Optimizing water hardness removal through electrodialysis: A comprehensive exploration using Box-Behnken design analysis

Abstract

Water hardness significantly impacts water quality, influencing both industrial processes and daily domestic applications. This study investigates the efficacy of electrodialysis (ED) in removing hardness, aiming for a balanced approach that avoids aggressive or scaling tendencies. Response surface methodology (RSM) was employed to determine the interaction between the inputs and the hardness removal, optimizing key parameters using the Box-Behnken design (BBD). The resulting regression model, validated through analysis of variance (ANOVA), demonstrated a high R2 value of 0.9761 and an adjusted R2 value of 0.9454, indicating a robust fitness for hardness removal prediction. The interaction of both voltage and initial concentration holds significance in our investigative study. A notable hardness removal efficiency of 87% was achieved at a demineralization time of 47 min, an applied voltage of 11V and an initial concentration of 5.3 mmol/L. This research enhances our understanding of critical operating parameters in ED, offering insights for optimizing the process toward effective water softening and long-term water treatment.