Anoxic phosphate uptake in the DEPHANOX process

The innovative nutrient removal process scheme DEPHANOX proved to be very efficient because it maximises the utilisation of organic substrate for phosphorus and nitrogen removal. The process solves the competition for organic substrates among Poly-P organisms and denitrifiers as well as the problem of overgrowing of slow nitrifiers by faster organotrophs, typical of activated sludge. In experiments, DEPHANOX showed better P removal efficiency than a JHB configuration, working with a very low influent COD/TKN ratio. This paper reports the results of a simulation study that has been carried out to better understand the behaviour of the two configurations with a wide variety of influent wastewater characteristics and under dynamic conditions. The results of the simulation confirmed the high P removal capacity of the DEPHANOX configuration with low influent COD/TKN ratios. (C) 1999 IAWQ Published by Elsevier Science Ltd. All rights reserved.