• Title/Summary/Keyword: cadmium metal

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Micellar Enhanced Ultrafiltration (MEUF) and Activated Carbon Fiber (ACF) Hybrid Processes for the Removal of Cadmium from an Aqueous Solution

  • Rafique, Rahman Faizur;Lee, Seunghwan
    • Korean Chemical Engineering Research
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    • v.52 no.6
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    • pp.775-780
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    • 2014
  • Micellar enhanced ultrafiltration (MEUF) was used to remove cadmium from an aqueous solution using sodium dodecyl sulfate (SDS) as a surfactant. Operational parameters such as initial permeate flux, retentate pressure, initial cadmium concentration, pH solution, molecular weight cut-off (MWCO), and molar ratio of cadmium to SDS were investigated. Removal efficiency of cadmium from an aqueous solution increased with an increase of retentate pressure, pH solution and molar ratio of cadmium to SDS, and decreased with an increase of initial permeate flux. Higher removal efficiency of cadmium from the aqueous solution was achieved using lower MWCO (smaller membrane pore size). Under optimized experimental condition, cadmium removal efficiency reached 74.6 % within an hour. Using MEUF-ACF hybrid process the removal efficiency of both cadmium and SDS was found to be over 90%.

Heavy Metal Levels in the Outdoor Workers Exposed in Yellow Sand (황사에 노출된 옥외 근로자의 혈중 중금속 농도)

  • Lee, Mi-Hwa
    • Korean Journal of Clinical Laboratory Science
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    • v.41 no.3
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    • pp.105-110
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    • 2009
  • Yellow sand (or Asian dust) occurs mainly in spring in East Asia. Yellow sand from China and its surrounding regions transports air pollutants, such as aerosols, ozone, and heavy metals. The outdoor workers are frequently exposed to heavy metals during yellow sand phenomenon. This study was carried out to investigate the heavy metal levels in blood among 75 outdoor workers (exposed group) and 86 indoor workers (controled group) in Gyeonggi province from March 2008 to May 2009. Heavy metal levels in blood were analyzed by atomic absorption spectrophotometer. Mean blood lead levels in exposed group and controled group were $5.19{\pm}1.64{\mu}g/dL$, $4.24{\pm}1.34{\mu}g/dL$, respectively. Mean blood cadmium levels in exposed group and controled group were $1.28{\pm}0.89{\mu}g/dL$, $0.90{\pm}0.59{\mu}g/dL$, respectively. Lead and Cadmium levels in blood of exposed group were significantly higher than those of controled group. In the comparison of smoking status, lead and cadmium levels of smokers were significantly higher than those of non-smokers. In conclusion, the heavy metal levels of outdoor workers were significantly higher than those of indoor workers. And smoking was hazardous factor to elevate heavy metal levels in blood.

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Bioaccumulation Patterns and Responses of Fleece-flower; Persicaria thunbergii to Cadmium and Lead

  • Kim, In-Sung;Kyung Hong kang;Lee, Eun-Ju
    • 한국생태학회:학술대회논문집
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    • 2002.08a
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    • pp.119-125
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    • 2002
  • Application of phytoremediation in the polluted area to remove undesirable materials is a complex and difficult subject without detailed investigation and experimentation. We investigated the accumulation patterns of cadmium and lead in plants naturally grown, the bioavailability of plants to accumulate these toxic metals and the responses of P. thunbergii to cadmium and lead. The soil samples contained detectable lead (<17.5$\mu\textrm{g}$/g), whereas cadmium was not detected in the soils of study area. The whole body of Persicaria thunbergii contained detectable lead (<320.8$\mu\textrm{g}$/g) but cadmium was detected only in the stem (<7.4$\mu\textrm{g}$/g) and root (<10.4$\mu\textrm{g}$/g) of P. thunbergii. Cadmium was not detected in Trapa japonica and Nymphoides peltata, whereas lead was detected in T. japonica (<323.7$\mu\textrm{g}$/g) and N. peltata (<177.5$\mu\textrm{g}$/g). Correlation coefficient between lead content in soil and in these plant samples represented positive correlation. The total content of lead in each plant sample increased in the order of N.peltata$\leq$P.thunbergii

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Bioaccumulation Patterns and Responses of Fleece-flower; Persicaria thunbergii to Cadmium and Lead

  • Kim, In Sung;Kang, Kyung Hong;Lee, Eun Ju
    • The Korean Journal of Ecology
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    • v.25 no.4
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    • pp.253-259
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    • 2002
  • Application of phytoremediation in the polluted area to remove undesirable materials is a complex and difficult subject without detailed investigation and experimentation. We investigated the accumulation patterns of cadmium and lead in plants naturally grown, the bioavailability of plants to accumulate these toxic metals and the responses of P. thunbergii to cadmium and lead. The soil samples contained detectable lead (<$17.5_\mu$g/g), whereas cadmium was not detected in the soils of study area. The whole body of Persicaria thunbergii contained detectable lead (<320.$8_\mu$g/g/g) but cadmium was detected only in the stem (<7.$4_\mu$g/g/g) and root (<10.$4_\mu$g/g/g) of P. thunbergii. Cadmium was not detected in Trapa japonica and Nymphoides peltata, whereas lead was detected in T. japonica (<323.$7_\mu$g/g/g) and N. peltata (<177.$5_\mu$g/g/g). Correlation coefficient between lead content in soil and in these plant samples represented positive correlation. The total content of lead in each plant sample increased in the order of N. peltata$\leq$P. thunbergii

Development of Biomarkers for Cadmium Toxicity (카드뮴 독성의 생체지표 (유전자 지표))

  • Lee, Mi-Ock
    • Proceedings of the Korean Society of Toxicology Conference
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    • 2003.05a
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    • pp.29-30
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    • 2003
  • The heavy metal cadmium is a xenobiotic toxicant of environmental and occupational concern and it has been classified as a human carcinogen. Inhalation of cadmiumhas been implicated in the development of emphysema and pulmonary fibrosis, but, the detailed mechanism by which cadmium induces adverse biological effects is not yet known.(omitted)

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Microbiological Characteristics of Heavy Metal Ion-Tolerant Microorganisms. (중금속 내성균주의 미생물학적 성질)

  • 유대식
    • Microbiology and Biotechnology Letters
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    • v.7 no.4
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    • pp.183-190
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    • 1979
  • Cadmium ion-tolerant microorganisms were isolated from the sludge and soil of a cadmium ion-polluted area, a zinc mineralized area, in Kyung Sang Pook Do, Korea. A strain, C-7, which showed tile highest tolerance to cadmium ion was selected by screening from 18 cadmium tolerant microorganisms. By the taxonomical characteristics of this strain, it was identified as a variant of Erwinia sp.. The strain grew in a medium cadmium ion up to a concentration of 2, 800 $\mu\textrm{g}$/ml and the maximum intercellular accumulation of Cd$^{2+}$ was measured to be 28.60 mg/g dried cells (57.2%) during incubation in medium containing 50 $\mu\textrm{g}$/ml under aerobic condition at 28$^{\circ}C$ for 24 hour.r.

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Plasma Membrane Transporters for Lead and Cadmium

  • Bressler, Joseph P.;Olivi, Luisa;Kim, Yong-Bae;Bannon, Desmond;Ko, Hong-Sook;Cheong, Jae-Hoon
    • Biomolecules & Therapeutics
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    • v.13 no.1
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    • pp.1-6
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    • 2005
  • Lead and cadmium are potent environmental toxicants that affect populations living in Europe. Americas, and Asia. Identifying transporters for lead and cadmium could potentially 1 help us better understand possible risk factors. The iron transporter, divalent metal transporter 1 (DMT1), mediates intestinal transport of cadmium, and lead in yeast and fobroblasts overexpressing DMT1. In human intestinal cells knocking down expression of DMT1 attenuated uptake of cadmium and iron but not lead. A possible explanation is the expression of a second transporter for lead in intestine. In astrocytes, however, DMT1 appears to transport lead in an extracellular buffer at pH value. At neutral pH, transport was not mediated by DMT1 but rather by a transporter that is stimulated by bicarbonate and inhibited by 4,4'-diisothiocyanatodihydrostilbene-2,2'-disulfonic acid. The identity of this lead transporter will beverified by future study.

Studies on the Active Materials of Alkaline Storage Battery. On Cadmium Electrode (알칼리 축전지의 활물질에 관한 연구. 카드뮴 전극에 관하여)

  • Ju Seong Lee;Choong Yeoul Joo;Park, Su Gil
    • Journal of the Korean Chemical Society
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    • v.25 no.5
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    • pp.325-330
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    • 1981
  • The electrochemical behavior of cadmium electrode for the nickel-cadmium battery system has been studied by cyclic voltammetry, controlled potential electrolysis and X-ray diffraction method. Cathodic polarization curve for cadmium hydroxide electrode prepared by electrochemical pretreatment of metallic cadmium showed two peaks. It has been found that cadmium hydroxide was reduced to cadmium metal at the first peak potential, whereas very activated metal of cadmium which was strongly oriented (002) rather than (101) was formed at the second peak potential. It was also found that the cadmium formed at the second peak potential reacted rapidly with oxygen. Therefore, it could be presumed that the cadmium recombination reaction with the oxygen was chemical, and could be represented as $2Cd + O_2 + 2H_2O\;{\longrightarrow}\;2Cd(OH)_2$.

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Complexation Studies for Cadmium (II) with Quercetin and (+)-Catechin (Quercetin과 (+)-Catechin의 카드뮴(II)에 대한 착물반응)

  • Lee, Jeong-Ho;Shin, Sun-Woo;Baek, Seung-Hwa
    • YAKHAK HOEJI
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    • v.53 no.6
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    • pp.342-350
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    • 2009
  • The interaction of cadmium (II) ion with quercetin and (+)-catechin was investigated in aqueous solution at various pH. The flavonoid/cadmium stochiometries for cadmium (II) binding to quercetin and (+)-catechin have been determined by UV-vis spectroscopy. 1 : 1 Cd (II)-Flavonoid complex had a maximum absorbance and showed the bathochromic shift of the long-wavelength band of the UV-vis spectra in the alkaline pH, that occurs upon complexation, due to a ligandto-metal charge transfer. These results suggest that Cd (II)-flavonoid complex has the optimal condition of chelation in 0.2 M $NH_3$ - 0.2 M $NH_4Cl$ (pH 8.0) solution.

Effect of Dietary Cysteine Level on Cadmium on Cadmium and Lead Toxicity in Rats (식이내 Cysteine 수준이 흰쥐의 카드뮴과 납중독에 미치는 영향)

  • 류정미
    • Journal of Nutrition and Health
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    • v.29 no.6
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    • pp.597-607
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    • 1996
  • This study has been investigated the potenial of increased dietary cysteine to alter the effects of cadmium and lead on tissure and bone metal concentrations, excretion and tissue metallothionein(MT) concentrations. Fifty-four male rats of Sprgue-Dawley strain weighing 149$\pm$17g were divided into 9 groups according to body weight. Nine experimental diets with different cadmium (0ppm, 400ppm), lead(0ppm, 710ppm) and cysteine (0.06%, 0.45%, 0.90%) levels were given to rats for 30 days ; Food intake, weight gain, F.E.R, and weights of liver, kidney and femur were decreased in cadmium supplied groups than in cadmium free groups. Urinary and fecal cadmium excretions were increased and MT synthesis we induced in liver, kidney and small intestine in cadmium supplied groups. In lead supplied groups, weight gain and F.E.R were decreased. With cysteine supplementation in cadmium supplied groups, weight gain and F.E.R, and weights of liver, kidney and femur were increased. Cadmium excretion in feces and MT concentrations in liver and kidney were also increased with cysteine supplementation. In lead supplied groups, there was no significant increase in food intake, weight gain and F.E.R with cysteine supplementation. Lead excretion in feces was increased in cysteine supplemented groups. In conclusion, effect of cadmium administration was more toxic than lead adminstration. Cysteine alleviated cadmium and lead toxicity by increasing metallothionein concentration and fecal excretions of heavy metals. Especially, effect of cysteine supplementation was more effective in cadmium groups than in lead groups. Effect of cysteine supplementation was not different with level of cysteine supplementation in both cadmium and lead groups.

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