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Nepheline, ideally Na3K(Al4Si4O16) is a key mineral of silica-undersaturated igneous rocks. Under subsolidus conditions, nepheline is intensively replaced by numerous secondary minerals, of which various zeolites (mainly natrolite, analcime, gonnardite), as well as cancrinite, muscovite and Al-O-H phases (gibbsite, böhmite, nordstrandite) are the most common. In the rocks of the Lovozero alkaline massif (Kola Peninsula, NW Russia), nepheline is extensively replaced by the association natrolite + nordstrandite ± böhmite ± paranatrolite. To reproduce the conditions for the formation of such a mineral association, a series of experiments were carried out on the dissolution of nepheline in deionized water, 0.5 mol/L NaCl, 0.5 mol/L NaOH, and 0.1 mol/L HCl at 230 °C for 1/5/15 days. When nepheline is partially dissolved, phases and mixtures of phases precipitate on the surface of its grains, and these phases were diagnosed using X-ray powder diffraction and Raman spectroscopy. Observations in natural samples and experimental studies have shown that the nepheline alteration in the rocks of the Lovozero massif with the formation of natrolite and Al-O-H phases occurred under the influence of a high to medium salinity solution at a pH of near 6. [ABSTRACT FROM AUTHOR]

Research of deionized water after filtration with shungite was performed. For the research of physicochemical parameters, the filtration lasted 24 hours for 50 g shungite in 1 L deionized water with conductivity 3.13 µS cm-1. For in vitro studies of microbiological parameters, the effect of shungite was studied for 12 and 36 hours. The research was performed with Staphylococcus aureus and Escherichia coli. The shungite was received from Russian Federation with Material Safety Data Sheet and Certificate of conformity. The study was executed according to Ordinance No. 9/2001 with determination of 31 physicochemical parameters and additionally of potassium (K), hydrocarbonates (HCO3 -) and carbonates (CO3 -). After filtration with shungite, all 34 parameters were in norm and the water was suitable for drinking. The pH of shungite deionized water was 6.30. The pH of deionized water before the research was 6.09. The study proved that deionized water after filtration through shungite is not saturated with minerals of greater value than the normal one. Analyzes for the filtering properties of shungite are shown. The antibacterial effect of shungite water (aqueous infusions of shungite) obtained for 12 and 36 hours was tested. Staphylococcus aureus-ATCC and TSA-MRSA and Escherichia coli ATCC strains were used in the studies. Both tested aqueous infusions of shungite reduced the amount of viable E. coli and S. aureus cells even when they were in high concentrations (106 cells mL-1). The effect of the 36-hour infusion was better, under the influence of which after 15 min the number of live bacteria from the two tested species decreased to 85.5 + 5.0 %. After 120 min, the 12-hour infusion completely inactivated E. coli cells and reduced those of S. aureus to 38.8 + 7.4%. However, about 25 % of S. aureus cells survived after 24 hours of exposure to both aqueous infusions of shungite, and 20 % of them - even after 96 hours of exposure to these infusions. The antibacterial effect of the two aqueous infusions of shungite was established. These results show prospects for the use of shungite water as a prophylactic and adjuvant treatment for bacterial gastroenteritis and other infections. [ABSTRACT FROM AUTHOR]

Borosilicate glass specimens incorporating 10, 15, and 20 wt % simulated high-level waste (HLW) were leached at 20, 90, and 120°C in deionized water following the procedure accepted in Russia, GOST (State Standard) R 52 126-2003. At 90°C, the altered surface layer is formed already from the first days of leaching. The main interaction in the system occurs at the phase boundary between the altered surface layer and water, rather than at the phase boundary between the glass and water through the porous surface layer as it is commonly believed. The altered surface layer acts as a natural barrier preventing transfer of simulated waste components to the liquid phase. The barrier properties of the altered surface layer are manifested to the greatest extent at 20 wt % content of simulated HLW in the initial glass and leaching temperature of 120°C. [ABSTRACT FROM AUTHOR]