Fluviatile Transport of magnetominerals
Duration: since 2011
Project leader: Dr. Michael Pirrung
Person in charge: Dr. Michael Pirrung
Key words: physical properties, fluvial sediments
The petrophysical parameter magnetic susceptibility is investigated on source rocks and recent sediments of fluvial systems. Aim is a better understandig of transport dynamics and –in preferred combination with geochemical data – of anthropogenic impacts like that of urban areas, mine heaps and eolian dust on drainage systems.
Abb. 1: Bilder des überbohrtes LIT-Experiment: (links) Segmentierte Kluftgeometrie zur Abschätzung der Ausdehnung der Bentonit-Gelschicht in der Scherzone (erstellt von Dr. Hinz, Math2Market mittels Volume Rendering in GeoDict), (rechts) überbohrte Grimsel Granodiorit Matrix (ca. 6m) bis zur Kontaktzone der Scherzone.
(KOLLORADO-e³) In-situ experiments in terms of bentonite long term stability and radio-nuclide mobility at the bentonite - crystalline surface boundary
Funding body + grant number: 02E11759A
Funding: 01.05.2019 - 31.12.2022
Project leader: Prof. Thorsten Schäfer
Person in charge: Janis Pingel
Key words: Bentonite, multi-barrier system, Na-montmorillonite, accessory minerals, erosion, colloids, CFM-iBET, CFM-LIT
The overarching goal of the project KOLLORADO-e3 is to further deepen the mechanistic understanding of the processes that, under near-natural, repository-relevant conditions in fractured granite systems, impair the integrity of the bentonite barrier and can lead to colloidal associated radionuclide transport.
μ-XRF element mapping of Ti, Ca, Fe und Al in a thin section to investigate secondary mineral phases. (from bachelor thesis N. Münch (2020).
Biological radionuclide removal using natural association processes
BMBF Project grant 02NUK066B
Project leader: Thorsten Schäfer
Person in charge:
Dr. Susanne Lehmann de
Duration: 01.09.2021 – 31.08.2024
The focus of the collaborative project RENA is to investigate the biological radionuclide removal of contaminated soils using natural association processes to develop a method for the ex-situ treatment of radionuclide-contaminated soils originating from the dismantling of nuclear facilities. The aim is to develop in the consortium a generalized reactive transport model which combines soil hydrodynamics and mineralogical, geochemical, radiochemical, microbiological aspects to enable predictions about efficiency, quantitative influencing factors and in particular transferability to other soil materials.
- USER II
Fig.1. Laserscanning by microdrone at testsite Gessenwiese to estimate tree height and biomass productivity of willow, birch, alder on different soil substrates in short-rotation-coppice.
Implementation of heavy metal landfarming for sustainable landscaping and for exploitation of renewable energies on radionuclide contaminated Areas: Optimizing strategies (USER II)
Funding body + grant number:
Federal Ministry of Education and Research
Duration 01.07.2019 bis 30.06.2022
The current project funded by the R&D program "Decommissioning and dismantling of nuclear facilities" focusses on radiation protection by establishing bioremediation methods for substrates contaminated by heavy metals and radionuclides.
- WTZ Granit
3D scan (XRM) of a drill core with colourcoded segmentation of different mineral groups and pore space (white).
Prediction of heterogeneous radionuclide sorption on fracture and fault surfaces in granitic rocks: Parameterization and validation of improved reactive transport processes.
BMWK-grant: 02 E 11911B
Duration: 01.05.2021 to 30.04.2024
Project leader: Prof. Thorsten Schäfer de
Key words: granitoids, trace element & REE sorption, fracture geometry, reactive transport
Deep geological repositories are an internationally recognized solution for the long-term disposal of high-level nuclear waste. Crystalline rocks such as granites or gneisses are one potential host rock. The safety analysis and optimization of the concept for the final disposal of highly radioactive and long-lived waste in granitoid formations is part of current research projects.
Component additive approach to predict Cement paste Rheology considering Secondary Cementitious Materials and their special effect on thixotropy and concrete de-airing behaviour (CONCERT-CCair)
Funding body + grant number: SPP2005 DFG, SCHA 1854/4-1
Duration: March 2021‒2024
Project leader: Univ. Prof. Dr. habil. Thorsten Schäfer de
Person in charge: Steffen Hellmann de
Key words: CSH phases, calcined clays, air-bubble de-airing, spICP-MS, AFM, surface complexation models
Description: The cement industry is stirring its research towards Secondary Cementitious Materials (SCMs) that will allow reducing the CO2 footprint of concrete. The goal of this project is to identify promising SCM alternatives such as calcined clays (CCs) and limestone powders (LSP). The first approach is to characterize the rheological behaviour of fresh cement admixtures with these SCM during the early stages of hydration in casting process. The second one focuses on their potential role in avoiding unwanted air-bubble entrapment before hardening. Experimental approaches involve characterization of particle interactions and paste rheology in model and realistic systems via a national collaboration between FSU, KIT, BUW and LUH.
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- Anthropogenic and geogenic sources of dust in urban areas in central Germany
Dust is collected via spider webs, moss bags and passive samplers in central Germany (focus on the city of Jena), taking samples in city centers as well as suburban areas and some more remote areas. The samples are characterized geochemically and statistical methods are applied to find out to which extent specific sources contribute to the chemical characteristics of deposited dust.
Control of biological investigations during the decontamination of heterogeneous, low-level radioactively contaminated geosubstrates for precautionary radiation protection (KOBIOGEO)
Low-level radioactive heterogeneous geosubstrates can be biologically decontaminated by phytoremediation, thus contributing to radiation prevention. By identifying the processes relevant for phytoremediation on a laboratory scale using the innovative rare earth element (SEE) fractionation method and transferring them to natural conditions, an increase in efficiency is achieved compared to previous, empirical approaches and experiences of decontamination of low-level radioactive geosubstrates. Naturally occurring rare earth elements and their distribution are used for process control and optimization in the uptake of heavy metals/radionuclides from geogenic materials into plant material. This provides the opportunity to identify biological and/or physical/chemical processes that occur during selective uptake of radionuclides and heavy metals through different fractionation patterns of SEE. Thus, effective transport processes during transfer can be inferred. Beyond the identification as well as control, an optimization of the biological decontamination processes can be achieved.
01.10.2004 bis 31.10.2008
KOLLORADO-e2 (Integrity of the bentonite barrier for the retention of radionuclides in crystalline host rock - experiments and modeling)
Persons in charge: Thorsten Schäfer (FSU) & Francesca Quinto, Madeleine Stoll, Franz Rinderknecht (all KIT-INE)
The knowledge on the colloid/nanoparticle problem, in particular on the prediction of the colloid/nanoparticle source term, colloid/nanoparticle stability and nanoparticle/colloid-mineral-surface interaction, including the surface roughness, has made great progress in recent years. In addition to the description of colloid/nanoparticle stability by means of electrostatic approaches, quantitative data on the erosion of the bentonite barrier have been generated in laboratory tests. All data on the colloid/nanoparticle -supported radionuclide transport indicate a strong dependence of the colloid/nanoparticle mobility on the fracture geometry / surface roughness, the complete dissociation of tetravalent actinides from the clay colloid surface being still an open question. The main objective of the project is to improve the mechanistic understanding of the erosion of the compacted bentonite and the radionuclide-colloid interactions under near-natural conditions by means of in-situ experiments and the relevance of the nanoparticle/colloid-borne radionuclide transport with regard to the long-term safety of a repository in crystalline rock formations. In addition, generic statements on colloid relevance and the mobility of radionuclides are developed.
Funding: 3/2016 – 2/2019
The BEACON project is funded under the Euratom research and training programme 2014-2018 Grant Agreement No 745 942.
- Regarding the project: Eifel volcanism during the Weichselian Glaciation
Regarding the project: Eifel volcanism during the Weichselian Glaciation
Person in charge:
Phd Thomas Lange
Due to its multitude of Maar volcanoes and cinder cones the Eifel is a morphologically exceptional region within Germany. In this project the focus is on the late quaternary Eifel volcanism around Gillenfeld and Strohn. Here the formation of the Wartgesberg Volcano Complex (WVC) almost 34 ka ago and the promotion of two lava flows provided a complete valley closure. The resulting genesis of glacial archives and the preservation of the land surface allow unique insights into the valley development of the Eifel during the last major ice age.
Implementation of heavy metal landfarming for sustainable landscaping and for exploitation of renewable energies on radionuclide contaminated Areas (USER)
Project leadership: Prof. E. Kothe, Prof. G. Büchel
Funding period: 01.12.2014 to 30.11.2018
Soil and water pollution by heavy metals and radionuclides (HM/R) is a major concern in many areas of the world, influencing the health of local populations, the use of the natural resources and the environmental equilibrium. In particular, soil, surface water and groundwater are likely to get an important input in different of these persistent pollutants, compromising the biosphere including humans on large areas. Bare soil or heaps are furthermore more likely to erode through the action of wind and precipitation, causing an eluviation of soil parallel to a spreading of contaminants in the air and water phase.
In this context, field scale investigations are applied to areas of moderate HM/R contaminated substrates at the testsites Gessenwiese and Kanigsberg, near Ronneburg, to investigate phytoremediation strategies (USER-project, PTKA, FKZ 02S9194). Here, the main focuses lie on designing sustainable landscapes by reducing the bioavailability of contaminants with carbonatic soil material (rendzina) and microbial amendments (VA-mycorrhiza Rhizophagus irregularis, actinobacteria Strepromyces mirabilis P16-B1), as well as the production of renewable energy with metal tolerant plants (Festuca rubra, Secale multicaule) within a short-rotation-coppice (SRC, landfarming). In this connection, production of woody biomass with fast growing plants (Betula pendula, Sorbus aucuparia, Alnus, Pinus, Salix) in SRC provides a positive effect on biodiversity and erosion protection.
Furthermore, quantification of biomass productivity and HM/R-transfer within the soil-plant-water system by using soil and microbial amendments are scopes of this project, and should lead to reduction in leaching of HM/R and soil erosion as well. Therefore, soil hydrological measurement stations and a lysimeter station are installed to get information about distribution, changes, transfer and output of HM/R in the water phase.
Additionally, biomass productivity, plant vitality and erosion processes should be monitored with a multispectral camera and a high resolution camera system (accuracy 5 mm) installed on a microdrone (project TerraSensE, FKZ 13007-715).
Project Transaqua - Hydrochemical and/or microbial impact on the transfer of radionuclides in groundwater
Radionuclides are released through water/rock interactions getting finally to drinking and surface water. Up to now, there is little known on the role of microbes in this process of release and transport.
Transport and transfer behavior of long-lived radionuclides along the causal chain Groundwater - soil surface - plant, taking into account long-term climatic changes
Funding body + grant number:
Federal Ministry of Education and Research
Duration: 01.09.2017 bis 30.06.2022
Project leader: Prof. Dr. T. Schäfer
Personnel in charge: Marcus Böhm, Dr. Daniel Jara Heredia
Key words: radionuclides, lysimeter, natural nanoparticulate phases, reactive transport
For long-term safety detection of potential repositories, the current radioecological models in accident scenarios proceed from a radionuclide entry into the biosphere via the water path. In addition to the path over rainfall and irrigation, the entry is particular interesting in the soil via fluctuating groundwater level changes. The aim is to provide a deeper understanding of the complex mechanisms of radionuclide transport from the groundwater zone to the plants, including climatic changes, which should lead to improved risk assessments for the exposure of the population over long periods. A significant step forward is the elucidation of the host mechanisms of radionuclides in crop plants at the molecular level, a concept which allows for far-reaching explanatory power beyond previous transfer factors.