Research Papers

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Road Dust Reduction by Filter Installed on Public Bus
(2023) Odbileg Norovrinchen1; Sungchil Lee; Baljinnyam Guntevsuren
In this research, to minimize road dust in the air which has a harmful effect on public health a new filtering device prototype was proposed. The proposed device was designed to be mounted on public buses. The best location of the device on the public bus was found from the airflow dynamic analysis around a public bus which runs in Ulaanbaatar city. It was found from the numerical simulation, the air flow around the bus is perturbed at the rear side of the bus. It produces vortices at the rear side of the bus. Considering the power supply to the filtering device, the engine room at the rear side of the bus was chosen as an optimal location for the device. The device was mounted on a public bus and had collected road dust for two weeks. From the test results, it is concluded that the proposed device has a very high performance in collecting road dust with minimum efforts.
Fatigue Strength Estimation Based on the Maximum Likelihood Method
(2023) Sungchil Lee; Odbileg Norovrinchen; Chinguunbileg Sumiyadorj
Fatigue strength is one of the core principles for designing mechanical components. It has been a constant concern for engineers, as mechanical failure occurs due to loading exceeding the fatigue strength. This concern has led to a necessity to develop new approaches to estimate the reliability of mechanical components. The conventional method that is used to test fatigue strength is the staircase method. However, the staircase method’s ability to calculate fatigue strength is potentially unreliable. The bias and scatter associated with fatigue testing shows the limitations of fatigue strength estimation when the staircase approach is used. The conventional methods of fatigue limit determination also have key flaws, in that they are subjective, time consuming, and costly. This research aims to develop a method that would reliably estimate the fatigue strength of materials, whilst using a lower amount of test results. The present study is intended to formulate and analyze a proposed method of estimating fatigue strength by utilizing a smaller number of tests. The aforementioned method that this paper aims to formulate, mainly focuses on a probabilistic estimation based on the Maximum Likelihood Procedure. The proposed method is applied to existing fatigue test data and its effectiveness is compared with other methods.
Advanced methods in processing deep-sea manganese nodules
(2024) Purev-Ochir Togtokhbaatar; Thomas Lütke; Peter Fröhlich; Martin Bertau
Deep Sea Manganese nodules are investigated by chemical leaching and solid-state chlorination (SSC) to explore a cheaper processing method. Mn nodules contain various essential elements of cobalt (Co), Nickel (Ni), Copper (Cu), Magnesium (Mg), and Zinc (Zn). The pulverized Mn nodule dissolved in Oxaline (1 oxalic acid + 1 choline chloride) completely within 30 min, and in Ethaline (1 Ethylene glycol + 1 choline chloride) within 72 hours. Also, diluted acids (1M H2SO4 and 1M HCl) leaching with reducing agents (H2O2 or C2H2O4) showed efficient dissolution rates. Furthermore, SSC was effective method to process Mn nodules in a presence of NH4Cl then processed nodules leached in diluted acids. Mn dissolution rate can be ordered at 300 °C (~ 50 %), 600 °C (~ 90 %) without reducing agents. Also, these leaching experiments were carried out with reducing agents and those enhanced the Mn dissolution rate by significant amounts. Finally, leaching solutions processed by the electro winning Mn and Cu are successfully deposited on the electrodes.
Natural rehabilitation potential in two distinct mining areas in Mongolia
(2023) Oyun-Erdene Tsogtsaikhan; Gantuya Ganbat; Martin Knippertz
Soil erosion in Mongolia has intensified, and the general level of soil fertility has decreased. The effects of global warming, and human activities such as grazing pastureland, mining operation, intensification of agriculture, urbanization, and road damage are the main causes of soil cover degradation. Due to the ecosystem characteristics of the geographical landlocked location within continental harsh, arid climatic conditions, there is clearly a different identification requirement in rehabilitation potential of mining areas. So, it is necessary to dig in to differentiate the possible rehabilitation characteristics on the most suitable ecosystems. And discrimination of the potentiality by the ecosystem and location makes how to achieve optimized mining rehabilitation results. In this work, the focus is to concentrate on the natural healing process and weigh into potentiality using pyramid concept [1]. Study area and soil characteristics are considered on 2 distinct mining areas located in 2 different ecozones of Mongolian, one is in sub northern area, Ecozone III, which covers both sandy Katsanoses soil and gravelly sandy kastanozem soil. The other comparison study area is Ecozone VI, which within the desert zone the soil specially forms in gravelly and sandy features, and the vegetation becomes scarce with its both species and biomass due to its hot, dry characteristics. Kastanozem soil has more fertile components and thicker humus layer than the desert gravelly and sandy features. Natural features consist of climatological features (precipitation, temperature, wind), soil types and vegetation index data were collected and analyzed using ArcGIS software. These mining areas followed up with verification areas weighted in Khuvsgul and Southgobi areas appointed 180 and 120 points respectively. However, the potential scores on rehabilitation expenses explain active regions that the chance of adjustable value on those planned rehabilitation budget, where sustaining the soil rehabilitation stick into long term natural healing process. These concludes that the pyramid concept should be applied to the other areas of Mongolian mining sites to enable natural rehabilitation potentiality into long term, sustainable mining rehabilitation plan.
Road Dust Reduction by Filter Installed on Public Bus
(2023) Odbileg Norovrinchen; Sungchil Lee; Baljinnyam Guntevsuren
In this research, to minimize road dust in the air which has a harmful effect on public health a new filtering device prototype was proposed. The proposed device was designed to be mounted on public buses. The best location of the device on the public bus was found from the airflow dynamic analysis around a public bus which runs in Ulaanbaatar city. It was found from the numerical simulation, the air flow around the bus is perturbed at the rear side of the bus. It produces vortices at the rear side of the bus. Considering the power supply to the filtering device, the engine room at the rear side of the bus was chosen as an optimal location for the device. The device was mounted on a public bus and had collected road dust for two weeks. From the test results, it is concluded that the proposed device has a very high performance in collecting road dust with minimum efforts.
Fatigue Strength Estimation Based on the Maximum Likelihood Method
(2023) Sungchil Lee; Odbileg Norovrinchen; Chinguunbileg Sumiyadorj
Fatigue strength is one of the core principles for designing mechanical components. It has been a constant concern for engineers, as mechanical failure occurs due to loading exceeding the fatigue strength. This concern has led to a necessity to develop new approaches to estimate the reliability of mechanical components. The conventional method that is used to test fatigue strength is the staircase method. However, the staircase method’s ability to calculate fatigue strength is potentially unreliable. The bias and scatter associated with fatigue testing shows the limitations of fatigue strength estimation when the staircase approach is used. The conventional methods of fatigue limit determination also have key flaws, in that they are subjective, time consuming, and costly. This research aims to develop a method that would reliably estimate the fatigue strength of materials, whilst using a lower amount of test results. The present study is intended to formulate and analyze a proposed method of estimating fatigue strength by utilizing a smaller number of tests. The aforementioned method that this paper aims to formulate, mainly focuses on a probabilistic estimation based on the Maximum Likelihood Procedure. The proposed method is applied to existing fatigue test data and its effectiveness is compared with other methods.
FTIR Study of Enriched Bituminous Ukhaa-Khudag Coal
(2023) Munkhtsetseg Sambuu; Nyamdulam Renten; Begzsuren Tumendemberel; Rene Tschaggelar; Anna Oleshkevich; Otgonchimeg Tuvdendorj; Munkhjargal Sharav; Shilagardi Goolimensee
In the present work we pay an attention to the molecular structural changes between raw coal and its enriched, dense productions. Bituminous Ukhaa-Khudag coal in the form of an enriched, dense coal product is currently used as an energy source by Mongolian consumers for everyday need. There are three types of samples from one source: it is a raw coal (sample 1) and two of industrial prod- ucts as an enriched, dopant (organic based) added coal (sample 2) and simply enriched coal (sample 3). The raw coal general characterization is given through the elemental analysis, thermogravimetry analysis, moreover functional groups were identified by Fourier Transform infrared spectroscopy. The differences in the FTIR spectra of the samples were done.Some details are as follows: hydroxyl group vibrations are existing, rather weak in agreement of TG result; vibrations of aliphatic group were rarely in the long wave near region, carbonate minerals in the region of 1300-900 cm−1 are visible but overlapped, and an isolated out-of-plane deformational vibration (around 800 cm−1) or two-adjacent (800-750 cm−1) or three-adjacent (around 700 cm−1) of sp2-hybrid bonded aromatic CHx-groups were still presenting.After the processing hydroxyl group bands were affected in enriched coals, sample 2 and 3. In the spectrum of the sample 2 the long wave bands were intensively blurred.Industry processing retains an amount of water in the productions. Water excess influenced absorbance bands were able to be removed via the drying processing, however, the affection to the spectral struc- ture in sample 2 was unrecoverable.
Exploring The Mastery Of English Articles Among Mongolian EFL Students
(2024) Nomindari Byambasaikhan; Enkhbaatar Tsedenbazar; Mungunchimeg Amar
Mastering the English article system is particularly challenging for students whose native languages do not include articles. This study examines the progression of article acquisition among Mongolian university students, highlighting their developing understanding of the English article system during interlanguage development. Twenty-five participants with different levels of English proficiency participated in an extensive evaluation, consisting of a fill-in-the-article cloze test and structured interviews. Through a combination of quantitative and qualitative analyses, the study explores participants' comprehension of essential factors such as hearer's knowledge, specific reference, uniqueness, and countability, which affect article errors across various proficiency levels. The results provide valuable insights into the step-by-step acquisition of the English article system and deepen the understanding of interlanguage phenomena. This research adds to the broader discussion on second language acquisition and informs teaching strategies aimed at enhancing learners' proficiency with English articles of Form
Reprocessing of tailing from Erdenet copper ores: Optimization of the flotation
(2023) Narangarav Terbish; Ankhchimeg Ganzorig; Dugar Davaajargal; Battsengel Baatar
The Erdenet tailing storage facility (TSF) is one of the largest in the world with a total area of 18.6km2. Over 40 years of history of Erdenet mining, the process tailing has been collected in the tailing dam and now becomes the biggest resource for research. The goal of this research work is to define the optimized condition of the flotation with the highest achievement of Cu recovery from the tailings of the Erdenet Copper Mining (EMC). Series of research and laboratory experimental works including physical and chemical characterization of the tailing samples, flotation experiments and analysis were carried out in order to define the optimized condition of the flotation. The best recovery of tailing sample with 0.1% of Cu was 1.4% of Cu grade and 32.27% of cumulative recovery.
Human impact and environmental conditions lead to a mass mortality event of David’s Myotis (Myotis davidii) in Mongolia
(2024) Munkhnast Dalannast; Joseph R. Hoyt; Delgermurun Byambajav; Uurdmunkh Munkhtaivan; Namsrai Narantsetseg; Bold-Erdene Batbold; Ariunbold Jargalsaikhan
Anthropogenic factors are an important driving force impacting bat populations across the globe. These include habitat loss and alteration, infectious diseases, climate change, and human persecution. Multiple factors typically impact populations simultaneously, which can have severe consequence for biodiversity. Mongolia has a large number of cave systems with over 500 documented in the country, of which only ~300 have been explored (Avirmed, 2020).
Embedded Generative Air Pollution Model with Variational Autoencoder and Environmental Factor Effect in Ulaanbaatar City
(2022) Bulgansaikhan Baldorj; Munkherdene Tsagaan; Lodoysamba Sereeter; Amanjol Bulkhbai
Air pollution is one of the most pressing modern-day issues in cities around the world. However, most cities have adopted air quality measurement devices that only measure the past pollution levels without paying attention to the influencing factors. To obtain preliminary pollution information with regard to environmental factors, we developed a variational autoencoder and feedforward neural network-based embedded generative model to examine the relationship between air quality and the effects of environmental factors. In the model, actual SO2, NO2, PM2.5, PM10, and CO measurements from 2016 to 2020 were used, which were assembled from 15 differently located ground monitoring stations in Ulaanbaatar city. A wide range of weather and fuel measurements were used as the data for the influencing factors, and were collected over the same period as the air pollution data were recorded. The prediction results concerned all measurement stations, and the results were visualized as a spatial–temporal distribution of pollution and the performance of individual stations. A cross-validated R 2 was used to estimate the entire pollution distribution through the regions as SO2: 0.81, PM2.5: 0.76, PM10: 0.89, and CO: 0.83. Pearson’s chi-squared tests were used for assessing each measurement station, and the contingency tables represent a high correlation between the actual and model results. The model can be applied to perform specific analysis of the interdependencies between pollution and environmental factors, and the performance of the model improves with long-range data.
A Collaborative Approach for Triggering Environmental Awareness: The 3Rs for Sustainable Use of Natural Resources in Ulaanbaatar (3R4UB)
(2023) Gabriella Esposito De Vita; Cristina Visconti; Gantuya Ganbat; Marina Rigillo
Current environmental challenges invite us to deeply revise policies, governance models, and resource management toolkits towards a circular approach, in order to meet Sustainable Development Goals (SDGs) requirements. In this framework, circular waste management is one of the pillars of responsible and foresighted planning for territorial sustainability. The “3Rs for a sustainable use of natural resources in Ulaanbaatar” (3R4UB) project aims at transferring a sustainable approach to urban solid waste management, especially focusing on providing effective opportunities for developing circular supply chains locally. In this framework, an integrated approach has been developed in order to adapt the communication/exploitation plan of sustainable waste management within a SWITCH-Asia Country (EU Program) by combining engagement tools and participatory processes for the collaborative design of a waste management masterplan. This paper explores the spatialization of resources/waste flows in the formal and informal settlements, while also considering cultural traditions, social structures, and community habits, in terms of a purposely designed combination of spatial planning, governance modeling, and capacity building activities. Starting from a preliminary communication plan, this paper sets the frame for discussing the role of community engagement tools and protocols in producing an effective and generalizable collaborative waste management masterplan.
Measurement and 3-dimensional Simulations of Carbon Monoxide (CO) Distribution in Mongolian Ger
(2023) Byambakhorol Battsetseg; Gantuya Ganbat; Battulga Nasanjargal
Ulaanbaatar is one of the most polluted cities in the world, especially in wintertime. During the past two decades, several national and internationally funded projects have been put in place to reduce air pollution. One of the implemented projects is the Government of Mongolia has decided to substitute household raw coal consumption with upgraded briquette fuels in Ulaanbaatar since 2019 in order to combat air pollution. Concentrations of particulate matter (PM2.5 and PM10) in wintertime from November 2019 to February 2020 were reduced by around 40% compared previous five years, respectively. Unfortunately, there are some negative impacts, for example, an increased number of incidences of carbon monoxide (CO) poisoning along with the coal substitution. Indoor CO poisoning causes risks to people living in Mongolian gers and houses. In this study, we performed a numerical simulation of CO distribution by using the COMSOL Multiphysics. The study enables us to understand the CO distribution in Mongolian ger. The numerical simulations show, that when ger is assumed empty, the CO concentration is the largest around the stove, then becomes less from stove to crown, and is minimum near the lattice wall. In addition, CO concentration in gers and houses were recorded during the heating period. The results of this study offer important information that can be used to develop recommendations for enhancing indoor air quality in gers. By understanding the dynamics of CO distribution within traditional dwellings, strategies can be advised to improve ventilation, stove, and CO detector placements, reduce the risk of CO poisoning, and promote healthier living conditions for residents.
Natural rehabilitation potential in two distinct mining areas in Mongolia
(2023) Oyun-erdene Tsogtsaikhan; Gantuya Ganbat; Martin Knippertz
Soil erosion in Mongolia has intensified, and the general level of soil fertility has decreased. The effects of global warming, and human activities such as grazing pastureland, mining operation, intensification of agriculture, urbanization, and road damage are the main causes of soil cover degradation. Due to the ecosystem characteristics of the geographical landlocked location within continental harsh, arid climatic conditions, there is clearly a different identification requirement in rehabilitation potential of mining areas. So, it is necessary to dig in to differentiate the possible rehabilitation characteristics on the most suitable ecosystems. And discrimination of the potentiality by the ecosystem and location makes how to achieve optimized mining rehabilitation results. In this work, the focus is to concentrate on the natural healing process and weigh into potentiality using pyramid concept [1]. Study area and soil characteristics are considered on 2 distinct mining areas located in 2 different ecozones of Mongolian, one is in sub northern area, Ecozone III, which covers both sandy Katsanoses soil and gravelly sandy kastanozem soil. The other comparison study area is Ecozone VI, which within the desert zone the soil specially forms in gravelly and sandy features, and the vegetation becomes scarce with its both species and biomass due to its hot, dry characteristics. Kastanozem soil has more fertile components and thicker humus layer than the desert gravelly and sandy features. Natural features consist of climatological features (precipitation, temperature, wind), soil types and vegetation index data were collected and analyzed using ArcGIS software. These mining areas followed up with verification areas weighted in Khuvsgul and Southgobi areas appointed 180 and 120 points respectively. However, the potential scores on rehabilitation expenses explain active regions that the chance of adjustable value on those planned rehabilitation budget, where sustaining the soil rehabilitation stick into long term natural healing process. These concludes that the pyramid concept should be applied to the other areas of Mongolian mining sites to enable natural rehabilitation potentiality into long term, sustainable mining rehabilitation plan.
Results of Simulations of Atmosphere-lake Interactions Using Numerical Model
(2022) Ganbat Danaa; Gantuya Ganbat
Lakes influence the regional atmosphere through modifying thermodynamic characteristics. This study examines the effects of the Baikal lake on meteorological parameters in summertime using the numerical model. Diurnal variations in the lakes’ impact on the atmosphere are found through changing the surface energy budget, which includes changes in sensible and latent heat fluxes. The changes in heat fluxes cause relatively lower surface temperature which leads to a shallow boundary layer over the lake surfaces. Greater heat capacity in water bodies compared to grasslands causes slower heating and cooling rates in the lakes. The amplitude of air temperature over the lake surfaces is smaller than that over the grasslands. Lakes promote diverging winds near the ground, furthermore, tend to stabilize the overlying atmosphere in the summertime.
Health Risk Assessment of Volatile Organic Compounds for Children in Indoor Air, Ulaanbaatar, Mongolia
(2023) Oyun-Erdene Otgonbyamba; Gantuya Ganbat; Ser-Od Khuyag; Enkhjargal Altangerel; Bilguun Ganbold; Altangadas Bayanjargal; Altangerel Bat-Erdene; Bataa Chuluunbaatar; Burmaajav Badrakh; Suvd Batbaatar
This study presents levels of volatile organic compounds (VOCs) measured indoors for the first time in Ulaanbaatar, Mongolia, and quantifies the health risk for children emphasizing the urgent need to improve control for indoor VOCs sources. The 583 samples collected at 144 sites, including new buildings, old apartments, schools, workplaces, kindergartens, baishin, and Mongolian traditional gers, hospitals, schools, and shopping centers are analyzed. Formaldehyde was detected in 95.7% of the samples, while benzene was in 24.2%. The levels of benzene, toluene, and xylene in new and old buildings and apartments exceed the recommended values of AGÖF for volatile organic compounds in indoor air. The probabilistic Monte Carlo simulation method was used to estimate the risk exposure of four types of VOCs (benzene, formaldehyde, toluene, and m,p-xylene) to the health of the study population. The risk of cancer for benzene and formaldehyde is high in the age group of 7 months–4 years, m,p-xylene, and toluene show non-cancer risk in this age group.
Urban Air Quality Studies in Mongolia: Pollution Characteristics and Future Research Needs
(2021) Tseren-Ochir Soyol-Erdene; Gantuya Ganbat; Barkhasragchaa Baldorj
For the last decades, Mongolia has seen an extensive escalation in population growth, urbanization, and industrialization, together with great increase in mining and usage of vehicles. As a result, a substantial increase has taken place in the types and number of emission sources of air pollutants, especially in urban areas. During the cold season, air pollution level in Ulaanbaatar, the capital of Mongolia, is frequently ranked as the highest in the world. However, due to the lack of air quality management, the country is suffering from a deterioration of air quality. Despite the worse air pollution situation, due to insufficient research capacity of the country, to date, research works on characteristics of air pollution have mainly been based on current capability and/or collaboration with foreign institutes. The research gap in this area necessitates numerous investigations, which could have great importance in developing mitigating strategies and minimizing the adverse impact of air pollution on local and regional scales. This paper reviews previously available studies and reports in international scientific journals on air quality in Mongolia. Based on the existing research works, future needs of studies on ambient air pollution in Mongolia are suggested.
Tackling soil erosion and contamination within the SDGs framework: a case study of the Erdenet copper‑molybdenum mine
(2024) Enkhjargal Sodnomdarjaa; Frank Lehmkuh; Daniel Karthe; Alexey V. Alekseenko; Martin Knippertz
Mining operations in Mongolia have contributed significantly to national economic growth. However, the lack of adequate mine land rehabilitation practices has resulted in various forms of land degradation, including land cover change, soil erosion and contamination with heavy metals and metalloids. These issues have negatively affected ecosystems and posed potential risks to human health due to the interconnected relationships between land, water and human activities. This study focuses on the copper-molybdenum mining site of Erdenet, the oldest and one of the largest copper mines in Mongolia, to investigate the main drivers of soil degradation and evaluate effective rehabilitation strategies. By combining findings from our previous studies on soil erosion and contamination in the Erdenet area with a review of existing research, we assess key rehabilitation priorities. Taking a Nexus approach, this study explores the interconnections between environmental, economic and social sectors, emphasizing the importance of balancing mining activities with sustainable land management. The previous studies suggest that for the next 10–15 years, priorities should focus on tailings storage facility rehabilitation and soil contamination remediation, while longer-term goals include developing sustainable environmental management strategies that foster cooperation between mining corporations and local communities, enforce regulations and improve monitoring in the Erdenet mining area. The study aligns these priorities with the Sustainable Development Goals, offering science-based recommendations for managing soil erosion and reducing contamination.
Resource conundrum in Mongolia: Soil contamination from coal and copper–molybdenum mining
(2024) Enkhjargal Sodnomdarjaa; Martin Knippertz; Daniel Karthe; Alexey V. Alekseenko; Gantuya Ganbat; Wolfgang Römer; Frank Lehmkuhl
Soil contamination and the resulting ecological disturbances are a common phenomenon in mining areas, including the vicinities of the largest and oldest open-pit mining areas in Mongolia. In this work, the potential ecological risk index (RI), Nemerow integrated pollution index (PIN), and Geoaccumulation index (Igeo) were used to estimate the level of soil contamination with Ni, Cu, Zn, As, Cr, and Pb in the top layer of the soils around Baganuur coal mine and Erdenet copper–molybdenum mine. Three different analytical methods were used: portable X-ray fluorescence (pXRF) for the first assessment of samples, and stationary X-ray fluorescence and Inductively Coupled Plasma Optical Emission Spectroscopy for the confirmation of results in the laboratory. Even though general contamination levels in both study areas were relatively low, some potentially toxic elements were found at contents several times higher than the maximum permissible level (MPL) according to the national standard of Mongolia. In the Baganuur area, Zn was up to 2.8 and As was up to 3.00 times higher, while in the Erdenet area, As was up to 2.4, Cr was up to 1.7, Cu was up to 8.1, and Zn was up to 1.2 times higher than MPL of the national standard in the vicinity to the mining and industrial area. The estimation of the pXRF measurement had generally similar results to the other two laboratory methods based on spatial distributions of heavy metal content. Among the different geochemical indices, the PIN showed a more accurately distinguished spatial distribution of contamination. For example, highly contaminated areas were found in the vicinity of the open pit, the tailings pond and the industrial area based on PIN results: 3.6%–4.9% of the total area in Baganuur and 3.1%–4.9% of the total area in Erdenet. The identified pollution levels emphasize the essential need for soil rehabilitation in mining areas, a key factor for Mongolia's economic development and environmental stability. In addition, the lack of documented soil rehabilitation initiatives underscores the pressing need for enhanced environmental responsibility in the country's expanding mining sector.
Soil environmental issues of coal-mining in Baganuur and Nalaikh, Mongolia
(2023) Martin Knippertz; Enkhjargal Sodnomdarjaa
This study focuses on the environmental issues of mining (related) activities in Mongolia, with a focus on soils in the coal mining areas of Baganuur and Nalaikh. Besides the ecological components (including erosion), also the socio-economic conditions are of importance for the derivation of recommendations for a better understanding and management of Mongolia’s environment. The soil features in both research sites are generally good, heavy metal concentrations are within the guidelines, accept for Arsenic (As) showing increased values. The Geoaccumulation index and the Surface enrichment factor indicate no major influence of mining activities on the soil quality around the mining. However, soil erosion increases near mining sites, which can have a negative impact on soil quality. Studying the long-term effects of mining on the soil and environment in Mongolia is one of the country's most important concerns. In this context, the aspect of rehabilitation in mining areas is becoming more and more important in Mongolian society. Ecological and especially geotechnical recommendations for the management of Baganuur’s and Nalaikh’s environment are of importance for the stakeholders.

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