Dynamic Process Response to Sludge Thickening Behavious in the Anareobic Sequencing Batch Reactor Treating High-Solids-Content Waste

摘要

Solid-liquid separation and its type greatly affected the stability and performance of the anaerobic sequencing batch reactor (ASBR) for municipal sludge digestion. Flotation thickening occurred in mesophilic ASBR, while solid-liquid separation in thermophilic ASBR followed a gravity thickening. The hydraulic retention time (HRI) and cycle period as well as type of thickening were key parameters governing sludge thickenability and critical solids accumulation. Thickened sludge volume was a critical operating variable in the ASBR with the gravity thickening, which had a poor performance because of the loss of thickened solids, and sludge interface disruption or instability of sludge bed due to internal gas evolution. A cyclic mutual effect between thickened volume an gas production was a serious in the gravity thickening, whereas it was insignificant in the flotation thickening.