Application of Electrodialysis in Purification and Reuse of Spent Alkaline Process Streams

Experiments using electrodialysis (ED) units for purification and recovering of spent alkaline process streams, which contain potassium hydroxide, were carried out. According to the experimental results, the spent alkaline process streams, which were produced in production of alkaline storage batteries, can be completely recovered and directly reused as the alkaline process streams. A great number of benefits has been obtained to recover the spent alkaline process streams by using the ED units. The process of the ED unit and the structure of the ED stack are discussed. In this case, optimal current density (170-200 mA/cm²) and current efficiency (75-80%) were observed.