ABSTRACT.The experiments carried out in this paper tested the effectiveness of the polysulfone-dimethyldioctodecylammonium bromide (PSU-DMOA) and polysulfone-Tween 80 in dead-end facilities. The efficiency of these membranes has been proved by determining the permeate flow and the retention coefficient. Analyzing the experimental data, it was found that for the polysulfone-dimethyldioctodecylammonium bromide composite membrane the retention rate is higher than for the polysulfone-Tween 80 composite membrane, the t values being obtained for the highest pressure used in the system.