Chapter 4: Activated Sludge Modelling - IqTMA-UVa

Processes for BiologicalPhosphorous Removal2- Anaerobic Contact Time: periods of 0.25 to 1 h are sufficient forrbCOD fermentation. Too long contact times (> 3 h) result in secondaryP release not associated to PHB accumulation3- SRT. Long SRT bring about lower P-REs due to:a)- at high SRT less PAO biomass is producedb)- at high SRT PAOs are in a more extended endogenousphase, consuming their intracellular storage products.4- Waste sludge Processing. The use of gravity thickeners for sludgeconcentration might result in a significant release of P that is recycled tothe process.5- Chemical precipitation might be needed when insufficient amounts ofrbCOD are present in the influent wastewater.58