| AVS 63rd International Symposium & Exhibition | |
| Applied Surface Science | Wednesday Sessions |
| Session AS+SS-WeM |
| Session: | Applications where Surface Analysis is Your Only Hope |
| Presenter: | Kateryna Artyushkova, University of New Mexico |
| Authors: | K. Artyushkova, University of New Mexico J. Blake, New Mexico Water Science Center L. Rodriguez-Freire, University of New Mexico S,. Avasarala, University of New Mexico A. Ali, University of New Mexico A. Brearley, University of New Mexico E. Peterson, University of New Mexico J.M. Cerrato, University of New Mexico |
| Correspondent: | Click to Email |
This talk will present application of X-ray Photoelectron Spectroscopy to understand the role of chemistry of metals in several environmental problems. In the first study, the chemical interactions of U and co-occurring metals in abandoned mine wastes in a Native American community in northeastern Arizona were investigated using spectroscopy, microscopy and aqueous chemistry. Elevated concentrations of metals are of concern due to human exposure pathways and exposure of livestock currently ingesting water in the area. This study contributes to understanding the occurrence and mobility of metals in communities located close to abandoned mine waste sites. Elevated U (6,614 mg/kg), V (15,814 mg/kg), and As (40 mg/kg) concentrations were detected in mine waste solids. The power of XPS in specific identification of the chemical states of these elements as U (VI), As (-I and III) and Fe (II, III) will be presented.
In the second study, the goal is to investigate the effect of metals associated with wildfire ash from wood collected from the Valles Caldera National Preserve, Jemez Mountains, New Mexico on water chemistry. Metals and other constituents associated with wildfire ash can be transported by storm event runoff and negatively affect water quality in streams and rivers. Microscopy and spectroscopy analyses were conducted to determine the chemical composition of ash. Metal-bearing carbonate and oxide phases were detected through X-ray spectroscopy analyses.
Finally, we integrated spectroscopy, microscopy, diffraction, and water chemistry to investigate the presence of metals in water and sediment samples collected 13 days after the Gold King Mine spill (occurred on August 5, 2015). Spectroscopy, microscopy, and XRD analyses suggest that Pb, Cu, and Zn are associated with metal-bearing jarosite (KFe3+3(OH)6(SO4)2) and other minerals (e.g. clays, Fe-oxides and oxyhydroxides) identified in sediments from Cement Creek, CO. The presence of sulfates and phosphates, Fe as 75% Fe2+ and 25% Fe3+, and 100% Pb2+ in the near surface region of these sediments was detectedby XPS analyses.
Additionally, phosphates and nitrogen species were found with XPS in the sediments from Farmington, NM, downstream the Animas River. The interaction of these metal-bearing minerals with biogeochemical processes occurring downstream could cause metal mobilization into the water.