Mariette Wolthers appointed professor of Aquatic Geochemistry

As of 15 December, Mariette Wolthers is appointed professor of Aquatic Geochemistry in the Earth Sciences Department of the Faculty of Geosciences. Wolthers currently works as associate professor in geochemistry at the same department and leads, among other things, her ERC consolidator project CRYSTAL CLEAR.

"With this chair in Aquatic Geochemistry, I focus on interactions between water and Earth materials in the earth's surface and their implications for sustainability and societal challenges and system Earth", Wolthers says. "My focus is on Earth materials, or minerals, that are composed of ions, for example lime and chalk, which consist of calcium and carbonate ions. Interaction of water with these minerals changes the composition of water and these minerals themselves, and have a broad application, both for fundamental understanding of system Earth and for highly applied issues."

An example is Earth's fresh surface water and groundwater that is our source of drinking water and water for food production. Methods to protect or clean these water sources are based on controlled mineral formation or immobilization on mineral surfaces. Wolthers uses insights from her fundamental earth-science research to make these methods more sustainable and to develop new ones. Wilco Hazeleger, Dean of the Faculty of Geosciences: "Mariette's work shows very well how fundamental knowledge about the earth system can be applied for a sustainable world. That combination fits perfectly with the teaching and research in our faculty."

The ocean is also important to society. More than a quarter of humanity's emitted CO₂ and the lion's share of the resulting excess heat is stored in the ocean. That absorption causes warming and acidification of ocean water which in turn affects marine calcifying organisms. Those organisms are at the base of our food web. "There are still gaps in our knowledge about the dynamics of formation and dissolution of calcium carbonate minerals in the ocean," Wolthers explains. "As a result, our current Earth system models cannot correctly describe these dynamics in the ocean, let alone predict what impact ocean acidification will have on these dynamics and the food web in the future."

"In my research, I combine experimental work in the laboratory with advanced analytical techniques and model calculations. Using these methods, my research group and I determine the mechanisms of mineral-formation and mineral-water interactions. This mechanistic knowledge is essential to know for different conditions how, how fast and why mineral-formation and mineral-water interaction occurs." Wolthers also likes to combine these approaches in teaching. "We aim to prepare our students to contribute to the complex problems our society faces today. For this they need both practical and digital skills and a highly developed ability to analyze and unravel problems. That is why I am integrating practical and digital skill-development into the new Bachelor subject Chemistry for Earth Sciences, which I am currently developing with colleagues."