Contact

Porträt Dr. Müller, Katharina; FWOG

Photo: André Wirsig

Dr. Katharina Müller

Head Surface Processes
k.muellerAthzdr.de
Phone: +49 351 260 2439

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Department of Surface Processes

The why? The how? The what?

The ultimate goal of our research, driven by scientific curiosity, is to gain fundamental and independent knowledge of the (geo)chemistry and environmental fate of long-lived radionuclides (RNs). One prominent and socially important application is the safe disposal of radioactive waste, to aid future generations in the responsibility of dealing with “our” legacy from energy production in nuclear reactors.

For this purpose we provide the radiochemical knowledge, namely structural and mechanistic data of important mobilizing and immobilizing reactions of RNs in solution, at interfaces, and in solids.

Our particular focus is using a variety of established and advanced microscopic and spectroscopic techniques, to accurately describe complex formation reactions and complex structures that govern RN interactions in the geosphere. In addition, we investigate the creation and chemical speciation of activation products in materials from nuclear power plants in the context of their safe decommissioning.

As part of a value chain, the derived structural information forms a sound basis for a reliable thermodynamic description of the investigated systems, which can be integrated in thermodynamic databases. The thermodynamic work is done in close collaboration with the department of Actinide thermodynamics.

Foto: Forschungsfelder der Abteilung Grenzflächenprozesse ©Copyright: Dr. Katharina Müller

Our core competencies

  • Chemistry of long-lived RNs – Expertise in handling RNs, ranging from fission- and activation products to transuranium elements, and access to radiation safety labs.
  • Structural characterization – Expertise in applying and coupling spectroscopic and microscopic as well as diffraction techniques for accessing molecular information.
  • Thermodynamic description of RN complexes – Using macroscopic, spectroscopic, and calorimetric information of reactant-water-surface phenomena as basis for the derivation of surface complexation models and their thermodynamic parameters.

Research fields

  • Coordination chemistry of RNs in aqueous solution and in human artificial biofluids, e.g. RADEKOR project.
  • Molecular characterization of RN reactions at natural and engineered mineral-water interfaces, e.g. REDOX project.
  • Incorporation of actinides and lanthanides in solid phases, e.g. AcE project.
  • Environmental technetium chemistry., e.g. Young Investigator Group TecRad.
  • Development of a method for pre-activity and dose rate calculations of components in the reactor vicinity based on neutron fluence distributions (EMPRADO) 12/2018 –03/2024, BMBF.

Latest Publication

Uranium(VI) interactions with Pseudomonas sp. PS-0-L, V4-5-SB and T5-6-I

Kasko, J.; Li, X.; Müller, K.; Ge, Y.; Vettese, G. F.; Law, G. T. W.; Siitari-Kauppi, M.; Huittinen, N. M.; Raff, J.; Bomberg, M.; Herzig, M.

Pseudomonas sp. are indigenous inhabitants of ombrotrophic bogs which can survive in acidic, nutrient-poor environments with wide temperature fluctuations. Their interactions with contaminant radionuclides can influence radionuclide biogeochemistry in boreal environment. Here, uranium (U(VI)) bioassociation by Pseudomonas sp. PS-0-L, V4-5-SB and T5-6-I isolated from a boreal bog was studied by a combination of batch contact experiments, spectroscopy and microscopy. All strains removed U from the solution and the U bioassociation efficiency was affected by the nutrient source, incubation temperature, time and pH. Highest U bioassociation occurred in the strains PS-0-L (0.199 mg U/gBDW) and V4-5-SB (0.223 mg U/gBDW). Based on in-situ attenuated total reflection Fourier transformation infrared spectroscopy (ATR FT-IR) analyses, the most likely functional groups responsible for U binding were the cell surface carboxyl groups. In addition, transmission electron microscopy with energy dispersive X-ray spectroscopy (TEM/EDX) showed dense intra-cellular round- and needle-like U accumulations in the cytoplasm and near to the inner cell membrane. The presence of U with phosphorus was indicated in elemental mapping. Modelled data showed ≡SOOHx-1 and ≡SOCO2Hx-1 as the dominant surface sites, contributing to the negative cell surface charge. The U removal efficiency depended on the U(VI) speciation under different pH conditions. At pH 5, the main species reacting with bacterial cell surfaces was UO22+, while at pH 9 UO2(OH)2 and UO2(OH)3- dominated the reactions. Further, U bioassociation increased with increasing aqueous U(VI) concentrations. Our data suggests U bioassociation on 1) outer cell membrane/cell wall associated carboxyl groups (e.g., proteins), and 2) intracellular phosphate groups (e.g., phospholipids).

Keywords: bioassociation; biosorption; bioaccumulation; modelling; carboxyl group; phosphate group

A list of publications can be found here.

Research groups

Currently running third-party funded projects

  • Interactions of technetium with microorganisms, metabolites and at the mineral-water interface – Radioecological considerations (TecRad) 07/2022 – 06/2027, BMBF
  • Redox reactivity of selenium in environmental geomedia (REDOX) 06/2022 – 05/2025, ANDRA
  • Speciation and transfer of radionuclides in the human organism especially taking into account decorporation agents (RADEKOR) 07/2020 – 12/2023, BMBF.
  • Fundamental investigations of actinide immobilization by incorporation into solid phases relevant for final disposal (AcE) 01/2021 – 12/2023, BMBF.
  • Development of a method for pre-activity and dose rate calculations of components in the reactor vicinity based on neutron fluence distributions (EMPRADO) 12/2018 –03/2024, BMBF.

An overview of finished projects can be found here.

Team

Head

NameBld./Office+49 351 260Email
Dr. Katharina Müller801/P2482439
k.muellerAthzdr.de

Employees

NameBld./Office+49 351 260Email
Daniel Butscher801/P3523154
d.butscherAthzdr.de
Aline Chlupka801/P2033198
2518
2523
a.chlupkaAthzdr.de
Sebastian Friedrich801/P3523154
s.friedrichAthzdr.de
Dr. Norbert Jordan801/P2182148
n.jordanAthzdr.de
Stephan Weiß801/P3162758
2523
s.weissAthzdr.de

Incorporation in solid phases

NameBld./Office+49 351 260Email
Dr. Nina Maria Huittinen801/P2182148
n.huittinenAthzdr.de
Dr. Astrid Barkleit801/P2073136
2512
2518
a.barkleitAthzdr.de
Luiza Braga Ferreira dos Santos801/P2543487
l.bragaAthzdr.de
Maud Emilie Zilbermannm.zilbermannAthzdr.de

"TecRad" Wechselwirkung von Technetium mit Mikroorganismen, Metaboliten und an Mineral-Wasser-Grenzflächen - Radioökologische Betrachtungen

NameBld./Office+49 351 260Email
Dr. Natalia Mayordomo Herranz801/P2522076
n.mayordomo-herranzAthzdr.de
Caroline Börnerc.boernerAthzdr.de
Arkadz Bureika801/P2012434
a.bureikaAthzdr.de
Irene Cardaio801/P2542251
i.cardaioAthzdr.de
Vijay Kumar Saini801/P3523328
v.sainiAthzdr.de

Alumni

Name at HZDR Derzeitigte Institution
Isabelle Jessat Doktorand ASML, Veldhoven, Netherlands
Quirina Isabella Roode-Gutzmer Doktorand Wismut GmbH
Maximilian Demnitz Ph.D. student,
graduated 2022
Eindhoven University of Technology, Department of Chemical Engineering and Chemistry, Het
Diana Marcela Rodriguez Hernandez Ph.D. student,
graduated 2021
Rotop Pharmaka GmbH
Henry Lösch Ph.D. student,
graduated 2021
Radiation Protection, Analytics & Disposal (VKTA)
Manuel Eibl Ph.D. student,
graduated 2020
Avantgarde Labs GmbH
Susanne Lehmann Ph.D. student,
graduated 2020
Institute for Geosciences at the Friedrich-Schiller-University Jena