The metal complex catalysis with participation of unsaturated hydrocarbons gains great interest because of ecological aspect and a possibility of re-using of the catalyst. It has a number of advantages in comparison with a heterogeneous catalysis, such as high activity and selectivity, low temperatures of reaction and pressure. A palladium-polyvinylpyrrolidone complex was synthesized and characterized by potentiometry, conductometry, mass-, and IR-spectroscopy. The complex was tested for catalytic activity in reaction of octene-1 oxidation by inorganic oxidizers (KIO4, NaBrO3, Na2S2O8, K2S2O8) in dimethylsulfoxide or dimethylformamide under mild conditions. The reaction product was octanone-2, obtained in good yield (80-98 %) and characterized by gas chromatography and mass spectrometry. The catalysts can be easily recycled five consecutive runs without significant loss of catalytic efficiency. The use of different surface analysis techniques, such as: Scanning Electron Microscopy (SEM) and Energy-Dispersive X-ray spectroscopy (EDX), led to a better understanding of the polymer promoting effect.

Silicate mineral powders (SMP) from weathered granite soil from Kazakhstan are proposed for the desalination of potash brines containing sodium, potassium and chloride ions. Batch adsorption experiments using acid-treated silicate (AS) achieved a Na⁺/K⁺/Cl⁻ recovery of ~13/28/6 mg/g. An isothermal study best fitted the Freundlich and Dubinin–Radushkevich models for Na⁺ and K⁺/Cl⁻. The kinetic data were best modeled by pseudo-second-order kinetics for Na⁺/K⁺ and pseudo-first-order for Cl⁻. Thermodynamic calculations showed spontaneity under natural conditions. For Na⁺/K⁺, physisorption is accompanied by ion exchange. To study the possibility of sorbent reuse, several cycles of K⁺/Na⁺ adsorption–desorption were carried out under optimal conditions. AS selectively adsorbed potassium ions, maintaining a high effectiveness during five cycles providing K-form silicate fertilizers. Leachates of spent AS contain high concentrations of K/Na/Ca/Mg and other microelements essential for plants. Thus, SMP resolve two issues: the desalination of brine and the provision of fertilizer.

Nowadays the problem of wastewater pollution by heavy metal (HM) ions is extremely urgent. HM are harmful for health and environment, they are not biodegradable and can accumulate in plants and body. Clay minerals are known for their high adsorption capacity towards heavy metal ions. There are many research studies on appliance of different types of clays for wastewater treatment. Chamotte clay is a white heat-treated kaolin clay with stone properties, resistant to aggressive media, which contains highly dispersed hydroaluminosilicates. The clay does not require additional purification after secondary use. It is used in industry in large quantities, though wastes of clay are needed to be utilized. In current work chamotte clay wastes are offered to be used as a sorbent for lead (II) and cadmium (II) ions extraction. The choice of the ions is based on the high toxicity and abundance of these metals in wastewaters. Polivynylpyrrolidone (PVP) was used as a modifier to increase adsorption capacity of the clay. The extraction degree of ions by initial chamotte clay reaches (97 ± 7.2) % and (67 ± 6.0) % for Pb2+ and Cd2+ respectively. The modification with PVP increases the extraction degree of Cd2+ to (86.0 ± 6.4) %. The initial and modified clay wascharacterized by scanning electron microscopy, energy dispersive spectroscopy and Fourier transform infrared spectroscopy methods. The adsorption process was carried out under static conditions at pH = 6 and T = 298 K, initial concentration of the metal ions was 10 mg/l. The optimal mass for the sorption of lead and cadmium ions was also determined during the study and is equal to1 g per 100 cm3 of solution. The use of chamotte clay as the basis for the development of sorbents helps reducing the cost of cleaning water bodies, and also allows solving the problem of wastes disposal.

The present work considers the production of a cheap and effective sorbent based on natural clay from the Kyzylsok deposit (Almaty region) in order to purify wastewater from heavy metal ions (Cd2+, Pb2+). It was found that the starting material is applicable for the extraction of Cd2+ ions (the degree of extraction is (97.00 ± 1.99) %), while for the extraction of Pb2+ ions the initial clay must be modified. The modification was carried out using polyvinylpyrrolidone (PVP). The degree of extraction of Pb2+ ions with modified clay increased from (70.00 ± 1.77)% to (98 ± 1.13)% The influence of PVP concentration in the composite material (modified clay) on its sorption properties was studied: the optimal concentration of PVP was 0.1 % solution. The desorption of metal ions was also investigated in the work, it does not exceed 2%. It was found that the sorption process is described by the monomolecular Langmuir isotherm model and the kinetic model of the pseudo-second order.

In this work, sorbents based on natural zeolite (Z) and chamotte clay (ChC) treated with NaCl and HNO₃ solutions were obtained to extract Na⁺ and K⁺ ions from saline water. The physicochemical characteristics of the obtained sorbents were studied by SEM, EDAX, and BET methods. It was found that successive treatment with NaCl and HNO₃ solutions has a positive effect on the sorption properties of the studied materials. The maximum increase in the specific surface area from 4.5 m²/g to 39.3 m²/g is observed for acid-treated Z, and the specific surface area of ​​ChC also increases almost 2-fold from 8.4 m²/g to 15.3 m²/g. Na⁺ and K⁺ ions are extracted from water due to ion exchange with Z and ChC cations. As a result of determining the cation exchange capacity (CEC) of the studied sorbents, it was found that treatment with a NaCl solution improves the ion exchange properties of the sorbent and leads to the formation of a “homoionic” form of aluminosilicates. Due to that the sorbents more easily enter ion exchange reactions. The authors established the sorption activity of the obtained materials based on natural Z and ChC with respect to Na⁺ and K⁺ cations. The maximum recovery rate is 28.45% for Na⁺ ions with the ChC-Na-H sorbent and 76.28% for K⁺ ions with the ChC-Na sorbent. Among Z-based sorbents, the most effective forms are Z-Na-H (15.44% Na⁺ recovery) and Z-Na (60.47% K⁺ recovery).