Evaluation of aerobic granular sludge SBR performances

Aerobic granular sludge has several advantages over conventional activated sludge flocs such as fast settling ability, high biomass retention and ability to withstand high organic loading including potential toxic substrates, leading towards a compact reactor system – aerobic granular sludge sequential batch reactor (AGSBR). Aerobic granules have been successfully cultivated, previously, in SBR systems from flocculated
activated sludge fed with synthetic medium with acetate as the sole carbon source or with real municipal wastewater. The main objective of this study was to investigate the possibility of an aerobic granular system to simultaneously remove the organic loading, nitrogen and phosphorus content. The experiments
were performed in a SBR reactor with a hydraulic reaction time of 12 hours at loading rates of up
to 3.0 kg m-3 day-1 COD and 0,2 kg m-3day-1 of N-NH4+. Compact granules with good settling
ability were maintained during the experimental period and high COD removal but ordinary global
nitrogen and phosphorus removal efficiency were registered. Aerobic granules possess high activity, compact structure and good settling ability, and have the potential to simultaneously treat wastewater with high organic and ammonium loading in sequential system at relatively low hydraulic retention times.