Optimization criteria of flow-electrode and feed water flow rate to achieve positive net power of flow-electrode capacitive mixing

Asymmetric Fe2+/Fe3+-Mediated Flow-Electrode Capacitive Deionization for the Removal of Chloride Ions in Reclaimed Water

“…There were two reasons; on the one hand, increasing the flow rate of the feedwater accelerated the ion replenishment in the chloride solution, thus reducing the ion migration resistance . On the other hand, increasing the flow rates increased their linear velocity, resulting in more AC particles flowing through the graphite plate, enhancing the effective contact between AC particles and graphite current collectors, which led to rapid electron transfer. , In summary, increasing the flow rates to some extent could promote the transport of chloride ions from the feed chamber to the flow electrode chamber. However, when the flow electrode flow rate was too high (e.g., 35 mL/min), the RE and CE decreased to 66.18 and 81.33%.…”

“…To date, typical strategies for improving the desalination performance include increasing the conductive content or adding redox-active materials. , In both approaches, the transfer of electrons is facilitated by lowering the resistance between the electrode particles, which then increases the adsorption capacity of the flow electrode . Although the method of adding conductive materials is simple and effective, adding too much solid material will inevitably increase the viscosity of the flow electrodes, in addition to increasing energy consumption, and may even clog the tiny flow channel . For example, Liang et al found that when the carbon black concentration reached 2 wt %, the flow electrodes flow slowly or even become immobile .…”

“…19 Although the method of adding conductive materials is simple and effective, adding too much solid material will inevitably increase the viscosity of the flow electrodes, in addition to increasing energy consumption, and may even clog the tiny flow channel. 20 For example, Liang et al found that when the carbon black concentration reached 2 wt %, the flow electrodes flow slowly or even become immobile. 21 In addition, excessive increases in the electrolyte concentration may reduce the charging efficiency.…”