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

Geosmin depuration from fish

“…Detection of geosmin in the air vented from a trickling filter confirmed removal by air-stripping (Podduturi et al, 2020). Geosmin adsorbed to suspended sludge (Guttman and van Rijn, 2009) or present in intact cells of suspended pieces of biofilm may be removed from the system by particle filtration (e.g.…”

“…Growth dilution affects geosmin levels in fish but not the absolute amount present. Fish tanks have been found to act as net geosmin producers, although outflowing water had only slightly higher geosmin concentrations than the inflowing water (Podduturi et al, 2020).…”

“…Research into geosmin dynamics in RAS is limited to a few studies (e.g. Lukassen et al, 2019;Podduturi et al, 2020) and consequently our understanding is limited. Within a RAS different compartments can be distinguished that may act as geosmin sources, reservoirs or sinks, depending on the processes taking place in each compartment.…”

“…Houle et al, 2010). Biofilms seem to act as temporary reservoir because geosmin levels do not differ in the in-and outflowing water of biofilters until they are manipulated (Podduturi et al, 2020). Apparently cells first need to disintegrate before geosmin is released to the water (Jüttner and Watson, 2007).…”

“…Geosmin adsorbed to suspended sludge (Guttman and van Rijn, 2009) or present in intact cells of suspended pieces of biofilm may be removed from the system by particle filtration (e.g. drum filters) (Podduturi et al, 2020). The water in the system acts as reservoir but certainly also as medium by which geosmin is exchanged between the different compartments.…”