Feedforward control of nitrification by manipulating the aerobic volume in activated sludge plants

A procedure was developed to manipulate the aerobic nitrification volume by means of model based respirometry. The objective was to oxidise all ammonia nitrogen. The required aerobic volume was calculated from the influent flow rate, the influent concentration nitrifiable nitrogen and maximum ammonia oxidation rate which were obtained from respirometric batch-experiments using model calibration and state estimation techniques. Automation of the procedure resulted in the development of the RESCUE (REspirometric activated Sludge and wastewater Characterisation Unit). The procedure was tested for a pilot scale plug-flow activated sludge plant with satisfactory results. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.