Defluorination by Donnan Dialysis with seawater for seafood processing

Donnan Dialysis (DD) is developed in this study for continuous removal of fluoride from Antarctic krill by using seawater or concentrated seawater as the receiving solution. Results show that RO concentrate (1.0 mol L−1 NaCl) got the highest fluoride removal efficiency (93.66% ± 0.81%) with three stages at 0.01  cm s−1 flow velocity. Afterwards, fluoride removal experiment with a real krill solution showed 89.34% ± 0.55% under the optimized conditions. The product has fulfilled the fluoride content of US FDA standard and Canadian Food Inspection Agency in fish and fish products. Results also showed a lower loss of amino acids and proteins in comparison of conventional methods. Finally, a techno-economic evaluation showed that 4.0 USD per ton of Krill solution can be expected by this DD process. This study proves that Donnan Dialysis may be a sustainable defluorination process in removing high fluoride content of seafood by seawater or concentrated seawater.