Electrochemical detection of the microbial activity of heterotrophic and autotrophic activated sludge organisms

The microbial activity of microorganisms in biological waste water treatment was determined by means of an electrochemical bioactivity sensor (BAS). The signal of the sensor system is proportional to the substrate degradation and thus to the decisive target value in sewage treatment. By using physiologically active substances the aptitude of the sensor for detecting inhibition of microorganisms in active sludge was investigated. The signals of the BAS were correlated with an established method for determining microbial activity. For this purpose the total dehydrogenase activity as the key enzyme of metabolism was investigated. A good agreement was found between the measuring results. The BAS delivers values online and thus these values are available for automation and control tasks. The electrochemical bioactivity sensor provides a novel measuring system for determining the activity of both heterotrophic and autotrophic microorganisms in biological waste water treatment