• Title/Summary/Keyword: Heavy Use

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Heavy Metal Removal by Fly Ash (石炭灰의 重金屬 흡착 特性 硏究)

  • 조희찬;오달용
    • Resources Recycling
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    • v.10 no.4
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    • pp.10-17
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    • 2001
  • The present work investigates the possible use of fly ash for the removal of heavy metal ions from aqueous solutions. Batch experiments were conducted and the influences of metal concentration, pH, and fly ash concentration were investigated. Heavy metals used in these studies were lead and zinc. Adsorption studies were done over a range of pH values (3~10) at $25^{\circ}C$ and heavy metal concentrations of 10~400 mg/L using fly ash concentrations of 10 and 20 g/L. Experiments were also conducted without fly ash to determine the extent of heavy metal removal by precipitation. Kinetic and equilibrium experiments were performed and adsorption data were correlated with both Langmuir and Freundlich adsorption models. The results of these studies indicate that 리y ash can be used as an adsorbent for heavy metals in the aqueous solutions, yet the degree of removal depends on the pH.

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Existing Forms of Heavy Metals in the Vicinity of a Smelter (제련소 주변토양 중금속 존재형태)

  • Woo, Sang-Duck;Kim, Geon-Ha;Kim, Young-Jin;Nam, Kyoung-Phile
    • Journal of Soil and Groundwater Environment
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    • v.15 no.5
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    • pp.16-22
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    • 2010
  • Heavy metals in soils exist in various forms dependent upon surrounding conditions. As the Janghang smelter area is of concern for its high elevated heavy metal concentrations, Korean government decided to remediate the area. Main objectives of this research were; to analyze heavy metal concentrations and their existing forms in the vicinity of the smelter; and to understand differences made by analysis techniques of heavy metals. Top soils of rice field, crop field, bare field, and forestry in the area were sampled and analyzed for their physicochemical characteristics. Concentrations of Cu, Cd, Pb, and As were analyzed with two pretreatment techniques adopted using 0.1 N HCl and aqua regia. To analyze existing forms of heavy metals, Tessier's schemes for sequential extraction technique were adopted. Exchangeable fraction and carbonate bound fraction of heavy metals may pose potential threat to environment and were in the order of Pb > As > Cu > Cd. If assessing mobile fraction of heavy metals by land uses, the order was forestry > bare land > crop field > rice field. When analyzed using Tessier's scheme, high ratio of residual fractions to total arsenic concentration should be considered for remediation design of the area.

Effect of Mobile Game Use Amount on the Satisfaction Level and Game Commitment(flow) (모바일 게임 이용량이 게임 만족도와 몰입에 미치는 영향)

  • Kim, Hye Bin;Park, Young Il
    • Journal of Korea Game Society
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    • v.15 no.3
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    • pp.31-40
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    • 2015
  • In this study, the effect of amount of use of mobile game (time of use, consumption cost) on the perceived satisfaction level (perceived enjoyment, service quality, and price) of game and commitment is to be observed. If the amount of game use is high, are the satisfaction level and commitment of game high as well? Is there any factor of negative effect on game commitment? As a result of study, among the mobile game use behaviors subjected in this study, higher the amount of use and consumption cost, more the level of satisfaction level and commitment on game. This study is to verify and analyze the high level of perceived satisfaction and commitment on mobile game by users with high amount of use to expand and to discuss the base of study of heavy mobile game user and heavy digital game user.

The Use of the Brown Algae Sargassum spp. in Heavy Metal Monitoring of the Marine Environment near Vladivostok, Russia

  • Khristoforova, N.K.;Kozhenkova, S.I.
    • Ocean and Polar Research
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    • v.24 no.4
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    • pp.325-329
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    • 2002
  • Concentrations of Fe, Mn, Zn, Cu, Pb and Cd in two seaweed species (Sargassum miyabei and S. pallidum) from different areas in Amursky Bay near Vladivostok were determined. An assessment of heavy metal pollution in this bay was made and the results were compared with those from some localities in the world ocean.

Reduction of Patient Dose Exposure and Improvement of Image Quality by Use of Additional Filtration in Digital Radiology (디지털 진단방사선촬영에서 부가여과판 사용에 따른 피폭선량 감소와 화질 개선)

  • Moon, Su-Jeong;Kim, Young-Keun;Lee, Seong-Kil
    • Korean Journal of Digital Imaging in Medicine
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    • v.12 no.1
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    • pp.19-25
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    • 2010
  • This study is mainly for the reduction of exposure dose by using a heavy elements filter(Gd) in the digital radiology. They contained heavy elements filter of Gd and X-ray beam hardening filters such as Al and Cu. According to the results of experimental evaluation, X-ray property was not changed with variety of kVp in the case of the Gd filter. The surface dose and absorption dose were increased in order of Cu and Al. The contrast of image showed the higher value in order of Cu, Al and Gd. While the use of Gd has increased the numerical value of the CR image, and grayscale has decreased noise value of the DR image.

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Reduction of Exposure by Use of Heavy Elements as Filters in Diagnostic Radiology (진단방사선 영역에서의 중원소 여과판 사용에 의한 피폭선량 감소)

  • 김영근;이경섭
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1999.05a
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    • pp.438-441
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    • 1999
  • This work characterized in terms of the reduction of exposure dose by use of the heavy elements filter in the diagnostic radiology. They contained heavy elements filter of Ho and X-ray beam harding filters such as Al and Cu. From the results of experimental evaluation, it was founded that in the case of the Ho filter, X-ray property was not changed with variety of kVp. The surface dose and absorption dose was increased in order of Cu, He and Al. The contrast of image showed the higher value in order of Cu, Al and Ho.

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The controversial points and a remedy on evaluation of heavy metal contamination in standard method for examination of soil in Korea. (국내 토양오염 공정시험방법중 중금속 관련 오염평가의 문제점과 개선책)

  • 오창환;유연희;이평구;박성원;이영엽
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2000.11a
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    • pp.298-301
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    • 2000
  • Heavy metals are extracted from stream sediments, roadside soils and sediments and soils and tailings from mining area using partial extraction, acid digestion and HF-digestion. Compared to amounts of heavy metals extracted using partial extraction, those extracted using acid digestion are higher by 2.0∼220.9 times in Cu, 2.4∼2806.1 times in Pb, 1.3∼121 times in Cd, 14.1∼1300885 times in Fe, 1.2∼271.5 times in Mn, 1.3∼372.5 times in Zn, 2.2∼1734.5 times in Cr. Although partial extraction, which extracts less amounts of heavy metals from soil compared to acid digestion, is used in domestic standard method for examination of soil, domestic soil standard for heavy metals in non-agricultural and industrial areas is higher than soil standard in foreign countries which use acid digestion, For improvement of the domestic standard method for assessment of soil, it is suggested to lower the domestic soil standard for heavy metals or to change pretreatment method for extracting heavy metals from partial extraction to acid digestion with modifying the soil standard.

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Heavy Metal Removal from Drinking Water using Bipolar Surface Modified Natural Mineral Adsorbents (천연광물의 양극성 표면개질을 이용한 상수원수 중 중금속제거 특성)

  • Kim, Nam-youl;Kim, Younghee
    • Journal of Environmental Health Sciences
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    • v.45 no.6
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    • pp.561-568
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    • 2019
  • Objectives: The most commonly detected heavy metals in rocks and soils, including Pb, Cd, Cu, Fe, Mn and As, are representative pollutants discharged from abandoned mines and have been listed as potential sources of contamination in drinking water. This study focused on increasing the removal efficiency of heavy metals from drinking water resources by surface modification of natural adsorbents to reduce potential health risks. Methods: Iron oxide coating and graft polymerization with zeolites and talc was conducted for bipolar surface modification to increase the combining capacity of heavy metals for their removal from water. The removal efficiency of heavy metals was measured before and after the surface modification. Results: The removal efficiency of Pb, Cu, and Cd by surface modified zeolite showed 100, 92, and 61.5%, respectively, increases compared to 64, 64, and 38% for non-modified zeolite. This implies that bipolar surface modified natural adsorbents have a good potential use in heavy metal removal. The more interesting finding is the removal increase for As, which has both cation and anion characteristics showing 27% removal efficiency where as non-modified zeolite showed only 2% removal. Conclusions: Zeolite is one of the most widely used adsorptive materials in water treatment processes and bipolar surface modification of zeolite increases its applicability in the removal of heavy metals, especially As.

울산 달천광산 인근의 식물체 중금속 축적에 관한 연구

  • Kim Cheol;Cheon Mi-Hui
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2006.04a
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    • pp.131-137
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    • 2006
  • This study was investigated the contents of heavy metals in plants at Dalcheun mine area, in order to offer basic data for phytoremedation on soil contamination by heavy metals. As the results of this study, the contents of Ni, As, Cd in plants were the highest at the west area of Dalcheun mine area. But the content of Zn was similar in all of Dalcheun mine area. For the herbaceous plants, the contents of heavy metals were higher in plants which were included in Gramineae and Compositae than any other families. And then the contents of Ni, Zn, Cd in root were higher $1.4{\sim}1.8$ times than stem, especially the content of As was higher 4 times. For the trees, the contents of heavy metals were usually high in Zanthoxylum piperitum, Pine tree, Chestnut tree, Quercus acutissima and Lindera obtusiloba. The contents of heavy metals with parts of tree were almost same range. All experimental result, we paid attention on two conclusions. First, the contents of heavy metals in herbs was higher than in trees. And second, if there were some spices that the content of heavy metal in leave were higher than in root, they could accumulate that kind of heavy metal. Therefore, It is above 2 times which the content of heavy metal in the leave is higher than in the root about herbs, that kind of plants was regarded as a accumulation species. According as the heavy metals, accumulation species were selected. We think that the accumulation species are able to absorb the heavy metals from the soil, they will make use of phytoremedation on contaminated soil by heavy metals.

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Development of External UHF PD Sensor for the Detection of Partial Discharge in $SF_6$ Gas-insulated Switchgear (가스절연 개폐장치의 PD검출용 UHF 대역 외장형 센서 제작 및 감도 특성)

  • Lee, Chang-R.;Hong, C.Y.;Choi, B.H.;Yoon, J.H.;Nam, G.C.;Jung, J.G.
    • Proceedings of the KIEE Conference
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    • 2004.07c
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    • pp.1799-1801
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    • 2004
  • We have developed the external-type PD sensors for detecting of the electromagnetic waves up to ultra high frequency (UHF) bands, propagating in various type of GIS. Sufficiently high sensitivity and accuracy for practical use were achieved for the external PD sensor. The experience at the fields and the criteria for the judgment are also discussed in detail.

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