• Title/Summary/Keyword: Mercury removal

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Changes in Mercury Content of Contaminated Vegetables by Cooking Method (오염(汚染)된 야채(野菜)의 조리방법(調理方法)에 따른 수은함량(水銀含量)의 변화(變化))

  • Kim, Young-Hee;Lim, Young-Sook
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.13 no.4
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    • pp.359-362
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    • 1984
  • This experiment was carried out to determine the effect of cooking methods of boiling and frying on the removal of mercury from vegetables. Garand chrysanthemums and the leaves of young radishes contained 0.23 and 0.15 ppm of mercury, respectively. When they were boiled, the content of the mercury decreases to 78 percent in garland chrysanthemums and 73 per cent in radish leaves. When they were fried, the content of the mercury decreases to 69 percent in garland chrysanthemums and 60 percent in radish leaves. After the vegetables were exposed to 0.11 ppm of mercury dichloride for 2 hours, the raw garland chrysanthemums and the raw young radish leaves were contaminated with 6.65, 6.10 ppm of mercury, respectively. When the vegetables were boiled after this contamination, the mercury was dissolved and. melted out about 10.0%, however, when the vegetables were fried the mercury was dissolved and melted out about $12{\sim}24%$. When the vegetables were exposed to 1.0 ppm of mercury dichloride, the raw garland chrysanthemums was contaminated with 10.79 ppm of mercury and the radish leaves 10.83 ppm of mercury. The mercury was dissolved and melted out about 10-20% and 10-30% when the vegetables were boiled and fried, respectively. From these results, it can be suggested that frying is more effective cooking method than boiling for the elimination of mercury from its contaminated foods.

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A Study on the Adsorption of Hg(II) Ion by Activated Carbon(1) (活性炭에 依한 Hg(II) 이온의 吸着에 관한 조사연구(1))

  • Lee, Hyun;Lee, Jong-Hang;Yun, O. Sub
    • Journal of Environmental Health Sciences
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    • v.14 no.2
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    • pp.65-71
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    • 1988
  • In this study, the method of adsorption by activated carbon in the removal of Hg(II) ion in waste water was treated. The influence of kinds of activated carbon and effect of temperature and the influence of coexistent salt on adsorption rates, the influence of pH in the adsorption, equilibrium and adsorption of mercury from activated carbon were investigated. From the adsorption on activated carbon of mercury(II) ion in the presence of cyanide or thiocyanate ion was found that mercury(II) was easily adsorved onto the activated carbon in the form of complex artion such as Hg(CN)$_4^{2-}$, Hg(SCN)$_4^{2-}$ respectively. ZnCl$_2$ activation method had a higher adsorptive ability than steam activation method in adsorption of Hg on activated carbon. Activated carbon adsorbed iodide ion is very effective on adsorption of Hg.

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A study on fetal toxicosis removal therapy (하태독법(下胎毒法)에 대한 문헌적(文獻的) 고찰(考察))

  • Chang, Gyu-Tae;Kim, Jang-Hyun;Kang, Mi-Sun
    • The Journal of Pediatrics of Korean Medicine
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    • v.17 no.1
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    • pp.29-51
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    • 2003
  • This study was progressed for oriental medical care of neonates by fetal toxicosis removal therapy, and the results as follows: 1. The purpose of fetal toxicosis removal therapy : It removes dirty blood in neonatal mouth and prevents diseases. 2. Kinds of fetal toxicosis removal therapy : Radix Glycyrrhizae(甘草), Rhizoma Coptidis(黃連), Cinnabaris-Mel(朱蜜), Calculus Bovis(牛黃), Sojae Semen Praepartum, Juice of Semen Allii Tuberosi(非汁) and mercury(汞粉). 3. A period of fetal toxicosis removal therapy : At birth, 3rd day or so, one week or so, after umbilical omission. 4. Methods of fetal toxicosis removal therapy: Purgative therapy(下法) and Emetic therapy(吐法).

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Effectiveness of gold nanoparticle-coated silica in the removal of inorganic mercury in aqueous systems: Equilibrium and kinetic studies

  • Solis, Kurt Louis;Nam, Go-Un;Hong, Yongseok
    • Environmental Engineering Research
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    • v.21 no.1
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    • pp.99-107
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    • 2016
  • The adsorption of inorganic mercury, Hg (II), in aqueous solution has been investigated to evaluate the effectiveness of synthesized gold (Au) nanoparticle-coated silica as sorbent in comparison with activated carbon and Au-coated sand. The synthesis of the Au-coated silica was confirmed by x-ray diffraction (Bragg reflections at $38.2^{\circ}$, $44.4^{\circ}$, $64.6^{\circ}$, and $77.5^{\circ}$) and the Au loading on silica surface was $6.91{\pm}1.14mg/g$. The synthesized Au-coated silica performed an average Hg adsorption efficiency of ~96 (${\pm}2.61$) % with KD value of 9.96 (${\pm}0.32$) L/g. The adsorption kinetics of Hg(II) on to Au-coated silica closely follows a pseudo-second order reaction where it is found out to have an initial adsorption rate of $4.73g/{\mu}g/min/$ and overall rate constant of $4.73{\times}10^{-4}g/{\mu}g/min/$. Au-coated silica particles are effective in removing Hg (II) in aqueous solutions due to their relatively high KD values, rapid adsorption rate, and high overall efficiency that can even decrease mercury levels below the recommended concentrations in drinking water.

Human body model electrostatic discharge tester using metal oxide semiconductor-controlled thyristors

  • Dong Yun Jung;Kun Sik Park;Sang In Kim;Sungkyu Kwon;Doo Hyung Cho;Hyun Gyu Jang;Jongil Won;Jong-Won Lim
    • ETRI Journal
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    • v.45 no.3
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    • pp.543-550
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    • 2023
  • Electrostatic discharge (ESD) testing for human body model tests is an essential part of the reliability evaluation of electronic/electrical devices and components. However, global environmental concerns have called for the need to replace the mercury-wetted relay switches, which have been used in ESD testers. Therefore, herein, we propose an ESD tester using metal oxide semiconductor-controlled thyristor (MCT) devices with a significantly higher rising rate of anode current (di/dt) characteristics. These MCTs, which have a breakdown voltage beyond 3000 V, were developed through an in-house foundry. As a replacement for the existing mercury relays, the proposed ESD tester with the developed MCT satisfies all the requirements stipulated in the JS-001 standard for conditions at or below 2000 V. Moreover, unlike traditional relays, the proposed ESD tester does not generate resonance; therefore, no additional circuitry is required for resonant removal. To the best of our knowledge, the proposed ESD tester is the first study to meet the JS-001 specification by applying a new switch instead of an existing mercury-wetted relay.

A Study on Applicability of Mercury-contaminated Tailing and Soil Remediation around abandoned Mines using Washing Process (세척공법을 이용한 광산주변 수은 함유 오염물질 처리 적용성 평가)

  • Kwon, Yo Seb;Park, So Young;Koh, Il Ha;Ji, Won Hyun;Lee, Jin Soo;Ko, Ju In
    • Economic and Environmental Geology
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    • v.53 no.4
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    • pp.337-346
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    • 2020
  • This study was carried out to evaluate the applicability of the soil washing process to remediation mercury-contaminated mine tailing or solid material (soil and sediments etc.) around abandoned mines. First, the physicochemical characteristics of mine tailing were analyzed through particle size analysis and sequential extraction. Secondly, laboratory scale washing experiments were performed using hydrochloric acid, nitric acid, potassium iodide and sodium thiosulfate. As a results of particle size analysis, mine tailing particle were concentrated below 40 mesh and the particle size below 200 mesh was the most analyzed. As a result of sequential extraction, elemental mercury fraction was analyzed as the highest with 69.12%, with strongly bound fraction 15.25% and residual and HgS fractions 11.97%, respectively. Laboratory scale washing experiments showed low applicability for nitric acid and sodium thiosulfate solutions. In case of hydrochloric acid solution, it was analyzed that mercury removal was possible at particle size of 200 mesh or more. Therefore, it is considered to be performed together with the physical sorting process. Potassium iodide solution was analyzed to have high washing efficiency at all concentrations and particle sizes. In particular, the mercury removal efficiency is high in the micro particles, and thus the applicability of the washing technology is the highest.

A Selective Determination Method of Inorganic and Organic Mercury (무기수은과 유기수은의 선택정량)

  • Kim, Chon Han
    • Journal of the Korean Chemical Society
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    • v.41 no.8
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    • pp.392-398
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    • 1997
  • A method of selective determination of inorganic and organic mercury compounds has been described. The $CHCl_3$ solution of a high molecular quaternary alkylammonium salt, Aliquat 336 was used for the simultaneous preconcentration of both inorganic, $Hg^{2+}$ as its thiocyanate complex, and organic mercury compounds, $CH_3HgCl$ and $C_2H_3O_2$ $HgC_6H_5$ by extraction from their aqueous solution. Selective separation of the inorganic mercury from the extract was followed by stripping with 3 M $HClO_4 $ solution for the subsequent determination by CVAAS. Organic mercury was also determined by CVAAS after removal of $CHCl_3solvent$ from the extract and decomposition of the residue with 4% $KMnO_4 $-1 MH_2$S0_4$. The mixtures of inorganic and organic mercury compounds contained 1.0 $\mug$ as Hg in 50 mL of sample solution(0.02 ${\mu}gHg/mL$) were analysed within ${\pm}6%$ by absolute errors.

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Development of Adsorbent for Vapor Phase Elemental Mercury and Study of Adsorption Characteristics (증기상 원소수은의 흡착제 개발 및 흡착특성 연구)

  • Cho, Namjun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.22 no.5
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    • pp.1-6
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    • 2021
  • Mercury, once released, is not destroyed but accumulates and circulates in the natural environment, causing serious harm to ecosystems and human health. In the United States, sulfur-impregnated activated carbon is being considered for the removal of vapor mercury from the flue gas of coal-fired power plants, which accounts for about 32 % of the anthropogenic emissions of mercury. In this study, a high-efficiency porous mercury adsorption material was developed to reduce the mercury vapor in the exhaust gas of coal combustion facilities, and the mercury adsorption characteristics of the material were investigated. As a result of the investigation of the vapor mercury adsorption capacity at 30℃, the silica nanotube MCM-41 was only about 35 % compared to the activated carbon Darco FGD commercially used for mercury adsorption, but it increased to 133 % when impregnated with 1.5 % sulfur. In addition, the furnace fly ash recovered from the waste copper regeneration process showed an efficiency of 523 %. Furthermore, the adsorption capacity was investigated at temperatures of 30 ℃, 80 ℃, and 120 ℃, and the best adsorption performance was found to be 80 ℃. MCM-41 is a silica nanotube that can be reused many times due to its rigid structure and has additional advantages, including no possibility of fire due to the formation of hot spots, which is a concern when using activated carbon.

Assessment of Advanced Oxidation Processes using Low and Medium-Pressure Lamps with H2O2 for Reclamation of Biologically Treated Wastewater Effluents (하수 2차 처리수 재이용을 위한 저압 및 중압 고도산화시스템의 성능평가)

  • Ahn, Kyu-Hong;An, Seok;Maeng, Seung-Kyu;Kim, Ki-Pal;Hong, Joon-Seok;Jung, Min-Woo;Kweon, Ji-Hyang;Ahmed, Zubair
    • Journal of Korean Society of Water and Wastewater
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    • v.17 no.4
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    • pp.542-549
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    • 2003
  • In the present study, the feasibility of $UV/H_2O_2$ systems was investigated using low and medium-pressure lamps on biologically treated wastewater effluents for secondary effluent reclamation. Two types of UV lamps were used as the light sources (a 39-W low-pressure mercury lamp and a 350-W medium-pressure mercury lamp). The results from these UV systems showed that the removal of organic compounds could be achieved in the contact time of longer than 30min (i.e., low UV doses). Efficiencies of color removal and disinfection were far better than those of organic matters measured as TOC, DOC and $TCOD_{cr}$. In the low-pressure lamp UV system, it has been found that DOC and color removals were 60.9 and 86.2% with 50mg/L of $H_2O_2$ and contact times of 30 minute, respectively. Whereas, with the medium-pressure lamp UV system, TOC, DOC and color removal were 27.1, 5.6 and 95% with 14.3mg/L of $H_2O_2$ and 14 minute of contact times, respectively. Both systems could be applied for the reclamation of secondary effluent treated with biological treatment processes.

Removal of taste and odor causing compounds in drinking water using Pulse UV System (Pulse UV 장치를 이용한 먹는 물의 이취미 유발물질 제거효과에 관한 연구)

  • Sohn, Jin-Sik;Park, Soon-Ho;Jung, Eui-Taek
    • Journal of Korean Society of Water and Wastewater
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    • v.26 no.2
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    • pp.219-228
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    • 2012
  • Problems due to the taste and odor in drinking water are common in treatment facilities around the world. Taste and odor are perceived by the public as the primary indicators of the safely and acceptability of drinking water, and are mainly caused by the presence of two semi-volatile compounds-2-methylisoborneol(2-MIB) and geosmin. Conventional treatment processes in water treatment plants, such as coagulation, sedimentation and chlorination have been found to be ineffective for the removal of 2-MIB and geosmin. Pulse UV system is a new UV irradiation system that is a non-mercury lamp-based alternative to currently used continuous wave systems for water disinfection. This study shows pulse UV system to be effective in treatment of these two compounds. Geosmin removal efficiency of UV process alone achieved approximately 70% at 10sec contact time. 2-MIB removal efficiency of UV only process achieved approximately 60% at 10sec contact time. The addition of $H_{2}O_{2}$ 7mg/L increased geosmin and 2-MIB removal efficiency upto approximately 94% and 91%, respectively.