Lifetime Studies and Optimization for AFT (Anti-Fouling Technology)-Treated Electrodialysis Membranes

摘要

The work determined the effect of Anti-Fouling Technology (AFT) treatment of electrodialysis (ED) membranes on system performance and lifetime. This study has helped to evaluate some of the critical performance parameters which must be considered in the application of AFT to the ED process. An experimental procedure was developed for coating membranes which were larger than any which had previously been coated using the apparatus. Although the data for the lifetime studies were not fully conclusive, they indicated that the application of an oriented monomolecular layer of a fluorinated surfactant by the Langmuir-Blodgett process may prolong the operating life of electrodialysis membranes. A designed experiment was conducted in order to characterize the response of the system to change in flow rate, concentration, foulant load, and the membrane coating showed that the coating appeared to lower the limiting current slightly. This is believed to be due to a lowering of the rate of ion transport across the boundary layer which is caused by the presence of the monolayer. The determination of the limiting current was subject to differences in interpretation since the current-voltage characteristic was somewhat anomalous.