Fly Ash as an Ingredient in the Contaminated Soil Stabilization Process

Fly ash is the main by-product of coal combustion characterized by a large specific surface area. In addition to oxides, it also contains unburned coal and trace elements. This study aimed to investigate the possibility of using fly ash from pit-coal combustion (CFA) for the treatment of benzene-contaminated soil (S). The CFA was used as a mixture with Portland cement (PC) (70% PC + 30% CFA). The soil was treated with a PC-CFA mixture in amounts of 40, 60, and 80% of soil mass. During the process, the concentration of benzene was monitored with the flame-ionization detector. Produced monoliths (S+(PC-CFA)x) were tested for compressive strength and capillary water absorption. The experiment confirmed that the PC-CFA mixture limited benzene emission. The highest reduction in benzene concentration (34–39%) was observed for samples treated with the PC-CFA mixture in an amount of 80% (S+(PC-CFA)80). The average compressive strength of monoliths S+(PC-CFA)40, S+(PC-CFA)60, and S+(PC-CFA)80 was 0.57, 4.53, and 6.79 MPa, respectively. The water absorption values were in the range of 15–22% dm.

Influence of Copper Pollution of Haplic Calcic Chernozem With Various Contents of Sand Fractions on Morphobiometric Indicators of Spring Barley

The growth and development of plants is one of the criteria for assessing the degree of soil pollution with heavy metals. Morphological and anatomical changes in test plants affected by pollutants, such as growth retardation, shoot bending, and decreased root length and mass, indicate the worsening of environmental conditions. The effect of various ratios of soil and sand polluted with copper (Cu) on morphobiometric parameters of spring barley (Hordeum sativum distichum), Ratnik variety, was studied in a model vegetative experiment. Haplic calcic chernozem was used as a substrate with different ratios of soil/sand. It was determined that an addition of sand into the soil in the amounts of 25%, 50% and 75% of soil mass resulted in the alteration of the physical properties of the chernozem, which was reflected in the morphometric parameters of the plants. The most notable changes in the parameters were observed after pollution of soil-sand substrates with Cu(CH3COO)2 in the amounts of 250 mg/kg, 500 mg/kg, 1000 mg/kg and 2000 mg/kg. The maximum growth and development retardation of the barley plants was found at the maximum content of sand and the maximum concentration of Cu. The pollutant reduced the root length and, to a lesser degree, the height of the aboveground components of the plant, which as a result, decreased the total plant biomass. Keywords: trace elements, soil, agricultural crops, particle size distribution

Perencanaan Perkuatan Lereng Menggunakan Geoframe di Jalan Raya Dampit-Lumajang

A Landslide is the movement of soil mass or rock constituents down the slope due to disturbance of soil stability. One of the factors that affect soil stability is the rainy season as happened in Sumberwuluh Village, Candipuro District, Lumajang Regency. The alternative used to stabilize the slope is by changing the slope geometry, then adding geoframe reinforcement. This study aims to determine the value of the factor of safety (SF) of unreinforced slopes, after changing the slope geometry, and after being given geoframe reinforcement. The method used in analyzing slope stability is the Ordinary/Fellenius method. The results of the calculation of slope stability without reinforcement using the Rocscience Slide software obtained a SF of 0.719, while the manual calculation obtained a SF of 0.7191. The two values ​​of the safety factor are less than 1.25, which means that landslides often occur. The results of the calculation of slope stability after changing the geometry of the slopes obtained a SF of 0.828 where the value is less than 1.25 which means that landslides often occur. The slopes that have been changed geometry are added with geoframe reinforcement. The results of the calculation of slope stability using geoframe reinforcement obtained a SF of 1.315 where the value is more than 1.25 which means that landslides are rare or slope in a safe condition.

The Stress-Strain State of the Tunnel Lining that Crosses the Fault Zone of Soil Blocks during an Earthquake

The study examines the question of the tunnel behavior under seismic or geophysical load in the zone of changes in the hardness of the surrounding soil mass. In the course of the study, the internal forces and displacements arising in the structure of a tunnel in the zone of intersection of the boundaries of soil layers with different properties, in the case when these layers move relative to each other, were determined by analytical and numerical solutions. The data obtained by the analytical method was compared to numerical models using practical examples.

THEORETICAL ANALYSIS OF STRENGTH RESISTANCE TO DISPLACEMENT OF IMPROVED DIGGING WORKING BODY OF POTATOE HARVESTING COMBINE

The amount of energy required to perform technological processes in agriculture largely depends on the size of the resistance to the displacement of the working bodies of machines. The main factor of energy consumption performing the technological process of potato harvesting is the resistance to the displacement of the digestive working body. In order to reduce the resistance to displacement an improved design of the digging body is proposed. An analytical study was conducted to determine the problem of moving the working body in the soil environment. The strength of the soil resistance is determined and the regularity of the influence on its change of parameters and the shape of the blade and separation parts of the digging working body is established. Calculations are made using the Mathematica application programm. The graphic dependences and contours of the isoline of the traction flange of the working part of the working body are obtained. Analysis of the calculations allowed to set the parameters of the surface of the dashboard, which provide a minimum of traction resistance. The schedule and contours of isolines of the change of the total resistance to the displacement of the soil mass with the tubers by the separation surface of the working organ in the function of the distance between the bars and the size of their intersection are also obtained. Analysis of the dependence of soil resistance and tubers on the separation surface indicates that an increase in the size of the geometric size of the intersection of the rods leads to a significant increase in the resistance of the medium. The material presented in the article can be used for analytical determination of the resistance of the excavation working body of potato harvesting machines of arbitrary geometric shape in the soil medium with tubers.

Settlement and Bearing Capacity of Rectangular Footing in Reliance on the Pre-Overburden Pressure of Soil Foundation

This article presents a solution for the quantitative evaluation of the stress–strain state (SSS) and the bearing capacity of rectangular foundations, factoring in the unit weight of the soil mass and different values of pre-overburden pressure (POP). In order to assess the SSS of the soil subgrade below a rigid rectangular footing under a uniformly distributed load, the authors applied the Boussinesq basic solution for an elastic half-space subjected to a vertical point load on its surface. As a result, the formulas for vertical stress, mean stress, shear strain, and volumetric strain for any point in Cartesian coordinates (x, y, z) and foundation settlement were determined. Additionally, the application of Hencky’s system of physical equations, with non-linear dependencies between mean stress and volumetric strain as well as deviator stress and shear strain, along with the experimental curves, depicts the relationships between bulk modulus and volume stress, and shear modulus and shear stress. The authors point out the non-linear behavior of the subgrade soil and propose a method for estimating the bearing capacity of a rigid rectangular foundation.

. MORPHOLOGICAL CHARACTERISTICS SOILS OF THE BELIGATIVE STRUCTURES OF THE KAMIANETS-PODILSKYI KAMIANETS-PODILSKYI STATE HISTORICAL RESERVE MUSEUM

The article presents micromorphological descriptions of soil profiles of key areas of the research territory. The results of micromorphological analysis and synthesis of selected soil samples are illustrated. For the first time the process-and-genetic features of urborendzins of beligerative structures were studied through the evaluation of their micromorphological structure. Urborendzins of the beligerative landscape complex of the Kamianets-Podilskyi State Historical Preserve Museum are intrazonal biolithogenic polygenetic soils with complex phylogeny exposed to a long-term anthropogenic influence. It is important to establish their genesis, which is accompanied by a number of obstacles caused by the significant amplitude of the soil profile, morphological features, physical-and-chemical features and the presence of buried horizons in such soils. To solve the problem of age and ontogenesis staging of urborendzins, along with comparative-and-geographical, we use a complex paleopedological method with active application of micromorphological analysis, which allows to establish process-and-genetic features of soils by diagnosing elementary soil processes according to sustainable features at the micro level of solid phase formation. Micromorphological structure evaluation makes it possible to consider soil as a system at the microscopic level and observe the natural flow of soil-forming processes in their interaction and ratio at all morphological levels - from microscopically small volumes of soil mass to soil profile in general. Consequently, micromorphological analysis is a unique one and possesses significant advantages over other methods of physical geography. Urborendzins of the object under study have a complex problematic genesis and the use of micromorphological analysis and micromorphological synthesis is acceptable to solve these problems. The evaluation of the micromorphological structure of these soils was carried out for the first time, their micromorphological features were not previously determined as well as the genesis in general. Our micromorphological analysis allowed us to establish the process-and-diagnostic features of the studied soils and shows that in comparison with the background soil, the deposits of the «Day Tower» are more carbonated. Under the conditions of the washing regime, fragments of limestone deposits provide constant involvement of new weathered carbonated material in soil formation processes, which promotes saturation of soil solutions with calcium cations and, accordingly, formation of more stable microaggregation of soil mass and reduction of mobility of silty particles downwards the profile, fixed through by micromorphological researches in the form of the presence of high-order microaggregates. Comparing the background soil with the sediments of the «Day Tower», it can be stated that the agrorendzin typical, in contrast to urborendzin, leached from carbonates, is characterized by the practical absence of microorshteins, humic substances are mainly in a dispersed state and signs of movement of organo-clay substances downwards the profile can be traced much more clearly. This indicates that the background agrorendzin is formed under conditions of active biogenic and accumulative processes, carbonate leaching and illimerization. Key words: micromorphological analysis, synthesis, soil, beligerative complex.

Microbiotic particles in water and soil, water-soil microbiota coalescences, and antimicrobial resistance

Bacterial organisms like surfaces. Water and soil contain a multiplicity of particulated material where bacterial populations and communities might attach. Microbiotic particles refers to any type of small particles (less than 2 mm) where bacteria (and other microbes) might attach, resulting in medium- long-term colonization. In this work, the interactions of bacterial organisms with microbiotic particles of the soil and water are reviewed. These particles include bacteria-bacteria aggregates, and aggregates with particles of fungi (particularly in the rhizosphere), protozoa, phytoplankton, zooplankton, biodetritus resulting from animal and vegetal decomposition, humus, mineral particles (clay, carbonates, silicates), and anthropogenic particles (including wastewater particles or microplastics). At they turn, these particles might interact and coalesce (as in the marine snow). Natural phenomena (from river flows to tides, tsunamis, currents, or heavy winds) and anthropogenic activity (such as agriculture, waste-water management, mining, soil-mass movement) favors interaction and merging between all these soil and water particles, and consequently coalescence of their bacterial-associated populations and communities, resulting in an enhancement of mixed-recombinant communities capable of genetic exchange, including antimicrobial resistance genes, particularly in antimicrobial-polluted environments. Particles also favor compartmentalization of bacterial populations favoring diversification and acquisition of mutational resistance by random drift. In general, microbial evolution is accelerated by the aggregation of microbiotic particles. We propose that the world spread of antimicrobial resistance might relate with the environmental dynamics of microbiotic particles, and discuss possible methods to reduce this problem influencing One Health and Planetary Health.

Model Testing on Deformation Characteristics of an Unsaturated Compacted Clay Slope Under Cyclic Wetting and Drying

The effect of wetting-drying cycles on deformation characteristics of an unsaturated clay model slope is investigated in this study. The model slope was compacted using kaolin clay mixed with thirty percent of fine sand. The deformations of slope were measured using particle image velocimetry (PIV) technique. The test results revealed that the model slope deforms mainly within a depth of 300 mm and the displacements of soil mass are nearly perpendicular to slope surface in the first two cycles. Such displacements, however, vanish gradually in the subsequent cycles. On the other hand, the magnitude of displacement along slope surface increases with the number of wetting-drying cycles. The depth affected by wetting-drying cycles increases gradually with the number of wetting-drying cycles and becomes stable finally.

Zeolite — natural ameliorant for dry meadow polluted by caesium-137

Исследовательская работа выполнена в Новозыбковском районе Брянской области на естественном суходольном лугу, подвергшемся радиоактивному загрязнению в результате аварии на Чернобыльской АЭС. Загрязнение территории радиоактивными веществами, возникшее в результате чернобыльской катастрофы, создало целый ряд проблем для ведения сельскохозяйственного производства. Одной из них является проблема использования естественных луговых экосистем, загрязнённых цезием-137, в качестве сенокосов и пастбищ. Травостой естественных лугов накапливает радионуклида больше, чем травостой, выращенный на обработанной сельхозорудиями почве. В этой связи поиск доступных, эффективных и экономически выгодных мер, позволяющих получать на естественных лугах продукцию, соответствующую нормативным показателям, имеет важное значение. Целью исследовательской работы было изучение влияния цеолита Хотынецкого месторождения на переход радионуклида из почвы в растение на естественном суходольном лугу. Для этого в августе на поверхность почвы опытных делянок вносили цеолит в объёме 0,5 и 1% от массы пахотного слоя. Через год отбирали сопряжённые пробы почвы и растений. После подготовки в них определяли концентрацию цезия-137, а также агрохимические, физико-химические показатели почвы и урожайность. В ходе выполнения исследовательской работы было установлено, что использование цеолита в качестве мелиоранта луга не оказало достоверного влияния на снижение радионуклида в травостое (сене) и на увеличение Hr, S, EKO, V, калия и фосфора. Однако достоверно увеличился показатель рН. Внесение цеолита на опытные делянки в количестве 0,5 и 1% от массы пахотного слоя почвы оказало выраженное положительное влияние на урожайность сена. The investigation took place in the Bryansk region. The territory of natural dry meadow was contaminated there due to the Chernobyl disaster. Radioactive contamination significantly impacts agriculture in the area. Caesium-137 presented in soil hinders hay and green forage production. Natural plant ecosystems accumulate more radionuclide than the ones grown on farm fields. Therefore, those methods are of the highest interest that allow production of healthy forage in that area. The aim of the research was to analyze the effect of the zeolite from the Khotynetskiy district on the radionuclide movement from soil to plants. In August the zeolite (0.5 and 1% of soil mass) was applied in soil. One year later soil and plant samples were tested for caesium-137 as well as agrochemical, physical, chemical properties and productivity. As a result, the zeolite had no significant impact on the accumulation of caesium-137 in hay as well as Hr, S, EKO, V, K or P. In contrast, рН grew significantly and hay yield increased.