The purpose of the Project related to Water Safety and Security is the creation of methods for the chemical modification and transformation of clinoptilolite and other natural zeolites to produce bactericidal filter materials suitable for use in water purification and decontamination. Several factors hinder the widespread use of zeolite bactericidal materials. So, the samples described in the literature have a rather low content of biologically active metals (no more than 0.3 meq/g), which determines the short duration of their action. When purifying drinking water, the possibility of secondary pollution of the treated water with these metals is very high, since the minimum inhibitory concentrations exceed the maximum permissible concentrations. Along with this, the mechanism of the bactericidal action of metal-containing zeolites is not clear, but the results of recent studies show that this activity is associated not only with metal ions, but also with the zeolite matrix itself.The group of researchers from the Institute of Physical and Organic Chemistry at Tbilisi State University (Georgia), South Kazakhstan State University (Kazakhstan) and Armenian National Agrarian University (Armenia), who presented the Project, believes that as a result of the project implementation, methods will be developed for obtaining new zeolite bactericidal filter materials with a high content of bioactive metals, but not releasing them into the aqueous medium, as well as materials that do not contain metals, but exhibit bactericidal activity.It is expected that due to the preliminary thermal and subsequent acid treatment of the raw zeolites, materials containing less impurities and more active centers on the surface will be obtained, as well as having a developed system of mesopores that ensure the free movement and adsorption of large molecules and ions that pollute water from various sources.In addition, as a result of pretreatment and ion exchange, materials with different content of silver, copper, and zinc (from zero to 1 meq/g) will be obtained, and subsequent thermal or combined treatment will allow obtaining metal-containing zeolites that do not release these metals into the aqueous medium. During the implementation of the Project, optimal conditions for the preparation of raw materials will be determined, the processes during thermal and acid treatment of zeolites, as well as ion exchange processes will be investigated, sorption and ion exchange capacities will be determined, as well as the bactericidal properties of the materials obtained; an environmental impact assessment will be carried out on the production of new zeolite materials. In the study of the composition, structure, and properties of the initial and modified zeolites, elemental analysis, X-ray diffractometry, Fourier transform infrared spectroscopy, scanning electron microscopy, and sorption measurements will be used.A full description of the properties of the original and modified zeolites will allow us to identify a possible cause of the bactericidal action of the zeolite matrix, which will be the main scientific result of the proposed Project. Based on these results, targeted modification of natural samples will make it possible to obtain bioactive-metal-free zeolites with similar properties and potential bactericidal activity. In general, the Project results will serve as a basis for creating a small or medium-sized enterprise for the production of zeolite materials for various purposes.
