Iron-bearing mineral phases are ubiquitous in natural environments where they heavily influence several key biogeochemical processes. Their high surface area and (redox) reactivity allow Fe-bearing minerals to control nutrient availability and contaminants mobility through adsorption or structural incorporation. It is therefore important to understand how Fe-bearing minerals interact with nutrients or contaminants when they form or transform in nature, and determine the key geochemical parameters that affect these mineral reactions.

Our current research is mainly focused on the formation and/or transformation of Fe-bearing minerals (e.g., (oxyhydr)oxides, carbonates, phosphates, sulfates) in the presence of co-existing nutrients (e.g., C_org, P, Si) and contaminants (e.g., As, Cr, Pb, Se). Specifically, we synthesize Fe mineral analogues and test them in the laboratory under simulated environmental conditions. We are therefore able to quantify how these elements affect the structure, morphology, phase stability and reactivity of Fe mineral phases; and conversely, how Fe mineral phases impact the speciation and distribution of these elements in the natural environment. In addition to lab-based studies, we also study Fe mineral reactions in natural environments such as in (sub)Arctic soils, wetlands and contaminated soils and groundwater.

PhD students of the Interface Geochemistry research group will provide semi-annual updates detailing their research to date. These can be accessed by clicking on the link below.

• 2022
• 2021

(authors from the group in bold)

Chen, Z., Perez, J., Smales, G. J., Blukis, R., Pauw, B. R., Stammeier, J. A., Radnik, J., Smith, A. J., Benning, L. G. (2024): Impact of organic phosphates on the structure and composition of short-range ordered iron nanophases. - Nanoscale Advances. https://doi.org/10.1039/D3NA01045G

Delina, R. E., Stammeier, J. A., Bazarkina, E., Benning, L. G., Perez, J. (2024): Partitioning and mobility of chromium in iron-rich laterites from an optimized sequential extraction procedure. - Environmental Science and Technology. https://doi.org/10.1021/acs.est.3c10774

Perez, J., Okhrymenko, M., Blukis, R., Roddatis, V., Mayanna, S., Mosselmans, J. F. W., Benning, L. G. (2023): Vivianite-parasymplesite solid solution: A sink for arsenic in ferruginous environments? - Geochemical Perspectives Letters, 26, 50-56. https://doi.org/10.7185/geochemlet.2325

Paskin, A., Reinsch, S., Blukis, R., Benning, L. G., Couasnon, T., Perez, J., Lobanov, S. (2023): Nucleation and Crystallization of Ferrous Phosphate Hydrate via an Amorphous Intermediate. - Journal of the American Chemical Society, 145, 28, 15137-15151. https://doi.org/10.1021/jacs.3c01494.

Perez, J.P.H., Schiefler, A.A., Navaz Rubio, S., Reischer, M., Overheu, N.D., Benning, L.G., Tobler, D.J. (2021): Arsenic removal from natural groundwater using ‘green rust’: Solid phase stability and contaminant fate. Journal of Hazardous Materials, 401, 123327. DOI: 10.1016/j.jhazmat.2020.123327.

Perez, J.P.H., Freeman, H.M., Brown, A.P., van Genuchten, C.M., Dideriksen, K., Tobler, D.J., Benning, L.G. (2020): Direct visualization of arsenic binding on green rust sulfate. Environmental Science & Technology, 4, 6, 3297-3305. DOI: 10.1021/acs.est.9b07092.

Füllenbach, L.C., Perez, J.P.H., Freeman, H.M., Thomas, A.N., Mayanna, S., Parker, J.E., Göttlicher, J., Steininger, R., Radnik, J., Benning, L.G., Oelkers, E.H. (2020). Nanoanalytical identification of siderite dissolution coupled Pb removal mechanisms from oxic and anoxic aqueous solutions. ACS Earth and Space Chemistry, 4, 11, 1966-1977. DOI: 10.1021/acsearthspacechem.0c00180.

Wang, H., Byrne, J., Perez, J.P.H., Thomas, A., Göttlicher, J., Höfer, H., Mayanna, S., Kontny, A., Kappler, A., Guo, H., Benning, L.G., Norra, S. (2020): Arsenic sequestration in pyrite and greigite in the buried peat of As-contaminated aquifers. Geochimica et Cosmochimica Acta, 284, 107-119. DOI: 10.1016/j.gca.2020.06.021.