Research Cooperation Project SURFTRAP



Development and Optimisation of a Process to
Biosynthesize Reactive Iron Mineral SURFaces for Water TReAtment Purposes

Research cooperation project at the special program GEOTECHNOLOGIEN,
main topic: ‘Mineral Surfaces: From Atomic Processes to Geotechnology’

Research code (FKZ):     03G0714            runtime:      2008/07/01 to 2011/06/30

Coordinator:                    Prof. S. Peiffer,   Department of Hydrology, University of Bayreuth



The object of this cooperative research project is the development of a low-cost technology to remove arsenic species from raw waters. The proposed technology is based on the reactivity of schwert­mannite, an oxyhydroxo sul­fate of the mean stochiometry Fe8O8(OH)6SO4. This mineral typically forms in acidic and sulfate rich mine waters as a secondary mineral upon oxidation of Fe(II) in a biologically mediated process. Schwertmannite can be generated in a biotechnological pro­cess after aeration of mining pro­cess waters. It rapidly transforms into ferric hydroxides of high specific surface area once exposed to water containing at least some alkalinity. Our rationale follows the concept to make use of this transformation reaction by adding biosynthesized schwertmannite to conta­minated raw waters where it generates a large sorption capacity to remove the pollu­tants. The proposed process to generate reactive surface sites is advantageous both, in eco­no­mical and ecological regard compared to existing techniques. It requires per mol iron oxide formed only 8 % of the amount of alkalinity compared to the use of Fe(III) containing salts, and releases only 4 % of the amount of salts.


SURFTRAP principal idea  

At the research cooperation project, these innovative water treatment concept should be developed from microbial and structural basics, upscaling and process optimisation at laboratory scale to the point of a first, practical application at pilot scale by three academic research groups,

·       the department of Environmental Microbiology, Institute for Biosciences, TU Freiberg (TUF, Germany)

·       the department of Hydrology, University of Bayreuth (UBT, Germany) and  

·       the department of Gematerial Research, University of Munich (LMU, Germany)

a medium-sized enterprise:

·       G.E.O.S. Freiberg Ingenieurgesellschaft mbH (GEOS, Halsbrücke, Germany)

as well as the collaboration of the industry partners  

·       Vattenfall Europe Mining AG (Cottbus, Germany) and Wismut GmbH (Chemnitz, Germany).


Cooperation scheme 

The scientific objectives of the project were investigated into different subprojects (SP):

·  SP 1 (TUF) will concern the optimisation of the schwertmannite syn­thesis process with special em­pha­sis on the under­standing of the role of biomin­erali­zation.

·  SP 2 (GEOS and Vattenfall Europe Mining AG) will contain the optimisation of the biotechnolo­gi­cal pro­cess for the schwertmannite generation in an existing pilot plant.

·  SP 3 (LMU) will provide a contribution to the understanding of the long-term stability of contaminants bound to the sur­fac­es of precipitated ferric (hydr)­oxi­des with re­ga­rd to binding stability and redox state in order to evaluate the potential for dis­po­sal of the sequestered substances.

·  SP 4 (UBT) will provide a contribution to understand kinetic aspects of the interaction between contaminated raw water and the surface of schwertmannite and its transformation products and concerns the optimisation of this process at laboratory scale.

·  SP 5 (UBT, GEOS and Wismut GmbH)  will contain a pilot scale test of the developed water treat­ment process in order to compare the novel technique with conventional treatment techno­lo­gies with regard to efficiency and costs emphasizing on arsenic containing effluents from mine sites.


powered by php + PostgreSQL - last modified 2009-05-13- Impressum