Providing cheap and sustainable energy, while not degrading environmental resources, is one of the world's largest challenges for the 21st century and will undoubtedly necessitate a portfolio of options. The biogeochemical behavior of redox active metals and metalloids (U, Cr, Se, As etc.) in environmental settings, comprising dissolved metals, organic ligands, native microbes, and mineralogical matrices is complex and in many cases poorly understood.  Here we seek to understand the biogeochemical controls on uranium and chromium following release into environmental settings.  Both redox active metals, their fate is often determined by their oxidation state. For example, the potential for uranium transport in the subsurface decreases in anaerobic conditions as compared to aerobic conditions, through the formation of the sparingly soluble UO2(s) phase, a process often facilitated by dissimilatory metal and sulfate reducing bacteria.  In engineered systems, treatment processes for metals in industrial waste streams can be cost prohibitive. Therefore, passive remediation strategies using natural materials and microbial processes have the potential to provide affordable solutions for removing metals from aqueous waste streams, which is important from regulatory and environmental quality perspectives. Here we explore key processes promoting 1) removal of chromium from an industrial stormwater treatment system by association with granular organic peat media and 2) factors controlling the mobility of uranium in environmental systems.

Dr. Stewart studied Chemical Engineering at the University of Colorado and Civil and Environmental Engineering at Stanford University.  During her graduate studies she found a niche studying soil and water contamination that satisfied her lifelong desire to work on improving the state of the environment.  Through international professional ski racing she has seen many of the planets most beautiful and pristine sites, providing continued motivation to seek solutions to pressing environmental problems.  She has worked as an environmental consultant on mining projects and as a research scientist at Montana State University and the University of Minnesota.  Dr. Stewart is interested in the interaction of contaminants and environmental systems and designing solutions to minimize our impact on natural settings. 

Event Details

Event location - ECB 203
Event date - 04/07/2023
Event start time - 11:30 a.m.
Event end time - 12:30 p.m.

April Archive