Building and Using Biogeochemical Reaction-Transport Models

Rather than being isolated systems that can be described entirely by thermodynamics, environments in the Earth's crust act as open biogeochemical reactors where chemical change is driven by the interactions between migrating fluids, solid phases, and organisms. The complexity of biogeochemical phenomena taking place in nature, particularly that which derives from coupling of transport and biogeochemical processes, suggests that we need a new generation of models to interpret observations from natural systems. Rather than focusing on building and using biogeochemical reactive transport models for predictive purposes (as in risk assessment analyses of nuclear waste repositories), here we stress the uses of reactive transport modelling as interpretive tools.