ADAPTIVE-CONTROL OF EXTERNAL CARBON FLOW-RATE IN AN ACTIVATED-SLUDGE PROCESS

In this study an adaptive carbon flow rate controller is applied to a pre-denitrifying pilot-scale plant. The goal of the control strategy i s to maintain a low nitrate concentration in the anoxic zone by contro lling the external flow rate of the carbon source. Results from practi cal experiments show that the control strategy works well and the nitr ate Concentration could be kept close to a desired set-point (referenc e value). The used nitrate sensor needed, however, frequent maintenanc e. During the experiment the carbon flow rate was automatically varied to keep the nitrate concentration at a constant low level. We conclud e that a low effluent nitrate concentration without an excessive carbo n flow rate is hard to achieve without an automatic control strategy. Copyright (C) 1996 IAWQ. Published by Elsevier Science Ltd.