Fast on-line measurement of the respiration rate in activated sludge systems

The measurement and utilization of the respiration rate or oxygen uptake rate (OUR) is very important in activated sludge system control. It provides information about the plant loading, activated sludge quality and can indicate the presence of toxic elements that can poison the system. The existing methods for continuously measuring and estimating the respiration rate have, generally, a long sampling interval of a few minutes. An alternative respiration rate meter with much shorter response time is proposed. The results of simulation studies, as well as experimental results of a microcontroller based data acquisition system connected to a PC, around a laboratory scale biological reactor are presented.