Treatment of sludge produced in a recirculating aquaculture system: test of different flocculants to improve the sedimentation of suspended solids

Sludge management is a challenge in aquaculture as its release into the environment has an impact on natural ecosystems. The present research, carried out within the SEA2LAND project, focuses on developing methods to treat sludge produced in Recirculating Aquaculture Systems (RAS), in order to recover the solid fraction, and re-send the clean water to the fish tanks. Flocculation, is a common method to increase the size of the suspended solid and promote their precipitation. The aim of this study is to identify the most efficient flocculants for the treatment of sludge produced in RAS where Atlantic salmon (Salmo salar) and European seabass (Dicentrarchus labrax) are farmed.