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Transport of phenylalanine (Phe) through a supported liquid membrane (SLM) containing di-(2-ethylhexyl) phosphoric acid (DEHPA) as carrier in a spiral-channel module was studied. The value of the molar flux of Phe through SLM increases with the velocity of the feed phase in the channel. However, soon at a velocity of about 1.5–4 cm.s!1, the maximum value is achieved. With increasing initial concentration of Phe in the feed phase, the transport rate increases. An increase in the concentration of DEHPA in the solvent did not result in an increase of the transport rate despite the fact that the value of the distribution coefficient increased proportionally. This is related to the slower kinetics of decomposition of the complex on the stripping interface. An analysis of mass-transfer resistances of Phe in pertraction through SLM showed that decisive resistances are based on the kinetics of chemical reactions of complex formation and decomposition, and their share in the overall resistance is about 25 and 35%, respectively. The lifetime of SLM with DEHPA as the carrier is less than 1 day for dilute aqueous feeds unsaturated with the membrane phase. It increases with the concentration of DEHPA that is connected with a relatively high solubility of DEHPA in diluted aqueous solutions. The spiral-channel module can be used for testing solvents for pertraction and membrane-based solvent extraction under defined hydrodynamic conditions.

The value of the molar flux of Phe through SLM and the overall mass-transfer coefficient increases with the velocity of the feed phase in the channel. However, soon, at a velocity of about 1.5 to 4 cm.s!1, a maximum value is achieved. The molar flux of Phe and the overall masstransfer coefficient are concentration dependent. With increasing concentration of Phe in the feed phase, the transport rate increases. An increase in the concentration of the carrier (DEHPA) in the solvent did not result in a proportional increase of the transport rate. Moreover, this dependence goes through a maxi-mum despite the fact that the value of the distribution coefficient increased proportionally with the carrier concentration. Such behaviour could be related to the decisive role of the kinetics of decomposition of the complex on the stripping interface. An analysis of mass-transfer resistances of Phe in pertraction through SLM showed that important resistances are based on the kinetics of chemical reactions of complex formation and decomposition, and their share in the overall resistance is about 25% and 35%, respectively. The lifetime of SLM increases with the concentration of DEHPA, which is connected to a relatively high solubility of DEHPA in diluted aqueous solutions. In experiments with aqueous phases saturated with the membrane phase, the lifetime of SLM was about 35 h for the concentration of DEHPA at 1.0 kmol.m!3. However, when using unsaturated aqueous phases, it is less than 15 h.