Abstract
Slightly acidic electrolyzed water, prepared by electrolyzing dilute hydrochloric acid, has a strong anti-microbial effect, and is widely used for various washing and disinfecting purposes. To obtain the desired effect, it is important to understand quantitatively how operating parameters affect available chlorine concentrations and pH in slightly acidic electrolyzed water. In this paper, the effect of the cell voltages, which was considered as one of the most important factors that controlled the electrochemical reactions, was examined. The previous model was modified to consider the existence of the leakage current and the voltage balance in the electrolysis cells. The calculated results represented well the tendency of the experimental data, which showed a remarkable increase in the current efficiency with a rise of voltages until 1.7 V. The calculated results also described the tendency of experimental data, which showed a decrease in pH with a drop of voltages. The modified model enabled us to predict the consumption rate of a hydrochloric acid in various conditions. With the model modified in this study, the operation conditions for adjusting pH, in which the addition of slightly acidic electrolyzed water to foods was permitted, were proposed in a very high or low hardness.
