The Effect of Setting Time to the Formation of Aerobic Granular Sludge in SBAR under Low Organic Loading

Abstract

The setting time was regarded as the selection pressure to make the particles which were unable to get acclimatized to that cultivation circumstance so as to get the aerobic granular sludge which own excellent setting ability with screening and beneficiation. The internal-circulate sequencing batch airlift reactor (SBAR) process was adopted in this experiment to investigate the effect of setting time to the formation of aerobic granular sludge in SBAR under low organic loading. The results showed that aerobic granular sludge with an average particle diameter of 4.0 mm had a good settling ability with spherical or ellipsoidal, smooth and dense on surface, furthermore, the removal rates of NH3-N,TP and CODCr were 96%, 94% and 90% ,respectively. The setting time can be treated as the dominant element for the control of formation and characteristics of aerobic granular sludge to a certain degree in its forming process.