Naoki Nakatsugawa

DEVELOPMENT OF METHANOGENIC ACTIVITY MONITORING EQUIPMENT AND ITS APPLICATION TO PROCESS CONTROL

ABSTRACT New monitoring equipment for methanogenic activity, incorporating image processing techniques has been developed which makes good use of the fluorescent property of factor 420 contained characteristically in methanogens. In bench-scale experiments, it was demonstrated that the equipment is capable of monitoring the methanogenic activity on a real time basis in good correlation with the concentration of extracted factor 420 measured by fluorometry. Moreover, the process kinetics, in which the activity monitored: by the equipment was used as the concentration of methanogens, was investigated in order to apply the monitoring equipment to the process control. Kinetic analyses of the experimental data obtained from a complete-mixed reactor showed that the monitored activity represents well the concentration of methanogens in the continuous culture system.