On-line stBOD measurement and toxicity control of wastewaters with a respirographic biosensor

This paper presents the results of the implementation of an on-line respirographic biosensor- RODTOX - for both BOD monitoring and toxicity control of incoming wastewater towards a full scale activated sludge treatment plant. The results showed that this on-line respirometer provided reliable BOD measurements. At two occasions the apparatus detected incoming toxicity and concomitant with these alarms a deterioration of the plant performance effectively occurred. Its reliability for toxicity detection has further been checked by deliberate intoxication experiments with creoline. The results showed that the RODTOX gave toxicity alarm in time so that preventive measures (interruption of the entrance of toxic wastewater) could be taken.