Lignite Mine Research Articles

Options for net zero emissions hydrogen from Victorian lignite. Part 1: Gaseous and liquefied hydrogen

This two-part paper investigates the feasibility of producing export quantities (770 t/d) of blue hydrogen meeting international standards, by gasification of Victorian lignite plus carbon capture and storage (CCS). The study involves a detailed Aspen Plus simulation analysis of the entire production process, taking into account fugitive methane emissions during lignite mining. Part 1 focusses on the resources, energy requirements and greenhouse gas emissions associated with production of gaseous and liquefied hydrogen, while Part 2 focusses on production of ammonia as a hydrogen carrier.In this study, the proposed process comprises lignite mining, lignite drying and milling, air separation unit (ASU), dry-feed entrained flow gasification, gas cooling and cleaning, sour water-gas shift reaction, acid gas removal, pressure swing adsorption (PSA) for hydrogen purification, elemental sulphur recovery, CO2 compression for transport and injection, hydrogen liquefaction, steam and gas turbines to generate all process power, plus an optional post-combustion CO2 capture step. High grade waste heat is utilised for process heat and power generation. Three alternative process scenarios are investigated as options to reduce resource utilisation and greenhouse gas emissions: replacing the gas turbine with renewable energy from off-site wind turbines, and co-gasification of lignite with either biomass or biochar. In each case, the specific net greenhouse gas intensity is estimated and compared to the EU Taxonomy specification for sustainable hydrogen.This is the first time that a coal-to-hydrogen study has quantified the greenhouse gas emissions across the entire production chain, including upstream fugitive methane emissions. It is found that both gaseous and liquefied hydrogen can be produced from Victorian lignite, along with all necessary electricity, with specific emissions intensity (SEI) of 2.70 kg CO2-e/kg H2 and 2.73 kg CO2-e/kg H2, respectively. These values conform to the EU Taxonomy limit of 3.0 kg CO2-e/kg H2. This result is achieved using a Selexol™ plant for CO2 capture, operating at 89.5%–91.7% overall capture efficiency. Importantly, the very low fugitive methane emissions associated with Victorian lignite mining is crucial to the low SEI of the process, making this is a critical advantage over the alternative natural gas or black coal processes.This study shows that there are technical options available to further reduce the SEI to meet tightening emissions targets. An additional post-combustion MDEA CO2 capture unit can be added to increase the capture efficiency to 99.0%–99.2% and reduce the SEI to 0.3 kg CO2-e/kg H2. Emissions intensity can be further reduced by utilising renewable energy rather than co-production of electricity on site. Net zero emissions can then be achieved by co-gasification with ≤1.4 dry wt.% biomass, while a higher proportion of biomass would achieve net-negative emissions. Thus, options exist for production of blue hydrogen from Victorian lignite consistent with a ‘net zero by 2050’ target.

Thailand’s net-zero emissions by 2050: analysis of economy-wide impacts

This paper aims at exploring the economy-wide impacts of achieving net-zero greenhouse gas (GHG) emissions by 2050 in Thailand. This study developed a recursive dynamic Asia-Pacific Integrated Model/Computable General Equilibrium (AIM/CGE) model of Thailand for the assessment. The macroeconomic impacts of Thailand’s net-zero GHG emission targets by 2050 are analyzed relative to its 2-degree pathway. Results indicate that Thailand should put more effort in GHG mitigation actions to achieve the emissions peak by 2025 and net-zero GHG emissions by 2050. Improvement in energy efficiency; increasing electrification; expanding renewable energy utilization; deploying green hydrogen; bioenergy; carbon capture, utilization, and storage (CCUS); and behavioral changes are the key identified pillars of decarbonization to drive Thailand towards the pathways of net-zero emissions by 2050. Results show that there is a possibility of attaining net-zero GHG emissions by 2050 at the expense of an economic loss for Thailand. The gross domestic product (GDP) loss would be as high as 8.5% in 2050 to attain net-zero emissions. Lower productivity from the energy intensive industries such as petroleum refineries, coal and lignite mining, manufacturing industries, and transport are the key contributing sectors to the GDP losses. The price of carbon mitigation would shoot up to reach USD 734 per tCO2eq in 2050 from USD 14 per tCO2eq in 2025 to attain net-zero emissions in 2050.

Assessment of soil loss using RUSLE around Mongolian mining sites: a case study on soil erosion at the Baganuur lignite and Erdenet copper–molybdenum mines

Mining constitutes an integral part of Mongolia’s national economy and dominates the country’s export revenue. At the same time, a wide range of mining impacts on soil, water resources, the atmosphere and the biosphere have been documented across the country. This case study addresses the long-term soil degradation around two mining sites located in the semi-arid steppe zone of Mongolia: the open-cast lignite mine of Baganuur about 140 km east of Ulaanbaatar, and the open-pit copper–molybdenum mine of Erdenet about 240 km northwest of Ulaanbaatar, both of which started commercial extraction in the late 1970s. For the assessment of soil erosion, the RUSLE model was applied in different seasons for the period from 1989 to 2018 at 3-year intervals, considering both climatic variation and the expansion of the mines based on maps and satellite imagery. Rainfall erosivity was identified as the most dominant factor driving soil erosion in the study regions, with mining leading to local increases in soil erodibility. The highest soil erosion rates were found in both areas in July 2018, reaching 7.88 t ha–1 month–1 in the Erdenet area and 9.46 t ha–1 month–1 in the Baganuur area. The spatial patterns of soil erosion showed higher soil loss rates were in the vicinity of the mines and adjoining industrial sites. Particularly high soil losses were identified in July 1998, July and August in 2013 and July 2018 in both mining areas. The combination of the RUSLE model, remote sensing and ground truth data as and their processing by GIS was found to be a time-saving and cost-effective technique for continuous monitoring of soil erosion and planning of preventive measures in and around mining areas.

Changes in Physical and Water Retention Properties of Technosols by Agricultural Reclamation with Wheat–Rapeseed Rotation in a Post-Mining Area of Central Poland

During opencast lignite mining, the natural landscape is damaged, along with soils, and new anthropogenic landforms are created which require reclamation. Usually, the evaluation of the effects of reclamation (mostly forestry) is concerned with changes in chemical properties in the first years, mainly in the surface horizon. This study analyzed the effect of long-term agricultural reclamation (43 years) on the physical and water retention properties of Technosols. The experiment involved cultivation of winter wheat and winter oilseed rape under 3 fertilization variants. After 43 years, an Ap horizon (Ap1 and Ap2) developed in fertilized Technosols, but was not clearly formed in unfertilized minesoil. In Ap1, there was improvement in the physical quality (S), bulk density (BD), particle density (PD), structural stability index (SI), soil porosity (SP), air-filled porosity (AFP), field capacity (FC) and plant available water capacity (PAWC). In Ap2, properties were comparable to those in the surface horizon of unfertilized Technosols and to those observed before reclamation. Regardless of fertilization, there was deterioration in physical quality in parent materials. In general, the properties of fertilized Technosols have improved in the surface horizons, but increasing fertilization above plant requirements does not lead to their further enhancement.

Health risk assessment of heavy metals in soil, plant, and water samples near “Gacko” power plant, in Bosnia and Herzegovina

This study assesses heavy metal content in soil, water, and plant material from sites located around the lignite mine and the power plant "Gacko", Bosnia and Herzegovina. The samples were collected, prepared, and analyzed for heavy metals content using the flame atomic absorption spectrophotometer. Samples were analyzed for cadmium, lead, copper, zinc, manganese, and iron. To identify the relationship among the metals in samples and their possible sources, Pearson's correlation and principal component analysis were performed. Health risk assessment was applied to establish potential health risks posed to humans caused by contaminants in different environmental compartments. The results of our analyses show that most soil samples contain copper, and one of those samples had a copper concentration of more than 70µg/g, which is a critical upper value for agricultural use. In the soil samples that were analyzed, cadmium was also detected, and its concentration was greater than 2µg/g. Lead, on the other hand, had a concentration that was higher than the maximum permissible for unpolluted soils in 40% of the soil samples that were analyzed. Lead and cadmium concentrations in surface waters mostly contribute to a non-carcinogenic risk in the scenario of recreational swimming exposure. The presence of Cd, a highly toxic element in water, may be explained by the leaching of artificial fertilizers used in the study area, whereas Pb's origin may be geological. The results of this study recommend routine heavy metal monitoring in samples of soil, water, and plants from the examined area so that, if metal concentrations continue increasing, remedial action should be advised to prevent accumulation in the food chain.

Numerical modeling of seismic wave propagation in loosely deposited partially saturated sands: an application to a mine dump monitoring case

Extensive mine dumps consisting of loosely deposited sands have been created as a result of open-pit lignite mining, with a risk of soil liquefaction under high water saturation and a corresponding initiating event. Soil compaction is one of the feasible methods for reducing the probability of liquefaction. For the monitoring of liquefaction events and the evaluation of compaction work, seismic survey methods with sensitivity to changes in soil saturation and structure may thus complement other methods. Compared to exploration methods for deep systems, the shallow subsurface presents some unique challenges. To this end, an open-source, customizable code based on Biot’s theory was developed in the FEniCS library, which takes into account partial saturation and porosity dependence of stiffness, permeability, and other quantities. Following code verification, a comprehensive investigation of parameter studies is conducted, from which the effects of different factors on wave propagation characteristics were obtained. The numerical model was applied to simulate the expected changes in seismic response following soil compaction. Furthermore, the position of the high saturation area could be detected from the reflection and refraction P waves. The goal of this work is to provide an analysis framework for the assessment of compaction works and monitoring liquefiable soils in mine dumps under conditions of variable saturation due to rising groundwater tables.

Genetics and epigenetics of Pinus nigra populations with differential exposure to air pollution.

Forest species in the course of their evolution have experienced several environmental challenges, which since historic times include anthropogenic pollution. The effects of pollution on the genetic and epigenetic diversity in black pine (Pinus nigra) forests were investigated in the Amyntaio - Ptolemais - Kozani Basin, which has been for decades the largest lignite mining and burning center of Greece, with a total installed generating capacity of about 4.5 GW, operating for more than 70 years and resulting in large amounts of primary air pollutant emissions, mainly SO2, NOx and PM10. P. nigra, a biomarker for air pollution and a keystone species of affected natural ecosystems, was examined in terms of phenology (cone and seed parameters), genetics (283 AFLP loci) and epigenetics (606 MSAP epiloci), using two populations (exposed to pollution and control) of the current (mature trees) and future (embryos) stand. It was found that cone, seed, as well as genetic diversity parameters, did not show statistically significant differences between the exposed population and the control. Nevertheless, statistically significant differences were detected at the population epigenetic level. Moreover, there was a further differentiation regarding the intergenerational comparison: while the epigenetic diversity does not substantially change in the two generations assessed in the control population, epigenetic diversity is significantly higher in the embryo population compared to the parental stand in the exposed population. This study sheds a light to genome dynamics in a forest tree population exposed to long term atmospheric pollution burden and stresses the importance of assessing both genetics and epigenetics in biomonitoring applications.

Effects of biogenic volatile organic compounds and anthropogenic NOx emissions on O3 and PM2.5 formation over the northern region of Thailand

Biogenic volatile organic compounds (BVOC), which are mainly emitted from plants, are a major precursor for the formation of ground-level ozone (O3) and secondary organic aerosols (SOA). In the northern region of Thailand, 63.8% of the land area is covered by forests. Herein we investigated the effects of biogenic volatile organic compounds (BVOC) emitted from plants and anthropogenic NOx emissions on ground-level ozone (O3) and fine particulate matters (PM2.5) formation. The Weather Research and Forecasting Model coupled with Chemistry (WRF-Chem Model) was applied to simulate three scenarios including baseline, noBio and modiAntho simulations. The modeling results over the northern region of Thailand indicate that BVOC emissions over the northern region of Thailand contributed only 5.3%–5.6% of the total concentrations of PM2.5 and BVOC had a direct relationship to glyoxal and SOA of glyoxal. The comparison between the observed and the modeled isoprene over the study site showed an underestimation (3- to 4-folds) of the simulated concentrations during the study period (June and November 2021). In June, decreases in anthropogenic NOx emissions by 40% led to PM2.5 reductions (5.3%), which corresponded to a zero BVOC emission scenario. While higher PM2.5 reductions (5.6%) were found to be caused by anthropogenic NOx reductions in November, small increases in PM2.5 were observed over the area near a power plant located in Lampang Province. Therefore, both VOC and NOx emission controls may be necessary for areas near the lignite mine and power plant. Since the areas within the vicinity of the power plant were under VOC-limited regimes, while the other areas were determined to be NOx-limited.

Isolation and Characterization of Micro-organisms found in Lignite Coal in Bharuch Mines of Gujarat

Gujarat provides a rich source of high-grade lignite coal accomplishing the fuel needs of the national economy, under Gujarat Mineral Development Corporation Ltd. However, the lignite mines in Bharuch district of Gujarat state are reservoirs to a huge microbial diversity, which might be important for various industrial applications. The present study focuses on the isolation and characterization of microorganisms found in the lignite coal from the Bharuch mines of Gujarat. The samples were resuspended in different diluents – water and Phosphate Buffered Saline and cultured on Nutrient Agar. Morphological characterization was done for the isolated strains followed by biochemical characterization for microbial identification. Based on the observations, two species were identified probably as Streptococcus sp. and Staphylococcus sp. on biochemical characterizations. The microbial isolates were further screened for their ability to produce lipase enzyme by qualitative screening tests for lipase production by Phenol Red Olive Oil Agar. All the isolates were tested positive for Lipase enzyme production were subjected to Tween-80 Hydrolysis tests for confirmation. This marks their potential to be studied for development of bioremediation strategies for crude oil contamination in soil or water bodies. This was followed by reviewing the use of such isolates for other applications including antioxidant studies, development of biodegradation strategies, etc.

The Emergence of Non-Energy Uses of Coal and the Future of Lignite Mining in a Region of Low Carbon Footprint, a Case Study

Abstract The rapid development of renewable energy sources, which has been going on for the last two decades, allows now the elimination of the coal use for power generation. Nevertheless, coal will continue to be used in key-industrial sectors, such as steel and cement production, which are crucial for maintaining the living standards of modern society. The future remains doubtful for coals of poor quality characteristics, such as lignite, which is used almost exclusively for power generation purposes. The present study aims to show that, even in the case of lignite, the transition to a zero-carbon economy must be decoupled from the mines closure. In this context, a combined SWOT–AHP analysis was conducted in order to compare seven potential non-energy uses of the lignite produced in the mines of Western Macedonia region, based on six criteria that are in line with the framework set by the European Union for the selection of the best technologies for every site-specific case. This comparison showed that the most promising technologies are related to the production of organic fertilizers and soil amendments, raw materials and products for the construction industry, activated carbon, and graphene. These technologies may contribute to the achievement of socioeconomic and environmental targets that are critical for the just transition of Western Macedonia region to a new, sustainable productive model.

Modeling Water Quality of AMD along the Flow Path

The water balance is severely disturbed in post-mining landscapes like Lusatia/Germany. Mine waters (amd) enter the environment and spread in groundwater and surface waters. Groundwater containing high amounts of pyrite weathering products flows into receiving waters due to lignite mining for several years. The Chair of Wassertechnik & Siedlungswasserbau at the Brandenburg University of Technology Cottbus-Senftenberg/Germany has developed a subsurface rehabilitation method using microbial sulfate reduction over the past 25 years. A continuation of the research is unlikely. This paper has presented some research results on the behavior of groundwater acidified by mining. The acidity in the surface and groundwater is specified via the negative neutralization potential. The dominant reactions in AMD genesis and migration through the aquifer are evaluated about their acidity formation or their buffering behavior. The behavior of AMD can be summarized in a simplified way in the acidity-sulfate diagram. A flow section model (PhreeqC2) was developed and parameterized based on this. This can describe the migration of quality changes in the groundwater/aquifer system. The aquifer passage is reduced to a filtration process, analogous to water treatment. The processes occurring at compartment transitions (dump-lake-aquifer-...) can be modeled from anoxic to oxic. A first case study produces the infiltration of neutralized opencast mining lake water into an aquifer influenced by mining. Measured absorption effects during a microbiological sulfate reduction are interpreted in the second case study with an extended flow path model. The results presented are recommended for use. A comprehensive summary of the results obtained over 25 years of research is being prepared.

Evaluation of Airborne HySpex and Spaceborne PRISMA Hyperspectral Remote Sensing Data for Soil Organic Matter and Carbonates Estimation

Remote sensing and soil spectroscopy applications are valuable techniques for soil property estimation. Soil organic matter (SOM) and calcium carbonate are important factors in soil quality, and although organic matter is well studied, calcium carbonates require more investigation. In this study, we validated the performance of laboratory soil spectroscopy for estimating the aforementioned properties with referenced in situ data. We also examined the performance of imaging spectroscopy sensors, such as the airborne HySpex and the spaceborne PRISMA. For this purpose, we applied four commonly used machine learning algorithms and six preprocessing methods for the evaluation of the best fitting algorithm.. The study took place over crop areas of Amyntaio in Northern Greece, where extensive soil sampling was conducted. This is an area with a very variable mineralogical environment (from lignite mine to mountainous area). The SOM results were very good at the laboratory scale and for both remote sensing sensors with R2 = 0.79 for HySpex and R2 = 0.76 for PRISMA. Regarding the calcium carbonate estimations, the remote sensing accuracy was R2 = 0.82 for HySpex and R2 = 0.36 for PRISMA. PRISMA was still in the commissioning phase at the time of the study, and therefore, the acquired image did not cover the whole study area. Accuracies for calcium carbonates may be lower due to the smaller sample size used for the modeling procedure. The results show the potential for using quantitative predictions of SOM and the carbonate content based on soil and imaging spectroscopy at the air and spaceborne scales and for future applications using larger datasets.

Concept and Implementation of Solutions Improving Water Relations in the Area of the Flooded Opencast Lignite Mine Kazimierz Północ in the East Wielkopolska Region (Central-West Poland)

Over a period of 30 years, the surface water level in the north-west of Konin, in the east of the Wielkopolska region, decreased by almost 6 m, resulting in a reduction of the surface area of the majority of nearby lakes, the disappearance of smaller water bodies and wetlands, and the drying out of streams draining the area. The causes of the decrease in the surface and groundwater level in the region are complex. They include both natural and anthropogenic factors, among others broad-scale mining activity. Based on knowledge of the hydrostructural composition of the analysed region and the functioning drainage system of opencast lignite mines, a concept was developed of a change in water supply to the flooded opencast lignite mine, Kazimierz Północ. The task of redirecting waters from the drainage of a nearby opencast mine, Jóźwin IIB, was implemented in 2020. Current observations and forecasts suggest that, owing to the applied solutions, the analysed opencast mine will be flooded in 2023, and not, as previously assumed, at the end of 2021. As a result, groundwater levels in the vicinity of the opencast mine as well as in lakes and rivers within the range of impact of the related depression cone will be restored faster, particularly in the Lake Powidzkie catchment. The objective of the study is to present stages of flooding of the former opencast lignite mine Kazimierz Północ, identify factors determining the process, and describe solutions accelerating it, with a simultaneous environmental impact assessment of the undertaken activities.

Analysis of Post-Mining Vegetation Development Using Remote Sensing and Spatial Regression Approach: A Case Study of Former Babina Mine (Western Poland)

The vegetation of the post-mining areas is subject to constant and significant changes. Reclamation works, carried out after the cessation of mineral extraction, contribute to the intensive development of new plant species. However, secondary deformations, occurring even many years after the end of exploitation, may cause the degradation of the vegetation cover. It is, therefore, an important issue to identify changes in flora conditions and to determine whether and to what extent past mining has a negative impact on the plant cover state. The objectives of this research have been as follows: (1) analysis of the flora condition in the post-mining area in the 1989–2019 period, (2) identification of sites with significant changes in vegetation state, and (3) modeling of the relationship between the identified changes in vegetation and former mining activities. The research was carried out in the area of the former opencast and underground lignite mine “Friendship of Nations—Babina Shaft,” which is located in the present-day Geopark (Western Poland), using Landsat TM/ETM+/OLI derived vegetation indices (NDVI, NDII, MTVI2) and GIS-based spatial regression. The results indicate a general improvement in flora condition, especially in the vicinity of post-mining waste heaps and former opencast excavations, with the exception of the northwestern part of the former mining field where the values of all of the analyzed vegetation indices have decreased. Also, four zones of statistically significant changes in the flora condition were identified. Finally, the developed GWR models demonstrate that former mining activities had a significant influence on changes in the plant cover state of the analyzed region.

Retention potential of a drained wetland in the Lusatian lignite mining district, Briesener Niedermoor, Germany, Europe

Acid mine drainage (AMD) is one of the most important global causes for polluted water. It occurs in mining areas due to oxidation of sulfide minerals. Depending on hydrological conditions, wetlands are considered suitable for passive treatment of AMD. The aim of the study was to characterize the long-term retention performance of a drained wetland, Briesener Niedermoor, in an iron and sulfate contaminated catchment area. The site is located in the Lusatian lignite mining district, Germany. Hydrological and hydrochemical measurements as well as time series of groundwater and surface water were evaluated and saturation conditions of iron species were determined using Phreeqc Interactive and EH–pH diagrams for the Fe–S–K–O–H system. Progressing peat degradation due to drainage leads to a hydraulic behaviour of the wetland that is more comparable to a rain bog than a fen, and thus to more pronounced oxic conditions. Groundwater feeds the wetland with significant loads of iron and sulfate, which are temporally stored in the wetland. At low surface water discharge, iron is removed and weak acidic pH is buffered by the dominant phase of schwertmannite (Fe8O8(OH)6SO4), usually during summer months. In winter, greater water availability initializes a high source strength from the wetland, that cannot be retarded. Thus, only during summer, there is a retention potential; in winter, the retention potential is not strong enough to prevent an inflow of iron and sulfate. Only a significant rewetting of the wetland may result in a restoration of the retention potential of the wetland Briesener Niedermoor.

GIS-Based Assessment of Hybrid Pumped Hydro Storage as a Potential Solution for the Clean Energy Transition: The Case of the Kardia Lignite Mine, Western Greece

Planned decommissioning of coal-fired plants in Europe requires innovative technical and economic strategies to support coal regions on their path towards a climate-resilient future. The repurposing of open pit mines into hybrid pumped hydro power storage (HPHS) of excess energy from the electric grid, and renewable sources will contribute to the EU Green Deal, increase the economic value, stabilize the regional job market and contribute to the EU energy supply security. This study aims to present a preliminary phase of a geospatial workflow used to evaluate land suitability by implementing a multi-criteria decision making (MCDM) technique with an advanced geographic information system (GIS) in the context of an interdisciplinary feasibility study on HPHS in the Kardia lignite open pit mine (Western Macedonia, Greece). The introduced geospatial analysis is based on the utilization of the constraints and ranking criteria within the boundaries of the abandoned mine regarding specific topographic and proximity criteria. The applied criteria were selected from the literature, while for their weights, the experts' judgement was introduced by implementing the analytic hierarchy process (AHP), in the framework of the ATLANTIS research program. According to the results, seven regions were recognized as suitable, with a potential energy storage capacity from 1.09 to 5.16 GWh. Particularly, the present study's results reveal that 9.27% (212,884 m2) of the area had a very low suitability, 15.83% (363,599 m2) had a low suitability, 23.99% (550,998 m2) had a moderate suitability, 24.99% (573,813 m2) had a high suitability, and 25.92% (595,125 m2) had a very high suitability for the construction of the upper reservoir. The proposed semi-automatic geospatial workflow introduces an innovative tool that can be applied to open pit mines globally to identify the optimum design for an HPHS system depending on the existing lower reservoir.

Numerical analysis of rainfall effects on the slope stability of open pit coal mines

As the world transitions away from coal, vast areas of closed coal mines and waste dumps must be appropriately reclaimed. One critical element for these areas’ safety is slope stability, given the massive slopes of these mines and dumps. This work examines the effect of extreme rainfall on coal mines’ slopestability by incorporating unsaturated soil mechanics principles in a practical way. Past extreme rainfall events recorded for a Greek lignite mining area were used, and climate projections concluded that this intensity is not expected to change. Then, rainfall infiltration was simulated using the Finite Element Method; a typical slope was employed concerning a lignite mining excavation of 200m height and 14° inclination on fine-grained soils. Finally, the stability was calculated using the Limit Equilibrium Method. Rainfall infiltration caused the Safety Factor to decrease, leading to failure. The groundwater rose at theslope’s face from the slope’s toe upwards and led to the development of a smaller and more local than the initial (before rainfall) sliding surface with a lower Safety Factor. Although this is a smaller surface than the initial one, it is still more than 50m high, proposing a significant hazard with severe consequences for the area.

Occupational risk assessment of mining workers at a lignite mine

This article analyses and assesses the occupational risks of workers employed in one of the lignite mines. The hazards occurring at the KWB were discussed and the procedure for carrying out an occupational risk assessment using the PHA (Preliminary Hazard Analysis) method was described. The occupational risk assessment of the employees was carried out on the position of a foreman. Appropriate preventive measures were then selected to reduce and eliminate potential hazards and minimise occupational risks. The entire article concludes with a summary and relevant conclusions.

Gujaratia indica, the oldest artiodactyl (Mammalia) from South Asia: new dental material and phylogenetic relationships

Diacodexeids are widely considered to be a paraphyletic group consisting of the oldest and most primitive artiodactyls that made their sudden appearance in all northern continents around the Palaeocene–Eocene boundary. In South Asia, the first record of artiodactyls is marked by the appearance of Gujaratia indica from the early Ypresian (∼55 Ma) Cambay Shale of the Vastan lignite mine, India, which is slightly younger than the oldest artiodactyls from Europe and North America. Here we describe new dental material of G. indica, documenting associated upper dentition, including P4, a new locus. Gujaratia (including G. pakistanensis and G. indica) is clearly distinct from all known diacodexeids in having the most triangular upper molars and lower molars with weaker paraconids. Cladistic analysis performed to assess the phylogenetic relationships of Gujaratia with other diacodexeids, dichobunoids, raoellids and pakicetids shows that Gujaratia is monophyletic while Diacodexis and Diacodexeidae are strongly polyphyletic. Gujaratia is found to be closer to the North American diacodexeids and D. gigasei and D. morrisi from Europe, which form a paraphyletic group. The European Diacodexis represents an unnatural grouping with D. antunesi being most closely related to a clade comprising dichobunids and homacodontids, and D. gazini and D. varleti occupying basal positions in a clade comprising raoellids and pakicetids. Dichobunidae is also recovered as a polyphyletic group whereas Homacodontidae is paraphyletic. Raoellids and pakicetids, long considered to be endemic to the Indian subcontinent, are monophyletic and without close affinities to Gujaratia, and appear to be more closely allied to some European dichobunoids, e.g., D. gazini, necessitating a reappraisal of current ideas about artiodactyl origins.

Impact of Kara-Keche lignite mining on the Kara-Keche River water composition and properties

On the evidence of the earlier research findings, as well as the full-scale and lab-scale test data of 2019–2020, this article describes the ecological situation at Kara-Keche lignite field being developed by five mining companies in the Jumgal district of the Naryn Region in the Kyrgyz Republic. It is found that the field development proceeds with insufficient adherence to legal documents and has a considerable adverse influence on the environment and water bodies. Many large-volume refuse dumps have no isolation from natural water bodies, which ends with acute pollution of the latter. Contamination of local rivers exists both below the coal mining sites and above them, because of winnowing of coal dust. The river water has the increased pollution indexes—the coliform indexes are 55–70, even in winter, and in summer, these indexes reach a few thousands units. The solid residue, suspended matters, chemical oxygen demand as well as the carbonate and total hardnesses at the points below the major pollution sources as against the averaged values at the points located above the pollution sources have very high values: 14% for the chemical oxygen demand; 43 for the dry residue; 86 and 35 for the carbonate and total hardness, respectively; 108 % for the suspended matter. The concentrations of all macro elements–cations (and anions) grow at a relatively small distance (~5 km) below the major pollution sources: by 11.2 % for sodium; 22 % for potassium 42.2 % for calcium and 79.9 % for magnesium. The analyses revealed no one of 22 trace elements (Ag, As, B, Be, Cd, Co, Cr, Cu, Hg, Mo, Ni, P, Pb, S, Sb, Se, Sn, Ti, U, V, W, Zn) in the Kara-Keche river water, supposedly, because of low sensitivity of the spectrometer. The concentrations of some trace elements (aluminum and barium) are noticeably lower (almost by 2 times) below the major pollution sources. The concentrations of the other trace elements at the points below the major pollution sources are higher than the averaged values at the points above the pollution sources: by 2.2 % for silicon; by 28.3 % for iron; by 76 % for strontium and by 83.4 % for lithium.