Biodegradation of Organic Micropollutants in Rivers – Revealing the Dynamics and Boundaries of a Crucial but Vulnerable Ecosystem Service

The self-purification capacity of rivers is an important ecosystem service (ES).

A complex aggregate of degradation power dominated by microbial biodegradation, it compensates for what wastewater treatment plants do not fully achieve: eliminating relatively stable and mobile compounds from the water cycle. These micropollutants (e.g. pharmaceuticals) pose a risk to ecosystems and human health.

While the ES protects the environment and our drinking water supply, our understanding of it is limited.

Also, factors controlling it such as temperature and flow regimes are changing, creating uncertainty about whether deterioration of the ES could threaten the quality of our water supply in the future.The project will a) pool expertise of 4 leading research institutes to combine hydrological, biogeochemical and analytical tools into one efficient workflow for in situ determination of biodegradation rates.

This will enable b) a first systematic assessment of biodegradation capacities and associated control factors in 20 rivers across climatic and biogeochemical gradients for hundreds of micropollutants.

I will c) quantify the influence of environmental factors on the transformation of compound groups to d) predict biodegradation capacities of different river types and map the importance of the ES for protecting water quality.

Embedded stakeholder issues to be addressed include e) strategies to promote the ES in a changing climate and optimization of drinking water resource management.