Abstract

Synthetic wastewater with glucose as carbon source was used for cultivation of aerobic granules in sequencing batch airlift reactor (SBAR). Grinded shell powder with diatmeter of 150-200 um used as carrier. SBAR was run at hydraulic retention time (HRT) 5.1 hours, airflow of 4 liters/m and airlift velocity of 4.2 cm/s. The experiment was run at two organic loading rates (OLRs). They were 2.6 and 5.2 kg COD/m°.day, corresponding to influent COD and N-ammonia of 600; 1200 mg/l and 26; 60 mg/l, respectively. After 61 days of running, aerobic granules with size of 1,0-1,2 mm are formed. The size of granules increased to 5 mm at 80th day. Aerobic granules had settling velocity of 36-56 m/h, SVI of 11,4-44.2 ml/g. COD and N-ammonia removal of SBAR were greater than 96% and 75-90%, respectively. It was found that nitrification and denitrification occurred simultaneously in granules.' The COD and N-animonia of SBAR decreased to 70% and 51%, respectively when filamentous sludge bulking and viscous bulking appeared simultaneously.