The extraction Of Solutes from aqueous Solutions across a hydrophobic flat-sheet micro-porous membrane to organic phase-containing complex carriers was modeled. The effects of the membrane extraction through a parallel-plate module with concurrent-flow, were investigated both theoretically and experimentally. The mass transfer efficiency enhancement is represented graphically and compared with the results obtained by experiment. Improvements in the extraction rate can be achieved by setting the barrier location to be moving away from centerline. The influences of the subchannel thickness ratio, aqueous phase flow-rate, concentrations of Cu2+, H+ and <((HR)(2))over bar> on the enhancement of the mass transfer efficiency are discussed. (C) 2008 Elsevier B.V. All rights reserved.