Study on electrochemical water softening performance of coke and stainless steel coupled cathode

Abstract

Using 304 stainless steel mesh as the outer support bed and serrated stainless steel mesh as the inner support structure，and filling coke in the serrated voids of the composite serrated mesh，a filled-bed electrode coupled with two materials of coke and stainless steel was prepared for solving the problem that the cathode for electrochemical water softening could not be operated efficiently in the long term. The optimal electrode structural parameters were explored，and the results showed that the electrode achieved the optimal softening rate of 46.873 g/（m2·h） for simulated circulating cooling water with a total hardness of 700 mg/L when the cathode-anode spacing，the number of mesh of the outer flat mesh，and the apparent current density were 1.5 cm，20 mesh，and 80 A/m2，respectively. When the surface of the electrode was covered by a scale layer resulting in a significant decrease in the softening rate，the electrode was regenerated by vibration，and the service life of the electrode was investigated，and the results showed that maintaining the electrode in continuous operation for 37 d，the electrode still maintained a high softening rate for the circulating cooling water，which could maintain the long-term efficient operation of the electrochemical water softening system. This study can provide a reference for solving the performance degradation problem of electrochemical water softening system caused by ineffective regeneration of electrochemical water softening cathode.

Keywords

• electrochemical water softening
• cathode regeneration
• long-life electrodes
• circulating cooling water