Removal of dissolved oxygen from water: A comparison of four common techniques.

Four common techniques for the removal of dissolved oxygen from water have been examined: boiling at 1 atm, boiling under reduced pressure, purging with N(2) and sonication under reduced pressure. After treatment, the residual oxygen in solution was analysed by the Winkler method. Nitrogen purging for 20-40 min at flow rate of 25 mL/s was found to be the most effective oxygen removal method. Boiling at 1 atm was found to be the least effective. None of the techniques evaluated here lead to complete removal of oxygen. The concentration of residual dissolved oxygen after purging for 20-40 minutes with nitrogen is 0.2-0.4 ppm.