title: Flow pattern analysis of a full-scale expanded granular sludge bed-type reactor under different organic loading rates.
abstract: The hydraulic characteristics of a lab-scale and a full-scale (275 m(3)) expanded granular sludge bed (EGSB)-type reactor under different organic loading rates varying from 10 kg COD m(-3)d(-1) to 45 kg COD m(-3)d(-1) were investigated. A modified combined model composed of two completely mixing regions and a plug flow region was sufficient for simulating the flow pattern of a full-scale EGSB-type reactor. Moreover, the outputs fitted the measured tracer distribution results well. The simplified model structure was in very good agreement with the physical structure of a full-scale EGSB-type reactor. The upflow (liquid+gas) velocity, high concentration of granular sludge, and gas hold-up effect may contribute to the generation of dead spaces (maximum of 19.5%). The bed expansion characteristics indicated that the sludge bed of the EGSB-type reactor performed as a suspended bed, in which the bed expansion was controlled between 20% and 30%, rather than the usually considered expanded bed.
authors.affiliation: Environmental Simulation and Pollution Control State Key Joint Laboratory, School of Environment, Tsinghua University, Beijing 100084, PR China.
authors.forename: M X
authors.initials: MX
authors.lastname: Zheng
authors.forename: K J
authors.initials: KJ
authors.lastname: Wang
authors.forename: J E
authors.initials: JE
authors.lastname: Zuo
authors.forename: Z
authors.initials: Z
authors.lastname: Yan
authors.forename: H
authors.initials: H
authors.lastname: Fang
authors.forename: J W
authors.initials: JW
authors.lastname: Yu
mesh_terms: D008962:Models, Theoretical; D012722:Sewage
chemical_list: D012722:Sewage