RESUMO
Three aerobic granular sludge systems were operated as sequencing batch reactors (SBR) with acetate, ethanol and glucose as carbon source. The SBR cycle was 6â¯h, with an anaerobic phase followed by an aerobic phase. The acetate granules (>1.5â¯mm) had the greatest microbial diversity and better results in terms of removal efficiency for carbon and nutrients (TNâ¯≈â¯72% and TPâ¯≈â¯42%) and also in the resistance tests. However, partial disintegration was observed. On the other hand, when ethanol was the substrate, the granules were stable, good nitrogen removal was achieved (TNâ¯≈â¯53%), but phosphorus removal was not favored (TPâ¯≈â¯31%). Glucose presented the lowest efficiency values for nitrogen (TNâ¯≈â¯44%) and phosphorous removal (TPâ¯≈â¯21%), and the granules formed (<1â¯mm) had the lowest microbial diversity. Therefore, the carbon source had a high impact on the characteristics of the granules.