Anti-icing Reagents Research Articles

Corrosion Activity of Low-Carbon Steel Under the Action of Multi-Component Anti-Icing Reagent

Corrosion Activity of Low-Carbon Steel Under the Action of Multi-Component Anti-Icing Reagent

Специальная оценка условий труда при зимнем содержании дорог и тротуаров

When processing roads and sidewalks, safety and labor protection requirements are often violated. There is a constant excess of the concentration of anti-icing reagents (AGR), the components of which at maximum concentrations adversely affect the human body. In particular, blood parameters, as well as the most important organs, such as the liver and kidneys, are affected. The concentration of AGR per unit area determines the intensity of the harmful effects of substances on the human body. The penetration of harmful substances into the human body occurs by airborne droplets or skin-resorptive action and depends on the method of distribution of AGR and the level of mechanization. The probabilities of the occurrence of a dangerous event when working with AGR, its severity and risk level are determined. Recommendations are given for employees involved in the treatment of residential and public areas with anti-icing materials.

Экологическая оценка качества воды Большого Садового пруда на территории Тимирязевской академии в Москве

The paper presents the results of the assessment of water quality in a Large Garden pond, which is located in the Timiryazevsky district of the Northern Administrative District of Moscow, on the territory of the park RGAU-MSHA named after K. A. Timiryazev. Oxygen dissolved in water, temperature, hydrogen index (pH) and the content of iron, copper, chlorides, nitrites and ammonium nitrogen were measured in the studied reservoir in winter and summer 2020 according to a single sampling and analysis scheme. Water sampling for analysis was carried out in accordance with GOST 51592-2000 "Water. General requirements for sampling" at 7 points distributed along the horizontal and vertical axes of the pond, at three levels (on the surface, in the middle of the water column and at the bottom). Determination of chemical indicators of water quality was carried out on the day of water sampling by photometric method, on the spectrophotometer "PC spectro Lovibond". Studies have shown a significant spatial variation of most of the studied indicators both in the pond area and in the depth of the reservoir, reaching multiple differences in the case of ammonium content and pronounced in the content of chlorides, iron and copper. On average, an almost twofold increase in the chloride content in winter indicates a significant impact on the water quality in the pond of the use of anti-icing reagents in the adjacent territory. The copper content increases significantly in the summer, with the highest values in the dam part of the pond with the maximum level of technogenic load. The lowest content of pollutants is observed in the upper part of the pond with minimal anthropogenic load. The negative impact of the roadway of Pryanishnikov Street is much more pronounced than the intense recreational load in the beach area. The anthropogenic alkalinization of the environment characteristic of Moscow is less evident in the central part of the pond with maximum depths. The dissolved oxygen content is closely related to the temperature of the water and the depth of its sampling. In summer, it is more at the bottom than at the surface of the pond. In winter, samples taken in the surface horizons of the reservoir are characterized by a lower temperature and are more saturated with oxygen than water samples taken at depth. The results obtained show the importance of the depth and area of the pond mirror for preserving the quality of its water in Moscow. Anthropogenic water pollution, which does not reach the maximum permissible concentrations, but is pronounced even in the conditions of one of the most environmentally friendly areas of the city, is actualized by the task of further reducing the regulated level of man-made load on the territories adjacent to urban reservoirs. The increased spatial variation of water quality and the patterns of its changes in the water area and depth of the reservoir noted in the work should be taken into account when planning and evaluating the results of monitoring and reclamation measures. Keywords: WATER QUALITY, AQUATIC ECOSYSTEMS, HYDROCHEMICAL PARAMETERS, TEMPERATURE, CHEMICAL ELEMENTS, DISSOLVED OXYGEN

THE STUDY OF PROPERTIES OF SODA PRODUCTION WASTES AS ANTI-ICING REAGENTS

The article considers the possibility of reducing the man-made load on surface and ground waters in Lysychansk-Severodonetsk industrial agglomeration caused by numerous sludge collectors and tailings storage facilities of various industries formed many decades ago. The paper provides information on the location and technical condition of the sludge collectors of the liquidated "LYSSODA" manufacture (Luhansk oblast), the amount of waste currently stored in them as well as the impact of these wastes on the quality of groundwater in the area where the sludge collectors are located. The work shows one of several possible options for using such wastes as a valuable secondary mineral raw material for obtaining a marketable product. The averaged data on the chemical composition of the solid phase of sludge and indicators of the liquid phase composition are given. According to the results of the analysis of scientific and technical information, it has been found that such wastes can ultimately be used for the production of anti-icing reagents. The obtained results of research on the dependence of the freezing point of working solutions on the concentration of salts, including the added corrosion inhibitors (triethanolamine, hexamethylenetetramine), indicate the feasibility of using soda ash production waste to obtain effective liquid anti-icing reagents without a mechanical component, while the optimal amount of added corrosion inhibitors is 0.5% wt. Such reagents can be used both undiluted at temperatures up to minus 20oC and strengthened to 15-20% wt. by calcium chloride at temperatures up to minus 40°C with consumption on highways at the level of about 100 g/m2 of the treated surface.

РАСЧЁТ ПЛОТНОСТИ РАСПРЕДЕЛЕНИЯ ПРОТИВОГОЛОЛЕДНОГО РЕАГЕНТА ОДНОЙ ФОРСУНКОЙ АЭРОДРОМНОЙ ПОЛИВОМОЕЧНОЙ МАШИНЫ

Within the framework of the proposed article, the key features of the operation of an airfield watering machine (APMM). The most efficient layout of the APMM, which is capable of having high operational and technical and economic indicators, has been revealed. The calculation of the probability of distribution of anti-icing reagent by one nozzle of an airfield watering machine was made. A certain flow rate of the medium liquid through one nozzle for a period of time. A certain optimal value of the stock of nozzles required of the required quality of spraying of water and a reagent to use the high-quality grip of the aircraft with the runway.

Molecular characterization of rare D--/D-- variants in individuals of Indian origin.

Rh antigens are critical in haemolytic disease of the foetus and newborn (HDFN). The D-- phenotype is a rare blood group characterised by the lack of expression of C, c, E and e antigens at the surface of red blood cells because of mutations in both RHCE alleles inactivating the expression of a "normal" protein. The aim of the study was to determine the molecular basis of D-- individuals of Indian origin. Ten Rh D-positive postnatal women who had produced antibodies against all Rh antigens, except D, leading to HDFN and foetal loss, were investigated. Extensive serological and molecular (polymerase chain reaction [PCR] using sequence-specific primers), quantitative multiplex PCR of short fluorescent fragments (QMPSF), and Sanger sequencing analyses were carried out. Serological testing with anti-C, anti-c, anti-E, and anti-e reagents showed absence of the four antigens in all ten index cases, as well as in three siblings. Flow cytometry indicated absence of these antigens with a typical exalted expression of the D antigen, thus confirming the rare D-- phenotype. Molecular analysis by QMPSF suggested homozygous CE-D hybrid alleles causing the D-- phenotype: RHCE-D(3-9)-CE (n = 11), RHCE-D(3-8)-CE (n=1), and RHCE-D(2-6)-CE (n=1). For the first time, we report the molecular basis of the D-- phenotype in the Indian population. Identification and characterisation of RHCE-null variants by molecular methods can help resolve transfusion-related problems in these individuals. Family studies of index cases helped to identify rare blood donors and offer counselling to females of child-bearing age on the complications involved in such pregnancies.

Ecological Monitoring of Road Chemistry Materials on Highways

The use of anti-icing reagents for road maintenance is accompanied by inevitable environmental consequences associated with the release of large amounts of chemicals into the environment. To reduce the negative consequences, environmental monitoring of the state of environmental objects is carried out, which makes it possible to assess the impact of the applied anti-icing reagents for the 4 most important environmental clusters: snow cover and water bodies, soil cover, green spaces and atmospheric air. At the next level of the developed monitoring system, specific geographic objects are shown. Samples were taken on 8 major highways of the city of Moscow. Environmental monitoring was carried out using a computer quality management system developed on the basis of CALS (Continuous Acquisition and Lifecycle Support) information technologies. 6 quality indicators have been added to the system for each geographic object: mass fraction of soluble salts, mass fraction of water-insoluble substances, pH value, specific effective activity of natural radionuclides, mass fraction of impurities and corrosiveness to metal. For each quality indicator, the system contains the most promising methods of analysis and instruments.

Особенности строения лесных почв под еловыми насаждениями Удмуртии

The article presents the data of studies of the state of forest soils under spruce stands. The research was carried out on the territory of the Udmurt Republic in the most common types of forest – spruce forests. To assess the soil horizons, soil sections were laid, chemical analysis of the soil was carried out, by determining the main indicators, such an important element of forest soils as forest litter was analyzed. It was revealed that the dark coniferous forests of the republic were formed on sod-podzolic soils. These soils are characterized by an acidic reaction of the soil solution and a low content of basic nutrients. In the context of the development of transport infrastructure, a high content of potassium (225 mg/kg or more) is observed due to the use of KCl as an anti-icing reagent. Soil acidity varies from highly acidic (3.9 pH) to acidic (4.9 pH), due to the influence of coniferous plants. In turn, this can negatively affect the state of the spruce stands. Keywords: SPRUCE STANDS, SOILS, SOIL HORIZONS, FOREST LITTER, CHEMICAL INDICATORS OF SOILS

Phase Equilibria along Sections of the Potassium Acetate–Glycerol–Water System at Temperatures from 0 to –62°C

Phase equilibria along sections of the potassium acetate–glycerol–water system at temperatures from 0 to –62°C were studied by visual-polythermal analysis. The potassium acetate to glycerol ratio in the sections studied varied from 3 : 1 to 1 : 3. Compositions forming low-temperature eutectics were found to be candidate new anti-icing reagents having good ice-melting ability.

Study of Meltwater Treatment Using the Industrial Waste and Natural Sorbents

In winter, a huge amount of snow contains the specific pollutants (anti-icing reagents, oil products, ion-metals and others) accumulates in the cities of the Northern Russian Regions. The special environmental requirements for operation and engineering equipment of the snow-landfills are not excited. In this case, the soil cover and nearby water bodies are contaminated by meltwater, and the engineering and geological conditions are changing at these areas. The specific composition of the snow masses requires the use of the special treatment methods to remove such major contaminants as oil products and chlorides. Currently, an effective and relatively cheap sorption material for the extraction of these pollutants from meltwater is being actively sought. In this paper, the sorption properties of the industrial waste (sawdust) and natural sorbents (kaolin, clay) were studied. The best results for the meltwater treatment from oil products and chlorides with kaolin were obtained. The sorption filter design, which is part of the proposed technological scheme for the meltwater treatment, has developed.

Mathematical description of automobile headlight contamination when driving on a wet road

The article describes the process of contamination of automobile headlights in order to calculate contamination speed using a mathematical model. The authors published results of the study aimed at solving the problem of negative application of the CAIM (chemical anti-icing materials) on winter roads. In particular, it was found that when driving vehicles on winter roads covered with CAIM, the headlights become contaminated. The headlight contamination with dirty droplets from under the wheels of a vehicle ahead was analyzed. The detachment of droplets from the moving wheel and the path of droplets from the wheel to the headlights of the vehicle behind were analyzed and described. Process is studied of contaminant film formation which decreases light transmission was carried out. Road experiments were carried out. Along with the physicomathematical description of the process under consideration, they give new knowledge about headlight contamination depending on the vehicle speed. The mathematical model supplemented by the experimental study allows us to predict the rate of headlight contamination by the wheels of vehicles ahead when moving along roads covered with chemical anti-icing reagents depending on the speed and the distance between the vehicles.

Methods for Prevention of Winter Slippery

There are several methods for prevention of winter slippery on the roads – frictional, thermal, chemical, combined and structural. The friction method of combating slippery has found quite wide application. The method is based on increasing a wheel grip with iced road. Sand, slag, screening of stone materials and friction materials subjected to heating are used as a friction raw material. A thermal method is divided in conductive and convective according to a surface heating type in which a pavement is heated from below (electric heating) or from above (with a heat stream). Disadvantages of this method are its high cost when using thermal jets and harmful effects of high temperatures on a road surface. Nowadays a chemical method is considered as the most popular one to combat winter slippery. Treatment with solid or liquid reagents is provided in order to prevent slipping on the road surface or removing ice from it. The principle of their action is to lower a freezing temperature of the solution on the surface of the roadway. The fight against winter slippage is mainly carried out in a combined way by sprinkling roads with a sand and salt mixture. Currently, there is a need to completely or partially abandon the use of chlorides in the fight against winter slippery. In this case, the most promising direction is to prevent icing by creating coatings for roads with anti-icing properties that is introduction of anti-icing reagents in the composition of the road surface (construction method). This method makes it possible to increase cost of a finished road surface.

NUMERICAL RESEARCH OF QUALITY CHARACTERISTICS OF REAGENT DISTRIBUTION BY COMBINED ROAD MACHINE

From the theory of aerohydrodynamics it is known that the design of hydraulic nozzles and the modes of their operation determine the nature of the distribution of droplets in space and the efficiency of the process. The subject of the research is the characteristics of the distribution quality of the liquid reagent, namely, the speed of dropping of droplets from the disk and the radius of the treatment zone formed by flying droplets on the coating. The question of the dispersion of the spray torch of a low-viscosity liquid, its role in the formation of the basic kinematic characteristics of moving drops, is considered. The article provides a numerical calculation and analysis of the effect of the dispersion of droplets of a distributed liquid (reagent) on the rate of dropping of droplets from a rotating disk and on the radius of the coating treatment zone. For research, two values of nozzle nozzle openings and a wide range of variation in the diameters of reagent droplets were selected. Based on the mathematical models previously developed by the authors of the process of dropping droplets from the nozzle and the movement of droplets in the air, implemented as part of a software product, the velocity of dropping of droplets from the nozzle nozzle and the rate of dropping of droplets from the disk at a given pressure were calculated. A cycle of calculations of the radius of the coating treatment zone was carried out with varying work and geometric characteristics of hydraulic equipment, providing high-quality and cost-effective implementation of the anti-icing reagent distribution process.

ANTI-ICE REAGENT ON THE BASIS OF DOLOMITE, NITROGEN ACID AND CARBAMIDE

For the safe operation of pavements in the cold season, especially in mountainous areas, antiicing means are required. The task was to develop the technology of their production from local raw materials. A domestic anti-icing reagent, from unbaked dolomite from Dekhkanabad deposit of Uzbekistan was offered, consisting of calcium, magnesium nitrates and carbamide. Standard chemical-analytical methods for investigating raw materials, laboratory technological methods, enlarged pilot-industrial approaches to the methods of its processing, followed by the development of technology for obtaining the required dolomite’s derivatives, as well as its implementation at JSC "Maxam-Chirchik" were used. Sulfur-hydrochloric acid’s processing of dolomite provided bischofite’s obtaining in industrial reactors. As the result, optimal conditions for obtaining anti-ice reagent were selected for its industrial production.

Temporal Variations in Chemical Composition of Snow Cover in Moscow

This article summarizes the data of the chemical composition and the acidity of the seasonal snow precipitation for the cold periods 1999-2006 (n=180), 2010-2013 (n=82) and 2018-2019 (n=18) in different parts of Moscow. Major ions content was measured, such as SO42-, НСO3-, Cl-, NO3-, Са2+, Mg2+, Na+, K+ and NH4+, also pH and sum of ions (mg/L) were measured. During the 2018-2019 season, snowpack samples were taken twice at 4 sites in Moscow: two in the North-East Administrative Okrug (NEAO) near the road and in the park at the distance of 3 km from each other, and two in the South- Western Administrative Okrug (SWAO) and in the Western Administrative Okrug (WAO) near the road and in the park at the distance of 6 km from each other. Samples were taken with a break of 5 days to determine the dynamics of the chemical composition within the beginning of the snow-melting. In each pair of sampling sites there was one that is located in the park and one located near the road. This experiment showed a slight variability of the chemical composition of snow during 5 days under the influence of the new snowfall. In general, there is a trend of changing the composition of snow from calcium carbonate to calcium chloride, which is mainly connected to the use of anti-icing reagents; for the same reason, the areas that are closer to the roads are the most polluted.

Content analysis of salts and suspended substances in snow and thawed water

The research article discusses the chemical composition of the anti-icing reagents, and presents the results of studies to determine the content of suspended solids and salts in the snow at different intervals from the edge of the roadside on the main streets of Izhevsk. The following dependence was revealed – a decrease in the concentration of salts and suspended substances in snow samples with distance from the edge of the roadway. The concentration of salts in the samples at different distances from the edge of the roads reached 5822 mg/l. The concentration of suspended solids in snow samples reached 13470 mg/l. It was found that when taking samples of snow at a distance of 25 meters from the edge of the roadway, there is an excess of the concentrations of salts and suspended solids in the snow, the values of the maximum permissible concentration for admission to surface water bodies.

Modeling the Uniform Treatment of Coatings with an Anti-Icing Liquid Reagent

The aim of this work is to study the uniformity of the treatment of coatings with an anti-icing liquid reagent using mathematical methods. The task of the modeling presented is to formulate the basic principles for the development of mathematical support and software for monitoring systems of road and airfield machines for the distribution of reagents. To do this, a mathematical model for the motion of droplets of a liquid anti-icing reagent in the air, taking into account the effect of the wind and the physical properties of the medium under consideration, is proposed. The original program code is developed based on it in the QtOctave environment. Using computer simulation, the influence of the height of the installed working element of the machine, i.e., the distributing disk, on the spraying density of the reagent is investigated. The QtOctave software product allows showing the plot of dependence of the uniform distribution of droplets over the length of the treated zone on the wind velocity. The character of the influence of the direction of the motion of air mass on the nonuniform settling of the reagent’s droplets on the coating is revealed. The calculation plot and results confirming the absence of relationships between the rotational speed of the drive shaft of the disk and deviation from the uniform distribution of droplets in the process of the anti-ice treatment of the airfield and road surfaces are presented. The numerical and analytical results should be used in the work of monitoring systems, the main purpose of which is to ensure the uniform dispersion of the reagent with an assigned range and flow rate.

Granulated Anti-Icing Reagent on the Basis of Dehydrated Magnesium and Calcium Nitrates

The phase composition of the product of thermal dehydration of a mixture of crystallohydrates of magnesium and calcium nitrates with a bulk composition Mg(NO3)2 · Ca(NO3)2 ⋅ 2.7H2O is determined via X-ray phase analysis and its IR spectrum is obtained. It is found that the sample solidifies upon cooling to form a compact nonhygroscopic mass. A sample with a higher concentration of water is hygroscopic and deliquescent in air. Deeper dehydration is accompanied by hydrolysis with the formation of basic salts. The anti-icing properties of the dehydrated nitrate sample are determined.

ECOLOGICAL AND HYGIENIC PROBLEMS OF THE APPLICATION OF ANTI-ICING AGENTS IN A LARGE METROPOLIS (FOR EXAMPLE, THE TERRITORY OF MOSCOW)

Anti-icing reagents (AIR) are one of the main soil pollutions of large cities of countries with the cold climate. The salinization adversely affects the environment and urban health. The data on the content of readily soluble salts, the response of the medium, and a number of other indices of soils of Moscow’s different functional areas are presented. Stocks of ion-pollutants in the root zone soil layers have been identified. The expansion of anomalies of salt reserves and enhancement of the salt process within individual functional areas was noted. The maximum pollution was observed in the soils of the transport zone (dissolved solids reached 0.19%), which corresponds to the average degree of salinity. According to the prevailing ionic composition, most of the soils was foundd to belong to the sodium chloride class. Revealed growth of fine silt fraction (fine dust) during soil salinization was detected.

Impact assessment of the anti-icing reagents application when conducting engineering-ecological surveys in cities

Impact assessment of the anti-icing reagents application when conducting engineering-ecological surveys in cities