ARS | Publication request: Gas transfer rates from airlifts used for concurrent aeration, carbon dioxide stripping, and recirculation

Submitted to: Book of Abstracts Aquaculture America
Publication Type: Abstract Only
Publication Acceptance Date: December 1, 2007
Publication Date: February 9, 2008
Citation: Hearn, R.A., Pfeiffer, T.J., Johnson, B.S., Malone, R.F. 2008. Gas transfer rates from airlifts used for concurrent aeration, carbon dioxide stripping, and recirculation [abstract]. Book of Abstracts Aquaculture America 2008: Beyond Magic-Competing in World Markets.p.159.

Technical Abstract: Airlifts simplify recirculating aquaculture systems and can potentially reduce capital costs and minimize maintenance issues. Airlifts have the ability to move and aerate water as well as degass the water of any carbon dioxide. This study evaluated the oxygen transfer and carbon dioxide removal abilities of airlift pumps ranging in size from 4 to 8 inches in diameter. A tank 10 feet in diameter and 4 feet deep filled with clean freshwater was used to obtain the oxygen and carbon dioxide transfer coefficients for the airlift pumps. Open airlift pipes were used for the air input and head loss for the system setup was kept between 6 and 18 inches. Air flow to water flow ratios ranged from 0.5 to 2.0 providing water flow rates between 45 and 130 gallons per minute. For the various gas to liquid ratios, head loss heights, and pipe diameters the oxygen transfer rates ranged from 0.05 to 0.19 kg oxygen per hour for the units, increasing with increasing pipe diameter. Although airlifts are capable of supporting brood stock systems, preliminary modeling data indicates in-tank aeration is necessary for higher carrying capacity systems.