Riverine waste plastics pollution: Modelling unnatural item flow and particle transport in a natural environment

The issues surrounding the discard and transport of plastic waste into our oceans has become a critical research theme in recent years, as the dire consequences are becoming clearer. Much of the transport of this plastic to the oceans is through our river systems. However, many of the fundamental physical processes governing the fluvial transport of these plastics is poorly understood, as they do not behave like other particles normally found within the natural environment (e.g. sediments). This is in part due to the variety of shapes and varied physical properties of discarded plastic, but also due to the way that these plastics change during transport (biofilms, UV degradation, fragmentation etc.). The aim of this project will be to identify the fluvial conveyance processes that govern the transport of these artificial particles within rivers by using computational fluid dynamic modelling. A range of plastic items down to particles, with a variety of characteristics, will be modelled as individual particles with CFD under fluvial conditions typical of river systems. The particle properties will be derived from research quantifying plastics occurring in our rivers. The possibility of modelling particles, which change their properties during transport (e.g. fragmentation or biofilming) will also be studied.