Optimizing granules size distribution for aerobic granular sludge stability: Effect of a novel funnel-shaped internals on hydraulic shear stress.
A novel funnel-shaped internals was proposed to enhance the stability and pollutant removal performance of an aerobic granular process by optimizing granule size distribution. Results showed up to 68.3±1.4% of granules in novel reactor (R1) were situated in optimal size range (700-1900μm) compared to less than 29.7±1.1% in conventional reactor (R2), and overgrowth of large granules was effectively suppressed without requiring additional energy. Consequently, higher total nitrogen (TN) removal (81.6±2.1%) achieved in R1 than in R2 (48.1±2.7%). Hydraulic analysis revealed the existence of selectively assigning hydraulic pressure in R1. The total shear rate (τtotal) on large granules was 3.07±0.14 times higher than that of R2, while τtotal of small granules in R1 was 70.7±4.6% in R2. Furthermore, large granules in R1 with intact extracellular polymeric substances (EPS) outer layer structure entrapped hydroxyapatite at center, which formed a core structure and further enhanced the stability of aerobic granules.
Department of Environmental Engineering, Zhejiang University, Hangzhou 310058, China; College of Civil Engineering and Architecture, Zhejiang University of Technology, Hangzhou 310014, China.
Jia-Heng
JH
Zhou
Department of Environmental Engineering, Zhejiang University, Hangzhou 310058, China.
Zhi-Ming
ZM
Zhang
Department of Environmental Engineering, Zhejiang University, Hangzhou 310058, China.
Hang
H
Zhao
Department of Environmental Engineering, Zhejiang University, Hangzhou 310058, China.
Hai-Tian
HT
Yu
Department of Civil and Environmental Engineering, Rice University, Houston, TX 77005, USA.
Pedro J J
PJ
Alvarez
Department of Environmental Engineering, Zhejiang University, Hangzhou 310058, China; Zhejiang Province Key Laboratory for Water Pollution Control and Environmental Safety, Hangzhou 310058, China.
Xiang-Yang
XY
Xu
Department of Environmental Engineering, Zhejiang University, Hangzhou 310058, China. Electronic address: lilithzhuliang@163.com.
Liang
L
Zhu
D000332:Aerobiosis; D019149:Bioreactors; D017886:Durapatite / Q000737:chemistry; D009584:Nitrogen / Q000302:isolation & purification / Q000378:metabolism; D010316:Particle Size; D011312:Pressure; D012722:Sewage / Q000737:chemistry; D013314:Stress, Mechanical; D014865:Waste Disposal, Fluid / Q000295:instrumentation* / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000302:isolation & purification
D012722:Sewage; D014874:Water Pollutants, Chemical; D017886:Durapatite; D009584:Nitrogen
Aerobic granular sludge; Funnel-shaped internals; Granules size optimization; Hydraulic shear stress; Inorganic inner core