Quantifying the impact of biofouling on microplastic transport: a modeling study

Biofouling is the attachment of microorganisms on microplastic and other substrate surfaces. In fluvial settings, biofouling is expected to play an important role in the transport and fate of microplastics, as it affects particle properties including size, shape, density, and attachment efficiency, which in turn all influence the settling velocity. However, quantified data on how biofouling affects each of these particle properties, and what this means for transport dynamics, is still lacking. To address this gap, different scenarios were simulated to see how the buoyancy of microplastics changes due to different biofilm thicknesses, suspended solids concentrations and turbulence levels. Microplastics are described using probability density functions (PDFs) in order to best capture the heterogeneity of environmental microplastics. Similarly, we capture biofilm thickness, suspended solid concentrations and turbulence levels with PDFs, to account for the variability of these parameters that is found in real-world settings. The results of these simulations will indicate the direction in which research on the effects of biofouling on microplastic transport should progress. Also see: https://micro2024.sciencesconf.org/558561/document