The toximeter NitriTox of LAR Process Analysers AG is a continuous operating analyzer for the determination of nitrification toxicity. Especially in water treatment, toxic substances can harm the waste water treatment plant's biomass in a negative way and in worst case lead to a entire plant shutdown. Therefore, the monitoring of toxicity is of special importance.
The toximeter monitors the oxygen consumption of the bacteria used by means of a nitrification respiration inhibition test and thus, determines the toxicity. For that purpose, NitriTox contains a bacteria culture (nitrifiers), which constantly and independently produces biomass. This means that the risk of the test organisms being contaminated within the analyzer is avoided, as every water sample is tested with a small and fresh amount of bacteria. In contrast to alternative toxicity tests, purchasing or time consuming breeding of test organisms is not necessary anymore. The used subset of nitrifiers is brought into contact with the waste water and then, they consume oxygen from the conversion of ammonia to nitrate. LAR's toximeter measures this oxygen consumption. Toxic substances in the sample inhibit the respiration of the bacteria, thus lowering their oxygen consumption. The NitriTox monitors this oxygen consumption and hence the toxicity. Depending on the application, the measurement results are available in 5-10 min. Hence, operators can take countermeasures, in case of a toxic load, to protect the biology of the waste water treatment plant effectively.