi
Applied Surface Chemistry, Chemical and Biological Engineering, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden. anna.martinelli@chalmers.se.
Anna
A
Martinelli
Department of Chemical Engineering, University of Malaya, Kuala Lumpur 50603, Malaysia. jaya_kumar@um.edu.my.
Natesan Subramanian
NS
Jayakumar
Department of Chemical Engineering, University of Malaya, Kuala Lumpur 50603, Malaysia. alihashim@um.edu.my.
Mohd Ali
MA
Hashim