Farewell to Andrew and Austin

July 7, 2023

This month the Hsu-Kim group bids farewell and congratulations to Dr. Austin Wadle and Dr. Andrew Middleton. Both recently completed and defended their PhD dissertations in Civil & Environmental Engineering.

Andrew and Austin June 2023

Last month Austin defended their dissertation titled "Microbe-mineral interactions: mercury homogenization, bacterial colloid surface acidity, and protocol transfeminism". This work explored the interstitial spaces of microbes and minerals in the environment and how the perspectives from which we study such phenomena guide our discoveries. Their work included an analysis of biogeochemical processes influencing mercury species distribution in aquatic ecosystems that receiving multiple inputs of this toxic metal. Austin also compared surface chemical properties of bacteria and their extracellular vesicles. Their dissertation research also highlighted new perspectives inspired from theories of feminist ecology and applied such concepts toward their exploration of bacterial-vesicle interactions.

Andrew's dissertation, titled "Recovery of Rare Earth Elements From Waste Materials: Leaching and Separation Using Supported Liquid Membranes" and defended last October, evaluated processes for the recovery of rare earth elements from coal ash and acid mine drainage. His work specifically examined the role of solution phase composition for controlling solubility of these critical metals in waste leachates. He also quantified how leachate chemistry, particularly interferring metals such as iron and aluminum, influence the recovery rates of rare earth metals during separations by supported liquid membranes.

Congratulations to both and we wish you the best in your next professional milestones - at Bucknell for Austin and the USEPA for Andrew!