Alternative Sources Of Raw Materials Research Articles

ТЕХНІКО-ЕКОНОМІЧНЕ ОБҐРУНТУВАННЯ ДОЦІЛЬНОСТІ ЗАСТОСУВАННЯ АСФАЛЬТОБЕТОННИХ ШАРІВ ІЗ ЗОЛОЮ ВИНЕСЕННЯ

Introduction. The road construction industry is currently one of the strategic industries of Ukraine, and the issue of quality and availability of basic building materials for road construction is particularly topical, which is directly related to its high material intensity. The known reserves of high-quality raw materials that could be used as asphalt concrete components are constantly decreasing, so it is necessary to look for alternative sources of raw materials for construction materials and explore the possibility of their use. In this regard, the most efficient use of local raw materials is the use of industrial waste, which can be one of the solutions to the problem of shortage of raw materials of inorganic origin. Problem statement. In road construction, when repairing or arranging road pavement layers, in particular asphalt mixtures, the need for carbonate mineral fillers, which are scarce in some regions, is constantly growing. Industrial by-products can be an alternative. One of these materials is fly ash from thermal power plants, which can be used instead of mineral fillers in asphalt mixtures. Objective. To perform a feasibility study of the use of asphalt concrete layers with fly ash. Materials and Methods. Analysis of information sources and the materials market of Ukraine and calculation of the technical and economic efficiency of fly ash application in asphalt mixtures.

Grades of cassava starch (flours) as sustainable substrates for use in neutral spirit and biofuel production—Industry approach

One way to mitigate the adverse impacts of climate change is through aggressive replacement of fossil energy sources with plant derived renewable energy. The potential of different grades of cassava starch, including decayed cassava starch, as viable alternative and cheaper source of renewable raw materials for bio-ethanol production was studied. The global population keeps expanding and poverty levels keep increasing. Conflict in the use of food-grade cassava starch as raw material for bio-ethanol production will pose a threat to food security. The highest alcohol yield (AY) of 539 LA/t dm was obtained from food grade cassava starch. Food grade cassava starch per-boiled for 5 min produced lower AY (524 LA/t dm). Cassava starch per-boiled for more than 5 min gave much lower AY (507 LA/t). The mildly decayed cassava starch gave a relatively higher AY of 491 LA/t dm than the more decayed cassava substrate that produced AY of 453 LA/t dm. The AY value obtained from the more decayed cassava starch is similar to the AY values obtained with some cereals. Decayed cassava is not fit for human consumption, would not compete with food requirements. This will assist in food security, secure our environment from pollution and other adverse effects.

A New Alternative Source of Clay Raw Materials for Ceramic Materials Based on the Muddy Deposits in Water-Reservoirs

A New Alternative Source of Clay Raw Materials for Ceramic Materials Based on the Muddy Deposits in Water-Reservoirs

Investigation of metabolic processes of alcohol yeast during the fermentation of buckwheat-corn wort

To expand the range of competitive alcoholic beverages with original organoleptic properties, it is promising to study the use of new types of plant raw materials in grain distillate technologies. The purpose of this work was to establish the influence of the characteristics of the composition of grain wort prepared with the joint use of an alternative raw material source — buck- wheat and corn, which is widely used in alcohol production, on the metabolic processes of the yeast Saccharomyces cerevisiae 985-T and alcoholic fermentation. The objects of the study were buckwheat and corn; enzyme preparations — sources of amylases, xylanases, β-glucanases and proteases; samples of grain wort, mash and mash distillates. The prospects of introducing mixed grain media prepared using non-traditional buckwheat raw materials into the technology of original alcoholic bever- ages are substantiated. It was shown that the use of buckwheat as a source of biocomplete protein, essential amino acids and minerals together with corn containing a high level of starch and a low level of non-starch polysaccharides contributed both to an increase in the yield of alcohol and a change in the quantitative content of secondary metabolites in the composition of volatile impurities. It was found that an increase in the concentration of soluble carbohydrates in the wort and a decrease in its viscosity by 15.5–40.3% occurred due to the inclusion of corn in the composition of the grain mixture, and the enrichment of the wort with nitrogen assimilated by yeast by 19.0–41.8% — as a result adding buckwheat. The optimal ratio of corn and buckwheat in the composition of the grain mixture (7:3) was selected, which made it possible to improve the biochemical and technological parameters of grain must, increase the efficiency of the vital processes of yeast and alcoholic fermentation, ensure an increase in the yield of alcohol by 1.8%, reduce the formation of side metabolites, especially higher alcohols, and change their composition in the direction of increasing the proportion of aldehydes and esters, which can have a positive effect on the organoleptic characteristics of the distillate.

Getting a Face Brick of Light Shades Based on Marl

The article reflects the topic of the shortage of raw materials for the production of face bricks of light colors. This problem has particularly affected producers in the European part of Russia due to the cessation of clay supplies from the territory of Donbass. Therefore, one of the relevant directions is the search for alternative sources of raw materials. The accumulated experience and laboratory tests have shown the possibility of producing light bricks using marl. As components of the ceramic mass, clays from the Vladimirovsky deposit in the Rostov region of the East Kazakhstan region, charge and marl KO-2 were also accepted from deposits in the Rostov region. By changing the percentage of marl and refractory clay and the firing temperature, it is possible to adjust the color of the fired products, as well as water absorption, average density, strength of products and their shrinkage. Industrial tests conducted on the basis of two brick factories in Rostov-on-Don and the region showed positive results. The use of marl ranged from 40 to 70% of the total weight. Clay from the East Kazakhstan region Vladimirovskoye deposit in the amount of 30 to 60%, respectively, acted as a plastic component. The brick turned out to be light beige to light yellow in color. One of the factories launched the “Svetly” brick into mass production. The material fully meets the requirements of GOST 530–2012. Thus, the problem of the shortage of light clays can be solved by using alternative raw materials – marl. The introduction of 50 to 70% of the mass into the composition is particularly effective. Preliminary calculations show the profitability of the technology by saving raw materials up to 20–25%, while increasing the aesthetic characteristics of the front brick.

Simulasi Aliran Daya Pada Pembangkitan PLTBG 1 MW Di Laboratorium Teknik Listrik Dengan Koneksi PLN Penyulang RA.01 Rantau Prapat Menggunakan Software Electric Transient And Analysis Program (Etap) 12.6.0

PT Pangkatan Indonesia is an oil palm plantation company operating in Labuhanbatu Regency, North Sumatra Province, with a plantation area of 7,134.8 ha and has built a palm oil mill with an installed capacity of 40 tons / hour. Liquid waste from the plant has the potential to be an alternative source of raw materials for Biogas Power Plants (PLTBg) which is also a distributed generation (DG). The parameters to be studied in this study are the decrease in power losses and the voltage profile of the electrical power produced. The simulation process produces voltage under normal conditions, which only increases about 0.3% of the nominal voltage (complies with Ministerial Regulation No. 4 of 2009). In addition, the results of interconnection analysis at the 1 MW PLTBG show that the voltage at the ends before and after the connection has increased. Furthermore, the ratio of the total current before and after (load 75% - 95% ) is fixed (no change). The conclusion of the results of this study is, the greater the load, the greater the power produced.

CHEMICAL STABILITY OF CELLULOSE NITRATES: REVIEW

The results of the analysis of literature data on updated methods for determining the chemical stability of cellulose nitrates are presented. The relevance of research is due to the need to control the operation and storage of a widespread component of solid rocket fuels and explosive compositions. The criterion for chemical resistance is the value of the decomposition rate or the time dependence of the degree of decomposition of the sample. It is shown that methods for assessing the chemical resistance of cellulose nitrates are based on determining the rate of its thermal decomposition, which is measured by a specific parameter accompanying decomposition. These parameters include weight loss, amount of gaseous decomposition products released, decomposition temperature or thermal effects. Studies are carried out at elevated temperatures and allow you to control the magnitude or rate of change in the parameter that accompanies thermal decomposition. The possibility of using modern analytical methods for evaluating chemical resistance is shown: differential scanning calorimetry, thermogravimetric analysis, chemiluminescent analysis, infrared spectroscopy, high-performance liquid and thin-layer chromatography, gas chromatography, electron paramagnetic resonance, mass spectrometry, X-ray diffraction analysis. The preference for methods of differential scanning calorimetry or differential thermal analysis is substantiated. The results of studies on improving the chemical resistance of cellulose nitrates and compositions based on it with the use of new stabilizers of the aniline series, stabilizers of natural origin with the advantage of the latter on the examples of curcumin and lignins are presented. Due to the insufficient stability of cellulose nitrates, stabilizers added to the formulation of explosive compositions lengthen the induction period of the decomposition of nitro compounds and do not allow the development of the autocatalytic decomposition stage. Methods for determining the chemical stability of cellulose nitrates obtained from alternative sources of raw materials are presented. For citation: Vdovina N.P., Korchagina А.А., Budaev I.А. Chemical stability of cellulose nitrates: Review. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2023. V. 66. N 5. P. 6-20. DOI: 10.6060/ivkkt.20236605.6725.

Architecting an Open-Source IIoT Framework for Real-Time Control and Monitoring in the Bioleaching Industry

Electronic waste (e-waste) contains toxic elements causing an important impact on environmental and human health. However, the presence of valuable metals, such as copper or gold, among others, make recycling a necessity for obtaining an alternative source of raw materials. Conventional metal recovery methods are environmentally unsound, prompting the exploration of greener alternatives like bioleaching, which utilizes the activity of microorganisms for a more sustainable recovery. However, the mechanisms involved in the process and the conditions to optimize the metabolic paths are still not completely known. Monitorization and automatization of the different stages composing the global process are crucial for advancing in the implementation of this novel technology at an industrial scale. For the first time, an open-source industrial IoT system is designed to enhance and regulate bioleaching by implementing real-time monitoring and control within the plant’s infrastructure. This system includes an Android app that displays real-time plant data from sensors and a robust server featuring a flexible application programming interface (API) for future applications. The app caters to specific needs such as remote sensor reading, actuator control, and real-time bioleaching alerts, ensuring secure access and proactive event management. By utilizing collected data, it minimizes downtime, equipment failures, and supply chain disruptions. The server maintains seamless communication with the plant controller, enabling efficient pump activation and sensor data transmission. A telegram bot demonstrates the API’s flexibility by forwarding plant alerts to users. During validation with concurrent remote user access, the application demonstrated its ability to prevent irreversible plant failures through an advanced alarm system. Ultimately, this IIoT system amplifies plant performance, safety, and efficiency by optimizing processes and decision-making capabilities. It emerges as a pivotal open-source tool, securing remote oversight and management of large-scale bioleaching plants, promising adaptability for future enhancements.

Unlocking hidden mineral resources: Characterization and potential of bitterns as alternative sources of critical raw materials

Mineral extraction from seawater brines has emerged as a viable solution to reduce Europe's reliance on imported Critical Raw Materials (CRM). However, the economic viability of this approach hinges on the local demand for sodium chloride, the primary product of such extraction processes. This study investigates the potential of residual brines, commonly known as "bitterns," generated during solar sea-salt extraction in traditional saltworks, as an alternative source of minerals. The Mediterranean region, encompassing South-European, North-African, Near East coasts, and parts of the Atlantic regions, is particularly conducive to exploring this prospect due to its extensive solar sea salt industry.Saltworks in the region, adopting various operational strategies based on feed quality or local climate conditions, produce different types of bitterns, each holding a latent resource potential that has remained largely unexplored. Within the framework of the EU-funded SEArcularMINE project, it was conducted an extensive analytical campaign to characterize bitterns collected from a diverse saltworks network. The analysis revealed the presence of sodium, potassium, magnesium, chloride, sulfate, and bromide in concentrations ranging from g/kg, while boron, calcium, lithium, rubidium, and strontium were found in the mg/kg range. Additionally, trace elements (TEs) such as cobalt, cesium, gallium, and germanium were detected at concentrations in the order of μg/kg.Detailed results on the composition of bitterns are presented, emphasizing the distinct characteristics observed at different sites. The estimated potential for mineral recovery from these bitterns is approximately 190 €/m3, considering the production capacity of about 9 Mm3 per year in the Mediterranean area. This finding underscores the significant contribution that mineral recovery from bitterns could make in securing access to CRMs for the European Union.

Application of Modified Seed Oils of Selected Fruits in the Synthesis of Polyurethane Thermal Insulating Materials.

The use of alternative raw material sources in polyurethane chemistry is necessary given the limited supply of fossil fuels, their rising prices and the concern for sustainability. The production of biopolyols from edible vegetable oils such as rapeseed oil, soybean oil or sunflower oil is often proposed. In order to avoid conflict with the global food economy, non-edible or waste oils are hoped to find application in chemical synthesis. The possibility of using oils from selected fruit seeds to obtain biopolyols is analyzed in this manuscript. Five biopolyols were obtained from watermelon, cherry, black currant, grape and pomegranate fruit seeds using the transesterification reaction of the oils with triethanolamine. Thermal insulating polyurethane foams were then obtained by replacing 75% of petrochemical polyol with the biopolyols in polyurethane systems. Based on an analysis of the foaming process, it was found that the incorporation of triethanolamine molecules into the biopolyols causes a catalytic effect. The use of such biopolyols allows eliminating the catalyst from a polyurethane foam formulation. The polyurethane biofoams obtained with the pomegranate-seed-based biopolyol were characterized by the highest content of closed cells (45 vol.%). The lowest content was found for the foams containing the currant-seed-based biopolyol (9%). The foams were characterized by thermal conductivity coefficients between 32 and 35 kW/m·K and densities of approximately 40 kg/m3. Good dimensional stability and compressive strength between 100 and 250 kPa make them suitable for use in construction.

Научное обоснование использования древесины осины в деревянных клееных конструкциях

One of the promising materials for construction are wooden glued structures. According to the current regulatory documents, for the production of such structures coniferous wood is usually used, the reserves of which in industrially developed areas have significantly decreased over the last decades. At the same time, in a number of regions of Russia there is a significant raw material reserve of aspen wood, which has been successfully used in the construction of buildings and structures for many centuries. Its physical and mechanical characteristics differ from pine wood from 3.2 to 18.6 %. Therefore, it can be considered as an alternative source of raw materials for wooden house construction enterprises. To assess the degree influence of the combination of coniferous and aspen wood on the strength of the glue joint, as one of the main indicators of the quality of wooden glued structures, a set of theoretical and experimental studies was carried out. Maximum tangential and normal stresses of glue joint in pine and aspen blanks, which are significantly higher than those of solid wood, were determined by calculation. The values of shear strength in glued pine and aspen lamellas (4.46–8.06 MPa), obtained during the experiments at the 1st stage of research, were close to the strength of solid wood. At the 2nd stage the method of dispersion analysis was used, the results confirmed the assumption that when gluing lamellas up to 20 mm thick, the difference in the strength of the glue joint of structures made of pine and structures made of pine and aspen is insignificant. The obtained data serve as a basis for further work on diversification of raw material resources in the production of wooden glued structures due to the involvement of low-demand aspen wood in processing. For citation: Titunin A.A., Gevorgyan M.S., Fedotov A.A., Vakhnina T.N., Susoeva I.V. Scientific Substantiation of Aspen Wood Use in Wooden Glued Structures. Lesnoy Zhurnal = Russian Forestry Journal, 2023, no. 6, pp. 149–161. (In Russ.). https://doi.org/10.37482/0536-1036-2023-6-149-161

Chemical and Organoleptic Properties of Dragon Fruit Gummy Candy and Apple Snail Collagen Extract with Carrageenan Addition

Gummy candy is a soft confectionery crafted from fruit juice, sugar, and gelling agents, known for its chewy texture. The utilization of dragon fruit juice enhances its nutritional value due to its antioxidant properties, phenolic compounds, and vitamin C content. Additionally, it aims to diversify products derived from dragon fruit. Meanwhile, the utilization of collagen from apple snails seeks to boost the economic value of these snails and provide an alternative source of collagen raw material. In this study, the gummy candy uses carrageenan as a hydrocolloid material to establish the chewy texture. This study's primary objective is to determine the optimal combination involving the proportion of dragon fruit juice, apple snail collagen extract, and carrageenan concentration for producing high-quality gummy candy. The research employed a Completely Randomized Design (CRD) with a two-factor factorial pattern and two replications. The first factor was the proportion of dragon fruit juice to apple snail collagen (70:30, 75:25, and 80:20), while the second factor was the carrageenan concentration (3%, 5%, and 7% w/w). Observational data were analyzed using Analysis of Variance (ANOVA), and if interactions were observed, they were further assessed with Tukey's test at a significance level of 5%. The treatment combination of a 75:25 proportion of dragon fruit juice to apple snail collagen and a 7% carrageenan concentration proved to be the most effective, yielding gummy candy with a moisture content of 13.21%, ash content of 0.95%, and organoleptic evaluation scores for aroma, taste, color, and texture of 3.25, 3.4, 3.4, and 3.7.

Alternative Fiber-Based Paperboard Adhesion Evaluation with T- and Y-Peel Testing

Due to increased pressure on the availability of wood biomass in the EU and the regulatory attempts to lower CO2 values, where wood-based biomass plays a crucial role in carbon sequestration, the use of cellulose derived from alternative sources is gaining increased interest in the pulp and paper industry as well as in other industries. The processing properties of alternative fiber-based packaging need to be checked in current processing operations with other types of materials and recycling workflows. For example, in the production of folding boxes, after printing other converting properties such as glueability are also of great importance. The adhesive absorption and bonding strength of materials are important as adhesive joints of packaging can interfere with the protective function. In the presented research, three different paperboards produced on a pilot scale from alternative raw material sources were tested. Two paperboards were produced from the alien invasive plants Japanese knotweed and black locust, and one from residual sawdust. The basic paperboard properties were tested regarding paperboard porosity, roughness, z-directional tensile strength, and dynamical behavior regarding liquid interaction (contact angle and liquid penetration dynamic), as water-based adhesives were used in the research. For adhesive joint strength testing, Y- and T-peel adhesion testing was performed on the joint paperboard samples, as still there is no fully standardized method for the evaluation of such fiber-based material properties. The results indicate differences in the penetration dynamics of liquids. This parameter had the highest influence on the peel adhesion strength, while porosity, roughness, and dynamic contact angle were not so significant. Regarding the two adhesive joint tests, the differences in separate materials regarding peel adhesion curves show similar results. However, the Y-peel maximum force values are higher due to the testing setup (in comparison to the T-peel test). The paperboards made from invasive plants showed adhesive joint failures which are more suitable for tamper-proof packaging due to their low surface strength and crack propagation into the fiber structure.

The chemical characterisation of nettle (Urtica dioica L.) seed oil

The past decade has seen increasing interest in plant oils in the food, pharmaceutical, and cosmetic industries due to their diverse functional and nutritional properties, as well as the high levels of consumer acceptance. As a result, there has been a spike in research interest in finding new sources of oils with good potential for industrial use. In this paper, the chemical characterisation (saponification, iodine, acid and ester numbers, as well as fatty acid composition) of nettle seed oil was given. Oil was analysed for its thermooxidative stability by differential scanning calorimetry. The kinetic parameters of oxidation (Ea, A, and k) were also determined. The results showed that nettle seed oil belongs to the group of edible oils of the linoleic type and it is nutritionally highly valuable, it has pronounced thermooxidative stability and could be an alternative source of raw material for the food, cosmetics, and other non-food industries.

Eco-friendly methodology for removing and recovering rare earth elements from saline industrial wastewater.

In this study, response surface methodology (RSM) was applied with a Box-Behnken design to optimize the biosorption (removal and bioconcentration) of rare earth elements (REEs) (Y, La, Ce Eu, Gd, Tb) by living Ulva sp. from diluted industrial wastewaters (also containing Pt and the classic contaminants Hg, Pb, Zn, Cu, Co, and Cd). Element concentration (A: 10-190 μg/L), wastewater salinity (B: 15-35), and Ulva sp. dosage (C: 1.0-5.0 g/L) were the operating parameters chosen for optimization. Analysis of the Box-Behnken central point confirmed the reproducibility of the methodology and p-values below 0.0001 validated the developed mathematical models. The largest inter-element differences were observed at 24 h, with most REEs, Cu, Pb and Hg showing removals ≥ 50 %. The factor with the greatest impact (positive) on element removal was the initial seaweed dosage (ANOVA, p< 0.05). The optimal conditions for REEs removal were an initial REEs concentration of 10 μg/L, at a wastewater salinity of 15, and an Ulva sp. dosage of 5.0 g/L, attaining removals up to 88% in 24 h. Extending the time to 96 h allowed seaweed dosage to be reduced to 4.2 g/L while achieving removals ≥ 90%. The high concentrations in REE-enriched biomass (∑REEs of 3222 μg/g), which are up to 3000 times higher than those originally found in water and exceed those in common ores, support their use as an alternative source of these critical raw materials.

Obtaining fine-dispersed cellulose from annual plants

Wood is not only of great economic importance as a building and finishing material, but is also one of the cheapest and most widely used raw materials for the industrial production of pulp. At present, it is the main source of raw materials as a starting material for the extraction of cellulose. The paper analyzes the negative consequences affecting the ecological situation in the world due to the increased demand for wood. An alternative source of raw materials to replace wood is considered. The possibility of obtaining fibrous and powdered cellulose from technical hemp is shown. The conditions for obtaining it are determined.

HYDROETHOXYCARBONYLATION OF CYCLOPENTENE IN THE PRESENCE OF A THREE-COMPONENT PdCl2(PPh3)2-PPh3-AlCl3 SYSTEM

Carbon monoxide-based synthesis is an extensive and promising branch of organic synthesis. The interest in this area is primarily due to the wide synthetic capabilities of C1 chemistry, as well as the gradual depletion of traditional sources of hydrocarbon raw materials and the rise in the cost of petroleum products. In this regard, the development of new processes based on alternative sources of raw materials is an urgent task.

Dynamical Simulation, Sensitivity, and Productivity Analysis of a Light-Photoacclimation Model for Microalgae-Based Carbohydrate Production in Continuous Photobioreactors

The world’s human population is increasing as is the demand for new sustainable sources of energy. Accordingly, microalgae-based carbohydrates for biofuel production are being considered as an alternative source of raw materials for producing biofuels. Microalgae grow in photobioreactors under constantly changing conditions. Models improve our understanding of microalgae growth. In this paper, a photoacclimated model for continuous microalgae cultures in photobioreactors was used to study the time-varying behavior and sensitivity of solutions under optimal productivity conditions. From the perspective of dynamic simulation in this work, light intensity was found to play an influential role in modifying metabolic pathways as a cell stressor. Enhancing carbohydrate productivity by combining nutritional deficiency and light intensity regulation modeling strategies could be helpful to optimize the process for the highest yield in large-scale cultivation systems. Under the proposed simulation conditions, a maximum carbohydrate productivity of 48.11 gCm−3d−1 was achieved using an optimal dilution rate of 0.2625 d−1 and 350 μmolm−2s−1 of light intensity. However, it is important to note that, a particular set of manipulated inputs can generate multiple outputs at a steady state. A numerical solution of the sensitivity functions indicated that the model outputs were especially sensitive to changes in parameters corresponding to a minimum nitrogen quota, maximum nitrogen intake rate, dilution rate, and maximum nitrogen quota compared to to other model parameters.

Development of productive pseudocapsulated compound feeds for rainbow trout grown in the Central Federal District of the Russian Federation

The decrease in catch of valuable fish species from natural water bodies is compensated by their intensive cultivation in artificial conditions. In order to realize the main task of trout farms associated with obtaining marketable products in the shortest possible period of time, artificial feed is used as a source of food. A economically feasible alternative source of raw materials is the products of plant origin. In the process of production of oil and fat products at various stages, numerous fat wastes and by-products are formed, wich have fodder value and are not used as feeding facilities in industrial scale. This is especially frue for fat processing (soapstock of Light oil, fatty bleaching clays, dezodoration chases, phosphatides, calcium salts of fatty acids), as well as waste oils in combination with fat processing waste. On the base of studying the classical technology of producing mixed fodders for valuable fish species and eliminating its drawbacks the technology of pseudocapsulated mixed fodders for salmon fish grown in the CFD of Russia Federation with given fodder value and a line for its realization is suggested. The best way to bring fats and vitamins contained in them to valuable fish species is to feed them as a part of mixed fodders. At present, however, it is difficult to increase the level of fat in feed on the existing Russian fats supply lines, since most plants can include up to 10% of fat in the bulk feed line. Therefore, the development of mixing formulations and techniques for valuable fish breeds using sturgeon fish with more than 10% fat in it as an addition of fat oily wastes such as epaulettes and phosphates is not only of scientific interest. In the course of studies optimization encapsulated optimal feeds for program "Feed Optima Expert" pseudorainbow trout were also developed. As a result, close results were obtained in terms of the rate of growth of trout, the development, conversion of feed and viability in comparison with the best feed counterparts on the Russian market.

Ecological assessment of Uncle Sam Gulch Creek water quality under conditions of acid mine drainage

The current stage of subsurface use development is accompanied by an annual increase in post-mining territories. This is partly due to a change in funding priorities in this area and their widespread reorientation to the search for alternative sources of raw materials to ensure the development of modern high-tech industries. One of the biggest threats to the environment in this development is the deterioration of the freshwater quality due to poor management of abandoned mining areas. And one of the most significant problems is often created by acid mine drainage. As a part of the study, information on the current environmental state of a past American mining territory located near Basin, Montana, USA, was analyzed and summarized; a conceptual exposure model was created regarding the studied natural and technogenic interactions; systematization and data updating on temporal and spatial changes in the qualitative characteristics of surface waters that are in direct contact with the abandoned mine were carried out; the level of efficiency of implemented reclamation works on the territory was determined. The results of the water quality environmental assessments proved that the measures taken thus far are absent of a sufficient level of effectiveness for its full rehabilitation. To accelerate the process of changing the water quality of the investigated water object, both in terms of condition and degree of purity, a combination of a passive treatment system coupled with an artificial reduction of acid mine drainage volumes was suggested.