Author
Pfeiffer, Tim | |
WILLS, PAUL - Florida Atlantic University |
Submitted to: Aquacultural Engineering
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 6/28/2011 Publication Date: N/A Citation: N/A Interpretive Summary: Three different commercially available plastic media were evaluated in a moving bed toriod filters under low salinity (11-12 ppt) warm water culture conditions at two different feed loading rates. The culture system consisted of nine separate modules that include a double drain fish culture tank and a moving bed toriod biofilter. The toriod filters were filled with 0.11 m3 of one of three different types of floating plastic media. The three types of media evaluated were K1 kaldnes media, MB3 media, and AMB media. The daily grams of total ammonia nitrogen (TAN) removed per m3 media-were determined for the three media types at daily feed load rates of 3.5 and 8.2 kg feed/m3 media. The feed provided to the fish in the tanks was a 4.8 mm slow sinking marine grower diet pellet (45% protein, 17% fat). The average daily TAN removal rates at the lower feed load for the three media types were 92.2 +/- 26.3, 86.1 +/- 27.5, and 82.5 +/- 25.9 g TAN per m3 of media for the MB3, AMB, and kaldnes media, respectively. At the higher feed load the average daily TAN removal for the three media types were 186.4 +/- 53.7, 172.9 +/- 47.8, and 139.9 +/- 38.9 g TAN per m3 media for the MB3, AMB, and kaldnes media, respectively. The TAN removal rates were lower than the removal rates for moving bed biofilters in freshwater systems with similar influent TAN concentrations. The MB3 media was best suited for use in the toriod filters because of the greater TAN removal rates, lower cost, and easier control of vertical bed movement in the filter chamber. Technical Abstract: Three different commercially available structural plastic media were evaluated in triplicate in moving bed toriod filters under low salinity (11-12 ppt) warm water culture conditions and two different feed loading rates. The culture system consisted of nine separate modules that include a double drain fish culture tank paired to a moving bed toriod biofilter. The toriod filters were filled with 0.11 m3 of one of three different types of floating plastic structured media. The three types of media evaluated were K1 kaldnes media, MB3 media, and AMB media. Volumetric total ammonia nitrogen (TAN) removal rates (g TAN removed / m3 media-d) were determined for the three media types at daily feed load rates of 3.5 and 8.2 kg feed/m3 media using a 4.8 mm slow sinking marine grower diet pellet (45% protein, 17% fat). Average (+/- standard deviation, SD) volumetric TAN removal rates (VTR) at the lower feed load for the three media types were 92.2 +/- 26.3, 86.1 +/- 27.5, and 82.5 +/- 25.9 for the MB3, AMB, and kaldnes media, respectively. At the higher feed load the average VTR for the three media types were 186.4 +/- 53.7, 172.9 +/- 47.8, and 139.9 +/- 38.9 for the MB3, AMB, and kaldnes media, respectively. Influent TAN concentrations varied by the feed load rate and ranged from 0.55 to 0.93 mg/L and 0.83 to 1.87 mg/L for the low and higher feed loads, respectively. The VTR results were lower than VTRs for moving bed biofilters in freshwater systems with similar influent TAN concentrations. The MB3 media is well suited for use in the toriod filters because of the greater VTR results, lower cost, and easier control of vertical bed movement in the filter chamber. |