Multi-Energy µXRF Mapping of Iron in Woody Biomass: Elucidating the Role of Iron Redox Reactions in Oxidative Decomposition of Wood in Aquat

This project examines the role that iron (Fe) redox dynamics play in the generation of reactive oxidants (e.g., hydroxyl radicals) that can degrade recalcitrant woody biomass and enhance the bioavailability of wood-derived carbon for denitrification. Wood samples with different concentrations of ferrihydrite mineral coating and incubated under different bulk redox conditions will be characterized using multi-energy µXRF mapping to produce 2D maps of Fe redox heterogeneity in decomposing wood. 2D maps of Fe redox interfaces will be correlated with maps of cellulose depletion obtained via X-ray scattering at NSLS-II to test mechanistic links between Fe redox interfaces, generation of reactive oxidants, and lignocellulose decomposition. Synchrotron results will complement bulk measurements of hydroxyl radical generation and release of organic carbon from wood. Results will provide new insights into how Fe redox dynamics impact the decomposition of woody biomass in aquatic systems.