The permeability resistance model and equations which describe the permeation resistance of Zn2+ through HFSLM(Hollow Fiber Supported Liquid Membranes)are presented. In this paper

the equations describing the behavior of HFSLM modules of once-through mode at low metal concentration was derived. It was proposed that the thickness of the aqueous boundary-la yer of metal concentration in the incompressible viscous parallel flow teed phase was directly proportional to minus one half power of average feed velocity. Results showed that this hypothesis was in good agreement with the data of experiments. The total resistance of mass transfer in this chemical system consists of the aqueous resistance of the boundary-layer of metal concentration in the feed phase and the organic resistance of the diffusion-layer ot the metal-complex concentration in the membrane phase.