A microbial sensor for detecting inhibitors of nitrification in wastewater

A biosensor for rapid and reproducible measurements of inhibitors of nitrification in environmental samples has been developed. The biosensor is mainly designed to be used for wastewater control and consists of a Clark oxygen probe as a transducer and an immobilised mixed nitrifying culture as the microbial component. The measuring principle is based on the direct determination of bacterial metabolic activity by measuring the oxygen consumption rate of the microbial immobilisate. Both the prototype of a laboratory device and a field device have been realised. The laboratory device can be used to determine the nitrification inhibiting effect of individual chemical compounds as well as of environmental samples. The field device was constructed for on-line monitoring of inhibitors in sewage systems.