Quantitative Description of the Sludge Granulation Process
The granulation process of activated sludge, taking the sludge in two sequencing batch reactors (SBRs) respectively fed with soybean-processing and fatty-acids-rich wastewaters as an example, is quantitatively described. Based on a mixed-culture biofilm model and a simultaneous storage and growth model, a new model incorporating microbial growth, oxygen transfer, substrate diffusion, increased granule size, and biomass detachment is formulated to describe the granulation process of activated sludge. Parameter estimation results of no evident cross-correlation and low 95 % confidence intervals indicate a good identification of the obtained parameter values. The model evaluation results of three different case studies demonstrate that the developed model is applicable to describing the aerobic sludge granulation process appropriately. With this model, the aerobic granulation process in terms of mean radius profiles could be quantitatively characterized.
KeywordsChemical Oxygen Demand Oxygen Uptake Rate Granular Sludge Granule Size Aerobic Granule
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