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Hydrodynamics and mass transfer coefficient in activated sludge aerated stirred column reactor: experimental analysis and modeling
Author(s) -
Jin Bo,
Lant Paul,
Ge Xiangyu
Publication year - 2005
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/bit.20516
Subject(s) - aeration , activated sludge , mass transfer , mass transfer coefficient , chemistry , continuous stirred tank reactor , chromatography , bioreactor , environmental science , environmental engineering , wastewater , organic chemistry
The aerated stirred reactor (ASR) has been widely used in biochemical and wastewater treatment processes. The information describing how the activated sludge properties and operation conditions affect the hydrodynamics and mass transfer coefficient is missing in the literature. The aim of this study was to investigate the influence of flow regime, superficial gas velocity ( U G ), power consumption unit ( P / V L ), sludge loading, and apparent viscosity (μ ap ) of activated sludge fluid on the mixing time ( t m ), gas hold‐up (ε), and volumetric mass transfer coefficient ( k L a ) in an activated sludge aerated stirred column reactor (ASCR). The activated sludge fluid performed a non‐Newtonian rheological behavior. The sludge loading significantly affected the fluid hydrodynamics and mass transfer. With an increase in the U G and P / V L , the ε and k L a increased, and the t m , decreased. The ε, k L a , and t m , were influenced dramatically as the flow regime changed from homogeneous to heterogeneous patterns. The proposed mathematical models predicted the experimental results well under experimental conditions, indicating that the U G , P / V L , and μ ap had significant impact on the t m , ε, and k L a . These models were able to give the t m , ε, and k L a values with an error around ±8%, and always less than ±10%. © 2005 Wiley Periodicals, Inc.