Cedomir Stevcic

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Project title: "The use of biological traps for water treatment in recirculating aquaculture systems"
Recirculating aquaculture systems (RAS) enable fish production in relative isolation from the surrounding environment, and they offer advantages such as reduced water consumption, improved opportunities for waste management and nutrient recycling. RAS production is growing worldwide and also in Finland, thus the potential for re-using valuable nutrients in RAS wastewater should be investigated to improve the ecological sustainability in aquaculture.
Algae are predicted to play an important role in tomorrow’s bio-economy. Furthermore, algae have a great potential to be used in aquaculture either as feed additive or as bio-filter (they remove ammonia, nitrate and CO2 and incorporate into their biomass). Recent algal research has concentrated on energy production (biofuels) or in treatment of municipal waste water, but there is practically no information on the possibilities to use microalgae to treat RAS effluents.
In this project, the possibility of using microalgae in reducing the nutrients of aquaculture wastewater will be investigated. The objectives are to evaluate (1) the effectiveness of microalgae to remove dissolved nutrients from the RAS’s wastewater; (2) the effects of environmental conditions on the algal biomass production; (3) the potential of Daphnia magna & lake mussel Anodonta anatina to filter the algae from the water. This project will produce new knowledge on nutrient recycling and thus supports the concept of circular economy.
Research hypothesis: By the combination of microalgae and filter feeder cultivation in RAS effluent the nutrient release into the environment can be significantly reduced.
The experiments will be carried out in laboratory scale. The most important environmental variables to be tested are temperature, light (wavelength and intensity), conductivity, dissolved oxygene and pH. The wastewater will be taken from the recirculation system of the department, but we may also test wastewater from a commercial farm. We will measure nutrient uptake of the algae especially for N and P. The relationship between algal growth and nutritional quality and the efficiency of filter feeders can be assessed by quantifying the algae concentration in the water with a spectrophotometer under different environmental conditions.

Fields of science

Personal keywords

filter-feeders, Recirculating aquaculture systems (RAS), nutrient uptake, microalgae

Keywords (YSO)


Last updated on 2021-25-03 at 10:34