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Application of Computational Fluid Dynamics to Closed‐Loop Bioreactors: II. Simulation of Biological Phosphorus Removal Using Computational Fluid Dynamics
Author(s) -
Littleton Helen X.,
Daigger Glen T.,
Strom Peter F.
Publication year - 2007
Publication title -
water environment research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.356
H-Index - 73
eISSN - 1554-7531
pISSN - 1061-4303
DOI - 10.2175/106143006x136748
Subject(s) - heterotroph , chemostat , bioreactor , computational fluid dynamics , activated sludge model , activated sludge , phosphorus , chemistry , environmental science , environmental engineering , sewage treatment , biology , mechanics , bacteria , physics , genetics , organic chemistry
Based on the International Water Association's (London) Activated Sludge Model No. 2 (ASM2), biochemistry rate expressions for general heterotrophs and phosphorus‐accumulating organisms (PAOs) were introduced to a previously developed, three‐dimensional computational fluid dynamics (CFD) activated sludge model that characterized the mixing pattern within the outer channel of a full‐scale, closed‐loop bioreactor. Using acetate as the sole carbon and energy source, CFD simulations for general heterotrophs or PAOs individually agreed well with those of ASM2 for a chemostat with the same operating conditions. Competition between and selection of heterotrophs and PAOs was verified using conventional completely mixed and tanks‐in‐series models. Then, competition was studied in the CFD model. These results demonstrated that PAOs and heterotrophs can theoretically coexist in a single bioreactor when the oxygen input is appropriate to allow sufficient low‐dissolved‐oxygen zones to develop.