University of Wisconsin–Madison

New Paper by Elizabeth Tomaszewski!

Elizabeth Tomaszewski’s first paper has been published in Chemical Geology! Congratulations Beth!

1-s2.0-S0009254116303084-fx1

The role of dissolved Fe(II) concentration in the mineralogical evolution of Fe (hydr)oxides during redox cycling

This paper examines the mineralogical evolution of ferrihydrite over eight redox cycles during which it reacts with dissolved Fe(II) in the absence of oxygen (anaerobic conditions) for 48 h and is subsequently exposed to air (oxic conditions) for 18 h. Using X-ray absorption spectroscopy (XAS) and 57Fe Mössbauer spectroscopy, the abundance of each mineral phase present after each anaerobic or oxic period, is quantified. Our results demonstrate that rapid redox cycling limits the extent of ferrihydrite transformation leading to disequilibrium between mineral phases while magnetite stoichiometry increases throughout the study despite periodic exposure to oxygen. A deeper understanding of poorly crystalline Fe (hydr)oxide transformation during multiple, short redox cycles can provide insight into reactions controlling the speciation of redox active nutrients and contaminants in soils and sediments

 

Tomaszewski, E. J.; Cronk, S. S.; Gorski, C. A.; Ginder-Vogel, M., The role of dissolved Fe(II) concentration in the mineralogical evolution of Fe (hydr)oxides during redox cycling. Chemical Geology.

http://dx.doi.org/10.1016/j.chemgeo.2016.06.016