Comparative analysis the performance of electrochemical water softening between high frequency electric fields and direct current electric fields based on orthogonal experimental methods

Abstract

Electrochemical water softening has been widely used in industrial circulating cooling water system; however, their low deposition efficiency is the main drawback that limits usage in medium to large enterprises. In this work, the effect of different parameters on the hardness removal efficiency and energy consumption of the electrochemical water softening system is experimental studied, and the performance of water softening applied by high frequency electric field and direct current electric field are comparative analyzed. The impact factors of the electrochemical water softening system are as follows: initial feed concentration of solute, magnitude of voltage, inter-electrode distance, area of cathode and frequency of power supply. To improve the analysis efficiency, the L25 (55) orthogonal table is used to investigate the five different factors at five levels. The experimental results are shown that the initial feed concentration of solute is the most significant factor affecting the hardness removal efficiency. The optimal combination for water softening in the group applied by high frequency electric field and direct current electric field are A3B2C1D4E3 and A2B5C3D1 respectively. The energy utilization of the device applied by high frequency electric field is 3.2 times of that applied by direct current electric field. The practice shows that under direct current electric field have a better softening effect, and it is more suitable for scaling ion removal. Particle Image Velocimetry (PIV) is used to observe the flow field induced by the electrolysis and find that the vertical and horizontal velocities of the flow field at low voltage are conducive to the migration of scaled ions to the cathode, and then the electrolytic reaction and deposition reaction synergy effect is the optimal.

Research Progress on Novel Electrochemical Descaling Technology for Enhanced Hardness Ion Removal

“…The random diffusion of H 2 bubbles generated from water electrolysis can cause flow disturbances near the cathode, creating turbulence [63,64], and water flow has also been found to accelerate ion diffusion [65,66]. Utilizing these characteristics, it is deduced that bubble diffusion and water flow can be harnessed to expedite the diffusion of OH − from the cathode surface and effectively separate OH − and H + .…”

Research on performance optimization and mechanism of electrochemical water softening applied by pulse power supply

“…High frequency power supply has significant advantages in reducing power consumption of electrochemical water softening technology. Lin et al (2021) compared the performance of the electrochemical water softening device in HF electric fields with that direct current (DC) electric fields, and found that HF electric fields can improve the energy utilization rate of the device. Yu et al (Wu et al 2018) used a pulsed power supply for electrochemical water softening treatment.…”