Interaction between phosphorus removal and hybrid granular sludge formation under low hydraulic selection pressure at alternating anaerobic/aerobic conditions.
The hybrid granular sludge (HGS) formation and its performances on phosphorus removal were investigated in a sequencing batch airlift reactor. Under conditions of low superficial air velocity (SAV = 0.68 cm s(-1)) and relatively long settling time (15-30 min), aerobic granules appeared and coexisted with bio-flocs after 120 days operation. At the stable phase, 54% of total suspended solid (m/m) was granular sludge with the two typical sizes (D(mean) = 1.77 ± 0.33 and 0.89 ± 0.11 mm) in the reactor, where the settling velocity was 98.7 ± 12.4 and 37.8 ± 0.9 m h(-1) for the big and small granules. With progressive extension of anaerobic time from 15 to 60 min before aerobic condition per cycle during the whole experiment, the HGS system can be maintained at a high total phosphorus removal efficiency (ca. 99%) since Day-270. The phosphorus content (wt %) in biomass was respectively 9.54 ± 0.29, 7.60 ± 0.48 and 6.15 ± 0.59 for the big granules, small granules and flocs.
a School of Chemical Engineering and Energy , Zhengzhou University , 100, Science Avenue, Zhengzhou 450001 , People's Republic of China.|c INSA, UPS, INP, LISBP, Université de Toulouse , 135 Avenue de Rangueil, Toulouse F-31077 , France.
Longqi
L
Lang
a School of Chemical Engineering and Energy , Zhengzhou University , 100, Science Avenue, Zhengzhou 450001 , People's Republic of China.
Junfeng
J
Wan
b Institute of Environmental Planning and Management, College of Environmental Science and Engineering, Tongji University , Siping Rd. 1239, Shanghai 200092 , People's Republic of China.
Jing
J
Zhang
a School of Chemical Engineering and Energy , Zhengzhou University , 100, Science Avenue, Zhengzhou 450001 , People's Republic of China.
Jie
J
Wang
a School of Chemical Engineering and Energy , Zhengzhou University , 100, Science Avenue, Zhengzhou 450001 , People's Republic of China.
Yan
Y
Wang
D000332:Aerobiosis; D000693:Anaerobiosis; D018533:Biomass; D019149:Bioreactors; D010758:Phosphorus / Q000737:chemistry* / Q000302:isolation & purification*; D011312:Pressure; D012722:Sewage / Q000737:chemistry*; D018508:Water Purification / Q000379:methods
D012722:Sewage; D010758:Phosphorus
EBPR; hybrid granular sludge; hydraulic selection pressure; nutrients' removal; phosphorus