• Title/Summary/Keyword: Soluble metal

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A Study on the Effect of Air Pollutants in Daegu Area by Biological Indicator of Roadside (道路 指標生物을 이용한 대기오염이 植物에 미치는 영향에 관한 연구)

  • Kang, Hoe-Yang;Cha, Sang-Eun;Ha, Cheong-Gun
    • Journal of Environmental Health Sciences
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    • v.14 no.2
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    • pp.29-41
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    • 1988
  • This study was performed to investigate the air pollution levels in Daegu area titrough measuring of contents of water, chlorophyll, water soluble sulfur and lead metal in the leaves of roadside trees and chemical properties of soil under the urban trees. The results can be summarized as follows 1. The range of water content was from 60.4% to 74.6%. The comparisons of chlorophyll, water soluble sulfur and water content were regression equation, chlorophyll=0.1981+ 0.0040 water content (July), water soluble sulfur=3,139-0.0416 water content (July). and correlation coefficient, r=0.561 and r=0.549 respectively 2. Average contents of chlorophyll, water soluble sulfur and lead metal in the leaves of roadside tree at sampling sites were chlorophyll 0.050, 0.072mg/cm$^2$, water soluble sulfur 0.244, 0.333%, and lead metal 12.25, 12.68ppm in Oct. and Jul. respectively. 3. Correlation between chlorophyll and contents of water soluble sulfur and lead metal in the leaves of roadside tree at sampling sites were water soluble sulfur r=-0.564, -0.613 and lead metal r=-0.693, -0.699 in October and July, respectively. 4. Correlation between chlorophyll and water content, water soluble sulfur and lead metal in the leaves of tree showed positive significance.

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Review of the Determination Methods for Metal Compounds with Different Occupational Exposure Limits Depending on Solubility (용해도에 따라 노출기준이 다른 금속화합물의 정량방법 고찰)

  • Park, Seung-Hyun;Ro, Jiwon;Jang, Miyeon
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.30 no.2
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    • pp.87-98
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    • 2020
  • Objective: The purpose of this study was to propose a sequential procedure for the simultaneous analysis of soluble and insoluble metal compounds. Methods: Methods for sampling and analyzing metal compounds such as ISO standards, NIOSH methods, HSE methods, and OSHA methods were reviewed. Results: Some metals have different OELs depending on the solubility of the compound. Therefore, we should take into account these characteristics and perform an exposure assessment. Soluble metal compounds are first extracted from the filter, and then the filter is digested by acids to analyze residual insoluble components. The extraction of soluble compounds can be completed by agitation for about 60 minutes with a leach solution (water) in a water bath at 37℃. For the analysis of insoluble compounds, the sample filter and the filtration filter remaining after the extraction of the soluble compounds are analyzed. This allows simultaneous determination of soluble and insoluble metal compounds. For hexavalent chromium compounds, soluble hexavalent chromium can first be extracted from the filter by using sulfate buffer. The insoluble hexavalent chromium remaining in the filter can then be extracted using carbonate buffer. Conclusion: Workers are often exposed to many hazardous substances with different exposure limits at industrial sites. The OELs for compounds of the same metal can be set differently depending on solubility. This study can help evaluate a worker's exposure to metal compounds by suggesting methods for the simultaneous determination of soluble and insoluble metal compounds.

Impact of Acidification on the Solubility of Metal Species in Asian Desert Dusts: Results from Laboratory Experiments (산성화 과정이 황사입자 내 금속성분의 용해도에 미치는 영향: 실험실 연구결과)

  • Sim, Soo-Young;Park, Seung Shik;Kim, Deok-Rae;Lee, Suk-Jo
    • Journal of Korean Society for Atmospheric Environment
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    • v.29 no.1
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    • pp.64-73
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    • 2013
  • Because some particulate matter emission sources may inherently produce soluble species, or some soluble species may be produced during atmospheric transport, it is important to understand the origin of a particles's solubility when water-soluble tracers are used in source apportionment studies. Laboratory experiments were performed on three types of soils (Mongolia grassland, Mongolia desert, and Korean rural soils), to study the impact of acidification by nitric acid vapor on the solubility of metals in the soils. To achieve this goal, concentrations of water-soluble metals (Na, Mg, Al, K, Ca, Mn, and Fe) in the soils measured before and after acidification. Contributions of concentrations of water-soluble metal species before and after acidification attack to their total concentrations varied little with soil type. Concentrations of water-soluble Mg, Al, K, Ca, Mn, and Fe from the soils after interaction with nitric acid vapor increased, with significant increases in soluble Ca and Mn for all soil types suggesting soil acidification enhances the amount of leachable metal species in soil dust. There was little increase in water-soluble Na and K after acidification for each soil type. This experiment demonstrates that quantities of water-soluble metal species in particulate matter are produced under high gaseous nitric acid conditions.

A Study on Adsorption of Heavy Metal Ions Using Water-soluble Chitosan Derivative (수용성 Chitosan 유도체를 이용한 중금속 이온 흡착에 관한 연구)

  • Lee, Kwang-Il;Kwak, Chun-Geun;Kim, Young-Ju;Jang, Buyng-Man;Kim, Sang-Ho;Lee, Ki-Chang
    • Journal of the Korean Applied Science and Technology
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    • v.13 no.2
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    • pp.85-92
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    • 1996
  • Chitosan itself has been prepared using chitin, one of the most abundant compounds in nature, as a starting material. We have synthesized the water-soluble chitosan derivative, N-dithiocarboxy chitosan sodium salt, through the reaction of water-soluble chitosan with carbon disulfide in the presence of alkali metal hydroxide. To elucidate this natural polymer capacity of adsorbing heavy metal ions, we have performed adsorption experiments using the water-soluble chitosan derivative various average molecular weight and of different percent contents of sulfur. The effect of pH, adsorption time and temperature on adsorption efficiency was also studied. The adsorbent derived from water-soluble chitosan of average molecular weight ranging $9,000{\sim}120,000$ was shown to have the highest capacity of adsorbing heavy metal ions. On the whole, adsorbing efficiency was increased as the reaction time goes longer and also increased as the reaction temperture goes higer in temperture range of $15^{\circ}C{\sim}45^{\circ}C$. The adsorption capacity at various pH, however, was appeared to vary depending on the heavy metal ions studied Judging from these finding, water-soluble N-dithiocarboxy chitosan sodium salt, a derivative of a biodegradable nature polymer, is believed to be a potential adsorbent for heavy metal ions since it not only is shown to lower the concentration of heavy metal ions to below the drainage quality standard, but also it would not cause acidification and hardening of soil which is one of the detrimental effects of synthetic macromolecular adsorbents present.

A Study on the Antimicrobial Activity of Copper Alloy Metal Fiber on Water Soluble Metal Working Fluids (수용성 절삭유의 부패 특성과 Copper Alloy Metal Fiber의 부패 방지 장치에 관한 연구)

  • Song, Ju-Yeong;Lee, Sang-Ho;Kim, Jong-Hwa
    • Journal of the Korean Applied Science and Technology
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    • v.26 no.1
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    • pp.69-73
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    • 2009
  • Copper alloy metal fiber was incorporated into the conventional water-soluble metal working fluids to increase the antimicrobial activity. Fluid treated by copper alloy metal fiber is shown that bacteria is disappeared whereas that untreated metal fiber is increased bacteria as increasing the life time. When the electrochemical potential of Cu/Zn ion is -268mV, radicals with molecular oxygen are easily made. Especially, hydroperoxide radical shows strong toxicity to the strains, leading to the conformational change of plasma membrane. As a result antimicrobial activity of copper alloy metal fiber in metal working fluid is superior to that of copper fiber.

A Study on the Antimicrobial Activity of Copper Alloy Metal Fiber on Water Soluble Metal Working Fluids (수용성 절삭유의 Copper Alloy Metal Fiber에 의한 항균 특성에 관한 연구)

  • Song, Ju-Yeong;Lee, Sang-Ho;Park, Keun-Ho
    • Journal of the Korean Applied Science and Technology
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    • v.24 no.3
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    • pp.233-237
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    • 2007
  • This study is focused on the possibility of copper alloy metal fiber for an antimicrobial activity in the water soluble metal working fluids. Electrochemical potential of Cu/Zn ion is -268mV, and easily makes radicals with molecular oxygen. Especially, hydroperoxide radical shows strong toxicity to the strains. Plasma membrane causes conformational change when hydroperoxide radical binds to plasma membrane. Elution of copper ion from copper alloy metal fiber is detected in metal working fluid. As a result antimicrobial activity of copper alloy metal fiber in metal working fluid is superior to that of copper fiber.

Desalting System for Excavated Metal Objects Using High Temperature, High Pressure Deoxygenated Water

  • IMAZU, Setsuo;KOEZUKA, Takayasu
    • Journal of Conservation Science
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    • v.5 no.2 s.6
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    • pp.35-44
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    • 1996
  • We propose a new method to remove salts that have permeated into excavated metal objects. This method cleans the excavated metal objects by using high temperature, high pressure deoxvgenated water containing inhibitors for corrosion of metals. The method greatly reduces the washing time compared with previous methods. Waste water from the method does not need treatment, nor do chemicals need to be removed from the metal objects. Furthermore, this method is applicable to some kind of metals(for example iron objects, bronze objects). We measured quantitatively the soluble salts dissolved from actual metal objects and found that there was a large difference between soluble chloride ions and sulfate ions.

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Chemical Properties in the Soils of Reclaimed and Natural Tidelands of Southwest Coastal Area of Korea (I) - Distribution of Heavy Metal Fractions - (우리나라 서남해안 간척지 및 간석지 토양의 화학적 특성 (I) - 중금속 오염물질의 형태별 함량 분포 -)

  • Cho, Jae-Young;Koo, Ja-Woong;Son, Jae-Gwon
    • Journal of The Korean Society of Agricultural Engineers
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    • v.48 no.1
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    • pp.3-10
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    • 2006
  • The chemical fractions of heavy metals were investigated in the soils of reclaimed and natural tidelands of southwest coastal area of Korea. The distribution pattern of each heavy metal in different fractions was in the order: 1) Cu : organic bound > organic complex > residual > exchangeable = water soluble. 2) Cr : residual > organic bound > organic complex > water soluble > exchangeable. 3) Pb : organic bound > residual > organic complex > water soluble > exchangeable. 4) Cd residual > organic bound > organic complex > water soluble = exchangeable. 5) Zn : organic bound > residual > organic complex > water soluble > exchangeable. The content of residual Zn showed positive correlation with organic matter content but organic bound Zn showed negative correlation with CEC. The content of residual and exchangeable Cd showed highly positive correlation with organic matter content but residual, organic bound, and exchangeable Cd showed negative correlations with CEC. Water soluble Pb showed positive correlation with CEC but organic bound Pb showed negative correlation with CEC.

Preparation of Water Soluble Chitosan Blendmers and Their Application to Removal of Heavy Metal ions from Wastewater

  • Seo, Sang-Bong;Toshio Kajiuchi;Kim, Dae-In;Lee, Soon-Hong;Kim, Hak-Kil
    • Macromolecular Research
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    • v.10 no.2
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    • pp.103-107
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    • 2002
  • High purity water soluble chitosans (WsCs) were employed as a flocculant to remove heavy metal ions from wastewater of industrial plating wastewater treatment complex. Their weight average molecular weights and polydispersities were 272,000~620,000 g/mol and 1.4~1.9 range, respectively and were readily soluble in water in the pH range of 3~11. Heavy metal ions such as chromium, iron and copper were removed well by WsCs. When WsCs was blended with either sodium N, N-diethyldithiocarbamate trihydrate (SDDC$_{T}$) or sodium salicylate (SSc), the removal efficiency was further increased primarily due to the excess amount of hydrophilic sulfonic and carboxylic groups. Especially, in the case of WsCs-SSc the remaining chromium and copper concentrations were 0.1 mg/L and 9.5 mg/L, which are 1/15 and 1/3 compared with that of pure WsCs, respectively. The former is within the acceptable limit, but the latter is not. Therefore, the effective copper flocculant remains to be studied.d.