Content Of Toxic Substances Research Articles

Development of the integrated IKTS-MADI complex for design and research of common rail fuel systems of diesel engines with electronic control

Further tightening of environmental rules and standards regulating the content of toxic substances in diesel exhaust gases, accompanied by an increase in the requirements for their fuel efficiency, creates prerequisites for the creation of Russian common rail fuel systems (CR). The performance of this task is possible with the use of new engineering solutions in combination with computational and experimental research methods implemented on the basis of the integrated computational and experimental complex IKTS-MADI. The complex consists of computing and research components. The computing component of the IKTS-MADI allows calculating the working processes of the entire high-pressure line when the high-pressure fuel pump (HPFP), rail and electro-hydraulic common rail injectors (CRI) work together, taking into account the influence of wave phenomena on the distribution of injection parameters across diesel cylinders. Obtaining new data to expand the library of existing technical solutions and testing of fuel equipment samples designed using mathematical modeling are carried out on the research component of IKTS-MADI. The CR and its components are tested together with the control system (control unit, sensors and wiring harnesses). The injection characteristics required for calculating the diesel operating process are recorded.

Research of aerosol gas phase of electronic nicotine delivery systems of different types

The study of the gas phase of aerosol produced by electronic nicotine delivery systems (ENDS) consists of assessing the content of carbon monoxide, which is included in the World Health Organization list of nine priority toxic substances. The article presents the results of determining the content of carbon monoxide (CO) in the gas phase of aerosol of electronic nicotine delivery systems (ENDS) with various design features obtained by collecting aerosol on a Cerulean SM 450 smoking machine according to ISO 20768 and in ISO 20768 experimental mode. Carbon monoxide content in the gas phase aerosol of electronic nicotine delivery systems of various designs has been compared. It has been found that the gas phase of the aerosol produced by the LogicPro devices contains trace amounts of CO, which is associated with the stable operation of devices with a relatively low power and temperature during aerosol generation and ranges from 0,007 to 0,05 mg / puff. The results on the production of CO by «eGo AIO» devices have shown that when using them, the CO content is from 0,18 to 1,18 mg per puff, obtained according to ISO 20768exp., which can cause more harm than smoking regular cigarettes, since according to the mandatory the requirements of Chapter 5 of CU TR 035/2014, the content of carbon monoxide in the smoke of one filter cigarette cannot exceed 10 mg per cigarette. The lack of standardized methods for collecting aerosol of nicotine-containing products, established technical requirements and standards for the content of toxic substances, a methodological basis for monitoring the composition of substances released during the operation of nicotine-containing products, as well as the content of CO in aerosols of ENDS of various designs, is an undoubted risk for consumers. It is necessary to develop and implement a system for technical regulation of nicotine-containing products and standardization of toxic substances in the aerosol of these products.

Study of nicotine content in the aerosols of ENDS of various designs

The aim of the research is to study the features of aerosol mixture on various types of electronic nicotine delivery systems (ENDS) on a laboratory linear smoking machine to develop requirements both for the devices themselves and for the nicotine content in aerosol of liquids for ENDS. The analysis of data on aerosol collection on various types of nicotine-containing products (NCP) is relevant and in the future will allow to develop recommendations and proposals for establishing safety requirements for such devices and the composition of the aerosol produced. Since manufacturers position ENDS (e-cigarettes) as low-risk for health devices, the study of ENDS is an urgent task. The principle of operation of the devices is not associated with the combustion of tobacco as when smoking cigarettes. The article presents the results of the analysis of the nicotine content in the solid-liquid phase of the aerosol of ENDS devices. The issues of assessing the content of nicotine in the aerosol of the solid-liquid phase of innovative nicotine-containing products of such brands as «LUXLITE», «Von Erl My» and «eGo AIO» have been considered. Currently, a unified approach to the regulation of NCP and control of the content of toxic substances in the aerosol has not been developed, which leads to the use of various modes of aerosol collection on laboratory smoking machines. The article presents the aerosol collection parameters, since there are no regulatory measures to control the safety of electronic nicotine delivery systems. To determine the nicotine content in ENDS aerosol, it is recommended to use the ISO 20768 method, since when using ISO 20768exp, the stable operation of ENDS devices decreases. It has been found that different devices produce different amounts of nicotine according to the ISO 20768: 2018 aerosol collection regime. The nicotine content in the solid-liquid phase of the ENDS aerosol is influenced by the duration of the puff, and the nicotine content in the aerosol of the ENDS solid-liquid phase depends on the individual characteristics of the device operation.

Areas of Probable Air Pollution in Mountains and Valleys

Many cities of the world are located in river valleys or are associated with mountains. The article presents the characteristic landscape positions of many cities in the world. Among them is very important to study the wind regime, which is located in the conditions of the basin. In these cities, general pollution and deterioration of the microclimatic regime of the atmosphere are observed during periods of windless weather, and especially during inversions. It occurs either due to the gradual accumulation of harmful impurities of road transport under adverse meteorological conditions. The contribution of vehicles to the total air pollution is up to 80%. Currently, their composition of vehicle exhaust gases contains more than 200 different substances. With 95 … 99% of emissions t represent an aerosol of complex composition, depending on the engine operating condition and the composition of the mixture. The composition of the atmosphere of cities should meet the established standards for the content of the main components of air and harmful impurities (dust, gases), taking into account existing state standards. Biomedical requirements for the composition of air in cities are determined by the maximum permissible concentrations (MAC). However, the content of toxic substances in the air at the level of the MPC cannot be considered as the optimal composition of the air environment. In cities located in the depressions, deterioration of air exchange conditions is observed, which is associated both with a drop in wind flow activity and a decrease in the intensity of solar insolation per unit area of exposed surfaces of the slopes. In the work to improve the wind mode, the base for establishing the main stages for regulation is set to be direct; recycling; and combined i-recirculation direct-flow, as well as direct-flow-recirculation schemes of natural ventilation. The formulas for determining the criterion for evaluating the effectiveness of ventilation are given. We used computer modeling technologies that significantly simplify the analysis of the wind regime and reduce the time spent on research, the purpose of which was to compare the results of experiments in a wind tunnel with the data of virtual studies of the wind flow around natural wind patterns in a wind tunnel with the use of SolidWorks 2015, with the addition of Flow Simulation.

Method For Determining The Content Of Toxic Substances In The Liver After Exposure To Pesticides In Experimental Animals

This scientific work is devoted to the study of the results of the action of pesticides on the organism of experimental animals. At the beginning, a brief review of the literature devoted to this problem is given. The author also describes a method for determining the content of toxic substances in the liver tissues of experimental animals. The corresponding conclusions on the simplicity of the method are made.

Quantitative risk assessment of an amine-based CO2 capture process

This study presents a risk assessment study on an amine-based CO2 capture process. Based on the critical risks identified by a hazard and operability study (HAZOP) conducted in our previous work, we performed detailed quantitative risk assessment, including frequency estimation using fault tree analysis (FTA) and consequence estimation using the process hazard analysis software tool (PHAST). As a result of our FTA study on explosion accidents in the absorber column as a top event, we identified 25 basic events and eight intermediate events that lead to the top event. The probability of a T-102 explosion was estimated to approximately 3.55E-03 per year, which satisfies international safety regulations. Additionally, we performed consequence estimation for three types of accidents in an absorber, namely toxic substance leakage, explosions, and fireballs, under two different weather conditions, namely modest and worst conditions. It was determined that in the event of a toxic substance leakage accident, the effect zone of acid gas with high toxic substance content is approximately four-times larger than that of raw gas.

Monitoring the auto-road air and reducing its toxicity

In order to simplify the air purification method and increase its efficiency in our studies conducted on the Vladikavkaz - Rostov highway, the sections between the forest plantations are covered with a layer of zeolite-containing clay - allanite, and crushed corn stumps in 4: 1ratio. In this case, the stumps are pre-soaked in Zamankul mineral water, and toxic substances accumulating on the layer surface are planted: chicory, phacelia, winter camelina and annual clover species. Covering sections of the park zone with natural sources of local origin in the form of allanite clay with plant waste mixture - corn stumps, which have high sorption ability and saturated boron-containing elements of Zamankul mineral water, reduces the highway air toxicity to the maximum permissible concentrations. The analysis on the toxic substances content in the air showed that the method used and its application provide favorable conditions for a normal environmental situation on the highway. It was revealed that due to the placement of plants accumulating toxic substances along the roads in the Vladikavkaz city, their number decreased to safe, maximum permissible concentrations. Thus, the concentration of contamination with lead salts and metals from the control infected option 0.105 μg / m3 decreased to 0.018 μg / m3. The amount of zinc, nickel, manganese also decreased several times. A significant reduction in toxic elements was observed for sulfur dioxide, nitrogen oxides, volatile organic compounds, carbon, ammonia, and methane.

SYSTEM OF PROTECTION FOR POTATO FROM PESTS AND DISEASES TO GET ECOLOGICALLY CLEAN PRODUCTS

Potatoes comprise a strategically important food crop in the Russian Federation. Enhanced chemicalization of potato production, while protecting it from pests and diseases, allows you to get high yields, but at the same time significantly affects the biological quality of products. The retail chain often receives lots of tubers with excess nitrates, while containing the so-called "long-playing" pesticides. Getting into the human body with products, toxic substances cause severe diseases. There is an acute problem of providing children with environmentally friendly products. This research developed an important task of neutralizing the accumulation of toxic insecticides and fungicides in tubers by the beginning of harvesting when cultivating medium-early varieties of potatoes. This was achieved when using the insecticide Celest TOP (Thiamethoxam, hazard class 2) in reduced by 25% norms, in combination with the use of biological preparations Siliplant or Albit and reduced by 40% norms of fungicides. The protection system included for tubers: Celestine 0.3 L/ha + Albite TPS 0.1 L/t. For tops: Ridomil gold MC VDG 1.5 kg/ha first, second and third treatments. Shirlan SK 0.24 L/ha 4-5-th treatment + Albit TPS 2 times for vegetation 0.05 L/ ha or Siliplant BP 2 times for vegetation 1.0 L/ha. Laboratory analyses revealed residual amounts of pesticides and nitrates in tubers. The resulting products, with the plant protection system developed by us, meet the requirements for children's and dietary nutrition. The inversion voltammetric method was used to determine the concentration of pesticides in tubers. Nitrates were determined using an ion-selective electrode. It is established that Prestige (Imidacloprid, hazard class 1) is impractical to use in producing ecologically clean potatoes. Using Celest (Thiamethoxam, hazard class 2) in combination with Albit or Siliplant increased the yield and reduced the content of toxic substances in tubers.

Lead and cadmium in conventional and organic carrots

AbstractToxic elements like lead and cadmium are considered harmful to human health. These elements do not have any useful function in an organism. They are known only for their negative actions, which can be tolerated by human body only in certain limits. Carrots may absorb these toxic elements from the soil they grow in. The presence of the contaminants depends mainly on the mode and site of cultivation, fertilizer, industrial infrastructure, level of transportation and roads around cultivation site or occurrence of municipal and agricultural waste nearby. The organic food is supposed to be healthier due to, among other things, less content of toxic substances, which results from more sustainable farming. The aim of this research was to determine the content of lead and cadmium in carrots from conventional and organic farming that were available on polish market.The research had been conducted for two years. Both kinds of carrots had been purchased at the same time in different supermarkets in Poland. Altogether, 36 packages, both conventional and organic carrots, were collected. The samples of carrots were dried and then reduced to ashes in 480 °C within few hours. Then the residues were dissolved in 1 M nitric acid and quantitatively transferred to measuring flasks, complemented with deionised water. The content of cadmium and lead was determined by application of electrothermal atomizer (graphite furnace) in iCE 3000 (Thermo Scientific, USA) spectrometer using adequate cathode lamps and Zeeman background correction. Wavelengths for analysis of lead and cadmium were 217 nm and 288.8 nm respectively.The results show that there are statistically significant differences in the average content of lead and cadmium in conventional and organic carrots. The concentrations of lead in conventional and organic carrots were 0.0192 mg kg-1 and 0.0118 mg kg-1 respectively. The concentrations of cadmium in conventional and organic carrots were 0.0050 mg kg-1 and 0.0023 mg kg-1 respectively.The research indicates that toxic elements like Pb and Cd are present in both types of carrots, but their amount is lower than permissible concentrations established by EU ordinance. The conducted experiments also showed that the content of Pb and Cd in organic carrots is lower than in the conventional ones. This may be resulted in the differences in farming.

Free Amino Acid Accumulation in Soil and Tomato Plants (Solanum lycopersicum L.) Associated with Arsenic Stress

Pollution of soils with arsenic leads to changes in biochemical processes both in the soil and in plants growing on it. Biochemically active compounds, such as free amino acids, strongly respond to the increase of the content of toxic substances in the environment. This article deals with the changes in the concentration of free amino acids in soil, roots, and aboveground biomass of tomato plants that took place when soil was contaminated with arsenic. Pre-grown tomato plants (Solanum lycopersicum L.) were transplanted into containers with soil contaminated with arsenate (As(V)) at the doses of 50 and 200 mg kg−1. In the soils, roots, and aboveground parts of plants, the changes in the concentration of 16–17 free amino acids were studied by the method of high-performance liquid chromatography. The results of the experiment showed that soil contamination with arsenic can lead to an increase in the concentration of all studied amino acids, both in soils and in tomato plants. Total free amino acid concentration in soil increased by 194.2% at 50 mg kg−1 of As(V) and by 349.6% at 200 mg kg−1 of As(V), in roots and aboveground biomass their concentration increased from 1.5 to 4.6 times. A particularly strong increase of concentration in soil was observed for serine and glycine, whereas in plant tissues, in comparison with other amino acids, aspartic and glutamic acids were intensively accumulated. The strong correlation between the content of free amino acids in the soils and in the roots (r = 0.85) or aboveground biomass of plants (r = 0.88) shows that both soil and tomato plants respond to soil contamination with As(V) in a similar way. However, the results of the study also showed that increasing of amino acid concentration in plant tissues in case of arsenic contamination can be associated with both their accumulations due to the plant’s response to stressful conditions and probably their uptake from the soil.

The impact of ignition system damage on the emission of toxic substances in a spark-ignition internal combustion engine

The article discusses the impact of ignition system damage on the emission of toxic subcategories in a spark-ignition internal combustion engine. The aim of the work was to develop an analytical model of ignition system diagnostics, test performance and comparative analysis of the results of simulations and experiments. The model developed allows to analyse the basic parameters of the ignition system affecting the content of toxic substances in the exhaust. Experimental tests were carried out using the MAHA MGT5 exhaust gas analyser for four different combustion engines fueled with petrol at various operating conditions. During the tests, the content of toxic substances in the exhaust gas of a properly working engine and the engine working with damage to the ignition system were registered. The tests will be used to assess the impact of the damage of the spark-ignition engine on the emission of individual components of toxic fumes.

Analysis of the impact of damage to the injection system on the emission of toxic substances in a spark-ignition internal combustion engine

The article presented analyses the impact of damage to the injection system on the emission of toxic subsumes in a spark-ignition internal combustion engine. The work focuses on the basic elements of the injection system, which include injectors, throttle position sensor, coolant temperature sensor and lambda sensor. In addition, a catalytic reactor has been included in the context of its direct cooperation with the injection system under set conditions. The toxicity of exhaust gases of different spark-ignition engines fueled with petrol or gas in determined operating conditions using the MAHA MGT5 exhaust gas analyser was tested. The content of toxic substances in the exhaust gases was recorded for the correct settings of the injection system and for the engine working with damage to this system. The tests carried out will allow to assess the impact of the damage of the injection system on the toxicity of exhaust gases.

Problems of Establishing Limits for Arsenic Content in Brown Algae and Brown Algae-Containing Medicinal Products

Algae tend to accumulate elemental toxic substances in high concentrations. Algae are widely used in the food and pharmaceutical industries, and this dictates the need to establish limits for the content of toxic substances that they may contain. The aim of the study was to analyse the requirements of the Russian and foreign pharmacopoeias and other regulatory documents concerning the limits for the content of arsenic in brown algae. The paper presents the results of analysis of monographs from the State Pharmacopoeia of the Russian Federation, XIII and XIV editions, draft version of the Pharmacopoeia of the Eurasian Economic Union, United States Pharmacopoeia, Japanese Pharmacopoeia, European Pharmacopoeia, and Ayurvedic Pharmacopoeia of India containing limits for the content of arsenic in herbal medicinal products (HMPs). In addition, the authors analysed Russian, international and foreign food industry and dietary supplements regulations, as well as scientific publications on arsenic content in brown algae. They also considered the nomenclature of arsenic compounds to be determined and controlled in medicinal products, highlighted the main approaches to and identified global trends in establishing the limits for their content in HMPs. The paper summarises specific aspects of inorganic arsenic compounds accumulation by brown algae. It was demonstrated that the majority of foreign pharmacopoeias either have specific norms for arsenic content in brown algae, which differ from the norms for HMPs, or have general norms that take into account different toxicity levels of organic and inorganic arsenic compounds. There is a tendency to control the content of elemental toxic substances based on their maximum allowable daily intake. The paper substantiates the need for separate determination of toxic inorganic arsenic compounds and potentially toxic methyl arsonate and dimethyl arsinate in HMPs.

Modification of urea- and phenol-formaldehyde adhesives by natural fillers for the production of plywood

For the manufacture of plywood and chipboard are used urea-formaldehyde and phenol-formaldehyde hot curing adhesives. When it is necessary to reduce the content of toxic substances, to increase the strength and reliability of gluing, other properties of adhesive bonding heat urea and phenol-formaldehyde resins are modified. Urea-formaldehyde and phenol-formaldehyde resins were used for research. Urea-formaldehyde resin was modified with technical lignosulfonates with particle sizes of 0.01-0.2 mm, shungites with particle sizes of 0.2-0.8 mm, black shales with particle sizes of 0.005-0.2 mm and aluminosilicates with particle sizes of 0.2 - 0.8 mm. Phenol-formaldehyde resin was modified with pectol, black shales with particle sizes of 0.005-0.2, technical lignosulfonates with particle sizes of 0.01-0.2, and cold sludge from aluminum production with particle sizes of 0.01-0.2. A comparative analysis revealed that all the modifiers under study improve the physicochemical parameters of urea-formaldehyde and phenol-formaldehyde resins, increase the performance properties of glued materials from wood. Plywood was tested for shear strength over the adhesive layer and for the content of free formaldehyde in accordance with Russian standards. Modification of urea and phenol-formaldehyde resins with the proposed substances increases the strength of plywood, at the same time reducing the free formaldehyde content in products.

Photochemical degradation of phenol in the of titanium dioxide nanoparticles

In this article, a description of the photochemical degradation of phenol with TiO 2 nanoparticles for the treatment of toxic substances in water basins is presented. Such research is of great relevance due to the discharge of wastewater into clean water basins resulting in a contamination of ecosystems with very ecological consequences. Due to the seemingly inevitable reduction in the world’s freshwater reservoirs, finding new methods for the high-level purification of contaminated waters so as to minimise the toxic substance content is of paramount importance. Composition and quantitative analysis of the photolysis solution was carried out using the gas chromatographic method. TiO 2 nanopowders were prepared using the sol-gel method from titanium IV isopropoxide (TTIP), isopropyl alcohol and ammonium hydroxide precursors under normal conditions without any post-heat treatment for crystallisation. The nanocrystalline rutile-phase TiO2 powders were characterised by X-ray powder diffraction (XRD). The size of nanoparticles as confirmed by transmission electron microscopy (TEM) was about 10–20 nm, while the Brunauer–Emmett–Teller (BET) specific surface area of the rutile nanopowder was 159.6 m 2 /g. The photocatalytic performance of the synthesised nanopowders photochemical was observed to enhance degradation of the phenol solution under UV irradiation. The phenol degradation was quantitatively analysed using a 6890N GC-MSD gas chromatograph with an Agilent 5975 highperformance mass-selective detector. Degradation of phenol in the presence of TiO2 nanopowders yielded a rate of 99%.

EVALUATION OF THE AEROGENIC IMPACT OF PRIORITY CHEMICAL FACTORS ON THE HEALTH OF THE CHILD POPULATION IN THE ZONE OF THE EXPOSURE OF ALUMINUM ENTERPRISES

Introduction. There is actual development of scientific and methodological support for the formation of the evidence base of the negative impact of environmental factors on public health. Material and methods. The hygienic assessment of the air quality of the territory with the placement of aluminum production and the territory without similar sources of emissions was carried out, carcinogenic and non-carcinogenic health risk was estimated, chemical-analytical and clinical-laboratory examination of 235 children was carried out to study the negative effects of the influence of the studied risk factors on critical organs and systems. Results. In the conditions of the existing quality of the atmospheric air, conditioned by the economic activity of the enterprise producing aluminum, an unacceptable risk of developing non-carcinogenic effects for the central nervous system, bone system, respiratory system, blood system, liver, kidneys (HI to 33.4) is formed. Children in the zone of exposure to risk factors have an increased (up to 4.0 times) content both of manganese, nickel, chromium in blood, and as the aluminum as fluoride ion in urine (up to 5.5 times) relative to the indices in the comparison group. Children with an elevated content of these compounds in bio medias revealed reliable deviations of laboratory parameters relative to similar parameters in children in the comparison group: a 1.2-fold increase in serum glutamic acid, a 2.2-fold increase in eosinophilia in the nasal secretion, C-terminal telopeptides, total and direct bilirubin, ACAT in blood serum by 1.2 times, β2-microglobulin in blood serum - by 1.8 times. The established negative effects in children, proven to be associated with an increased content of toxic substances in the bio medias, are confirmed by the increased detectability of functional disorders of the autonomic and central nervous system (5.5 times more often), respiratory diseases (2.9 times), musculoskeletal diseases system (in 1.3-1.5 times). Substantiated indices of negative effects must be taken into account when conducting sanitary and epidemiological examinations and developing measures for the prevention of functional diseases of the central nervous system, bone system, respiratory system, liver, kidneys in children permanently residing in a residential building in the zone of emission sources of aluminum plants.

Neutralization of sewage sediments by utilization of steel industry wastes

Utilization of sewage sediments as a soil modifier is one of effective ways of man-caused disturbed lands reclaiming. To meet modern ecology requirements to reclaimed territories, the sediments must be safe by sanitary indices, have good organoleptic and grain-size properties, apart from being correspondent to norms by heavy metals and other toxic substances content in them. Wastes of urban sewage treatment plants were studied, as follows: raw sediments; excessive active mud, a mixture of wastes. Wastes of JSC EVRAZ ZSMK operation were used as neutralizing additives, as follows: aspiration dust of limestone burning plant, blooming scale. Studies showed a significant decrease in the content of water-soluble compounds of zinc, lead, copper, fluorine due to their precipitation when reacting with the added additives. The effectiveness of the deposition depends on the type of additive, its content, mixing conditions. By simply mixing of the neutralizing additive with the sample under investigation, a decrease of concentration of water-soluble compounds of zinc, copper, and fluorine was achieved. The selective effect of additives on individual elements established. Lime dust provided an excellent effect on zinc – a decrease by 50%, but had no effect on copper. The addition of scale led to a 25% reduction in the content of water-soluble copper, but did not lead to zinc precipitation. Regarding fluorine, lime was significantly more effective (a decrease by 53%) comparing with scale (a decrease of 27%). The total reduction of water-soluble compounds of the elements under study was 32.2% for lime and 32.6% for scale. Mixing the raw sediment with a neutralizing additive under heating conditions contributed to a significant increasing effect regarding copper: the decrease of its water-soluble ions down to 77% was obtained.

Possibilities of improvement fuel atomization process in CI – engines

Modern combustion engines development is targeted on respect of environment protection. Engine constructor main task is lowering toxic substances emission in exhaust. This trend is the same for CI and spark ignition engines. Toxic substances content in exhaust depend on many factors like combustion chamber construction, the sort of fuel and inlet system, fuel – air mixture organize process, the sort of fuel and engine work environment. It was very important period in motorization development implementing electronic engine work steering systems. The factors influence on emission in exhaust analysis shows that there is possibility reduce toxic substances in fumes through correct organizing fuel – air combustion mixture in CI – engine. The injecting fuel streams parameters influence on combustion mixture forming process. The article presents fuel injector modification concept. The aim of modern fuel injector modification is improvement of fuel stream parameters like range, width, atomization and obtuse angle. The performing researches show that making changes on non – working needle part influence especially on particles and carbon monoxide emission.

БЕЗОПАСНОСТЬ АГРОЛАНДШАФТОВ ДЛЯ ПРОИЗВОДСТВА ОРГАНИЧЕСКОГО МЯСНОГО СЫРЬЯ В ЮФО

As a result of environmental safety monitoring, including soil and feed of their own production of organic meat suppliers farms “Branch of ZDMK “Tikhoretskiy “AO” Danon Russia”, the content of toxic substances in the soil, food plants, animal feed was defined. In the agricultural areas of the actual farms, supplying organic meat products, the ordinary (carbonate) chernozems, low-humus super-powerful and powerful ones predominate. The acidity level of soils varies from neutral (pH 6.9) to alkaline (pH 8.6). The humus proportion varies from 1.79 to 5.84%; the mobile phosphorus content varies from 11.3 to 73.0 mg per 100 gramm; fraction of exchangeable potassium - from 17.12 to 31.94 mg per 100 gramm. The content of total and mobile forms of toxic elements in the soil of steppe and foothills areas of the Southern Federal District commodity does not exceed the allowable levels, estimated concentrations and total content of: mercury - <0.005; cadmium - <0.11; lead - <17.8; arsenic - <0.2; copper <65.0; zinc - <85.0 mg per kilogramm. Accumulation of toxic elements in feeds, feed additives is approximated to the maximum permissible levels. Accumulation of cadmium is noted in sunflower cake in the amount of 0.18 mg per kilogramm (Kanevskiy district of Krasnodar region). Fodder crops contain insignificant amounts of lead, which is explained by the low content of mobile lead forms in the soil and in the vegetative mass of plants. The content of copper and zinc in feeds is much lower, than the maximum permissible levels, respectively, ≤ 30.0 and ≤ 74.0 mg per kilogramm (Kanevskiy region). The mercury and arsenic content is insignificant: less than 0.001 mg per kilogramm.

Methods of modification of phenol-formaldehyde resins applied in the production of glued-wood materials. A review

This review considers methods for the modification of phenol-formaldehyde resins to improve the characteristics of adhesive compositions made on their basis (lower viscosity, higher viability, initial strength gain, and complete strength gain of the adhesive bond; higher elasticity, heat resistance, vibration resistance, and stickiness of the adhesive; ready-glue cost reduction) and to improve the quality of glued-wood materials by reducing the content of toxic substances in the adhesive and their emission.