ANALYSIS OF ELECTRODIALYZER FOR ELECTRODI ALYSIS CULTURE USING A MODEL ORGANIC-ACID SOLUTION

The dynamics of pH in a dialysis compartment of an electrodialyzer fit ted on a fermentor for organic acid production was investigated. Some calculations based on dissociation equilibrium and ion transfers revea led the existence of a critical pH of influent that caused an abrupt p H change of the effluent. This abrupt change was observed experimental ly with the use of a model fermentation broth of acetic acid - sodium acetate solution. The distribution of pH in the compartment, which was confirmed both experimentally and theoretically, made it clear that t he change happened in specific local positions. The value of the criti cal pH was dependent on ion flux through the ion-exchange membrane, su rface area of the membrane, volumetric flow rate of bulk into the comp artment and total concentration of organic acid. Design and control st rategies are discussed, using the theoretical and experimental finding s.