Abstract

The simultaneous removal of carbon and nitrogen from saline salmon plant effluents in fixed biofilm tubular reactors were studied. Two organic load rates were used: 1.49 kg COD/m3 d (situation 1) and 11.46 kg COD/m 3 d (situation 2) for 2800 and 5000 mg COD/L respectively, using C/N ratios of 18, 39, 80 and 142 mg COD/mg N-N03. The nitrate abatement was 98% in both cases while up to 88% removal for condition 1 and less than 50% removal for condition 2 were achieved. Ammonia was mainly produced by the anaerobic digestion and not by nitrate reduction to ammonia. It is concluded that it is technically possible to remove nitrates form saline salmon plant effluents observing that as the organic load rates decreases the removal efficiency increases.