The climate change, growing world population, together with a widespread use of chemicals in industry and our everyday life, are projected to reduce water availability in sufficient quantity and quality and increase a global demand for clean water. The NATSORB project will try to meet those expectations and explore the possibility of employing the mineral dypingite (Mg5(CO3)4(OH)2·5H2O) - as a nature-inspired functional mineral, able to sequestrate heavy elements from water. The early experiments suggest that dypingite has excellent sorption properties, and removes elements such as such as lead, cadmium and chromium from water, more efficiently than other tested materials. NATSORB aims to develop a new type of water filters based on this natural chemical compound. However, before the proposed technology can be designed, it is necessary to fully characterise the mineral. Although dypingite has been known for more than 50 years, its atomic structure is still not fully understood. Thus, in the project we will combine various analytical techniques to expand our understanding of the naturally occurring dypingite before making its synthetic analogues, with properties optimized for the water cleaning technology. The project is a collaboration between the University of Oslo, SINTEF, NIVA, University of Münster and the municipality of Røros, where field tests of the new functional materials, created in this project, will be performed in flooded abandoned metal mines.
A fortuitous observation revealed that dypingite, a poorly investigated magnesium hydrocarbonate mineral present in weathered serpentinites, is capable of remarkable heavy metal sorption. This exciting finding motivated a team of experts in geology, materials science, sorbent technology and water research to explore the development of a totally new class of geomimetic sorbents based on dypingite. In nature, dypingite typically crystallizes by adopting the “desert rose” texture, but the role of this hyperbranched and self-assembled microstructure on the sorption behavior of dypingite is unknown.
The present project will establish a fundamental body of knowledge necessary to initiate the efficient use of these materials as superior eco-friendly sorbents. The crystal structure of natural and synthetic dypingite will be determined by laboratory and synchrotron powder X-ray diffraction combined with powder neutron diffraction, while probe corrected scanning transmission electron microscopy will be used to investigate local defect structures and sorption sites. The sorption mechanisms will be scrutinized by nuclear magnetic resonance, fluid cell atomic force microscopy and in situ X-ray diffraction experiments. The advanced experimental work will be used to propose local configurations for the sorption sites, for which activation and sorption energies will be computed using atomistic and electronic modeling. Sorbent technology will be employed to test natural, synthetic and chemically modified dypingite and to benchmark these against state-of-the-art sorbents.
NATSORB is expected to be a key contribution to clean water and to sorbent technologies. Scientific and technological findings will be directly applied in designing an environmentally friendly intervention to remediate the problem of heavy metal contamination in Røros. As dypingite is a product of carbon sequestration, our findings will be important for science communities beyond the sorbent technologies.