Speaker: Judy Yang, assistant professor of civil, environmental, and geo-engineering, University of Minnesota
A wide variety of global environmental issues involve physical and biological interactions among fluids, particles or surfaces, and microbes at both micro- and macro-scales.
For example, macro- or channel-scale sediment transport, a key process that controls coastal erosion, can vary by several orders of magnitude due to micro-scale sediment-sediment and sediment-bacteria interactions, including aggregation and biofilm formation. Other examples include clay algae flocculation, one of the most promising methods to remove harmful algal blooms, and soil carbon storage, responsible for the uptake of about 20% of annual anthropogenic carbon emissions, both of which are strongly impacted by the physical and biogeochemical interactions between particles and microbes at the micro-scale. Experimental studies of fluid-particle/surface-bacteria interactions across both micro- and macro-scales are needed to address these issues, yet such experiments are currently lacking.
In this talk, Yang will discuss how her research group designs microfluidic experiments to study biofilm formation on surfaces under various flow conditions and the sorption and degradation of organic matter in soil. Second, she will discuss how we design meso-scale (centimeter- to decimeter-scale) experiments to study bacterial spreading in a model soil. Third, Yang will discuss how we design macroscale flume experiments to study the impact of microscale aggregation and mesoscale biota on sediment transport and hyporheic exchange. She will conclude with a discussion on how her research group is integrating technologies at different scales to advance fundamental understanding of multiscale biota-particle-fluid interactions to address a variety of environmental issues.