Environmental Reactivity of Akaganeite: Phase Transformations and Contaminant Reduction
Academic Research Topics in Environmental Measurement and Monitoring
Oral Presentation
Prepared by M. Cruz-Reyes1, J. Schultz2, W. Arnold3, K. McCully1, R. Penn1
1 - University of Minnesota-Twin Cities, 207 Pleasant St. SE, Minneapolis, Minnesota, 55455, United States
2 - Northwestern University, 2190 Campus Dr, Evanston, Illinois, 60208, United States
3 - University of Minnesota – Twin Cities, 500 Pillsbury Drive SE, Minneapolis, Minnesota, 55455, United States
Contact Information: cruzr007@umn.edu; 612-625-3098
ABSTRACT
Iron oxides and oxyhydroxides, collectively called iron oxides, have found widespread use in environmental and technological applications such as ground water remediation or drug delivery because these materials are naturally abundant and have low toxicity. In this work, we study the behavior of akaganeite (β-FeOOH) – an iron oxide that forms in chlorine rich environments – in aqueous systems. We quantify the rate at which this mineral transforms to more stable iron oxides in the presence and absence of dissolved Fe(II) and the rate at which adsorbed Fe(II) effects the reduction of nitroaromatics. Results demonstrate that both rates are sensitive to solution conditions (e.g., pH, concentration of Fe(II), etc.). In addition, we perform experiments using solutions that contain natural organic matter, in order to simulate environmental conditions. Solids are characterized by powder X-ray diffraction and transmission electron microscopy before and after experiments, liquid chromatography is used to track the reduction of the model pollutant. These results will enable better predictions of fate, transport, and chemical behavior of metastable iron oxides in complex environments.
Academic Research Topics in Environmental Measurement and Monitoring
Oral Presentation
Prepared by M. Cruz-Reyes1, J. Schultz2, W. Arnold3, K. McCully1, R. Penn1
1 - University of Minnesota-Twin Cities, 207 Pleasant St. SE, Minneapolis, Minnesota, 55455, United States
2 - Northwestern University, 2190 Campus Dr, Evanston, Illinois, 60208, United States
3 - University of Minnesota – Twin Cities, 500 Pillsbury Drive SE, Minneapolis, Minnesota, 55455, United States
Contact Information: cruzr007@umn.edu; 612-625-3098
ABSTRACT
Iron oxides and oxyhydroxides, collectively called iron oxides, have found widespread use in environmental and technological applications such as ground water remediation or drug delivery because these materials are naturally abundant and have low toxicity. In this work, we study the behavior of akaganeite (β-FeOOH) – an iron oxide that forms in chlorine rich environments – in aqueous systems. We quantify the rate at which this mineral transforms to more stable iron oxides in the presence and absence of dissolved Fe(II) and the rate at which adsorbed Fe(II) effects the reduction of nitroaromatics. Results demonstrate that both rates are sensitive to solution conditions (e.g., pH, concentration of Fe(II), etc.). In addition, we perform experiments using solutions that contain natural organic matter, in order to simulate environmental conditions. Solids are characterized by powder X-ray diffraction and transmission electron microscopy before and after experiments, liquid chromatography is used to track the reduction of the model pollutant. These results will enable better predictions of fate, transport, and chemical behavior of metastable iron oxides in complex environments.