Research of Zeolite and Zeolite Water from Rhodope Mountains, Bulgaria

The physicochemical composition and antibacterial effect of aqueous zeolite infusion (spring zeolite water Sevtopolis with zeolite from deposit Beli plast, Bulgaria) obtained for 12 and 36 hours was tested. Ordinance No. 9/2001, Official State Gazette, issue 30, and Decree No.178/23.07.2004 regarding the quality of water intended for drinking and household purposes were applied to study the physicochemical composition. Staphylococcus aureus-ATCC and TSA-MRSA and Escherichia coli ATCC were used in the studies. Both tested zeolite waters reduced the amount of viable E. coli and S. aureus cells even when they were in high concentrations (106 cells/ml). The effect of the 36-hour infusion was better, under the influence of which after 60 minutes the number of live bacteria of both tested species decreases by almost half compared to the initial amounts. Slightly higher sensitivity to two zeolite waters was shown by E. coli, whose cells were reduced to about 35% after two hours of exposure zeolite water tested. However, about 20% of the cells of the tested bacteria survived even after 96 hours of exposure to these waters. Only in E. coli no growth was found after 96 hours of exposure to 12 hours zeolite water. These results show the effectiveness of zeolite for water purification from Gram-positive and Gram-negative bacteria, as well as prospects for the use of zeolite water as a prophylactic and auxiliary treatment for bacterial infections.

First-Generation Organic Reaction Intermediates in Zeolite Chemistry and Catalysis

Zeolite chemistry and catalysis are expected to play a decisive role in the next decade(s) to build a more decentralized renewable feedstock-dependent sustainable society owing to the increased scrutiny over carbon emissions. Therefore, the lack of fundamental and mechanistic understanding of these processes is a critical "technical bottleneck" that must be eliminated to maximize economic value and minimize waste. We have identified, considering this objective, that the chemistry related to the first-generation reaction intermediates (i.e., carbocations, radicals, carbenes, ketenes, and carbanions) in zeolite chemistry and catalysis is highly underdeveloped or undervalued compared to other catalysis streams (e.g., homogeneous catalysis). This limitation can often be attributed to the technological restrictions to detect such "short-lived and highly reactive" intermediates at the interface (gas-solid/solid-liquid); however, the recent rise of sophisticated spectroscopic/analytical techniques (including under in situ/operando conditions) and modern data analysis methods collectively compete to unravel the impact of these organic intermediates. This comprehensive review summarizes the state-of-the-art first-generation organic reaction intermediates in zeolite chemistry and catalysis and evaluates their existing challenges and future prospects, to contribute significantly to the "circular carbon economy" initiatives.