• Title/Summary/Keyword: mine production

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Environmental Issues for the Hydraulic Fracturing Applied in the Process of the Shale Gas Development (셰일가스 개발 시 적용되는 수압파쇄공법에 의한 환경문제)

  • Han, Hyeop-Jo;Kim, Kyoung-Woong;Na, Kyung-Won;Park, Hee-Won;Lee, Jin-Soo;Shim, Yon-Sik
    • Economic and Environmental Geology
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    • v.46 no.1
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    • pp.63-69
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    • 2013
  • This paper discusses important environmental issues that must be considered during shale gas development. Shale gas has been attracting many attention as the next key energy resource with its large abundance through easily accessible production fields, and its lower carbon dioxide & sulfur dioxide emission profile upon combustion when compared to the conventional oil and natural gas resources. Successful development of a shale gas field requires the use of hydraulic fracturing to recover hydrocarbon through the very tight shale formation, which has been frequently associated with environmental contamination issue of water, soil, and atmosphere. Therefore, environmental issues and their solution to minimize environmental impact should be considered for successful development of shale play in a future.

A study on membrane technology for surface water treatment: Synthesis, characterization and performance test

  • Haan, Teow Yeit;Shah, Mubassir;Chun, Ho Kah;Mohammad, Abdul Wahab
    • Membrane and Water Treatment
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    • v.9 no.2
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    • pp.69-77
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    • 2018
  • The use of membrane as an innovative technology for water treatment process has now widely been accepted and adopted to replace the conventional water treatment process in increasing fresh water production for various domestic and industrial purposes. In this study, ultrafiltration (UF) membranes with different formulation were fabricated via phase inversion method. The membranes were fabricated by varying the polymer concentration (16 wt%, 18 wt%, 20 wt%, and 21 wt%). A series of tests, such as field emission scanning electron microscope (FESEM), pore size and porosity, contact angle, and zeta potential were performed to characterize the membranes. The membrane performance in terms of permeation flux and rejection were evaluated using a laboratory bench-scale test unit with mine water, lake water and tube well as model feed solution. Long hour filtration study of the membranes provides the information on its fouling property. Few pore blocking mechanism models were proposed to examine the behaviour of flux reduction and to estimate the fouling parameters based on different degree of fouling. 21 wt% PVDF membrane with smaller membrane pore size showed an excellent performance for surface water treatment in which the treated water complied with NWQS class II standard.

Effective Removal of Gaseous BTEX Using VPB During Treatment of Briny Produced Water (VPB를 이용한 효율적인 Gas 상태의 BTEX 제거에 관한 연구)

  • Kwon, Soondong
    • Journal of Korean Society on Water Environment
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    • v.27 no.2
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    • pp.167-177
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    • 2011
  • Billions of barrels of briny produced water are generated in the United States every year during oil and gas production. The first step toward recovering or reusing this water is to remove the hazardous organics dissolved in the briny produced water. Biological degradation of hazardous volatile compound could be possible regardless of salinity if they were extracted from briny water. In the current work, the effectiveness of a vapor phase biofilter to degrade the gas-phase contaminants (benzene, toluene, ethylbenzene and xylenes, BTEX) extracted from briny produced water was evaluated. The performance of biofilter system responded well to short periods when the BTEX feed to the biofilter was discontinued. To challenge the system further, the biofilter was subjected to periodic spikes in inlet BTEX concentration as would be expected when it is coupled to a Surfactant-Modified Zeolite (SMZ) bed. Results of these experiments indicate that although the BTEX removal efficiency declined under these conditions, it stabilized at 75% overall removal even when the biofilter was provided with BTEX-contaminated air only 8 hours out of every 24 hours. Benzene removal was found to be the most sensitive to time varying loading conditions. A passive, granular activated carbon bed was effective at attenuating and normalizing the peak BTEX loadings during SMZ regeneration over a range of VOC loads. Field testing of a SMZ bed coupled with an activated carbon buffering/biofilter column verified that this system could be used to remove and ultimately biodegrade the dissolved BTEX constituents in briny produced water.

Deformation and permeability evolution of coal during axial stress cyclic loading and unloading: An experimental study

  • Wang, Kai;Guo, Yangyang;Xu, Hao;Dong, Huzi;Du, Feng;Huang, Qiming
    • Geomechanics and Engineering
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    • v.24 no.6
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    • pp.519-529
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    • 2021
  • In coal mining activities, the abutment stress of the coal has to undergo cyclic loading and unloading, affecting the strength and seepage characteristics of coal; additionally, it can cause dynamic disasters, posing a major challenge for the safety of coal mine production. To improve the understanding of the dynamic disaster mechanism of gas outburst and rock burst coupling, triaxial devices are applied to axial pressure cyclic loading-unloading tests under different axial stress peaks and different pore pressures. The existing empirical formula is use to perform a non-linear regression fitting on the relationship between stress and permeability, and the damage rate of permeability is introduced to analyze the change in permeability. The results show that the permeability curve obtained had "memory", and the peak stress was lower than the conventional loading path. The permeability curve and the volume strain curve show a clear symmetrical relationship, being the former in the form of a negative power function. Owing to the influence of irreversible deformation, the permeability difference and the damage of permeability mainly occur in the initial stage of loading-unloading, and both decrease as the number of cycles of loading-unloading increase. At the end of the first cycle and the second cycle, the permeability decreased in the range of 5.777 - 8.421 % and 4.311-8.713 %, respectively. The permeability decreases with an increase in the axial stress peak, and the damage rate shows the opposite trend. Under the same conditions, the permeability of methane is always lower than that of helium, and it shows a V-shape change trend with increasing methane pressures, and the permeability of the specimen was 3 MPa > 1 MPa > 2 MPa.

Development of Digestion Gas Production and Dewatering Cake Management in WWTP by Using Data Mining Technology (데이터 마이닝 기법을 활용한 하수처리장 소화가스 예측 및 탈수 케이크 관리 기법 개발)

  • Kim, Dongkwan;Kim, Hyosoo;Kim, Yejin;Kim, Minsoo;Piao, Wenhua;Kim, Changwon
    • Journal of Korean Society of Environmental Engineers
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    • v.37 no.1
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    • pp.1-6
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    • 2015
  • The purpose of this study is to suggest the effective operation method by developing prediction model for the gas production rate, an indicator of the effectiveness of anaerobic digestion tank, using data mining. At the result, gas production estimate model is developed by using ANN within 10% error. It is expected to help operation of anaerobic digestion by suggesting selected parameter. Meanwhile case based reasoning is applied to develop dewatering cake management technology. Case based reasoning uses the most similar examples of past when a new problem occurs, therefore in this study, management measures are developed that proposes dewatering cake minimization with the minimum change by applying the case based reasoning to sludge disposal process.

Optimal Production of N-acetyl-$\beta$-D-glucosamine Using Chitinolytic Enzyme (Chitinolytic Enzyme을 이용한 N-acetyl-$\beta$-D-glucosamine의 최적생산)

  • 이천우;이은영장상목김광
    • KSBB Journal
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    • v.11 no.6
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    • pp.696-703
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    • 1996
  • The bacterium Serratia marcescens QM Bl466 produces selectively large amount of chitinolytic enzymes(about 1mg/L medium). Enzymatic hydrolysis of chitin to N-acelyl-${\beta}$-D-glucosamine(NAG) is performed by a system consisting of two hydrolases : chitinase and chilobiase. Objectives of this study included optimization of a microbial host by using chitin particles for chitinase/chitobiase production and secretion and also development of batch fermentation system for high cell density cultivalion of S. marcescens QM B1466. Also, the influence of chitin source and carboxymethyl(CM) chitin on chitinase/chitobiase production and NAG production was investigated. When carboxymethyl chitin was substituted for colloidal and practical grade chitin, the chitinase activity was increased about 7∼10U/mL. In this case, the ratio of chitinase/chitobiase was 30.03U/3.44U(9:1). The highest amounts of NAG(3.0g/L) was obtained.

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Studies of concrete utilization of waste sludge by-producted in aggregate mines (석산골재광산에서 발생한 잔토의 콘크리트 유효이용에 대한 연구)

  • 엄태선;백상현;백원준;김창수
    • Proceedings of the Korea Concrete Institute Conference
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    • 1998.10c
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    • pp.7-12
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    • 1998
  • The waste sludge is by-produced about 20-30% of total production and arised to the severe problems of this mine's surrounding environmnet. This study was invested the composition of component, particle of size of the waste sludge by Chemical Analysis, X, R, D, Particle Size Analyzer and the physical properties (air content, slump, strength, etc) of concrete when the waste sludge is added into concrete. so, It's recomended the proper content of the waste sludge to be added into concrete. and then, is verified to be applied at batch plant in field. Above the results, the recomeded content of the waste sludge is about 2-4% (about 4-8% in cement) in aggregates and when it's added the recomended content, they are detected to be more or less changed the physical properties of concrete, ( equally strength and durability, little less air con tent, little increased shinkage, etc). but the application of the recomended content don't arise the problem of the basic quality control of concrete and physical properties.

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Trends for the Promising Career of Science and Engineering Workforce: Job Outlook of Korea.USA.Australia (이공계 인력의 미래 유망직업 연구동향: 한국.미국.호주의 직업전망을 중심으로)

  • Han, Jiyoung
    • Journal of Engineering Education Research
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    • v.15 no.5
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    • pp.140-150
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    • 2012
  • The purpose of this study was to compare and analysis researches related the promising career and job outlook and to provide the direction for job choice to engineering students. Literature review and expert council were used to achieve the objectives of study. The result of this study was analyzed that these jobs were promising, that is, environmental scientist and specialist, earth scientist and hydrologist(education and research related career), architecture and architectural engineer, civil engineer, landscape technician, land surveyor map production expert photo surveyor surveying technician(construction related career), material engineer (mechanics and material related career), mine and geology engineer(chemistry, fiber and environment related career), computer system design and analyst, system software engineer, application software engineer, web specialist, and computer support specialist (electrical and telecommunication related career) and food engineer(food related career). In addition, health silver specialist, bio biomedical engineer, renewable energy specialist etc. were promising by considering social and economic trend for demographic change like aging and green growth.

The hygroscopic and swelling properties of Korean Red Pine wood (적송재(赤松材)의 흡습(吸濕)과 팽창성(膨脹性)에 관(關)하여)

  • Lee, Pill Woo
    • Journal of Korean Society of Forest Science
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    • v.4 no.1
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    • pp.30-32
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    • 1965
  • Many kind tree species are growing in Korea. However most of them are inferior in wood qualities and production for commercial utilization except several species. Among the useful several species Red Pine (Pinus densiflora S. et. Z.) is growing in main tree species and most generally utilizing wood in korean forest. It is used widely as mine timbers, cross ties, boxes, floorings, pulpwoods, constructions and engineerings. Although this species is most useful and economical in this country, the basical properties on relation between wood and relative humidities were not studied certainly. This study was performed by need of inspection the hygroscopic and swelling properties to be apllied for physical manufacturing. According to the results the Equilibrium Moisture Contents of each relative humidity conditions are as table (3), and the swelling values of sap and heartwood are as table (4) and (5) in text. In this study sapwood moisture contents are higher than heartwood in each relative humidities conditions. Tangential and radial ratios of average swelling values are 1:1.971 in sapwood and 1:2.178 in heartwood.

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A Study on Chemical Neutralization and Production of Planting Porous Concrete Using Low-Grade Iron Ore (저 품위 철광석을 사용한 식생용 투수 콘크리트의 중성화 및 제작에 관한 연구)

  • Eun, Hee-Chang;Lee, Min-Su;Bae, Choong-Yeol
    • Journal of Industrial Technology
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    • v.27 no.A
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    • pp.31-38
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    • 2007
  • Recently produced concrete has a tendency to overcome environmental defects. Porous and planting Eco-concrete requires the neutralization process and enough void in concrete to contain water, to pass air freely, and provides necessary nutrients to vegetation roots. The biological environment in concrete is not suitable for planting because the concrete possesses strong alkali constituent of pH 11-13. This study evaluated the strength and serviceability of concrete as well as the chemical characteristics of concrete mixed by low-grade iron ore left in the abandoned mine and treated by Ammonium monohydrogen phosphate, $(NH_4)_2HPO_4$. Test variables include two kinds of coarse aggregates such as crushed stones and low-grade iron ore, the duration time and the period for neutralization treatment by Ammonium monohydrogen phosphate, $(NH_4)_2HPO_4$, and the proportion ratio of cement, blast furnace slag and silica fume.

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