Velocity Fields around Single and Interacting Particles Sinking in Mucus-rich Water

Exopolymers dispersed in water create mucus-rich environments that can modify sedimentation dynamics when secreted in excess by microorganisms.Here we use PIV measurements combined with shear and extensional rheology to demonstrate non-Newtonian effects of mucus-rich water including extended flow, negative wake, and aggregation of solid spheres in test solutions.The methodology designed in this study allows the future development of analogue experiments to model the sinking dynamics of microplastic pollutants and mineral grains and organic aggregates in algal bloom-afflicted regions or wastewater treatment plants.