Study on the aerobic granulation and properties of aerobic granules

The granulation process of aerobic granular sludge was studied in a sequencing batch reactor (SBR) with experiment method, using the floccules activated sludge as seeding sludge. Meanwhile, the properties of the aerobic granules and the removal of COD with the growth of the granules were also investigated. Through 140 days continuous operation, aerobic granular sludge was successfully cultivated in the reactor. The aerobic granules, oval and black, were structure close-grained with the particle size approximately 2-3mm. The SVI of sludge was about 40 ml/g, and the settle ability was 10cm/s. Feeding with the influent COD about 1000mg/L, the effluent COD was only maintained lower than 100 mg/L with the removal ratio more than 90%.