Characteristics of Aerobic Granular Sludge Cultivated by Promoting and Inhibiting Filamentous Bacteria

Using conventional flocculent activated sludge as seeding sludge, two types of mature aerobic granular sludge were respectively cultivated in the same two sequencing batch reactors (SBR) by promoting and inhibiting filamentous bacteria growth. In R1 reactor the mature aerobic granular sludge was cultivated by promoting filamentous bacteria growth, and the whole cultivation process lasted for 15d. At the same time, another kind of mature aerobic granular sludge was cultivated in R2 reactor by restraining filamentous bacteria growth, and the whole cultivation process lasted for 120d. The comparative analysis showed that the sludge granules produced in R1 reactor had a settling velocity of 45 m/h, SVI (sludge volume index) of 35~45 mL/g, SOUR (sludge oxygen consumption rate) of 1.35 mg/(g•min) and main diameter distribution ranged 2~4 mm; while the sludge granules cultivated in R2 reactor had a settling velocity of 61 m/h, SVI of about 30 mL/g, SOUR of 1.21 mg/(g•min) and main diameter distribution ranged 1~1.6 mm.