My PhD project is part of the ERC Synergy MARIX project. This project is an interdisciplinary collaboration between the geochemistry group of Utrecht University and the microbiology group of Radboud University. The aim of the project is to gain more understanding of the removal of methane and ammonium in coastal marine environments. During my PhD I will focus on the interactions of methane, ammonium, iron and manganese within marine sediments via a combination of fieldwork data and reactive transport modelling.