Silylation of clay minerals from Cherkasy deposit (Ukraine) montmorillonite (layer silicate) and palygorskite (fibrous silicate) was performed using organosilane (3-aminopropyl)triethoxysilane (APTES). Solvents with different polarity (ethanol, toluene) were used in synthesis. The structure of modified minerals was characterized by complex of methods (X-ray powder diffraction, Fourier transform infrared spectroscopy, nitrogen adsorption-desorption at −196 °C and thermal analysis). Studies of adsorption characteristics of APTES-modified clay minerals were carried out in relation to uranium (VI). The results indicated that modified montmorillonite and palygorskite were effective materials for water purification from UO22+.

Materials based on CeO2-La2O3-Eu2O3 and La2O3-Eu2O3 systems are promising candidates for a wide range of applications, but the phase relationship has not been studied systematically previously. The phase relations in the CeO2-La2O3-Eu2O3 ternary system at 1500?C and binary La2O3-Eu2O3 system at 1600-1500?C were studied in air by X-ray diffraction (XRD) investigation in the overall concentration range. The isothermal section of the phase diagram for the CeO2-La2O3-Eu2O3 system has been constructed. It was established that in the ternary CeO2-La2O3-Eu2O3 system there exist fields of solid solutions based on hexagonal (A) modification of La2O3, cubic modification of CeO2 with fluorite-type structure (F), cubic (C) and monoclinic (B) modification Eu2O3. It was established that in the binary La2O3-Eu2O3 system there exist fields of solid solutions based on hexagonal (A) modification of La2O3 and monoclinic (B) modification Eu2O3. The phases were separated by two-phase fields (A+B). The refined lattice parameters of the unit cells for solid solutions and microstructures of the definite field of compositions for the systems were determined.

Based on the modern ideas about environmental protection, this paper reports a study into the utilization of water-treated waste from heavy metals (using copper(II) compounds as an example) for the manufacture of ceramic building materials. The examined clay minerals from local deposits and the optimal conditions for their heat treatment (at 1,100 °C) have been proposed for the sorption removal of pollutants of inorganic origin from wastewater. The use of wastewater after its treatment makes it possible to address several tasks at the same time: to protect the environment from pollution by technological wastewater, as well as to reuse wastewater in order to resolve the issue of water scarcity. Ceramic building materials were manufactured based on water purification waste (in the amount of 5 %) and clay raw materials. Their structural-mechanical and physicochemical characteristics have been comprehensively studied. Sintering processes begin at lower temperatures, which is why, with an increase in the annealing temperature to 1,000 °C and higher, their strength rapidly decreases. In the temperature range of 600‒1,100 °C, there are possibilities to apply ceramic technology to immobilize heavy metals in ceramic matrices. The prospect of utilizing water purification waste in the technological process of manufacturing inorganic ceramic materials has been shown. The safety of the building materials, manufactured by leaching pollutants from the ceramic samples using various aggressive environments (leaching to 6.4 %, 0.083 mg·cm2/day) has been investigated. The high strength and degree of the copper ion fixation in the structure of polymineral clay have been confirmed while secondary environmental pollution is almost absent

No abstract

No abstract