Quantitative simulation of the granulation process of activated sludge for wastewater treatment

Abstract

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 simulated in this work. On the basis of 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. © 2010 American Chemical Society.