PhD position available in the Holmboe group!

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.

Link to add in English  

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. 

Paper published detailing the mineral characteristics of Holocene lake sediments

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).

New paper detailing DNA-hotspots in sediments by H. Kanbar and Holmboe

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:


  1. Lake sediment geochmemistry plays a significant role in the sorption.
  2. Clays were the main sedimentary components to host DNA.
  3. Both clay-mineral and organo-clay complexes govern the sorption of DNA.
  4. A DNA infrared fingerprint was determined in sediments via spectral subtraction.
  5. DNA-hotspots in lake sediments were revealed using geochemical approaches.

New associate professor in inorganic chemistry!

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!

Effects of gamma-radiation on Bentonite project funded by SSM

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.

Paper on smectite hydration accepted by ACS Earth and Space Chemistry

Deconvolution of Smectite Hydration Isotherms

Authors: Jerry Lindholm, Jean-Francois Boily and Michael Holmboe.
Sorption isotherm models have traditionally served as an invaluable tool to characterize synthesized and natural mineral particles, but often fail to describe the behavior of swelling materials. This research presents a novel composite isotherm model that describes water uptake by adsorption, step-wise intercalation, and condensation.