A Study of Dissolved Gas Dynamics in Mixed Stream Electrolyzed Water

Supersaturated hydrogen and oxygen solutions of pH-neutral tap water were created through electrolysis and subsequently blended back together. The blended solution was monitored as a function of time with dissolved gas meters and time-lapse photography. While the pH of the blended anodic and cathodic electrolysis streams returned to neutral pH within seconds, the blended solution was observed to retain significantly elevated dissolved gas concentrations on a timescale of hours. The analysis of dynamic bubble formation along the surfaces of the container, along with dissolved gas measurements, indicates that exsolution of dissolved hydrogen gas takes place on a very similar timescale. The measured total mass balance of gas produced electrolytically suggests that while a significant fraction of gas is exsoluted immediately before mixing of the anodic and cathodic streams, there are dissolved gases that take hours to exsolute completely from an undisturbed solution. Additionally, these signatures were studied as a function of electrolysis current. (C) The Electrochemical Society of Japan, All rights reserved.