The Influence of Operating Experience on Wastewater Treatment Plant Design in San Francisco, California, USA

Three main areas will be covered regarding the design and operation of a pure oxygen activated sludge plant. 1. Air entrainment occurred in RAS and influent lines and gas entrainment occurred at the sixth stage effluent weirs in an enclosed pure oxygen aeration basin. This caused the oxygen feed to be shut off due to overpressurization and resulted in a combination of high apparent O2 usage and high vent gas purities. 2. The use of an anaerobic selector for Nocardia control is discussed. Anaerobic digester operation has been adversely affected by Nocardia-dominated waste activated sludge. 3. The effect of thick anaerobic digester foams on the ability to pump digested sludge is discussed.