Synergistic optimization and mechanism exploration of electrochemical water softening modulated via low-frequency...

This laboratory-scale study investigates the effects of pulsed electric fields on electrochemical water softening using a strategy combining low-frequency pulse co-regulation, grey relational analysis, and neural network optimization. Results indicate that initial hardness, duty cycle, and frequency significantly influence hardness removal efficiency in descending order. Optimized pulse parameters enhance softening efficiency by balancing ion reaction and mass transfer rates, reducing energy consumption and concentration polarization. Under low hardness (≤600 mg L^-1), pulsed operation increases descaling per unit energy by 28.23-43.59% compared with direct current. High-speed imaging revealed that pulse intervals optimize bubble dynamics, promoting detachment with higher density and larger specific surface area, which weakens crystal-electrode adhesion and reduces ion diffusion resistance. The GA-MLP model, combined with grey correlation analysis, optimized softening under high hardness, determining ideal parameters for different hardness levels. Experimental verification confirmed these parameter combinations. The study provides new recommendations for optimizing electrochemical water softening parameters across varying hardness conditions based on laboratory-scale data.