Authors:S. Chowta, P. Mohapatra, S. Tripathi, B. Tomar, and V. Manchanda
An emulsion liquid membrane (ELM) containing di-2-ethylhexylphosphoric acid (D2EHPA) as the carrier extractant and SPAN 80
as the surfactant was used to pre-concentrate Am3+ from dilute acid solutions. Effects of various factors such as: external phase pH, internal phase conditions, equilibration
time, D2EHPA concentration, SPAN 80 concentration, etc. on Am3+ mass transfer were investigated. Emulsion was broken by the addition of solvents such as acetone and the actual mass transfer
obtained after breaking the emulsion agreed well with that obtained by the difference method.
Authors:I. Miesiąc, K. Schügerl, A. Hasler, and J. Szymanowski
The extraction of Penicillin G (Pen G) and its conversion to 6-aminopenicillin acid (6-APA) and phenylacetic acid (PAA) was performed by means of Penicillin G Amidase immobilised in the emulsion liquid membranes. Using various surfactants as emulsifiers and an appropriate carrier it is possible to obtain different extraction rates of Pen G as well as back transfer rates of the hydrolysis products. The surfactants with polyoxyethylene chain facilitate the back transfer through the membrane phase, whereas the more hydrophobic surfactants, e.g., Paranox 100, tend to accumulate Pen G hydrolysis products in the internal aqueous phase.
Emulsion liquid membranes (ELM) with di-2-ethylhexylphosphoric acid in n-alkane, and dipicrylamine and cobalt(III) dicarbollide in nitrobenzene stabilized in double emulsions by SPAN 80/85 surfactant were used for preconcentration of radioactive fission products (137Cs,90Sr,139Ce, and152Eu) from slightly acidic nitrate solutions. The efficiency of sulfuric, phosphotungstic and silicotungstic acids as stripping agents, and picric acid as the bulky anion additive was investigated. A group separation of the fission products is possible by the ELM technique and can be considered for their removal from waste water solutions.
Authors:I. Miesiąc, K. Schügerl, and J. Szymanowski
Potassium leakage was studied in liquid membrane systems containing various emulsifiers and compared with emulsion, stability in the storage test. The effects of various parameters upon emulsion stability and the leakage of standard traces are discussed. The transfer of cations can be caused by emulsion breaking, by transport with the specific carrier and/or with surfactants used as emulsifiers. The latter case becomes especially important when hydrophilic surfactants, e.g. ones containing polyoxyethylene chains, are present in liquid membranes. In systems containing hydrophobic emulsifiers the transfer of potassium is relatively low. In each case considered the effect of emulsifiers upon the transfer of the standard tracer should be checked prior to using the leakage test to characterize emulsion stability.
Halogenated hydrocarbon emulsion liquid membranes (e.g. trichlorobenzene) which were stabilized with polyamine tenside, using 18-crown-6 and picric acid as carriers, were applied to separation of strontium and calcium. Application in the separation of Sr/Ca enable us to enhance preconcentration factor for strontium due to decreasing occlusion of freed solution and better hydrodynamic parameters of the emulsion.
The determination of uranium by a fluorimetric method using a conventional spectrophotometer has been elaborated. The quenching effect of the matrix was reduced by separation with liquid-liquid extraction and emulsion liquid membrane extraction methods using D2EHPA as a selective extraction reagent. The method was employed for uranium determination in radioactive waste solutions and proved to be very fast and easy to perform. It was found that it is possible to determinate as low as 0.2 ppm of uranium in a 10 ml sample.
Authors:M. F. Pinheiro da Silva, L. S. Soeira, K. R. P. Daghastanli, T. S. Martins, I. M. Cuccovia, R. S. Freire, and P. C. Isolani
Ge , M , Guo , C , Li , L , Zhang , B , Feng , Y , Wang , Y 2009 Preparation of CeO 2 novel sponge-like rods by emulsionliquidmembrane system and its catalytic oxidation property . Mat Lett 63 : 1269 – 1271 10.1016/j.matlet.2009