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ARS Home » Southeast Area » Stoneville, Mississippi » Warmwater Aquaculture Research Unit » Research » Publications at this Location » Publication #389641

Research Project: Improving the Productivity and Quality of Catfish Aquaculture

Location: Warmwater Aquaculture Research Unit

Title: Design of a Vacuum Degassing Apparatus to Reduce Nitrogen Supersaturation and Maintain Hypoxia in Well-Water

item Ott, Brian
item Torrans, Eugene
item ALLEN, PETER - Mississippi State University

Submitted to: North American Journal of Aquaculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/8/2022
Publication Date: 8/9/2022
Citation: Ott, B.D., Torrans, E.L., Allen, P.J. 2022. Design of a Vacuum Degassing Apparatus to Reduce Nitrogen Supersaturation and Maintain Hypoxia in Well-Water. North American Journal of Aquaculture.

Interpretive Summary: Well water that is directly pumped from underground sources may have undesirable characteristics that make it unsuitable for use in rearing fish or conducting fish experiments. Scientists at the USDA-ARS Warmwater Aquaculture Research Unit collaborated with a scientist from Mississippi State University to create a vacuum degasser that provides a relatively simple, small, and low-cost device to reduce gas supersaturation while maintaining desirable dissolved oxygen concentration. A detailed description of the parts needed and instructions for construction of the degasser are all included in the text. This vacuum degasser was used extensively to provide the appropriate water quality conditions for numerous experiments conducted at USDA-ARS WARU and has the potential for adoption across a number of facilities and industries that require manipulation of gases dissolved in water.

Technical Abstract: Water derived from an underground well or spring is commonly supersaturated with nitrogen and low in dissolved oxygen. These conditions are generally harmful to fishes and water must be treated to reduce total dissolved gases and adjust dissolved oxygen concentrations to desired levels. Typically, corrective methods remove nitrogen while increasing the oxygen concentration, but this is not desirable for situations where hypoxic conditions are needed for experimental purposes. In this project, a vacuum degasser was designed to remove excess nitrogen from well water while keeping dissolved oxygen concentration low (i.e., = 2.0 mg/L). Additionally, in a parallel system, a head-tank water treatment system was designed to remove excess nitrogen while simultaneously increasing the oxygen concentration to create normoxic conditions. These systems provide solutions to overcoming gas supersaturation in well water and produce the desired dissolved oxygen concentration without requiring the use of consumable gas cylinders.