Better understanding of blue-green algae growth

In Groenlo, the Netherlands, Regional Water Authority Rijn and IJssel is testing a new measuring setup supplied by Royal Eijkelkamp for measuring blue-green algae concentrations. This can lead to a better understanding of the growth of blue green algae.

It involves a Multiparameter meter, which takes measurements every fifteen minutes, day-in, day-out. One of the sensors measures the presence of blue green algae,' explains Annemarie Kramer, senior planning specialist at the Regional Water Authority. Blue-green algae are cyanobacteria, many of which produce toxic substances' that are dangerous to humans when grown at an extreme rate.

The Multiparameter meter measures the concentration of these bacteria and provides continuous data. For example, the meter not only measures the concentrations of algae and blue-green algae but also temperature, acidity and conductivity. 'All measurement data are sent via the Global Data Transmitter Multiple by Royal Eijkelkamp,' says Kramer-Hoenderboom. 'From that moment on, they are also available to us.'

Collecting data in a new way

The measuring set-up is new for the Regional Water Authority, as is the way in which the data are collected. 'Until now I went around the area with a blue-green algae meter', says technical employee Bob van IJzendoorn. 'With the new setup, there is a continuous measurement. As a result, a growth in blue-green algae will, in principle, be noticed sooner.'

With the density of the blue-green algae, parameters such as temperature and conductivity are also recorded. The Regional Water Authority analyzes the combined parameters and can link the growth of the algae to the other values.

'Perhaps based on this we can predict blue green algae growth earlier in the future,' explains Annemarie Kramer. The Regional Water Authority works with the Multiparameter meter that can contain up to ten measuring sensors. It is a compact unit that is easy to move to another location. The meter is equipped with a wiper that cleans the sensors frequently. 'This means I don't have to clean the sensors as often and I also have the impression that the measurements remain stable, which means I don't have to calibrate as often,' says Bob van IJzendoorn. I still have to find out exactly which frequency is satisfactory in practice.'

The application of the meter is still in a test phase. 'We are now collecting a lot of data that will still be analyzed,' adds Kramer. 'Perhaps this will provide information about the cause of the blue green algae.'