The flow through CDI cell used in this study utilized symmetric, pristine, carbon electrodes obtained from Kynol®. The CDI system, fitted with a pressure regulator and gauge, allows for operation at elevated pressures, up to 60 psi, within the cell. Figure 1, depicts the CDI system components with the pressurized and non-pressurized regions highlighted. The natural pressure gradient that occurs across the cell due to flow resistance remains constant because the entire cell lies within the pressurized portion of the system. This operating method takes advantage of Henry’s Law (where more dissolved oxygen is found at higher pressure) removing oxygen from the cell.
Initial data, shown in Figure 2, demonstrates the response of dissolved oxygen to changes in system pressure for a ~5mM aerated sodium chloride solution. A CDI system, treating the same concentration sodium chloride solution, operating at increased pressure demonstrates a similar increase in dissolved oxygen, which decays back once the trapped air is removed.
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