Molecular Geochemistry at Umeå University
connecting atoms with mountains
The ATOM MATLAB library which can be used to build, manipulate and analyze atomistic structures used in molecular simulations has a new ChatGPT-based tutor (requires chatgpt plus for now..). It sort of works, but occasionally suffers from some hallucinatory behaviour… Try it out!
 The ATOM tutor (BY DALL-E) |  |
Many countries such as Sweden rely on nuclear power to meet their energy needs. As a result, various types of deep geologic repository concepts for the disposal of nuclear waste are being planned worldwide. The goal of this PhD project is to study radiation-induced chemistry at the molecular level in the context of nuclear waste disposal, using advanced theoretical and experimental techniques, such as molecular simulations, gamma-radiation and X-ray synchrotron-based methods. This 4-year PhD project is funded by the Swedish Radiation Authority (SSM), and builds upon prior research in the Holmboe group in collaboration with Prof. Mats Jonsson, Applied Phys. Chem, KTH, Sweden.
Figure 1. Schematic of flip-flopping of structural Fe(III) to Fe(II) and back, due to reactions with the primary radicals from water radiolysis.
Based on a plethora of experiments and advanced geochemical analysis techniques, Hussein Kanbar in the Holmboe group (Department of Chemistry/UMU), in a collaboration with PhD student Fredrik Olajos and Professor Göran Englund from the Department of Ecology and Environmental Sciences/UMU, has published a paper in the Journal of Soils and Sediments, detailing the mineral and geochemical characteristics of Holocene lake sediments from the Hotagen lake in west Sweden (Jämtland). Read more here:
Kanbar, H.J., Tran Le, T., Olajos, F. et al. Tracking mineral and geochemical characteristics of Holocene lake sediments: the case of Hotagen, west-central Sweden. J Soils Sediments (2021). https://doi.org/10.1007/s11368-021-03012-y
Hussein Kanbar and Michael Holmboe has collaborated with EMG/UMU Prof. Göran Englund and PhD student Fredrik Olajos, on the faith of (ancient)DNA adsorbed onto minerals in 10,000 y old Swedish lake sediments. Their first publication is now available online at: doi.org/10.1016/j.apgeochem.2020.104728.
Michael Holmboe which initially joined the Chemistry Dept. at Umeå University in 2015 as an assistant professor, has now been appointed to associate professor (universitetslektor) in inorganic chemistry!
Thanks to recent grants from SSM and VR, his groups research is set to start two new projects regarding radiation-induced redox effects in clay minerals and organic/minerals interactions using molecular simulations!
moleculargeo.chem.umu.se/effects-of-gamma-radiation-on-bentonite-project-funded-by-ssm/
moleculargeo.chem.umu.se/project-grant-from-the-swedish-research-council-awarded-to-michael-holmboe/
The Swedish Radiation Safety Authority, or SSM in short, are funding a 1-year project in the Holmboe group!
In the context of nuclear waste disposal in Sweden and many other countries, this project will investigate the effects of redox and physicochemical changes induced by gamma (γ) irradiation on compacted Bentonite clay and its main component montmorillonite. This is relevant since in nuclear waste repository concepts such as the Swedish KBS-3, the compacted and water saturated Bentonite clay buffer will unavoidably be exposed to significant doses (40-200kGy) of ionizing 137-Cs radiation, which may induce redox-changes in the structural Fe(II)/Fe(III) sites in the clay mineral lattice.
A recent article in NyTeknik (link) highlights recent findings in a US study funded by the DOE titled ‘Self-accelerated corrosion of nuclear waste forms at material interfaces’. In the NyTeknik article associate prof. Michael Holmboe is interviewed and comments on the relevance of the results for the planned nuclear waste disposal in Sweden.
The Swedish Research Council (Vetenskapsrådet, VR) has awarded Michael Holmboe a 4-year research project grant, for a project focusing on adsorption of biogeochemical organics to clays and similar minerals!
Deconvolution of Smectite Hydration Isotherms
Michael Holmboe’s collaboration with researchers (Ruth Tinnacher, CSUEastBay and Christophe Tournassat, LBNL, BRGM) in the US focusing on uranyl complex – clay transport and interactions was highlighted in the evening newspaper Expressen, forskning.se and (initially) by the faculty news.
