The Effect of Lactose on the Transport Properties of Ion-Exchange Membranes

Abstract

The influence of lactose on the basic transport characteristics of ion exchange membranes, including cation-exchange membranes modified by polyaniline, has been studied. A positive effect on biofouling by Bacillus sp. or Shewanella oneidensis MR-1 cell cultures of modified MK-40 and Ralex CMHPES membranes has been found. That is mainly due to the different area of the conductive surface of these membranes. It has been revealed that the presence of lactose in a solution leads to a decrease in the conductivity of all studied membranes. However, the most significant effect is manifested for MK-40 membrane modified by polyaniline: its electrical conductivity is reduced by 15–25%. The diffusion permeability of the anion-exchange and initial cation-exchange membranes is poorly dependent on the presence of lactose in the solution. However, its decrease is observed by 2–2.5 times in the case of cation-exchange membranes modified by polyaniline. A significant effect of lactose on the current-voltage characteristics of the anion-exchange membranes has been found. This fact indicates significant adsorption of lactose on membrane surface in an external electric field. It is shown that ion-exchange membranes remain quite effective for electrodialysis of hydrochloric serum solutions, but their use is more effective at under limiting current modes.