Emulsion liquid membranes, mathematical modeling

In this paper an overview of the developments in liquid membrane extraction of cephalosporin antibiotics has been presented. The principle of reactive extraction via the so-called liquid-liquid ion exchange extraction mechanism can be exploited to develop liquid membrane processes for extraction of cephalosporin antibiotics. The mathematical models that have been used to simulate experimental data have been discussed. Emulsion liquid membrane and supported liquid membrane could provide high extraction flux for cephalosporins, but stability problems need to be fully resolved for process application. Non-dispersive extraction in hollow fib er membrane is likely to offer an attractive alternative in this respect. The applicability of the liquid membrane process has been discussed from process engineering and design considerations. 

Huang CR, Wang KC, and Zhou DW. Mathematical modelling of carrier-facilitated transport in emulsion liquid membranes. In Bartsch RA, Way JD, eds. Chemical Separations with Liquid Membranes, Washington, DC American Chemical Society, ACS s3miposium series 642, 1996 115-122. 

In Chapter 6, characteristic features of emulsion liquid membrane systems are examined by Yurtov and Koroleva. The effects of surfactant and carrier concentrations and external and internal phase compositions upon the properties of the extracting emulsions are discussed. Several mathematical models for the rheological curves are considered, and regions of applicability for the models are evaluated. An influence of nanodispersion formation on mass transfer through the interface and on the properties of extracting emulsions for cholesterol is demonstrated. 

Mathematical Modeling of Carrier-Facilitated Transport in Emulsion Liquid Membranes... 

Since Norman N. Li (1) introduced the emulsion liquid membrane in 1968, many publications have appeared both on experimental work and on theoretical modeling of such separations. Most of the theoretical work was concentrated on mass transfer in the ELM process in a mixing vessel where the water-in-oil emulsion is mixed with an external aqueous phase and globules of emulsion are formed and suspended in the external phase. The solute, after a series of mass transfer steps, is transferred from the external aqueous phase to the internal aqueous receiving phase through the oil membrane phase. Many mathematical... 

Experimental Measurements. Removal of arsenic firom metallurgical wastewater by emulsion liquid membrane was studied experimentally (9). One set of experimental data is used here to verify the mathematical model. The experiment on emulsion liquid membrane removal of arsenic was conducted as follows. 

The mass transfer of an emulsion liquid membrane process has been modeled mathematically. An analytical solution which allows prediction of concentrations of solutes in the external phase, membrane phase, and external phase-membrane interface was obtained. Experimentally, arsenic was selected as a solute in the external phase to be removed by the ELM process. Our model gives an excellent representation of the experimental data for the external concentration of the arsenic versus time. In addition, the model predicts the concentration distribution in the membrane phase at any time. Thus, the overall distribution of solutes in three phases (external, membrane and internal) at ahy time of the ELM process can be evaluated. From the model, it was found that the ELM process was characterize by two dimensionless groups. One group for the transport phenomena governs the rate of mass transfer or the Biot number. The other group includes the... 

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