February 15-18, 2009 Washington State Convention Center Seattle ...

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ORGANIC CARBON AND NITROGEN REMOVAL FROM GARFISH AQUACULTURE
USING SEQUENTIAL BATCH REACTOR - A LABORATORY SCALE STUDY
Dhritikshama Roy* and Raj Boopathy
Department of Biology
Nicholls State University
Thibodaux, LA 70310 USA
Royd425@its.nicholls.edu
Garfish is a fresh water fish that can tolerate moderate range of salinity. Research is underway at Nicholls State University to
grow garfish under various salinity levels because of the availability of saline water. Aquaculture of garfish is in experimental
stage in Louisiana. The experimental aquaculture system involves feeding garfish with 40% protein diet. This higher protein
diet resulted in the accumulation of high concentration of dissolved organic carbon (~ 6500mg/L), ammonia-N (~ 600 mg/L),
nitrite-N (~ 400 mg/L)) and nitrate (~650 mg/L)) in garfish aquaculture system.
The objective of this study was to treat the garfish aquaculture waste water using Sequential Batch Reactor (SBR). Sequential
batch reactor (SBR) is an activated sludge treatment with a combination of variable period of aerobic and anaerobic modes.
The experiment used garfish waste water of three different concentrations of salt – 4.0 ppt, 8.0 ppt and 12.0 ppt. Garfish waste
without salt served as control. Performance of SBR showed significant removal of dissolved organic carbon and total nitrogen
within 15 days with 11 days of aerobic condition followed by 2 days of anaerobic and 2 days of aerobic modes for various
salinity garfish waste water. The removal rate was concentration dependent. The quantitative effect of heterotrophic bacteria in
garfish aquaculture was also noticeable during waste removal process through SBR.