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The paper presents the results of biological tests of granular complex humic fertilizers (CHF) with the addition of carbamide (urea) and simple superphosphate. CHF samples were obtained from lignite (brown coal) of the Tisulskiy deposit (the Kaychakskiy plot, Kemerovo Region), their production method is given. Samples of complex granular fertilizers, initial coal and humic acids (HA) were characterized using ¹³С CP/MAS NMR, technical and elemental analysis. An integral indice, i. e. the index of phytoactivity (IP) that was calculated as the average value of the sum of indicators of the germinative energy, the seedling height (SH) and root length of seeds was used for objective testing. It was performed on seeds of spring wheat Iren by soaking them in an aqueous solution of CHF. Seeds were germinated under the conditions of GOST 12038-84. The effect of major components that were HA and mineral additives contained in the composition of CHF was determined. It was found that alongside with the composition of CHF, the functional group composition parameters might affect biological activity. It was demonstrated that the synergistic effect of HA and introduced mineral additives was observed. The presence of HA in CHF allowed decreasing the concentration of the solution to soak seeds without decreasing its biological activity. The tested CHF showed high phytoactivity (IP = 1.19-1.45). The maximum biological activity was noted in samples treated with superphosphate. The ability of HA to decrease the suppressive effect of large concentrations in solutions of mineral fertilizers was determined.

Major characteristics of cellulose obtained from fruit shells of oat by the hydrotropic method were studied. It was demonstrated that bleaching of technical cellulose sample contributed to cellulose concentration and the removal of the bulk of noncellulosic compounds in the product. Samples of esters close by major characteristics to mastic-lacquer colloxylins were synthesised under conditions of preparation of highly soluble cellulose nitrates. Cellulose fibres of fruit shells of oat and cellulose nitrates obtained were characterized by scanning electron microscopy (SEM) techniques. It was found by IR spectroscopy that hydrotropic cellulose was identical to cellulose from traditional types of plant raw materials by major adsorption bands. It was demonstrated that the resulting esters were cellulose nitrates.

Polymeric guanidine derivatives occupy a special place among antimicrobial compounds. Guanidines are well soluble in water, have a wide spectrum of antimicrobial action and durable effects, nontoxic, and also meet modern medical requirements. Due to the high reactivity of guanidine to interact with various functional groups, we manage to carry out a number of new chemical modifications that allow obtaining new biologically active low and high molecular mass compounds. The present paper presents preparation of water-soluble guanidine derivatives of pectin and carboxymethyl cellulose bound between each other with the amine bond. A process for the preparation of guanidine derivatives of pectin and carboxymethyl cellulose consists of the following stages: periodate oxidation of polysaccharides, the condensation reaction of guanidine with oxidized pectin and carboxymethyl cellulose, –C=N bond reduction. The structure and composition of the resulting compounds were studied by IR spectroscopy, X-ray structural and elemental analysis (by nitrogen content). It was determined that the maximum number of guanidine groups in the resulting products was contained during the interaction of dialdehyde derivatives of pectin and carboxymethyl cellulose with guanidine in a 1.0 : 2.3 molar ratio. Antimicrobial activity of resulting guanidine derivatives of pectin and carboxymethyl cellulose against Staphylococcus aureus, Staphylococcus epidermidis, Klebsiella, Escherichia coli and Streptococcus faecalis was explored. It was found that bacteriostatic effect began to increase with an increase in the concentration of the obtained compounds. The paper gives acute toxicity studies results on guanidine derivatives of pectin and carboxymethyl cellulose, upon the results of which they can be referred to class IV slightly toxic substances.

The paper studied the effect of conditions of oxidative treatment of comminuted rubber with nitrogen (I) oxide (the so-called ketonization) obtained by mechanical grinding of truck and passenger tires on the main characteristics of the resulting regenerate samples. As established, treatment of comminuted rubber with the initial amount of nitrogen (I) oxide of 2 mol for 1 h or 1 mol for 6 h at the process temperature of 230 °С ensured obtaining the regenerate with the optimum ratio of oligo- and macromolecules containing statistically distributed С=О groups. The reactive oligomeric component formed in the technical synthesis process provides the regenerate with the level of rheological properties required for the use in the content of elastomeric compositions. The presence of functional groups in the oligomer and polymer components of pilot regenerate samples leads to a decrease in the induction period of vulcanisation, which is driven by the acceleration of the formation process of a benzthiazolyl radical arising during decomposition of a vulcanisation accelerator and by the involvement of free sulphur that enters into regenerate composition into the vulcanisation process. The found character of the influence of pilot regenerates on structurisation processes of carbon-chain polymers allows carrying out the optimisation of the content of compositions in which it is planned to use the regenerate, and also adjusting technological modes for vulcanisation of rubber mixtures. As demonstrated in the carried out comparative study of strength-elastic properties of the pilot and industrial regenerate samples, vulcanisates based on trial regenerate samples had high conditional tensile strengths at 200 % elongation. The resulting effect of an increase in strength is reached due to a more homogeneous distribution of the applied load and realisation of orientational phenomena in a low-modulus elastomeric matrix.

The contents of di-n-butyl phthalate (DBP) and di (2-ethylhexyl) phthalate (DEHP) were assessed in the Lake Baikal pelagic zone. The spatial heterogeneity of the distribution of phthalates in the upper and deep water levels for all basins of Lake Baikal was determined from 0.06 to 3.1 µg/dm³ of DBP and from 0.03 to 1.4 µg/dm³ of DEHP, seasonal variability of the total concentrations of phthalates in the pelagic zone of the lake being up to 10 times. Background stations of the reference section in three lake basins were proposed as reference areas for monitoring, and the average concentrations of phthalates in the upper aqueous layer (5–200 m) were proposed to assess the present content of phthalates in the water of the lake. The contents of DBP and DEHP in Lake Baikal Water over the period 2015–2016 were 0.35–0.89 and 0.06–0.32 µg/dm³, respectively, and do not exceed the MPC for water bodies specified in Russia. A simultaneous change in DBP concentration in the upper water layer of the pelagic zone of the southern lake basin and in its coastal area as pollution indicator was noted. Phthalates were determined by liquid-liquid extraction of analytes into n-hexane, direct analysis of extracts using chromatography-mass spectrometry in selective detection mode (m/z 149 and 153) and measurements by the internal standard method using di-n-octylphthalate-3,4,5,6-d₄ as a surrogate standard. Secondary pollution of water and extracts with laboratory phthalates was regarded as the systematic error that was assessed by the value of reagent blanks and subtracted from analysis results. The total error was assessed using the values of 25 and 20 % for DBP and DEHP, respectively.

The paper studied joint transformations of vacuum gas oils characterised by the group composition with various vegetable oils under catalytic cracking conditions. It was determined that the distribution of target cracking products depended not only on the carbon component of mixed raw materials but also on the fatty acid composition of vegetable oils. The greater was the number of C=C double bonds in the composition of triglycerides of vegetable oil, the more pronounced promoting effect it had for vacuum cracking of gas oil, as established. This was related to the progression of hydrogen transfer reactions. Olefins that act as hydrogen acceptors were formed during cracking of initial glycerides, and paraffins and naphthenes in vacuum gas oils were donors. Herewith, an increase in the contents of mono- and polyaromatic hydrocarbons was noted in the composition of liquid products. Additionally, it was found that the higher was the content of unsaturated fatty acids in the composition of glycerides of vegetable oils, the higher was the yield of target cracking products (light olefins, gasoline). It was demonstrated that a high content of aromatic hydrocarbons in the composition of vacuum gas oil during the transformation of mixed raw materials resulted in a decrease in the yield of target cracking products with a simultaneous increase in the yield of liquid products and coke. This is related to the fact that aromatic hydrocarbons were poorly subjected to transformations and concentrated in highly-boiling fractions, with the result that an increase in the yields of light and heavy gas oils was observed. Additionally, heavy aromatic hydrocarbons actively took part in condensation reactions with the formation of polyaromatic compounds and coke, as evidenced by the increased formation of coke deposits on catalysts.

The paper carried out X-ray phase analysis of arsenic sludge, whereby the following compounds were detected: (CaSO₄) • 2H₂O, Cu(OH)₂, Ni(OH)₂, Fe(OH)₃, Ca(OH)₂, and Zn(OH)₂. The presence of arsenic (III) as calcium metaarsenite (Ca(AsO₂)₂) was also determined. Options for extraction of non-ferrous metals from multicomponent hydroxide raw materials containing significant amounts of arsenic were considered. Solutions of sulphuric acid, ammonium salts, oxyethylidenediphosphonic (OEDP), ethylenediaminotetraacetic acid (EDTA), alkaline metal tartrates were explored as reagent solvents. The values for the logarithms of the stability constants of copper (II), nickel (II), and calcium (II) complexes with appropriate ligands were presented. According to experimental data, the use of substances that ensure the copper and nickel extraction as complexes while maintaining pH > 5 allows for almost complete elimination of arsenic dissolution. It was experimentally proven that ammoniacal leaching and leaching in solutions of EDTA salts did not lead to arsenic contamination of the filtrate ensuring copper and nickel extraction from sludges. The use of EDTA and its salts also simplified technology and equipment selection for further solution processing. The findings led to the conclusion that the use of EDTA solutions at leaching of sludges of neutralising industrial solutions was promising.

The paper studied some regularities of extraction of dihydroxybenzenes (DHB) using toluene organic solutions of amine and phosphine oxides with the purpose of extraction concentration and determination of trace amounts in aqueous solutions. Distribution coefficients of DHB between toluene solutions of organic oxides and water versus the position of OH group in the molecule and the donor ability of oxides were determined. Pyrocatechin has higher extraction characteristics than resorcin and hydroquinone. The maximum distribution coefficients of DHB were reached, which provided their 95–97 % extraction from aqueous media at 50-fold concentration and single extraction. A method for determination of trace amounts of DHB (10^–7–10^–5 mol/dm³) in water samples with pre-concentration with toluene solutions of trioctylphosphine and trioctylamine oxides (0.5–0.7 mol/dm₃) followed by voltammetric detection in extract with a glassy carbon electrode (GCE) against acetonitrile and a solution of sodium perchlorate in isopropyl alcohol was developed. The current-voltage curves reflecting the kinetics of oxidation of analytes in a disk GCE at voltammetric detection of DHB in the organic phase were obtained. Calibration curve method was used for quantitative voltammetric determination of each isomer in individual solutions or binary mixtures of catechol, resorcin, and hydroquinone, resorcin, and also total DHB (in terms of pyrocatechin) in an extract. The level of reliable determination of DHB concentrations is 0.5–1 MPC; relative error does not exceed 5 %. A method for total determination of DHB, and also each isomer in individual samples or binary mixtures of pyrocatechin and resorcin, and hydroquinone and resorcin is recommended for use in analytical laboratories for monitoring the quality of natural and treated waste water.

The paper studied an opportunity of obtaining bismuth formates from solid basic bismuth nitrate by its interaction with formic acid solutions of different concentrations at process temperatures of (22±1) and (55±2) °С. Interaction products of bismuth oxohydroxonitrate having the composition Bi₆О₄(ОН)₄(NO₃)₆ • H₂O with formic acid solutions were studied by X-ray phase analysis (XPA), thermogravimetry (TG), electron microscopy, IR spectroscopy, and chemical analysis. It was found that solubility isotherms had two branches driven by the formation of bismuth formates with the composition BiOCOOH and Bi(COOH)₃ and proceeded via a maximum at bismuth concentrations in solutions of 31 and 23 g/L at 22 and 55 °C, respectively. An opportunity to obtain bismuth oxide formate was demonstrated through treatment of bismuth (III) formate with water at the mass ratio of water to bismuth formate of 10. Bismuth oxide formate is spherical particles with a size of about 6 µm comprising of smaller crystals, and middle-sized bismuth is needles crystallised as druses with a size of about 100 µm. It was demonstrated that thermal decomposition of basic bismuth formate in air allowed obtaining tetragonal (β) bismuth oxide. It was found that thermal decomposition of a mixture of bismuth oxide formate and oxohydroxynitrate (~50 %) proceeded in several steps, began at 200 °С and completed at 560 °С with the formation of monoclinic (β) bismuth oxide. It was demonstrated that thermal decomposition of a mixture of bismuth oxonitrate/oxoformiate was a promising synthesis method of basic bismuth oxonitrate with the composition Bi₅O₆(NO₃)₂OH or Bi₅O₇NO₃.

The paper examines a facile and efficient method for dehydration of sludge from chemical water treatment of the Surgut Thermal Power Plant using a water-soluble powdered high molecular mass polymer i.e. the sodium salt of carboxymethyl cellulose (Na-CMC), as an additive. The integral mass loss and volume loss of samples vary within 70–80 % for 10–15 days when using this method. The optimum amount of the introduced binder is 3–5 % of the mass of the initial sample to obtain dense smooth shaped samples, as established. The data of morphology, structure, phase composition, and particle size in the initial and final products, and also in waste dehydration process are given. Changes in the waste surface during the interaction with Na-CMC accompanied by the formation of hydroaluminate, hydrosulphoaluminate, and hydrosulphoalumoferrite particles with a size of less than 300 nm were recorded. The particles generate a primary alumoferrite frame of a hardening system of coagulation and crystallization structures, as established in a more detailed study. During dehydration and binding processes, it is suggested to dispose of the dry product in the construction industry as an additive for manufacturing cements, foam blocks, foam concretes, in mortars or producing plasters due to the formation of the space frame of iron (III) and aluminium hydroxides. The presence of small amounts of Na-CMC binder will make a positive contribution since it is introduced to reduce setting time when manufacturing construction materials. The results offer prospects for solving environmental issues related to liberating overfilled sludge pits of the thermal power station.