- Seksjon for miljøkjemi
My main research interests focus on understanding the geochemical behavior of radionuclides and co-contaminants in surface and subsurface environments, as well as optimizing and testing analytical methods for radionuclide determination. Until present, I am working or have worked in projects on:
- study of alum shale weathering and the release and retention of associated leachable radionuclides, U and Ra, as well as looking into optimal storage solutions for alum shale rock waste.
- characterization of the biodistribution of U and U nanoparticles in the model organism C. elegans.
- determination of Sr-90 in biological samples and Cs-135/Cs-137 in soils and sediments by ICP-MS/MS after radiochemical separation.
- characterisation of nuclear fuel particles from contaminated soils and sediments of Chernobyl's and Fukushima's exclusion zones.
- determination of rates and mechanisms of uranyl oxyhydroxide and phosphate minerals dissolution under a flow-through porewater regime, and study the effect of dissolved carbonate concentration on dissolution.
- development of an ion exchange model to obtain a thermodynamic database describing the sorption of trace elements (U and Ra) on clays (kaolinite) in the presence of major ions.
- mechanistic understanding of the interactions between anthropogenic complexing agents (EDTA, NTA, ISA, picolinic acid) and radionuclides (Tc, U, Th, Sr, Cs) and their effect on mobility in different solid phase systems (natural sand, silty loam soil).
Due to my analytical chemistry background, my research always features a wide range of analytical, radioanalytical and spectroscopic techniques, and when necessary I have developed and optimized the methodology. Among these techniques are: ICP-MS/MS, ICP-OES, IC, TOC, UV-Vis spectrometry, gamma spectrometry (NaI and Ge-detector), beta spectrometry (LSC), as well as solid phase characterization techniques such X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDX), autoradiography, micro X-ray fluorescence (µ-XRF), and X-ray absorption spectroscopy (XAS) and nano-XRF at synchrotron light source facilities. Moreover, the use of chemical, geochemical and reactive transport calculations and modelling (HYDRA/Medusa, Visual MINTEQ, PHREEQC, CrunchFlow) is included when possible to support experimental work and gain further mechanistical understanding.
Recently, I have also been working in the development and optimization of analytical methods to analyze Se and As species by HPLC--ICP-MS. Samples matrices encompassed animal plasma (seleno proteins and aminoacids to study the effect of dietary Se sources on the growth and health of fast-growing pigs in the Norwegian porcine industry) and plant materials (As(III), As(V) and As organic species to study the transfer of As from kelp fertilized material into crops). Moreover, I have been working on determining the microbial activity in soils impacted by waters of different salinity levels. The method requires the incorporation of H-3 labelled leucine into the soil's microbe population to determined (by LSC) the protein turnover and thus the level of microbial activity in the soil.
Publikasjoner
Mer om meg og CV