Laurent Charlet, is Full Professor of Water Biogeochemistry at the University Grenoble-I (UJF) in Grenoble. He has published > 150 peer-reviewed papers (h = 41), and is Editor in Chief of Journal of Hydrology. He earned his PhD at the University of California, Riverside, USA (advisor: Prof. Sposito) and performed postdoctoral research in Switzerland at EAWAG (mentor: Prof. Stumm) and at the University of Bern (mentor: Prof. Schindler). His group maintains a modern trace element analysis, surface chemistry and cell culture laboratory and makes use in several project of synchrotron X-ray techniques (XAS and µXRF), Neutron scattering, ESR, XPS, Mössbauer spectroscopy, as well as molecular dynamics modeling. He has been awarded the UJF gold medal for services to Students and the CNRS silver medal for research. He was for many years Head of the “Groundwater Geochemistry” Master programme. He was WP leader for AsiaLink CALIBRE programme and AQUATRAIN Marie Curie network. He has been Visiting Professor in USA (Berkeley), Netherlands (Utrecht) and Switzerland (Lausanne). He is presently UJF Chancellor International Research Advisor. His research focuses on water geochemistry, investigating the biogeochemical processes in soils and aquifers, and their influence on mobility, bioavailability, biotransformation and chemical speciation of trace elements, in terrestrial aquatic environments under varying redox and hydrological conditions. His long-standing work on natural nanoparticle reactivity was recently extended to engineered nanoparticles and nanotoxicology. The aim is to develop general methods for understanding the fate of trace elements and nanoparticles in nature, as a means of predicting biogeochemical processes that are relevant to environmental quality, sustainability, paleoenvironment reconstruction, risk assessment and human health.