RIBES research theme I: Macronutrients and Chemicals of Emerging Concern

In this Theme, we aim to better understand balance and perturbations of ecosystems caused by high inputs of major nutrients and chemicals of emerging concern (CECs). The excessive use of fertilizers, fossil energy, pesticides, and pharmaceuticals is profoundly impacting ecosystem degradation worldwide, also in the Netherlands where fragmentation, intensive agriculture and industry are exacerbating these stressors and their consequences. Climate change further heightens these challenges for aquatic organisms, and understanding their (in)ability to adapt to future conditions is essential for effectively restoring ecosystems to a healthier state. Therefore, we aim to unravel, understand and predict the fate and effects of excessive amounts and stoichiometric imbalances of macro-elements and contaminants of emerging concern (CECs) in freshwater and terrestrial systems.

Research on the microbial nitrogen cycle

Over the next few years, we aim to understand the ecology and physiology of novel nitrogen cycle bacteria in various aquatic ecosystems and apply these bacteria in drinking water and wastewater plants for the removal of residual nitrogen and pharmaceuticals. To resolve metabolic and adaptation strategies at the molecular level, a complementary array of state-of-the-art methods will be used. Building on these research efforts, we will further focus on N-removal at the ecosystem scale by a cascade of invertebrates and aquatic macrophytes, in concert with microbial activity, in circular wastewater treatment plants.

Excess N deposition in past decades has led to acidification and eutrophication (including excess of P in agriculture) with cascading effects on declining animal and plant populations. The Ecology and Plant & Animal Biology departments have the ambition to develop and test new evidence-based methods to counteract the effects of N deposition. The challenge in the next years is to define novel methods to improve soil conditions and nutrient cycling in natural and agricultural systems. In tandem with ecological restoration, we will contribute to societal and economic changes in order to modernize Dutch agriculture to a world-class example of sustainability and efficiency. To this end, RIBES ecologists have initiated the interdisciplinary Healthy Landscape consortium, in which Radboud researchers from 5 different faculties are collaborating.


Chemicals of Emerging Concern (CECs) have chronic and toxic effects on aquatic life even at low nanogram quantities, and their presence in the environment is slowly but steadily increasing due to the use of personal care products, pharmaceuticals, and pesticides. In the next years, we will expand our research efforts in this area by combining the expertise of several research groups to assess the risk posed by these compounds and find sustainable solutions to remove them from aquatic environments. At a higher scale, landscape characteristics will be integrated with population and ecotoxicological modelling to better assess the effects of pharmaceuticals.

Icon in the shape of a droplet with pollutants and microorganisms inside


In 2024, the coordinators of theme I are Sebastian Lücker, Annelies Veraart, and Fiona Wang. You can contact them if you have any questions, ideas, or suggestions about the topics in theme I. 

The coordinators are responsible for (internal) events and communication about theme I, such as through the internal Teams channel. 

Related content

Dr Conall Holohan (left) and dr Cornelia Welte in white lab coats next to their bioelectrochemical systems in the lab

Radboud-Glasgow microbiology collaboration to unlock physiology behind electricity-producing nitrogen-removing bacteria

Dr. Cornelia Welte and Dr. Conall Holohan of RIBES have been awarded a Radboud-Glasgow Collaboration Grant to advance solutions to the global and local Nitrogen crisis with ammonium-removing bacteria that can also produce electricity.


Contact one of the theme coordinators (Sebastian Lücker, Annelies Veraart, and Fiona Wang) or the RIBES office for more information about this theme.