Natural micro-scale heterogeneity induced solute and nanoparticle retardation in fractured crystalline rock

► We present, for the first time, 3D micro-scale simulations of flow and mass transport in a natural granite fracture. ► Simulations extend previous 2D studies to 3D providing advances in the process understanding of fracture flow and transport. ► Real fracture geometry induced heavy tailings (non-Fickian transport behavior) in the mass residence time distribution. ► The paramount importance of flow path heterogeneity as a retention process for solutes and nanoparticle transport is verified.