Pollution of soils and water sources with heavy metals exerts negative impact on the environment related to the disturbances of ecosystem balance and harm to the health of living organisms and man. Organometallic frame sorbents capable to efficiently extract heavy metal ions from aqueous solutions have been synthesized to solve this problem. The authors have studied the regularities of the adsorption of cadmium, lead, copper, cobalt, and nickel ions using synthesized frame sorbents based on benzene-1,3,5-tricarboxylates (MBTC) and benzene-1,4-dicarboxylates (MBDC). The identification analysis by diffractograms of CoBTC and NiBTC powders shows the presence of structures [Co3(BTC)2⋅12H2O] and [Ni3(BTC)2⋅12H2O]. Contrary to NiBTC, NiBDC dicarboxylate is crystallized in triclinic syngony (spatial group P 1̅ , Z = 1) and corresponds to the crystal structure [Ni3(OH)2(BDC)2⋅4H2O]. The sample of CuBTC is crystallized in cubic symmetry with the space group Fm 3̅ m (Z = 16) and corresponds to the crystal structure [Cu3(BTC)2⋅3H2O], while the structure of the CuBDC compound is assigned to the monoclinic symmetry. The results of the analysis of isotherms of low-temperature nitrogen adsorption, using synthesized MOFs, enable the determination of important textural characteristics of sorbents. It is revealed that a strong adsorbate-adsorbent interaction is realized for CoBTC in the micropore region. It is shown that the specific surface area of synthesized sorbents calculated by the Brunauer–Emmett–Teller (BET) method varies widely: 276.0 and 9.0 m2/g for CoBTC and NiBTC compounds, respectively. These differences are related to a large number of micropores in the CoBTC sorbent. In most cases, the kinetic patterns of the adsorption of heavy metal ions may be described by a pseudo-second-order equation. Adsorption of copper ions on the NiBDC sorbent is the only example of the process, proceeding according to the kinetic equation of the pseudo-first order. Cobalt, nickel, and copper ions are better absorbed by sorbents containing the corresponding same-name ions according to the Peneth–Fajans rule. The linear relationship found between the sorption capacity and the logarithm of the ratio of the radius of ions to their electronegativity implies that the mechanism of adsorption of metal ions on MOFs is determined by physicochemical properties of the ions themselves. The developed organometallic frame compounds may be effectively used in technologies for purification of water resources from toxic heavy metal ions.

The thermodynamic parameters of formation reactions (total energy at 0 K, enthalpy, and Gibbs free energy at a temperature of 298.15 K and a pressure of 101 325 Pa) were estimated in the B3LYP-D3(BJ)/6-311++G** approximation for the products of ionic alkylation of adamantane and lower alkyladamantanes with ethylene and propylene. Aluminum chloride was used as an acid catalyst model. The quantum-chemical calculations demonstrated the effect of methyl groups in adamantanes and the molecular weight of the olefin on the energetics of formation of the corresponding alkyl- and alkenyladamantanes.

It has been stated that the use of complex titanium-containing agents can significantly increase the efficiency of wastewater treatment and achieve a reduction in residual concentrations of heavy metal compounds down to standard values. For further separation of coagulated sludge from purified water, it is proposed to use filtration methods with ceramic tubular filters. A significant increase in the filtration rate of titanium-containing coagulation sludge has been confirmed, leading to an increase in the productivity of treatment equipment by 20–30 %. It is recommended for purification of acid-base and chromium-containing wastewater to combine the process of coagulation of impurities by treating the wastewater with a complex titanium-containing coagulant, followed by filtering the resulting sludge using special ceramic tubular filters.

A multi-stage process is considered for the formation of vinyl adamantane via the ionic alkylation of adamantane with ethylene using aluminum chloride as a catalyst. A feature of the ionic alkylation of adamantane with olefins is the formation of saturated and unsaturated derivatives. Quantum chemical methods means are used to study the kinetic and thermodynamic parameters of the corresponding elementary acts of chemical reactions. A comparative analysis of the characteristics of the reaction for the production of unsaturated adamantane derivatives via ionic alkylation with ethylene is performed using alkylation with propylene.

The study investigates propane conversion in the presence of rare-earth metal zirconates Ln2Zr2O7 (Ln = La, Gd, and Lu) prepared by high-temperature solid-phase synthesis at 500, 1000, and 1500°C. In the La2Zr2O7 → Gd2Zr2O7 → Lu2Zr2O7 series, the phase transitions were found to follow the pyrochlore → defective fluorite → δ-phase route. This changed the parameters of the crystalline and local structures and, in particular, led to the appearance of oxygen vacancies in pyrochlore-based compounds. As a result of the structural changes, propane dehydrogenation prevailed over propane degradation. Therefore, the Lu2Zr2O7 catalyst exhibited a higher propylene selectivity (up to 65

The comparative study of the catalytic behavior of K-modified CoMoS2-catalysts supported on Al2O3, carbon covered alumina (CCA) and graphene coated alumina (GCA containing 0.4, 1.2, and 1.7% of graphene) in synthesis gas and ethanol conversion (separately) to higher alcohols (HAS) and other oxygenates has been carried out. The supports and catalysts were characterized by N-2 adsorption-desorption isotherms, pyridine adsorption, SEM, EDX, and TEM. In HAS from syngas, the catalyst supported on GCA materials showed better catalytic performances than the catalysts supported on alumina and carbon coated alumina (Cat-GCA > Cat-CCA > Cat-Al2O3). The spectroscopic results have established that the homogenous uniform coating of alumina by graphene nanosheets follows the order: GCA1 (1.7%) > GCA2 (1.2%) > GCA3 (0.4%). The yield of ethanol has a positive correlation with graphene wt. % in GCA. In ethanol conversion, graphene attenuate the interaction of the support/active site KCoMoS2 and with it its selectivity toward dehydrogenation/condensation reactions. The GCA1 supported catalyst exhibits low activity for the water-gas shift (WGS) reaction compared to its counterpart. Explanations of the observed phenomena have been suggested.

We presented the results of a study of the adsorption capacity of domestic activated carbon grades AR-A and AR-B, and a coal from Baojun Activated Carbon (China) with respect to benzene vapor. All used adsorbents are designed to purify air from vapors of volatile organic compounds, but differ in production technology and physicochemical characteristics. It has been established that the efficiency of Baojun Activated Carbon’s activated carbon in the adsorption of benzene vapor is higher than that of domestic samples of AR-A and AR-B grades. At the same time, among foreign-made coal, the most effective sample was Baojun 4.0/90, which has a high adsorption capacity, declared in relation to carbon tetrachloride vapor. It has been experimentally shown that in all cases the kinetics of the adsorption process is well described by the Ho and MacKay pseudo-second order equation. Similar results were obtained using the Morris --- Weber model, which takes into account the role of diffusion processes in the adsorption of benzene vapor by activated carbons. The use of the Lagergren equation and the simplified Elovich model for processing experimental data showed less significant results

The effect of substitution of cobalt by iron in perovskite-type oxides GdCoxFe1-xO3 (x = 0; 0.5 and 1) on their physical properties and catalytic performance in dry reforming of methane (DRM) was investigated. The perovskites were synthesized by sol-gel technology and characterized by XRD, DTG/TG, BET specific area, TPR and SEM. It was established that the introduction of cobalt into the B site of the perovskite-type structure of ferrite leads to an increase in catalytic performance, and, consequently, to a decrease in the process temperature. It was found that catalytic activity depends on the proportion of cobalt in the B site and increases in the row: GdFeO3 < GdCo0.5Fe0.5O3 < GdCoO3. Probably, such behavior of Co-containing catalysts is associated with the formation and stabilization of a more catalytically active Co-Gd2O3 system under the action of the reaction mixture. It has been assumed that the element in A-site (Gd) is responsible for dissociative chemisorption of CO2 and ions in site B (Fe and Co) are responsible for the formation of atomic hydrogen.

This review discusses various issues related to the synthesis of unsaturated adamantane derivatives, to the development of novel methods for their preparation, and to the polymerization reactions. Furthermore, we appraised the potential of quantum-chemical calculations for investigating the electronic structure of adamantane derivatives and for elucidating the mechanisms for their chemical and catalytic transformations.

A potentiometric study is conducted of equilibria of the formation of silver(I) complexes with thiourea and N-phenylthiourea (L) using a silver electrode in the 278.16–318.16 K range of temperatures at an ionic strength of I = 0.11 M (0.1 NaNO 3 + 0.01 HNO 3 ). It is found that mono- and binuclear complexes are present in the studied systems in a wide range of concentrations of Ag + ions (1 × 10 −5 –1 × 10 −3 ) in solution at different temperatures, and the Ag 2 L 3 2+ form dominates in both systems. It is shown that the stability of mono- and binuclear complexes falls as the temperature rises. Thermodynamic parameters (Δ H °, Δ G °, and Δ S °) are determined for mononuclear complexes.

Composite catalysts containing various forms of metallic or oxide iron ((Fe0 or FexOy, Fe3+) in combination with an inert matrix (gamma-Al2O3) were obtained and their catalytic ability in the propane cracking reaction was studied. It is shown that for pure aluminum oxide, no catalytic effect is observed in this reaction. The synthesis methods im-plemented in this work allowed us to obtain various catalytic centers that can effectively carry out electron transfer by changing the degree of iron oxidation during the transformation of the initial substances into the target reaction products. It is proved that the use of iron nano-particles for formation of catalytic centers does not lead to a noticea-ble improvement in the technological yield of propylene compared to the Fe3+/Al2O3 material. Use of an inert oxide substrate (gamma-Al2O3) and various iron compounds makes it possible to create a bifunctional catalytic center contain-ing Fe(III) and Al(III) ions, which provides an energetically favorable interaction with the propane molecule and further breaking of the strongest C-H bond at a primary carbon atom. The synthesized catalytic systems can be used for thermocatalytic processes in natural gas processing instead of catalysts based on noble metals.

Silver(I) complex formation with thiourea (Tu), N-phenylthiourea (Phtu), N,N'-diphenylthiourea (Bphtu), N-acetylthiourea (Aсtu), and thiosemicarbazide (Tsc) in aqueous solution at temperatures in the range 278.2–328.2 K at the ionic strength I = 0.11 mol/L (0.1 NaNO3 + 0.01 HNO3) was studied potentiometrically. The reactions yield various complexes by the scheme Ag+ + iL = $${\text{AgL}}_{i}^{ + }$$ where i = 1–3, at $$C_{{{\text{A}}{{{\text{g}}}^{ + }}}}^{0}$$ = (1–5) × 10–5 mol/L. The thermodynamic characteristics (logβi, ΔrG0, ΔrH0, and ΔrS0) for these reactions were determined. The highest rise in exothermicity (ΔrH0) was observed for the second complex formation step: AgL+ + L = $${\text{AgL}}_{2}^{ + }.$$ The exception is the reaction with thiosemicarbazide. The stabilities of monocoordinated complexes vary in the order Aсtu < Tsc < Bphtu < Phtu < Tu, in good match with the protonation constants of the respective ligands. For the $${\text{AgL}}_{2}^{ + }$$ and $${\text{AgL}}_{3}^{ + }$$ complexes of Phtu and Bphtu, this trend is spoiled because of the influence of phenyl substituents on the complex-forming properties of these thiourea derivatives.

The development of modern thermocatalytic technologies for processing oil and gas raw materials is one of the promising areas for the advancement of chemical production. New highly efficient catalytic systems with the required technical characteristics and long service life play an essential role in solving these issues. The paper focuses on obtaining propylene by selective propane dehydrogenation. In the course of the experiments, composite iron-containing catalysts were synthesized, in which the active component is iron oxide in combination with an inert carbon matrix. FAS activated carbon and carbon nanotubes were used as the matrix. As a result of the synthesis on the catalyst surface it was possible to obtain catalytic centers that transfer electrons by changing the degree of iron oxidation when converting the starting materials into the target reaction products. Findings of research show that the obtained iron-containing catalysts significantly increase the efficiency of the process in comparison with the efficiency of thermal cracking of propane. Thus, the Fe3+/FAS catalyst showed a conversion rate of the initial reagent of 68 % and a propylene selectivity of about 42 %. Further transition to catalytic systems based on singlelayer and double-layer carbon nanotubes modified with iron oxide (Fe3+/CNTI and Fe3+/CNTII) made it possible to obtain propane conversion up to 37--40 % with a decrease in propylene selectivity to 29--30 %. Studies of the service life of the synthesized catalytic systems and the possibility of their regeneration show that, with account for the regeneration, the activity of the catalysts and the main technical characteristics of the propane-to-propylene cracking process remain unchanged for 10 working cycles

The effect of gamma irradiation on physico-chemical properties of petro-diesel fuel using different rate and absorbed doses has been studied. The diesel fuel samples were exposed to gamma radiation for 1.3 h using different absorbed doses: 3, 6, 10, and 15 kGy, with dose rates 2.27, 4.5, 7.4, and 11.15 kGy/h, respectively. Physico-chemical characteristics of diesel fuel were determined according to the standard test methods assigned by ASTM, characteristics are: cetane number, distillation recovery points, flash point, calorific value, density, and kinematic viscosity. The effect of gamma irradiation doses on organic compounds of diesel fuel was study using GC/MS technique. Experimental results show that the density, distillation, kinematic viscosity and flash point were decreased at absorbed doses 3, 6 and 15 kGy whereas increases at 10 kGy, corresponding with rate doses. Cetane number of diesel fuel increased after exposure to 3, 6, and 15 kGy but decreased at 10 kGy. These results can be attributed to the broken and formed bonds as a result of the high applied energy. The formed fragments at (10 kGy; 7.5 kGy/h) made a new compounds that have physical parameters affected negatively on the overall properties of diesel fuel. The formed fragments in diesel fuel after exposed to 3, 6, and 15 kGy (2.27, 4.5, and 11.15 kGy/h) have converted some of cyclic, aromatic, and branched organic compounds to linear hydrocarbons, which supported increasing of cetane number to 54. All characteristics have been improved within limits assigned by ASTM.

This paper describes non-catalytic and catalytic pyrolysis of plastic waste materials. Four types of waste plastics were used in study: high density polyethylene (PE), low density polypropylene (PP), polyethylene terephthalate (PET). Plastic waste was decomposed into three fractions under pyrolysis conditions: gas, liquid and solid residual. The use of vanadates MeVO4 and vanadites MeVO3 of REM (Me=La, Gd, Lu) as catalysts let to change the yield of the gas fraction and change the composition of the gaseous pyrolysis products. Catalytic decomposition increased the amount of the gaseous products by 15-20 %, reduced the condensate, and changed their composition with regard to the non-catalytic process at the same pyrolysis temperature. The total number of reaction products was determined in each fraction. The quantitative analysis of the composition of the gas fraction was performed by gas-liquid chromatography. The study of non-catalytic pyrolysis of plastics and thermogravimetric analysis let to determine the most favorable temperature conditions for the implementation of the catalytic pyrolysis. The catalytic pyrolysis of plastics was carried out in order to obtain the maximum yield of valuable gaseous products. The synthesized vanadites and vanadates of REM were used as catalysts. When using catalysts based on lanthanum and gadolinium compounds, a regular change in the amount of gaseous substances was observed without significant changes in their composition. The use of lutetium vanadate and lutetium vanadite demonstrated a phenomenal result that is associated with the cardinal change of structure of degradation products of PET. The syngas was obtained instead of acetaldehyde. This result is related to the structure of the used catalyst.

The low solubility of a biologically active substance in an aqueous medium is often the main reason for the reduced therapeutic effect of drugs. The most common approach to solve this problem is to obtain a watersoluble salt of the active substance and an appropriate preparatory formulation based on it. In this case, the solubility of the obtained compound in hydrophobic systems decreases dramatically, which decreases the rate of transmembrane transport and changes the pharmacokinetic laws of the process. In practice, not only the dependence of the therapeutic effect on the salt compound properties, but also a complete loss of the drug active ingredient activity can be observed. The use of biologically active compound solid dispersions in watersoluble polymers is the most promising approach to increase the therapeutic effect of drugs while maintaining the hydrophobic nature of the active component, to reduce the dose load on the patient’s body and obtain prolonged action. In experiments we obtained solid dispersions of mefenamic acid in polyvinylpyrrolidone and studied kinetic regularities of solubility of this promising drug form in aqueous solution of phosphate buffer. By means of mathematical modelling it was found that the phenomenon under study is well described by Ritger --- Peppas model, which considers diffusion of biologically active component into solution according to Fick's law with possible influence on mass transfer at swelling and degradation of polymer matrix

The paper studies the process of analysis of tetracycline and paracetamol with the use of the HKUST-1 organometallic framework sorbent by high performance liquid chromatography. To obtain experimental data using the previously described technique, a sample of the material under consideration was synthesized and its physicochemical properties were studied. It has been established that individual sorbent particles have an octahedral shape and have a porous structure capable of adsorbing chemical compounds of various nature. The specific surface of the sample was calculated using the BET method and was Ssp = 551.3 m2/g. The study notes that when water or aqueous-organic media are used as eluents for chromatographic analysis, sorbents based on HKUST-1 have low stability; their degradation is observed when passing eluent solutions in an amount equal to 300--500 volumes of the chromatographic column. When only organic solvents are used for chromatographic analysis of tetracycline and paracetamol in the temperature range of 25--45 °C, no decomposition of the HKUST-1 sorbent and no degradation of the analyzed drugs are observed. Findings of research show that the efficiency of the eluent increases in the tetrahydrofuran--methanol--acetonitrile series. For all organic solvents used, the retention times were determined, the degree of separation, HETP, and the speed of response were calculated at various temperatures. A complex of studies has proved the possibility of using the organometallic sorbent HKUST-1 for the effective separation of drug mixtures by high-performance liquid chromatography