This paper presents a study of As(V) transfer through a supported liquid membrane (SLM) with trioctylphosphine oxide (Cyanex 921) in kerosene. Transport of As(V) from 2 M H2SO4 aqueous solutions was studied as a function of parameters such as the nature of the stripping solution, extractant concentration and stirring rate. Of the stripping solutions studied, Na2SO4 presents the highest As(V) transfer (close to 94%) in 120 min at concentrations where the ionic strengths of the feed and stripping solutions are equal. Additionally, when the extractant concentration was increased from 0.05 to 0.12 M, higher As(V) transfer values were obtained. The highest As(V) transfer was found at a Cyanex concentration of 0.12 M. The study of stirring rate influence indicates that at 16.66 Hz (1000 rpm) the thickness of the limit layer reaches a minimum; thus, we consider that at this point the mass transfer coefficient is essentially constant. Finally, a simple mass transfer model (based on the stationary state) was developed to determine the mass transfer coefficients at the feed solution-membrane and membrane-stripping solution interfaces. (c) 2007 Elsevier B.V. All rights reserved.