Department Water Resources and Drinking Water

A promising approach to mitigate climate change is the geological sequestration of CO₂ in deep aquifers. However, leakage risks due to imperfect sealing remain a major concern. Converting CO₂ into solid carbonates through microbial biomineralization could offer a safer, permanent storage solution. This project explores the potential of extremophilic bacteria to induce CO₂ mineralization under harsh subsurface conditions—high temperature, pressure, salinity, and pH. Using geomaterial microfluidics that replicate in situ environments, we will identify which microbes can survive and remain metabolically active, determine the most efficient CO₂-fixation enzymes and pathways, and assess how microbial processes affect subsurface ecosystems and water quality. We will test bioaugmentation strategies in Swiss sedimentary rocks such as limestone and sandstone, and in cation-rich rocks like basalt, to enhance mineralization rates. The project aims to advance the development of secure and sustainable CO₂ storage solutions in Switzerland and internationally, including in Iceland. By integrating microbiology, geochemistry, and innovative experimental tools, this research positions Eawag at the forefront of biogeochemical carbon storage innovation.