stability of aerobic granular biomass treating the effluent from a seafood industry

the aerobic granular systems represent a good alternative to substitute the conventional activatedsludge process in the treatment of industrial effluents due to the lower surface requirements. in this work the effluent from a seafood industry, characterized by a high variability and the presence of residual amounts of coagulant and flocculant reagents, was used to study the development of aerobic granular biomass and its stability. in a first stage with olrs between 2 and 5 kg cods/m3.d the development of aerobic granular biomass was promoted with good physical properties: svi of 35 ml/g tss, density of 60 g vss/lgranule and average diameter of 2.8 mm. in a second stage the continuous change in the olr applied from 3 to 13 kg cods/ m3.d, to simulate the real conditions of the industry, showed that the removal of organic matter was not affected (90%) but the aerobic granules disintegrated. the maximum olr treated in the system without granules disintegration was around 4.4 kg cods/m3.d. the nitrogen removal was 30% (for biomass assimilation) and the maximum ammonia removal was around 65% and depending on the solids retention time, the free ammonia concentration and the average granule diameter.