Prospects of Using Soil Microbiome of Mine Tips for Remediation of Anthropogenically Disturbed Ecosystems

Introduction. Coal industry increases soil pollution with heavy metals and polycyclic aromatic hydrocarbons. Therefore, resoiling is an urgent problem that requires an immediate solution. The present research objective was to substantiate the use of microorganisms from mine tips in order to decrease soil pollution with heavy metals and oil compounds. Study objects and methods. The review featured five years of publications in Scopus, Web of Science, and Elibrary, which were subjected to analysis, systematization, and generalization. Results and discussion. Coal industry changes landscapes, flora, fauna, and soil microbiome. Bioremediation uses various microorganisms as means of resoiling. Some microorganisms isolated from coal mining waste are resistant to heavy metals and polycyclic aromatic hydrocarbons and are able to utilize them. For instance, such bacteria as Bacillus and Pseudomonas aeruginosa are capable of degrading oil pollutants. Microorganisms of Enterobacter and Klebsiella species were found to be resistant to copper, iron, lead, and manganese. Bacteria of the genera Bacillus, Arthrobacter, Pseudoarthrobacter, and Sinomonas are now to be resistant to nickel, arsenic, and chromium. Arbuscular mycorrhizal fungi increase the activity of soil enzymes, improve soil fertility, and decompose various organic compounds. Conclusion. Sequencing methods make it possible to determine the species composition of soils in mine tips in order to search for new strains capable of restoring former mining areas.

Jumping Risk Communities in the Energy Industry: An Empirical Analysis Based on Time-Varying Complex Networks

This paper uses the 5-five-minute high-frequency data of energy-listed companies in China's A-share market to extract the jump of energy stock prices and build a dynamic stock price jump complex network. Then, we analyze the clustering effect of the complex network. The research shows that the energy stock price jump is an important part of stock price volatility, and the complex network of energy stock jump risk has obvious time-varying characteristics. However, the infection problem of stock price jump risks needs specific analysis. China's coal industry has an important influence on the development of China's energy industry. According to the clustering analysis results of the network community, the clustering effect of the network community has time-varying characteristics. After October 2017, the clustering effect of the jumping risk of the coal industry and the new energy industry is obvious. The risk contagion within the new energy industry community is a key point for the development of the new energy industry.

A Novel Approach to Charcoal Fine Waste: Sustainable Use as Filling of Polymeric Matrices

This study aims to evaluate charcoal fines as potential reinforcing agents in biocomposites. Charcoal has both high carbon content and surface area depending on the manufacturing temperatures. Charcoal is a common residue in the coal industry that we propose using it to reinforce filling agents in several matrices in order to add value to this residue. This study investigated charcoal fines when using three pyrolysis temperatures (400, 600, and 800°C) to identify the most suitable charcoal to be used as raw materials in producing carbon biocomposites. We evaluated apparent density, porosity, morphology, and immediate chemical composition, and then performed a Fourier-transform infrared spectroscopy (FTIR) and an X-ray photoelectron spectroscopy (XPS). Charcoal fines produced at 800°C showed promising results as a polymeric matrix filling due to their higher porosity (81.08%), fixed carbon content (96.77%), and hydrophobicity.

Effect of sodium hydroxide concentration on the compressive strength of geopolymer mortar using fly ash PLTU Tanjungjati B Jepara

Geopolymer concrete is concrete that uses environmentally friendly materials, using fly ash from waste materials from the coal industry as a substitute for cement. To produce geopolymer concrete, an alkaline activator is required, with a mixture of Sodium Hydroxide and Sodium Silicate. This research is an experimental study to determine the effect of variations in the concentration of sodium hydroxide (NaOH) 8 Mol, 10 Mol, 12 Mol, and 14 Mol on the compressive strength of geopolymer concrete. Mortar Geopolymer uses a mixture of 1: 3 for the ratio of fly ash and sand, 2.5: 0.45 for the ratio of sodium silicate and sodium hydroxide as an alkaline solution. The specimens used a cube mold having dimension 5 cm x 5 cm x 5 cm, then tested at 7 days and 28 days. The test resulted that concentration of NaOH 12 Mol obtained the maximum compressive strength of geopolymer concrete, that is 38.54 MPa. At concentrations of 12 Mol NaOH and exceeding 12M, the compressive strength of geopolymer concrete decreased.

Applying Artificial Pillar to Replace the Coal Pillar Protecting Roadway to Increase Production Efficiency and Sustainable Development in the Vietnamese Coal Industry

Vietnam's domestic coal production is growing fast and is expected to reach 68.9 million tonsin 2030, nearly 1.5 times higher than today. Open-pit mines will gradually reduce production and close,and underground mining coal output will increase progressively year by year and take a leading role.Besides the investment in new mines to achieve these goals, it is necessary to maximize the coal reserveexploited annually of existing underground mine projects, which its coal reserve in pillars protectingroadways currently accounts for 12−15%. The further exploitation of this coal reserve will decrease thecosts of preparation of underground mines and granting mining rights and depreciation of infrastructureassets. Moreover, it will help reduce the loss of non-renewable resources and contributing to thesustainable development of Vietnam’s coal industry.

PROSPECTS AND CHALLENGES OF FAIR TRANSFORMATION OF COAL REGIONS OF UKRAINE

The paper analyzes the changes taking place in recent years in the coal industry of Ukraine and the world and examines measures for innovation in energy. The main goals, challenges and prospects of fair transformation of coal regions are revealed by analyzing the current state of the coal industry of Ukraine and world trends. The instruments of the state policy on providing the fired workers of the coal regions with jobs in case of liquidation / transformation of mines are defined and the alternatives of the policy of promoting the employment of the fired workers for making effective decisions are established. Peculiarities and factors of creation of technological or eco-technological parks on the basis of coal enterprises are studied. It is concluded that one of the effective solutions for the fair transformation of coal regions can be the transformation / transformation of the mine as a state enterprise into a park system by involving energy companies. The implementation of investment projects using the infrastructure of the mine for other activities is promising. Significant work should be done on job creation programs and training / retraining / retraining of workers, design of industrial parks and implementation of innovative projects.

Current Status of Coal Mining and Some Highlights in the 2030 Development Plan of Coal Industry in Vietnam

Coal mining is one of the key mining industries in Vietnam. Coal is also an important fuel formany other industries. Currently, coal mining is mainly concentrated in Quang Ninh coal basin, theproportion of open-pit coal mining and underground mining is quite similar. However, according toDecision 403/QD-Ttg on approving the adjustment of the Vietnam coal industry development plan up to2020, considering the prospects by 2030, the mining output will be from 51 to 54 million tons by year2025 and from 55 to 57 million tons by 2030. In which, the proportion of underground coal mining willincrease gradually compared with that of open-cast mining, specifically, by 2030, the proportion of thelater compared to that of the former will be only 11%. According to this plan, open-pit coal mines havebeen shifting to underground mining technology, due to the increasingly deep conditions of coal seams.The following article will analyze the current status of coal mining in Vietnam and some highlights of thecoal industry development plan to 2030, in order to provide a general picture of Vietnam’s coal industryin the future.