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ARS Home » Southeast Area » Stuttgart, Arkansas » Harry K. Dupree Stuttgart National Aquaculture Research Cntr » Research » Publications at this Location » Publication #175689
Title: EXPERIMENTAL EVALUATION OF A FLOATING BEAD BIOCLARIFIER AND FLUIDIZED SAND FILTER FOR A SMALL-SCALE RECIRCULATING AQUACULTURE PRODUCTION SYSTEM

Author
item Pfeiffer, Tim
item RILEY, KENNETH - HBOI

Submitted to: International Conference on Recirculating Aquaculture
Publication Type: Proceedings
Publication Acceptance Date: 6/5/2004
Publication Date: 8/10/2004
Citation: Pfeiffer, T.J., Riley, K. 2004. Experimental evaluation of a floating bead bioclarifier and fluidized sand filter for a small-scale recirculating aquaculture production system. International Conference on Recirculating Aquaculture. p. 591.

Interpretive Summary: Small-scale recirculating aquaculture systems have received increasing attention because of their potential to produce high densities of fish in systems that occupy a relatively small area. A small-scale RAS was designed and developed to optimize the use of water, energy, and technology to produce multiple crops of tilapia without the use of supplemental oxygen. The system employed) with two types of solids removal devices, a swirl separator and floating bead bioclarifier and two biofilters, the floating bead bioclarifier and a fluidized sand filter for ammonia removal. The swirl separator and floating bead bioclarifier efficiently removed solids at the highest daily feed rate of 4.5 kg per day. Nitrification rates for ammonia removal in the floating bead filter improved as the feed rate increased but was limited by carbon dioxide accumulation in the system which reached 60 mg/L. Nitrification in the fluidized sand filter was stable and provided greater nitrification due to additional surface area of the media however its nitrification ability was mainly limited by oxygen availability. Further addition of feed to improve growth and production rates of the tilapia in the system would require some form of aeration or oxygen supplementation to improve oxygen concentration and carbon dioxide removal.

Technical Abstract: In the past decade, small-scale recirculating aquaculture systems (RAS) have received increasing attention because of their potential to produce high densities of fish in systems that occupy a relatively small area. In this study, a small-scale RAS was designed and developed to optimize use of water, energy and technology in a demonstration system for tilapia production. The goal was to use a two-phase RAS to produce multiple crops of tilapia without the use of supplemental oxygen. A recirculating aquacultural system (RAS) with two different types of solids removal devices (swirl separator and floating bead bioclarifier) and two different types of biofilters (floating bead bioclarifier and fluidized sand filter) were evaluated for performance at four different feed rates in this study. The specific objectives were to 1) evaluate solids removal using dual-drain technology, a swirl separator and a floating bead bioclarifier; 2) evaluate nitrification across a floating bead bioclarifier and fluidized sand filter and; 3) monitor oxygen consumption in the culture units and filtration components. The swirl separator and floating bead bioclarifier efficiently removed solids at the highest daily feed rate, 4.5 kg per day. Nitrification rates for ammonia removal in the floating bead filter improved as the feed rate increased. Nitrification in the fluidized sand filter was stable and provided greater nitrification due to additional surface area of the media. The system design was oxygen limited at the highest feed rate of 4.5 kg per day and further addition of feed would require some form of aeration or oxygen supplementation.