The BiWAS technology

BiWAS (Biological Water alarm system) is a compact, early warning system for monitoring the quality of drinking water. The system is composed of a software network that lets the users observe the water quality at multiple locations in near real time (see figure 1) and a sensor component containing two detection modules.

Overview of the BiWAS component in a water distribution system
Figure 1: The BiWAS sensor component can be placed in strategic positions throughout the water distribution network
The BiWAS sensor component
Figure 2: The BiWAS sensor component connected to a water pipeline

The software can be configured to trigger an alarm when the water quality drops below a set threshold in one or multiple locations. The sensor component can be connected directly to the water pipe (see figure 2), and can either be powered by an external power supply, or by an internal battery pack.

The Chemical Detector

The chemical detection module is an early warning system for the detection of toxic substances. The module is based on the canary principle using the bioluminescent bacteria Vibrio fischeri (see figure 3).

Vibrio fischeri
Figure 3: Vibrio fischeri bacteria emit bioluminescent light under regular conditions

Under regular conditions, the bacteria glows at a set intensity. If there is no change in intensity, the bacteria are healthy and there are no toxic substances in the drinking water. When there are toxic substances, e.g. heavy metals or toxic chemical compounds present in the drinking water (see figure 4), some of the bacteria will die, and the light intensity will decrease (see figure 5).

Vibrio bacteria in toxic water
Figure 4: A toxic substance is introduced in the drinking water together with vibrio bacteria
Vibrio bacteria killed by toxic water
Figure 5: The toxic substance kills some of the Vibrio bacteria and the intensity of the bioluminescent light decreases

The Biological Detector

The biological detection module takes advantage of a physiochemical phenomenon called intrinsic fluorescence. Intrinsic fluorescence occurs when a chemical compound called a fluorophore is exposed to a specific wavelength of light called the excitation wavelength, that excites the compound. This wavelength often has a high frequency. Within a short time of the compound being excited it emits a new wavelength with a lower frequency, at the emission wavelength. Some fluorophores can be found naturally in bacteria and other pathogens.

Unwanted bacteria
Figure 6: Unwanted bacteria in drinking water

The biological detection module continuously exposes the drinking water to a high frequency excitation wavelength of a known fluorophore and measures the intensity of the lower frequency emission wavelength. If there are bacteria in the drinking water (see figure 6), they will be exposed to high frequency light (see figure 7), and emit lower frequency light (see figure 8).

Bacteria exposed to light
Figure 7: The module exposed the drinking water and potential bacteria to high frequency light

The intensity of the emission wavelength is directly related to the total number of cells present in the drinking water.

Fluorophores in bacteria emit light
Figure 8: The fluorophores in the bacteria cells emit light with a lower frequency

Road map

We have completed a Horizon 2020 phase 1 project, and our technology is being verified in 3 verification projects partly financed by Hovedstadfondet and Oslofjordfondet. We will establish production in 2019, and start deliveries in 2020.