Content of PhD-studies
Hydrogeochemistry and Modeling
From a general point of view, my researches are focused on the processes involved in groundwater chemistry in a deep fractured bedrock environment. Three areas in Sweden are of particular interest to work on such specific environment: Äspö Hard Rock Laboratory (Äspö HRL), Laxemar/Simpevarp and Forsmark. All these sites have specific facilities built by Swedish Nuclear Fuel and Waste Management Company (SKB). Äspö HRL is an experimental laboratory in the Swedish deep repository program. It is a tunnel 500 meters deep and gives the opportunity to conduct experiments and collect samples under realistic conditions at repository depth [400- 700m] via many boreholes drilled in the fractured bedrock. Laxemar and Forsmark are investigation areas for the final Swedish repository, where many deep boreholes are also available from the surface to do research and understand the complex natural environment. Indeed the study and the understanding of the groundwater chemistry residing in Proterozoic bedrock in near-coastal boreal settings (such as at Äspö HRL, Laxemar and Forsmark) is complex as the chemical composition varies strongly in both temporal and spatial dimensions. The reason for this is that waters with different origin and chemical composition have been infiltrating the bedrock, and when such waters over time mix and attain new chemical equilibrium in changing environments.
Presently, I am working with existing data from Sicada (SKB database) to increase the understanding of the drilling water influence on the groundwater chemistry. The main objectives are to define the chemical processes generated on the original groundwater system by addition of water used during the borehole drillings and if possible to evaluate there chemical sensitivity. The study is mainly focused on major elements and led via modelling with Phreeq’C software (Parkhurst and Appelo, 1999).
At the same time, I am involved in the updating of the hydrogeochemical modelling of Äspö groundwaters (Äspö SDM) led by SKB (project leader: Dr. Birgitta Kalinowski) to model the mixing process between the different kind of water explaining partly the groundwater composition present in the different fractures of the area at depository depth. The work is fulfilled with the use of M3 software which is a geochemical code based on multivariate statistics (Laaksoharju et al, 1999).
The both topics are led with the supervision from Prof. Mats Åström (University of Kalmar), Dr. Marcus Laaksoharju (GeoPoint AB) and Dr. Birgitta Kalinowsky. All this work is funded and supported by the Swedish Nuclear Fuel and Waste Management Company (SKB), Linnaeus University and the Nova Högskole Centrum.
List of publications
Peer-Reviewed Papers
Mathurin. F.A., Kalinowski. B.E., Åström. M., Laaksoharju. M., 2010. Temporal evolution of the groundwater chemistry in fractured bedrock at depth between 400 and 700m: Results of M3 modelling. In: P.Birkle & I.S. Torres-Alvarado (eds), Water-Rock Interaction: Proceedings of the 13th International Symposium on Water-Rock Interaction, Guanajuato, Mexico, August 15-20th 2010, Taylor & Francis group, London pp. 785- 788.
Conference Abstracts
Colbeaux-Picot. G., Mathurin. F, Bergmo P-E., Audigane. P., 2009. Short term reactive multiphase flow modelling for performance assessment of CO2
storage at Sleipner, North Sea. Proceedings of the Workshop on Modeling and risk assessment of geological storage of CO2, August 3 - 7, 2009, Longyearbyen, Svalbard, Norway
Audigane. P., Chiaberge. C., Mathurin. F., 2009. A Numerical Tool for Handling Heterogeneous 3D Model of CO2. Geological Storage with the Reactive Transport code TOUGHREACT. Proceedings of the Workshop on Modeling and risk assessment of geological storage of CO2, August 3 - 7, 2009, Longyearbyen, Svalbard, Norway
References
M. Laaksoharju, C. Skårman and E. Skårman (1999). Multivariate mixing and mass balance (M3) calculations, a new tool for decoding hydrogeochemical information. Applied Geochemistry, 14: 861-871
D. L. Parkhurst, C. A. J. Appello (1999). User’s Guide to PHREEQC (Version 2), a computer program for speciation, batch reaction, one dimensional transport, and inverse geochemical calculations. Science Report WRRIR 99-4259, US Geol.Surv.