Free and immobilized cultures of Spirulina maxima for swine waste treatment

We have analyzed the behavior of Spirulina maxima at increasing concentration of ammonium nitrogen present in swine waste when it is either growing in suspension or immobilized in polymeric supports. We compared the response of Spirulina maxima growth to different concentrations of aeration stabilized swine waste (total phosphorus, ammonium nitrogen) as a way to determine the treatment efficiency of both systems. At a dilution of 50% of swine waste, the suspended system reached the best results for biomass concentration and nutrient removal. In the immobilized system at dilutions of 25 and 50% of swine waste, more than 90% ammonium nitrogen removal was obtained, and the optimal cell concentration for immobilization was 2 g/l (wet basis).