Dissertation: Oxidants alleviated off-flavour problems in recirculating aquaculture, but did not yet provide a solution
What did you study?
I studied how off-flavour compounds occurring in recirculating aquaculture systems could be removed from the water using oxidizing compounds before they accumulate to fish flesh. The studies were conducted in two separate phases at the Natural Resources Institute Finland’s (Luke) Laukaa fish farming facility, in a research-scale recirculating aquaculture system, using different doses of ozone and hydrogen peroxide.
What were the results of your research, or what was the main finding?
Based on the results, we found that ozone alone was an ineffective option for removing off-flavour compounds. In contrast, hydrogen peroxide and a combination of hydrogen peroxide and ozone produced positive results when used as part-time, intensive treatments. We also gained valuable information about the origins of off-flavour compounds in recirculating water. For example, hexanal clearly enters the systems through lake water, whereas geosmin most likely originates within the system water through microbial activity.
How can the results be applied? What new information did the research provide?
Based on our results, the techniques used to remove off-flavour compounds from recirculating water can be further developed. There is still much we do not know about the origin, behaviour, and removal of these compounds, so all new information on the subject is valuable. In the future, I would focus particularly on different advanced oxidation processes, such as the combination of ozone and hydrogen peroxide used in our study. Based on its properties and effects, this approach appears to be the most promising option.
MSc Samu Pettersson’s doctoral dissertation will be examined on Friday, 2.10.2026 at 12:00 in auditoria YAA 303 of the Ambiotica building at the University of Jyväskylä.
Opponent: Professor Emeritus Niels O. G. Jorgenssen (University of Copenhagen)
Custos: Professor Lotta-Riina Sundberg (University of Jyväskylä)
Language of the defence: English
Contact: samu.j.pettersson@jyu.fi
