title: Optimization of hydraulic shear parameters and reactor configuration in the aerobic granular sludge process.
abstract: The hydraulic shear acts as an important selection pressure in aerobic sludge granulation. The effects of the hydraulic shear rate and reactor configuration on structural characteristics of aerobic granule in view of the hydromechanics. The hydraulic shear analysis was proposed to overcome the limitation of using superficial gas velocity (SGV) to express the hydraulic shear stress. Results showed that the stronger hydraulic shear stress with SGV above 2.4 cm s(-1) promoted the microbial aggregation, and favoured the structural stability of the granular sludge. According to the hydraulic shear analysis, the total shear rate reached (0.56-2.31)×10(5) s(-1) in the granular reactor with a larger ratio of height to diameter (H/D), and was higher than that in the reactor with smaller H/D, where the sequencing airlift bioreactor with smaller H/D had a high total shear rate under the same SGV. Results demonstrated that the granular reactor could provide a stronger hydraulic shear stress which promotes the formation and structural stability of aerobic granules.
authors.affiliation: a Department of Environmental Engineering , Zhejiang University , Hangzhou 310058 , People's Republic of China.
authors.forename: Liang
authors.initials: L
authors.lastname: Zhu
authors.forename: Jiaheng
authors.initials: J
authors.lastname: Zhou
authors.forename: Haitian
authors.initials: H
authors.lastname: Yu
authors.forename: Xiangyang
authors.initials: X
authors.lastname: Xu
mesh_terms: D000814:Aniline Compounds / Q000302:isolation & purification / Q000378:metabolism; D001420:Bacteria, Aerobic / Q000502:physiology*; D019149:Bioreactors / Q000382:microbiology*; D003198:Computer Simulation; D008954:Models, Biological; D011312:Pressure; D012212:Rheology / Q000379:methods*; D012722:Sewage / Q000382:microbiology*; D033081:Shear Strength; D013314:Stress, Mechanical; D014874:Water Pollutants, Chemical / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D000814:Aniline Compounds; D012722:Sewage; D014874:Water Pollutants, Chemical; C004658:4-chloroaniline
keywords: aerobic granule; bioreactor; hydraulic shear parameters; hydromechanics; optimization