The electrodialysis (ED) process employing ion-exchange membranes has been used mainly for the desalination of brackish water and concentration of seawater. Of late ED has become a unique process for the separation of ionic and non-ionic substances from chemical mixtures. In such manufacturing processes, glyoxal is produced by the oxidation of acetaldehyde with nitric acid. After the reaction, the product contains nitric acid, acetic acid, glycolic acid, etc., which are to be separated from the mixture. Attempts were made to make use of ED to separate electrolytes from nonelectrolytes and to separate nitric acid and weak organic acids from glyoxal. The experimental results obtained from the separation of nitric acid, organic acids and glyoxal under different experimental conditions are presented and discussed.