Comparison of the dynamics, biokinetics and microbial diversity between activated sludge flocs and aerobic granular sludge.

This work aimed to compare the dynamics, biokinetics, and microbial diversity between activated sludge flocs (ASF) and aerobic granular sludge (AGS) whose systems were operated under similar experimental conditions in terms of inoculum, feeding, substrate source, etc. Therefore, the kinetic parameters involved in the organic matter removal, nitrification, denitrification, and dephosphatation were determined, as well as the microbial changes were assessed by metagenomics analysis. Regarding the kinetic parameter yield coefficient (Y), values of 0.55 and 0.36 g VSS/g COD were found for ASF and AGS, respectively, showing a higher sludge production in ASF and the importance of feast/famine periods for lowering sludge production in AGS systems. AGS presented a lower sludge production and a higher endogenous consumption rate than ASF. The activity of phosphorus-accumulating bacteria was remarkably higher in AGS. Although both biomasses were aerobic, their kinetic parameters had significant differences.