Development of the Ammonia Biosensor Monitoring System

Abstract

The ammonia biosensor system was newly developed for monitoring ammonia in a river and in secondary effluent from a wastewater treatment plant. The detector of the ammonia biosensor is nitrifying bacteria immobilized by two acetic cellulose membranes and the transducer of the sensor is a dissolved oxygen probe. The microbial probe performs excellent selectivity and quick response to ammonia although control of pH with a phosphate buffer solution and control of temperature with an isothermal water bath are required. The developed ammonia biosensor system processes automatic calibration, sampling, and measurement as a monitor in the field. Accuracy and reliability of the biosensor system were also demonstrated by field tests accomplished at a wastewater treatment plant and at a river quality monitoring station.