Biological excess phosphorus removal in activated sludge systems

Includes bibliographies.When this investigation was commenced in 1983 two activated sludge systems had been developed in South Africa that accomplish biological excess phosphorus (P) removal, the UCT and modified Bardenpho systems. To predict the P removal in these systems, an empirical model had been developed. In the empirical model, P removal was formulated in terms of some of the system parameters, such as anaerobic mass fraction, available readily biodegradable COD and active mass concentration. Organisms directly implicated in biological excess P removal (poly P organisms) did not feature in the model and the P removal was not linked to any basic biological or biochemical behaviour. Clearly, there was a need for a more fundamentally based model. The objective of this thesis was to develop such a model