Multiphase Flow Behavior of Anaerobic Granular Sludge Reactors

In biological wastewater treatment, microorganisms remove organic pollutants. Anaerobic granular sludge technology is widely applied to treat wastewaters that are highly polluted with organic matters. In these reactors, microorganisms grow into compact clusters called anaerobic granular sludge. They break down organics and produce biogas, which can be used as energy source.
Reactor performance depends on the formation and retention of dense, strong, and biologically active granular sludge. One influential factor affecting granule development and retention is hydrodynamics: how wastewater, granules, and biogas bubbles move within the reactor. Yet studying reactor hydrodynamics is difficult because of high concentrations of granular sludge and limitations in fluid velocity measurement methods.
To address this challenge, this thesis used imaging-based velocity measurement tools to develop methods for quantifying (waste)water flow. It investigated how hydrodynamic conditions affect granule properties and what these changes may mean for treatment performance. The results can guide the operation of anaerobic granular sludge reactors and improve their efficiency.