Phosphorus removal in the modified activated sludge process

The principal objective of this investigation was to enquire in what measure calcium phosphate precipitation and luxury biological uptake contributes to excess removal of phosphorus in activated sludge systems, i.e. removal in excess of the basic biological requirement for metabolic purposes. This objective was pursued by imposing conditions in which one or the other of the two mechanisms had negligible influence. From the series of batch and continuous activated sludge experiments the following conclusions are made regarding excess phosphorus removal