Weathering and cementation of historic kimberlite residues from South Africa: Implications for residue stabilization and CO sequestration.

Enhanced weathering and carbon dioxide (CO) mineralization of ultramafic mine wastes, including kimberlite residues from diamond mining, provides secure storage of this greenhouse gas and may physically stabilize mine impoundments. Yet, the outcomes of these processes over extensive periods (i.e.

The Mining Industry's Role in Enhanced Weathering and Mineralization for CO Removal.

Enhanced weathering and mineralization (EWM) aim to remove carbon dioxide (CO) from the atmosphere by accelerating the reaction of this greenhouse gas with alkaline minerals. This suite of geochemical negative emissions technologies has the potential to achieve CO removal rates of >1 gigatonne per year, yet will require gigatonnes of suitable rock. As a supplier of rock powder, the mining industry will be at the epicenter of the global implementation of EWM.

Microscopic Raman study of fungal pigment using the genetically amenable rock inhabitant Knufia petricola as a model organism.

Fungal pigments such as melanin and carotenoids are distinctive markers of animal and plant pathogenic fungi as well as their environmental relatives. These complex pigments play important roles in pathogenicity and stress tolerance while also being useful as biomarkers. Accordingly, it is important to be able to identify in situ the pigments in black fungi, a group of clinical and environmental importance.

Environmental and Mineralogical Controls on Biosignature Preservation in Magnesium Carbonate Systems Analogous to Jezero Crater, Mars.

Jezero Crater on Mars is a paleolacustrine environment where Mg-carbonates may host evidence of ancient life. To elucidate the environmental and mineralogical controls on biosignature preservation, we examined samples from five terrestrial analogs: Lake Salda (Turkey), Lake Alchichica (Mexico), Qinghai-Tibetan Plateau (China), Mg-carbonate playas (British Columbia, Canada), and a mine with fine-grained ultramafic tailings (Yukon, Canada). The mineralogical compositions of the samples varied, yet were often dominated by either aragonite (CaCO) or hydromagnesite [Mg(CO)(OH)·4HO].

Carbonation, Cementation, and Stabilization of Ultramafic Mine Tailings.

Tailings dam failures can cause devastation to the environment, loss of human life, and require expensive remediation. A promising approach for de-risking brucite-bearing ultramafic tailings is in situ cementation via carbon dioxide (CO) mineralization, which also sequesters this greenhouse gas within carbonate minerals. In cylindrical test experiments, brucite [Mg(OH)] carbonation was accelerated by coupling organic and inorganic carbon cycling.

The role of chitin-rich skeletal organic matrix on the crystallization of calcium carbonate in the crustose coralline alga Leptophytum foecundum.

The organic matrix (OM) contained in marine calcifiers has a key role in the regulation of crystal deposition, such as crystalline structure, initiation of mineralization, inhibition, and biological/environmental control. However, the functional properties of the chitin-rich skeletal organic matrix on the biological aspect of crystallization in crustose coralline algae have not yet been investigated. Hence, the characterization of organic matrices in the biomineralization process of this species was studied to understand the functions of these key components for structural formation and mineralization of calcium carbonate crystals.

CaCO3 biomineralization on cyanobacterial surfaces: insights from experiments with three Synechococcus strains.

In the present paper, the impact of freshwater (ARC21 and LS0519) and marine (PCC8806) Synechococcus cyanobacteria on calcium carbonate (CaCO3) precipitation has been examined in respect of the formation rates and morphology of crystals. Acid-base potentiometric titrations were employed to study surface functional groups, while CaCO3 experiments have been carried out in presence and absence of cells at low to near-equilibrium conditions in respect to CaCO3. During these experiments, the pH values have been monitored, Ca and alkalinity were measured and precipitates have been investigated by Raman spectroscopy and Atomic Force and Scanning Electron microscopy.

Uranium accumulation by aquatic plants from uranium-contaminated water in Central Portugal.

Several species of plants have developed a tolerance to metal that enables them to survive in metal contaminated and polluted sites. Some of these aquatic plants have been reported to accumulate significant amounts of specific trace elements and are, therefore, useful for phytofiltration. This work focuses the potential of aquatic plants for the phytofiltration of uranium (U) from contaminated water.