Effects of concentration boundary layers in a transport of electrolyte solutions through horizontal mounted polymeric membrane.

The results of experiment of diffusive transmembrane transport in a single-membrane osmotic-diffusive electrochemical cell were presented. In all experiments one of the vessels was filed with pure water, and the second one--with aqueous potassium chloride solution in aqueous ammonia solutions of constant concentration. The flux of potassium chloride was assigned according to the following measure procedure. In a first step we assigned the time dependence of potassium chloride flux in conditions of uniform mechanically stirred solution with speed of 500 rpm. In a second step those characteristics were assigned in conditions of mechanically unstirred solution. Each experiment was made for two configurations of gravitational membrane system: (i) with the water in a vessel above the membrane and solution below it (configuration A) (ii) with the solution in a vessel above the membrane and water below it (configuration B). Taking under the consideration the values of potassium chloride flux in steady state for different solution concentration of the same substances and the same configurations of membrane system, the dependencies of potassium chloride flux from the solution concentration differences were made appropriately. On the base of those experiments the solute flux concentration boundary layers effects (jCBLE) were counted. Moreover it was shown that single-membrane osmotic-diffusive electrochemical cell has rectifier and amplifying of diffusive flow features. The coefficients, appropriately, of asymmetry and amplification of diffusive flux are the measurements of those features.