This paper explores the practice of using ash and slag and fly ash from thermal power plants in road construction as one of the ways to dispose of industrial waste. The purpose of the study is to determine the chemica l composition of TPP ash and slag to study the possibility of using it as a raw material for road construction. To achieve the goal, the following tasks were set: to determine the main physical and chemical properties of ash and ash and slag from thermal power plants, to give an environmental assessment of the use of these wastes in road construction. Chemical analysis of ash and slag from Zmievskaya, Krivorozhskaya, Trypilskaya, Slavyanskaya TPPs was carried out to determine the main components: SiO2, Al2O3, Fe2O3, CaO, MgO, SO3, Nа2О and К2О. The content of heavy metals was determined using the method of atomic absorption analysis. The migration ability of heavy metal compounds from the roadway using ash and slag in the construction of roads has been studied using the construction of concentration-logarithmic diagrams. To predict the migration of heavy metal compounds into the environment when they are used in road construction, a separate dependence of the concentration of the most probable ions was plotted (for example, cuprum) [Cu(OH)n 2-n] on the pH of the environment. The lack of migration of cuprum compounds in a neutral and alkaline environment has been proven, which makes their use safe. Similar calculations were made for other metals.
Purpose. The aim of the study is to analyze the geochemical composition of ash and slag waste at the Zmiiv Thermal Power Plant (TPP) and to identify the features of migration of heavy metals (HM) from the place of storage of ash and slag waste into the ecosystem. To achieve this goal, the following tasks were solved: geochemical analysis of ash and slag waste at Zmiiv TPP; study of the reliability of HM migration into the soil in the places of ash and slag waste storage. Methods. The content of heavy metals in ash, slag and soil were investigated using atomic absorption analysis (AAA) on a spectrophotometer S-115. X-ray diffraction analysis was used to determine the solid inorganic part of ash and slag. Results. Ash and slag of Zmiiv TPP contain Cu, Cr, As, Cd, Ni, Pb in quantities that are several times higher than the maximum permissible concentration (MPC). For ash and slag waste, the total pollution index is Zc = 43, which corresponds to a high level. That is, this artificially created horizon is dangerous. HM migrate into groundwater and into the soil near the ash dump due to the infiltration of atmospheric precipitation, emissions from water pipelines, filtration of water through the base of the ash dump of the Zmiiv TPP. To determine soil contamination near the ash dump, soil analyzes were performed at a distance of 0 ... 100 meters. At a distance of up to 100 meters from the dump, there is an excess of MPC in the soil for the content of Ni, Cu, As, Cr. At a distance of up to 100 meters from the dump, an excess of the MPC in the content of Ni, Cu, As, Cr is observed. Concentration factor exceeds unity for Cr, As, Cu, Cd, Ni. The content of Pb and Zn reaches background values only at a distance of more than 100 meters. The calculation of the total soil pollution indicator allows us to classify these soils as moderately hazardous and permissible. However, there are several significant disadvantages of the Zc indicator. First of all, it does not take into account the differences in the potential hazard of chemical elements, and, most importantly, the synergistic effects of polymetallic pollution. The coefficient of the synergistic effect of heavy metals is 26.64 (in the soil of the ash dump), then it decreases, but even at a distance of 100 meters it is 11.23, that is, at a distance of 0 ... 100 m from the ash dumps, the condition of the coefficient of synergistic effect is less than one. It has been established that Cu, Ni, Zn and Cr are characterized by low mobility in the soil near the ash dump, therefore they accumulate in the ecosystem near the ash dump, which is explained by the neutral and slightly alkaline soil pH values (pH = 8.0 ... 8.5). The ratio of mineral phases to glass is unstable; however, it should be noted that aluminosilicates, calcium silicates and glass predominate in ash and slag. Сompounds with HM are confined mainly to amorphous clay aggregates and sooty-carbon formations of ash, to a lesser extent to slag glass and even less to grains of quartz sand. Conclusions. Since the ash contains such fractions that can be easily carried by wind, it should be assumed that the HM entry into the ecosystem is also by air, which also contributes to air pollution. The solution to the problem of ash and slag waste disposal should be found in the production of building materials, in road construction, but it is necessary to study the composition of ash and slag and the probability of HM migration depending on the conditions of use.
The aim of the work is to increase the reliability of remote methods of measuring the surface temperature of the human body. Common use of non-contact infrared (IR) devices for temperature screening. But it is important to pay attention to the accuracy of these systems to identify visitors or staff with an infectious disease. The following areas of improvement of metrological characteristics of non-contact devices for measuring human body temperature in a pandemic are identified: 15 cm, the presence in the equipment of a calibrated thermostable source of radiation, called the absolute black body (APT). An effective method of providing the most accurate measurements of skin surface temperature is associated with the use of "baseline sampling". To implement this method, a thermal imager measures the temperature of a specially selected group of perfectly healthy people, with whom the temperature of all others is compared. As a result of the conducted research the requirements to carrying out measurements of body temperature by IR thermometers for reception of reliable results are substantiated and offers on maintenance of these requirements for the purpose of increase of collective safety are put forward. It was found that the lack of calibration when measuring the body temperature of 50 university visitors with an IR thermometer is the cause of gross systematic error, which needs to be corrected by correcting. To increase the reliability of measurements, it is necessary to develop and test a simple and effective method of calibrating IR thermometers, suitable in normal operating conditions. Therefore, it is necessary to calibrate the IR thermometer before the measurements, which eliminates the systematic measurement error. The practical significance of the study is to determine the optimal conditions for the use of the device for non-contact temperature screening in a pandemic. The results of the work will be useful both for further study of increasing the reliability of the results of remote temperature measurement, and may be useful in the learning process.
Currently, society and industry are developing at a rapid pace, and an increas- ingly serious problem of the modern world is environmental pollution, requiring recycling and reuse wastes. Modern technologies in the field of road construction involve the use of polymeric materials obtained from waste recycling. Almost nothing is known about soil contamination by plastic in general and the destruction of roads in particular; probably because of lack of awareness and absence of standard methods for quantifying plastic components in soil. The contemporary data suggest that flow of plastic has already reached a value similar to that found for other contaminants, such as heavy metals. In particular, migration is observed for plastic microparticles, but so far, their effect on groundwater has not been studied. Therefore, additional research is urgently needed to shed more light on the fate and impact of these persistent materials in the terrestrial environment. The purpose of the study was a geoecological analysis of the risks of using polymer waste in construction of roads to the geological environment. To ensure environmental safety in the implementation of technologies for the utilization of polymer waste, it is necessary to take into account their chemical composition, the ability to form hazardous products in increasing temperature, hazard class, physical and chemical properties. We propose criteria for assessing the possibility of recycling polymer waste in road construction, namely for the manufacture of asphalt concrete. According to the pro- posed overall criterion, taking into account not only technical and economic indicators, but also the environmental component, we can recommend the use of HDPE and LDPE, as well as PP for use in road construction. Taking into account the total criterion, we recom- mend using HDPE, LDPE as the most acceptable waste for road construction,, as well as PP. The technological scheme should include the collection, sorting of these plastics, as those that do not contain hazardous chemicals. Temperature conditions for manufacturing asphalt involve heating and converting the components into the liquid phase for uniform mixing of the entire composite. Under those temperature conditions, chemical compounds that are harmful to the environment and humans would not be created. The possibility to substitute part of the bitumen, to obtain asphalt concrete with high performance, increased service life shows the cost-effectiveness of using these groups of polymer waste in the technology of manufacturing asphalt concrete. The lack of regulatory framework and technical standards for working with polymers for paving brings the problem of plastic roads to the legislative level.
Purpose. Detection of post-pyrogenic transformation of biogeochemical properties of soils in pine forests of the Kharkiv region under technogenic loading. Methods. Determination of the pH of the water extract by the potentiometric method, the content of humus and gross nitrogen according to the Tyurin method, the granulometric composition according to Kachynskyi, the mobile forms of phosphorus and potassium according to Machigin. The content of mobile forms of heavy metals was determined by the atomic absorption method. Results. There is a certain dependence of the post-pyrogenic transformation on the age of fire impact on the soil. Relatively recent consequences of a fire of medium intensity on the soil were marked by a clear reaction of the complex of their properties. Physical-chemical properties of soils in the post-fire period deteriorate due to a significant decrease in the amount of nutrients in the soil: humus burns, nitrate nitrogen content decreases. The acid-alkaline reaction according to the pH index in the soils affected by fires shifts to neutral, which should be explained by the saturation of the absorbing complex of soils with alkaline earth elements. Forest lowland fires significantly transform the morphological appearance of the upper part of the soil profile. Under the influence of fires, there are changes in pH, the content of exchangeable cations, gross and mobile forms of nitrogen, etc. The behavior and content of heavy metals in the forest floor is determined, in addition to the effect of fire and the geochemical state of the region, the speed of water migration and biological absorption, and the topography of the area. The concentration of heavy metals in the surface horizons of the soils of pine forests increases several times and exceeds the background concentrations as a result of the mineralization of the forest floor and grassy vegetation from combustion and subsequent migration of chemical elements. Conclusions. As a result, the surface horizons of soils change, in particular, a new pyrogenic horizon is formed, which differs in a certain way from natural analogues. Fires, on the one hand, improve the conditions for seed penetration into the soil, but worsen the conditions for the germination, growth and development of coniferous tree species. The concentration of heavy metals in the surface horizons of pine forest soils is an ecological hazard. Further research on the transformation of soil properties under the influence of pyrogenic factors is of significant theoretical and practical importance in the development of scientific approaches to the restoration of ecosystems in the post-fire stage of development.
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