Adaptive controller considerations for an activated sludge process within a waste water treatment plant

The activated sludge process is a biological process used for secondary treatment of sewage and is probably the most widely used method in the waste water industry. However there are still a number of problems that are required to be solved and these may be broadly categorised in terms of external disturbances and internal complexities, the effects of which are both exacerbated due to the nonlinear behaviour of the process. To overcome the problem in the presence of inherent plant nonlinearities requires adjustment/adaptation of controller gains. The problem which has been identified in this work is that of minimising the effects of disturbances on the plant, which include changes in external loading conditions affecting the influent flow and concentration.