Aquaculture

Geosmin fluctuations and potential hotspots for elevated levels in recirculated aquaculture system (RAS): A case study from pikeperch (Stizostedion lucioperca) production in Denmark

Publication date: 1 January 2020

Source: Aquaculture, Volume 514

Author(s): Raju Podduturi, Mikael Agerlin Petersen, Martin Vestergaard, Niels O.G. Jørgensen

Abstract

Effect of water treatment on concentrations of the off-flavor geosmin was examined in a RAS facility for commercial production of pikeperch (Stizostedion lucioperca). Short-term (minutes) and long-term (days) variations in concentrations of geosmin were measured in grow-out tanks, at inlet and outlet of biofilters and at the denitrification unit. Geosmin in water of the grow-out tanks ranged typically from <10 to about 20 ng/L. Only a minor increase in geosmin (1–3 ng/L) was observed during recirculation of water through the tanks. Water passage through the biofilters did typically not affect the geosmin concentration, while the denitrification unit caused a 3.5–5-fold increase in the geosmin content. Cleaning caused a temporary outburst of geosmin up to 100–200 ng/L (in biofilters) and 210 ng/L (in denitrification unit). The geosmin level stabilized at the initial level after about 30 min passage of system (grow-out tanks) water. The study of the pikeperch RAS shows that management practices with respect to water treatment, especially when using denitrification, should be considered to maintain a low geosmin concentration. For biofilters, increased cleaning of the filter-bed carriers might also help reduce the observed geosmin outburst.

Glossaire technique

Elevage commercial d'animaux marins ou d'eau douce et de plantes...
Première phase de l'élimination biologique de l'azote, réalisée notamment...
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