Online Water Quality Monitoring

The iTOXcontrol is a unique system for on-line monitoring of the chemical toxicity of waste, surface, drinking or process water. It is an early warning system to signal sudden peak values of chemical and other toxic pollutions, like heavy metals, within 30 minutes. In any event or breakdown it is possible to act within minutes, compared to routinely measured parameters that take hours or sometimes days to signal sudden changes in the water quality. So it is possible to limit potential damage.

The TOXcontrol uses a decrease in luminescence of the luminescent bacteria as an effect endpoint to measure the toxicity of water samples. The acute test with this bacteria species is one of the best known ecotoxicity tests and has been used in ecotoxicological research since the 1980’s (Diehl et al). A large volume of literature on the sensitivities of this test is available and was reviewed by (Kaiser et al, 1991). Because of the sensitivity to different substance groups and the short time needed to perform the test, the toxicity assessment with Vibrio fischeri is internationally standardized and accredited (ISO 11348 Determination of the inhibition effect of water samples on the light emission of Vibrio fischeri).

The BACTcontrol detects the presence of bacteria activity in water and can be used as an online screening monitor for total and specific bacteria in water. It is based on an enzymatic reaction that makes the bacteria visible for fluorescence detection. The BACTcontrol can be used for detection of E. coli, coliforms and total bacteria activity in water. In 2016 the detection of enterococci bacteria activity will be introduced as an extension to the enzyme detection of the BACTcontrol.

The BACTcontrol is an “early warning system”, complementing the officially accepted methods for the detection of microbiological activity. The measurements are realized in a short period of time, 1–2 hours. This is in contrast to classical microbiological methods, which are labour-intensive and in which cultivation of the organisms is required, taking several days before obtaining reliable results (24–48 hours).

The BACTcontrol detects the microbiological activity in water. It measures the specific enzymatic activities of β-galactosidase (coliforms), β-glucuronidase (E.coli) and alkaline phosphatase (total activity, biomass), as an indicator of the presence of bacterial contamination. The enzyme activity is detected by adding reagents which contain a fluorescent indicator. The reagents are substrate-specific for the enzyme to be detected, meaning that there is an increase in fluorescence when the enzyme is present in the sample.