Primary Sludge Fermenters
Sludge from the primary clarifiers is pumped to the fermenters, large enclosed tanks with a rotating stirring mechanism. Sludge is fermented to produce the volatile fatty acids (VFAs) needed in the BNR bioreactors for the removal of phosphorus. The VFA-rich remaining liquid from the fermenter is pumped to the BNR bioreactor. The residual sludge after fermentation, along with the scum formed on the top of the fermenter, is pumped to the sludge digesters for digestion. Foul air formed in the headspace of the fermenters is extracted through a blower and bubbled up through the bioreactors to scrub out odours.