Arsenspeziation in Bergbauabfällen - Fallstudien in von Eisen Sulfoarsenaten dominierten Systemen

• Antragsteller: Professor Juraj Majzlan, Ph.D.
• Fachliche Zuordnung: Mineralogie, Petrologie und Geochemie
• Förderung: Förderung von 2012 bis 2016
• Projektkennung: Deutsche Forschungsgemeinschaft (DFG) - Projektnummer 231489005

Arsenic is a metalloid of environmental concern, toxic to all living organisms. A substantial portion of the today's environmental load of arsenic has entered the environmental compartments owing to the action of humans, mostly commonly mining and benificiation of the ores. Here, we propose to investigate highly arsenic-rich mining waste at selected localities with respect to the mineralogy, geochemistry, speciation of arsenic and the associated microbiological communities. We suggest that the extreme arsenical loads of the waste and its unusual mineralogy will provide clues as to which phases could be used for arsenic immobilization in other arsenic-rich waste forms. The work will be performed as a close collaboration between the PI of this proposal and a Czech partner, Dr. P. Drahota, within the framework of the agreement between DFG and the Czech Science Foundation.Within this proposal, we will solve the crystal structure of bukovskyite, Fe2(AsO4)(SO4)(OH).7H2O, and basic ferric arsenate-sulfate (BFAS), Fe(AsO4)x(SO4)1-x(OH)1-x. These phases are known to occur or may be suspected to occur at the studied sites. BFAS is not known as a mineral so far but has been proposed as a phase for the immobilization and storage of arsenic in waste forms. Additionally, we will determine the thermodynamic properties of these phases, evaluate their solubility, and assess their potential as storage phases for arsenic. Dr. P. Drahota will focus on extraction and analysis of pore fluids from the wastes, mineralogical investigation, development of sequential extraction protocols on these materials, and the analysis of bacterial/archeal communities in the waste. The project will end by the synthesis of the data from both collaborators, especially by integrating the thermodynamic data with the mineralogy and the pore fluid composition. We will attempt to describe the activities of the microorganisms in these waste form with respect to the mineral formation and set up a model which explains how do the minerals present originate.

• DFG-Verfahren: Sachbeihilfen
• Internationaler Bezug: Tschechische Republik
• Partnerorganisation: Czech Science Foundation
• Beteiligte Person: Dr. Petr Drahota