Two-stage digestion upgrade
Problem
A major expansion at the London (Ohio) Wastewater Treatment Plant would raise the design capacity to 5.8 mgd and include a biosolids processing facility to replace conventional digesters. The city wanted a system that improved reliability and ran automatically.
Solution
Design engineer CH2M HILL selected the two-phase Class A system with ATP/ESD process from CB&I to handle 34,000 gpd in 10 to 12 batches. The reactor in the anoxic thermophilic process (ATP) acidifies the feed materials and maintains 149 degrees F for one hour to reduce pathogens.
Thickened primary and waste activated sludge are blended, then heated with a hot water
