Title: Application of airlift technology in recirculation aquaculture systems Authors
|Malone, Ronald - LSU|
Submitted to: Global Aquaculture Advocate
Publication Type: Trade Journal
Publication Acceptance Date: July 30, 2007
Publication Date: March 1, 2008
Citation: Pfeiffer, T.J., Malone, R.F. 2008. Application of airlift technology in recirculation aquaculture systems. Global Aquaculture Advocate. p.66-68. Interpretive Summary: Basically, there is a lack of system information and design characteristics for employing airlift pumps in recirculating systems. Recirculating aquaculture is energy intensive because water must move continuously through the system to remove system wastes and replace the oxygen. The common method for moving water in a recirculating aquaculture system is the use of a centrifugal pump. The airlift pump is an alternative pumping mechanism which uses the buoyancy of the entrained air bubbles to lift the water. For low-head systems, air lift pumps are more energy efficient and provide additional aeration, CO2 removal, and foam fractionation for dissolved solids removal. Capital and operational costs are lower than standard electrical centrifugal pumps and system design is simplified. Information for utilizing airlift pumps in recirculating aquaculture systems is limited and simple design criteria for implementation lacking. This article discusses design criteria for implementing airlift technology in a recirculating aquaculture systems and oxygen transfer obtained with an airlift unit.
Technical Abstract: Marine hatcheries implementing recirculating aquaculture technology require pristine water quality and must be designed to provide a disease free environment as much as possible to limit disease transmission. Given the aggressive nature of a variety of marine pathogens, design considerations with regards to the water treatment is essential. The use of airlifts (aeration, carbon dioxide stripping, and circulation) allows individual treatment of system tanks by centralizing the treatment utilities while limiting the potential for cross contamination of waters from diverse tank systems. This article presents the rationale underlying the use of airlift technology for decentralized modular treatment systems while providing interim sizing criteria for airlifts with the use of static bed floating bead media filters or moving bed bioreactors.