Our research interests encompass a wide variety of environmental systems - ranging from groundwater to marine sediment and hydrothermal vents - and cover spatial scales from micrometers (microbial scale) to kilometers (marsh settings), and time scales from seconds to thousands of years. We integrate process-based knowledge from different disciplines into numerical reactive-transport models, to test our understanding of the natural environment, to reason on natural variability and, potentially, predict responses to natural variations and human activity. We appreciate support from