Generic distributed parameter model control of a biological nutrient removal (BNR) activated sludge process

This paper addresses nonlinear control of a class of distributed parameter systems by the generic distributed parameter model-based control (GDPMC) strategy. Case studies on a complex biological nutrient removal (BNR) activated sludge process for nitrogen and phosphorus removal show that the GDPMC strategy is applicable for controlling species of interest in specific bioreaction zones. The designs give much improved performances compared to well-tuned PI controllers in terms of the integral time absolute errors (ITAE). In a study on control of the entire BNR activated sludge plant, a multi-unit decentralised GDPMC strategy is shown to be robust to 25% plant-model mismatch in three sensitive and uncertain kinetic parameters. The advantages of the GDPMC strategy over lumped-model generic model control (GMC) are demonstrated in a comparative study on soluble phosphate control within the anaerobic zone of the plant. (C) 1999 Elsevier Science Ltd. All rights reserved.