Technical Notes: Overview of Techniques for Removing Oxygen from Water and a Description of a New Oxygen Depletion System

Experimental oxygen depletion systems reduce the oxygen content of water by decreasing oxygen solubility, by chemically or biologically extracting oxygen, or by reversing the oxygen gradient. We review the advantages and drawbacks of these methods and describe a nitrogen displacement system that can lower the oxygen content of 20 L of water below detectable limits in about 2 h. The apparatus is constructed with common laboratory equipment and offers an economical means of reducing dissolved oxygen at predictable rates.