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VIDI grant for biological removal of micropollutants

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December 6, 2021

Nora Sutton, associate professor at ETE, has been awarded a VIDI grant in the NWO talent scheme Veni, Vidi, Vici, for her project on biological removal of micropollutants in groundwater. The VIDI award is offered to young, talented scientists, that got their PhD within the last 8 years. Sutton receives a personal budget of € 800.000. ‘Together with co-financing from drinking water companies, we can spend around a million euros on this project’, she says. ‘This gives us the possibility to add two PhD students and one postdoc to the team.’

Health hazard

Micropollutants are contaminants, that are present in trace amounts in surface and groundwater sources. Pharmaceuticals, cosmetics, and pesticide residues are the most common micropollutants in The Netherlands. Groundwater is an important drinking water source, which is usually clean and free of pollutants. However, pesticides originating from agricultural resources, may end-up in some of these water bodies, posing a possible health hazard to consumers. Sutton’s project aims to safeguard these water resources by degrading these contaminants on site in the groundwater, using microorganisms that are naturally present. This is quite a challenge, since microbial activity is low due to anaerobic and nutrient-poor conditions. ‘We aim to boost these bacteria’s growth by adding growth substrates, like humus, also called dissolved organic carbon (DOC)’, Sutton explains. ‘But this may pose a risk too, since groundwater is generally clean and contains little bacteria. Adding DOC may result in excessive bacterial growth resulting in a new source of contamination. Therefore, it is a delicate balance to add enough carbon to support the bacteria to degrade micropollutants without adding too much carbon.’ Finding and especially understanding this balance to support the biological cleaning procedure is an important part of Sutton’s research.

Complex molecules

Another important issue is the choice of the added DOC. Since the micropollutants generally consist of large, complex molecules, Sutton aims to add similarly large and complex DOC molecules, to favor bacteria that are likely able to degrade these pollutants as well. ‘During this project, we plan to do both laboratory as well as field experiments to find out which method works best’, Sutton says. ‘Also, we will model groundwater flows together with bacterial growth under different circumstances.’

Fundamental methodology

The project will provide a fundamental scientific methodology for micropollutant degradation in groundwater that can be applied to other points in the water cycle as well. The project is scheduled to start January 2022 and will last until 2027.