STATE AND PARAMETER-ESTIMATION FOR PHOSPHORUS REMOVAL IN AN ALTERNATING ACTIVATED-SLUDGE PROCESS

Biological phosphorus removal involved in the advanced activated sludg e process requires more efficient on-line monitoring and process contr ol. However, the substantial complexity of the process behaviour and t he limited availability of reliable on-line measurement challenge the application of advanced process control techniques. This paper present s an application of state and parameter estimation techniques in an al tering activated sludge process with regard to biological phosphorus r emoval. A simplified model describing the phosphorus dynamics in an al ternating activated sludge process is proposed based on insight into t he process with a mechanistic activated sludge model. State and parame ter estimation problems relating to the non-measurable dynamics of a m ost important limiting substrate poly-hydroxyalkanoate (PHA) are formu lated and discussed. Several schemes are presented which involve a sta te estimator designed with the extended Kalman filter algorithm, two s pecific parameter estimation procedures and an adaptive scheme for sim ultaneous state and parameter estimation. All these schemes are orient ed to practical application and therefore same techniques dealing with the implementation are also provided. Simulations and experimental de monstrations are presented which illustrate the performance of these p rocedures and schemes.