Chemical persistence in river water

I am working in the Department of Environmental and Resource Engineering at DTU Sustain, specifically in the field of environmental chemistry, dealing with environmental contamination through micropollutants. My PhD project is about the persistence of chemicals as one of the many properties that can cause adverse effects for aquatic ecosystems and human health. We address this by performing tests where we simulate microbial degradation in rivers. For this purpose we combine an aqueous sample with chemicals, e.g. an effluent sample from wastewater treatment, with a sample containing microorganisms. For our tests we are using 6 different river water samples from Central-/Northern European and from Western Indian rivers. A specific time after the combination of the samples, they are tested again for their chemical content. By this we can identify the chemicals that are still existent and thus were not degraded by the microorganisms from the river. This allows us to see how many chemicals that are emitted to the environment are a potential long-term hazard (=persistent). The final aim is to use these information to close data gaps on chemical persistence and accelerate the adjustment of chemical production and usage towards less harmful substances. The research project is not focused on specific mechanisms of microbial degradation such as bacterial enzyme functions but rather on the bulk degradation, caused by all microorganisms that are present in a river. That can also include viruses, fungi, protozoa, archaea, algae or protozoa. Our analysis of this microbial composition is not focused and will only be assessed externally by another department.

This research is relevant to society since we are all surrounded and handling chemicals in our everyday life. And even though these chemicals and the respective degrading microorganisms are not visible with the naked eye, they are playing a crucial role for every single one of us. They may be pharmaceuticals that cure diseases or a common headache, additives to food that we consume or hidden in a shower product that we apply to our skin. Their benefits are undeniable and our modern society is highly dependent on their production. However, these extremely important products can turn into hazardous pollutants when emitted into the environment. It is important to consider the whole life-cycle of a product and prioritize products in chemical production that have the least possible impact after their end of usage. We want to work towards a sustainable chemical producing industry and a decreased unwanted chemical exposure of the environment and ourselves. This implies an increased water quality of our rivers. Moreover, we do not only want to investigate this in a European framework but make international comparisons. Chemical production and trade is extremely interconnected globally. We are convinced that chemical management and research should therefore strengthen global partnerships. Therefore we initiated a collaboration with the Indian Institute of Technology Bombay (IITB) to compare biodegradation between different regulatory and environmental conditions.

The way that I would like to convey this in a classroom is to start with an introduction about chemicals in our society and the environment - depending on the age and knowledge the students already have - and then go a little bit deeper in the experiment that we are doing here at DTU. I am open to the use of quizzes, bringing props, or incorporating small exercises for the students to work on during the class. However, I have no experience in teaching - especially not high school students, so I would definitely be in need of some discussion beforehand on what is realistic and what not.

A little bit more about myself personally: I am 28 years old and went to high school in Duesseldorf, Germany. My path towards a PhD in natural sciences and engineering was everything but straightforward. During my high school time I was most passionate about arts, literature, languages, and sports. I also really enjoyed biology but didn't consider myself working in that field at some point. After high school I spent two years with working and doing internships for orientation. In this period I became more and more sure that I do love arts and cultural science but want to keep it as a hobby and not perform a professional career in it. When I then applied for universities, I still wasn't sure what to choose and did not feel passionate about anything specifically. I ended up receiving three study program confirmations for Architecture, Business administration and Georesources Management. Out of a gut feeling I chose the third one and never regretted to choose natural sciences after that. Due to the encouragement of one of my lecturers I focused on geochemistry and continued with a parallel Master study of Engineering Geohazards and Environmental Engineering afterwards. During my studies I did internships in South-America and Germany and worked in an engineering office specialized on groundwater contamination. I finished my studies in Switzerland and then applied at DTU where I started in February 2025.