Respirometry based optimal control of an aerobic bioreactor for the industrial waste water treatment

A methodology and mathematical simulation for the time optimal control of an activated sludge sequencing batch reactor (SBR) for toxic waste water degradation is presented. An optimal strategy for the input flow was obtained using techniques of optimal control theory, such that the reaction time is as small as possible. The degradation time was controlled through the substrate concentration estimated from the liquid oxygen concentration, which is much simpler to measure. The simulation of a toxic effluent containing phenol showed that the degradation time, obtained with the optimal strategy, was a half of that obtained when the reactor is stopped at the end of the reaction period but filled without the optimal strategy. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.