Multi-scale individual-based model of microbial and bioconversion dynamics in aerobic granular sludge
Authored by Loosdrecht Mark C M van, Cristian Picioreanu, Joao B Xavier, Kreuk Merle K De
Date Published: 2007
DOI: 10.1021/es070264m
Sponsors:
Portuguese Foundation for Science and Technology (FCT)
Platforms:
No platforms listed
Model Documentation:
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Mathematical description
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Abstract
Aerobic granular sludge is a novel compact biological wastewater
treatment technology for integrated removal of COD (chemical oxygen
demand), nitrogen, and phosphate charges. We present here a multiscale
model of aerobic granular sludge sequencing batch reactors (GSBR)
describing the complex dynamics of populations and nutrient removal. The
macro scale describes bulk concentrations and effluent composition in
six solutes (oxygen, acetate, ammonium, nitrite, nitrate, and
phosphate). A finer scale, the scale of one granule (1.1 mm of
diameter), describes the two-dimensional spatial arrangement of four
bacterial groups-heterotrophs, ammonium oxidizers, nitrite oxidizers, and phosphate accumulating organisms (PAO)-using individual based
modeling (IbM) with species-specific kinetic models. The model for PAO
includes three internal storage compounds: polyhydroxyalkanoates (PHA), poly phosphate, and glycogen. Simulations of long-term reactor operation
show how the microbial population and activity depends on the operating
conditions. Short-term dynamics of solute bulk concentrations are also
generated with results comparable to experimental data from lab scale
reactors. Our results suggest that N-removal in GSBR occurs mostly via
alternating nitrification/denitrification rather than simultaneous
nitrification/denitrification, supporting an alternative strategy to
improve N-removal in this promising wastewater treatment process.
Tags
systems
Activated-sludge
Waste-water
Phosphate removal
Biofilms
Sequencing batch reactor
Shear force
Airlift reactor
Blanket reactor
N-removal