The main objective of this research is to develop mainstream biological nutrient removal processes that balance flocculent and granular growth to intensify existing activated sludge systems. Pilot granular reactors will be tested to understand how substrate surface loading and diffusion resistance affects both granule and floc formation and performance. The influence of substrate loading will be investigated in terms of the type of concentration of substrate fractions (i.e., readily biodegradable, slowly biodegradable, and particulate). The possible synergy of maintaining a mixed floc and granule system to allow for high removal rates and good effluent quality will be explored. Unless granular sludge can be implemented in existing configurations such as plug flow reactors, which are common in North America, the many benefits of intensifying nutrient removal and treatment capacity will remain unrealized or require a significant shift in the manner in which infrastructure is managed.
Originally funded as WERF project U1R14.