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The anatase phase of titanium dioxide TiO₂ is metastable and irreversibly converts to rutile at a temperature above 700 °C. This is accompanied by a significant decrease in the specific surface area and a change in the porous structure. Modification of titanium dioxide by the addition of alumina leads to the formation of the nanocrystalline structure of anatase and to a significant increase in the temperature of anatase to rutile phase transition up to 950 °C. After high-temperature annealing, the Al₂O₃-TiO₂ sample is characterized by a higher specific surface area and a better developed porous structure than those of pure anatase with the regular crystal structure. The high thermal stability of the anatase phase in supported Pt/(Al₂O₃-TiO₂) catalysts under calcination provides a high dispersion of platinum particles, which leads to the rather high catalytic activity of these catalysts in CO oxidation.

The use of copper oxide complexes (CC) of various structures: CC-I (copper tetrammine complex with the ground state of copper ions (d_x² - d_y²), characterized by a weak exchange magnetic interaction in the EPR spectra) and CC-III (Cu²⁺ ions with the ground state (d_x² - d_y²), with the strong exchange magnetic interaction) in the synthesis of Cu/ZSM-5 catalysts allowed us to study the effect of their structure on the physicochemical and catalytic properties in the decomposition of nitrogen (I) oxide (N₂O). It was demonstrated by means of H₂-TPR and IR spectroscopy of adsorbed CO that the nature of the reduction of Cu/ZSM-5 catalysts is determined by the state of copper in the catalyst. It was established that the highest catalytic activity is observed for the catalysts prepared using CC-III. Extraframework CuO-like clusters stabilized on the outer surface of zeolite crystallites prepared using CC-III are the most effective centres for the decomposition of nitrous oxide, and the activity of catalysts increases with an increase in copper content.

Processing of the nitric solutions from the production of bismuth compounds by adding water was studied by means of X-ray phase and chemical analyses, and electron microscopy. It is shown that bismuth gets precipitated from solutions at the process temperature of 65±5 °C and pH 0.7-1.0 in the form of oxohydroxonitrate [Bi₆O₄(OH)₄](NO₃)₆•H₂O, and washing with water causes hydrolysis with the formation of high-purity [Bi₆O₅(OH)₃](NO₃)₅•3H₂O compound. These compounds are used as precursors for obtaining high-purity bismuth compounds through a solid-liquid reaction. It is demonstrated that the treatment of bismuth oxohydroxonitrate with the solutions of citric, gallic, tartaric, salicylic, nitric acids and ammonium carbonate may result in obtaining bismuth citrate BiС₆Н₅О₇, bismuth oxogallate trihydrate C₆H₂(OH)₃COOBiO•3H₂O, bismuth ditartrate trihydrate [Bi(C₄H₄O₆)(C₄H₅O₆)]•3H₂O, bismuth oxide salicylate Bi(C₇H₅O₃)O, bismuth nitrate pentahydrate Bi(NO₃)₃•5H₂O, bismuth oxocarbonate (BiO)₂CO₃, respectively. The powders of metal bismuth with particle size 1-5 and 10-50 mm were obtained by the reduction of oxohydroxonitrates of the compositions [Bi₆O₄(OH)₄](NO₃)₆•H₂O and [Bi₆O₅(OH)₃](NO₃)₅•3H₂O, respectively, in the solution of benzyl alcohol. The reduction of these oxohydroxonitrates in ethylene glycol solution in the presence of hydrazine hydrate in the case of [Bi₆O₄(OH)4](NO₃)₆•H₂O results in the formation of bismuth glycolate, while in the case of [Bi₆O₅(OH)₃](NO₃)₅•3H₂O - in the formation of metal bismuth with particle size 10-50 mm. The powders of metal bismuth with particle size 1-5 and 10-50 mm were obtained by means of the reduction of the compounds [Bi₆O₄(OH)₄](NO₃)₆•H₂O and [Bi₆O₅(OH)₃](NO₃)5•3H₂O, respectively, in the aqueous medium with sodium borohydride as the reducing agent, with the molar ratio of bismuth/sodium borohydride = 1, pH 12 and a temperature of 25 °C.

The review of the data on the chemical composition and biological activity of the genus Monarda L. represented by 20 species growing in North America is given. M. fistulosa L., M. didyma L. and M. citriodora Cervantes ex Lag. are successfully cultivated in various regions of Russia. The essential oils of Monarda are distinguished by the high content of phenols (67-89 %). Their composition depends on the species of Monarda , vegetation phase, site of growth, weather conditions. Under the conditions of a sharply continental Siberian climate (Novosibirsk), M. fistulosa has a high content (up to 4.16 %) of essential oil, more than in the Crimea and the North Caucasus. The phenolic complex contains flavonoids, anthocyanins and phenolic acids. Specific to the species of this genus is monardein, 3-O-(6-O- trans - p -coumaryl-β- D -glucopyranosyl)-5-O-(4,6-di-O-malonyl-β- D -glucopyranosyl)pelargonidine. The essential oil and extracts of Monarda have a high bactericidal, antiviral, antifungal activity, anti-inflammatory, analgesic, immunomodulatory, antioxidant, radioprotective, antioncological, etc . action. The oil extract of the aerial parts of M. fistulosa showed antimicrobial activity against pathogenic microorganisms: Staphylococcus aureus , Enterobacter cloacae , Streptococcus faecalis , Escherichia coli , etc . The aqueous-ethanolic and aqueous extracts showed high antiviral activity against influenza virus, subtype A/Aichi/2/68 (H3N2) (human) and A/chicken/Kurgan/05/2005 (H5N1) (birds). The extracts of Monarda also possess pronounced fungicidal properties. The activity of oil, water and water-alcohol extracts of M. fistulosa against the yeast-like fungus Candida albicans was very high. Thymol and thymoquinone from M. fistulosa are cytotoxic against certain lines of human tumour cells. The essential oil from M. citriodora and its main component, thymol, inhibit the proliferation of HL-60, MCF-7, PC-3, A-549 and MDAMB-231 cancer cells. Carvacrol also has an antioxidant and antitumour effect. Essential oil is used in the cosmetic and food industry to flavour vermouths, stabilize wines, and also as a natural flavouring agent, preservative and antioxidant instead of synthetic food additives. To expand the domestic market of raw materials, it is advisable to grow Monarda in culture.

The problem of sawdust utilization represents a challenge for almost all regions of Russia. At the same time, agricultural lands suffer from acute deficiency of organic fertilizers. The technology of sawdust composting using an association of microorganisms, which has been developed at the Irkutsk Institute of Chemistry SB RAS, allows, at least partially, addressing both of these problems. The paper deals with the main agrochemical indicators of the fertilizer produced from sawdust. Composting is carried out using different types of sawdust (deciduous and coniferous) over different years in various regions of Russia. It is shown that regardless of the substrate composition, time and place of composting, the fertilizer is stable in terms of composition and basic agrochemical indicators. The total amount of nitrogen, phosphorus, and potassium in the compost is comparable to that in high-quality organic fertilizers like high-moor peat, while the content of the mobile forms of main biogenic elements is higher. These substances, as well as humic acids, which are contained in the fertilizer, ensure the effective growth and development of plants during the vegetation season. The finished compost has a high cation exchange capacity and low hydrolytic acidity, which allow decreasing the removal of cations from plough layers. The advantages of the compost include close-to-neutral pH value and the absence of weed seeds and phytopathogens. The fertilizer does not contain phytopathogenic microorganisms and parasites, and the amount of toxic and hazardous substances is much lower than the maximum permissible concentrations established for soils. The use of this compost will not only increase the yield of agricultural crops, but also permit to eliminate the large-tonnage waste of timber processing enterprises.

Biodiesel is synthesized from five different types of vegetable oils (sunflower, mustard, linseed, corn and camelina). The yields of the target product, the physicochemical and low-temperature properties of the obtained biodiesel fuels are determined. The effect of the additive on the low-temperature properties of biodiesel and its blends with petroleum diesel fuel is investigated. It is shown that the low-temperature additive for petroleum diesel fuels is ineffective for improving the low-temperature properties of biodiesel. It is established that the efficiency of the low-temperature additive decreases with an increase in the proportion of biodiesel in the blend with diesel fuel. The expediency of using biodiesel as a blend component of commercial diesel fuels is shown. Recommendations on the use of “biodiesel/diesel fuel/low-temperature additive” blends as commercial diesel fuels of the Summer grade and Off-Season grade according to GOST (State Standard) 305-2013 “Diesel fuel. Technical Specification” are developed.

Analysis of the chemical and physical methods of water decontamination is carried out, the advantages and shortcomings of their application are revealed. A new approach to water treatment at centralized water-preparation stations is proposed. The approach involves the treatment of natural surface water, as the source of drinking water supply, by means of air floatation using ceramic membranes, coagulation (with aluminium sulphates or hydroxochlorides), filtration (through sand filters) to prevent biofouling and to enhance the efficiency of decontamination of purified transparent water after filtration, irradiation with ultraviolet light and subsequent water conservation by carbon dioxide (to restrain the growth and propagation of microflora in the distributing network). Additional decontamination of water from the city water supply in the case of the necessity to use it for drinking purposes may be carried out by boiling. This will allow complete elimination of the chlorination of piped water and the negative effects of this kind of treatment.

The samples of humic acids (HA) isolated from brown coal, both native and modified with hydrogen peroxide and n- butanol, were obtained and studied by means of elemental and technical analysis. The changes of structural parameters and the concentration of paramagnetic centres (PMC) of modified HA were revealed by means of ¹³C NMR, IR, EPR spectroscopy. The biological activity of native and modified HA was evaluated by means of phytotesting with the seeds of Iren wheat as an example. A trend to a decrease in the biological activity of HA with a decrease in PMC content was discovered. An increase in biological activity is connected with an increase in parameter F₁ depicting the relations between hydrophilic and hydrophobic elements in HA structure.

Mannich reaction of 6-methyluracil with salsolidine and substituted 1-aryl-6,7-dimethoxy-1,2,3,4-tetrahydroisoquinolines was studied. The use of equimolecular amounts of reagents led to the production of new conjugates - 5-(1-(aryl-6,7-dimethoxy-1,2,3,4-tetrahydroisoquinolyl)-2-methyl)-6-methylpyrimidin-2,4(1 Н ,3 H )-dions with 61-84 % yields. When studying the effect of these conjugates on the growth and viability of tumour cell lines (HeLa, HEp-2), it was found that the formation of tetrahydroisoquinoline derivatives with 6-methyluracil molecule does not contribute to the manifestation of cytotoxic effect.

Systematic studies in the field of the synthesis of ethers based on glycerol and polycyclic unsaturated hydrocarbons have been carried out. The reactions of glycerol addition to cyclohexene, bicyclo[2.2.1]hept-2-ene, tricyclo[5.2.1.0^2,6]deca-3,8-diene, tetracyclo [4.4.1^2,5.1^7,10.0^1,6]dodec-3-ene and their alkyl-substituted derivatives were carried out in the presence of a homogeneous catalyst - boron trifluoride etherate (BF₃ · OEt₂). It was revealed that the BF₃ · OEt₂ catalyst promotes the successful transformation of the above-indicated polycyclic olefins and their alkyl-substituted derivatives into glycerol monoethers in the yields of 70-87, 81 and 64-74 %, respectively. The effects of temperature, reaction duration, the molar ratio of initial components and the amount of the catalyst on ether yields were studied, and the optimal conditions for the synthesis of bi-, tri- and tetracyclic glycerides were determined. The synthesized ethers may be used as additives to synthetic oils.