Land based aquaculture is rapidly expanding, and Norway is a leading developer of recirculation aquaculture systems (RAS) with companies like Nofitech that produces module-based RAS. The water effluent from RAS is minimized, but rich in minerals such as nitrogen, and may lead to unwanted growth of algae or weeds if released to a recipient. Water treatment and N removal represents a cost and it is relevant to consider re-use of the N-rich effluent in production of new biomass which can be used e.g. in feed production. In WASTELESS we will perform water treatment using a novel cultivation concept where biomass is growing on a bioreactor. The biomass consortium will consist of different microorganisms such as microalgae, cyanobacteria and ciliates, and they will work together in a balanced system. Using monitoring and process control, it is possible to harvest almost all the N before the water is released or returned to the RAS. The produced biomass is rich in proteins, carbohydrates, essential oils and other valuable ingredients, which can be used in feed and substitute other non-sustainable ingredients such as soy and fish meal.
