• Title, Summary, Keyword: heavy metals

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Effect of Sludge Concentration on Removal of Heavy Metals from Digested Sludge by Thiobacillus ferrooxidans (Thiobacillus ferrooxidans를 이용한 소화 슬러지의 중금속 제거에 미치는 슬러지 농도의 영향)

  • 류희욱;김윤정;조경숙;강근석;최형민
    • KSBB Journal
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    • v.13 no.3
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    • pp.279-283
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    • 1998
  • To investigate the feasibility of the microbial process for removal of heavy metals from the high solid content sludge, the effect of sludge concentration on the solubilization of heavy metals by an iron oxidizing bacterium Thiolbacillus ferrooxidans was examined. With increasing the sludge concentration, the removal efficiency of heavy metals and the oxidation rate of iron were inhibited. Especially, when the sludge concentration is over 5% (w/v), the activity of T. ferrooxidans was remarkably inhibited. This inhibition is considered to occur due to the dissolved inhibitory materials such as organic compounds, heavy metals, and others which were extracted from the sludge during incubation period. In conclusion, the microbial process by T. ferrooxidans is only effectively used in ranges of 1.3 to 4.0% (w/v) sludge concentration.

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Simultaneous Removal of Heavy Metals and Diesel-fuel from a Soil Column by Surfactant Foam Flushing (계면활성제 거품(Foam)을 이용한 토양칼럼 내 유류 및 중금속 동시 제거 연구)

  • Heo, Jung-Hyun;Jeong, Seung-Woo
    • Journal of Soil and Groundwater Environment
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    • v.16 no.5
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    • pp.90-96
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    • 2011
  • Simultaneous removal of heavy metals (Cd, Pb) and diesel-fuel from a soil column was evaluated by respectively flushing with sodium dodecyl sulfate (SDS) solution, mixture of SDS and sodium iodide (SDS + NaI), and surfactant foam (SDS + NaI foam). First, this study evaluated these flushing methods to the heavy metals only-contaminated soil for removal of heavy metals from the heavy-metal only contaminated soil column. After 7 pore volume flushing of the soil column, Cd removal efficiencies from the soil were 40% by SDS solution, 50% by SDS + NaI mixture, and 60% by surfactant foam. The flushing results implied that anionic surfactant and ligand can be efficiently applied to extraction of Cd from the heavy metal contaminated soil. Furthermore, surfactant foam flushing showed an increased flushing efficiency with enhancing the contact between surfactant solution and soil. However, Pb removal efficiency by these flushing methods did not show any difference unlike those of Cd. Second, this study eventually evaluated flushing methods for simultaneous removal of heavy metals and diesel-fuel from the soil column with 7 pore volume flushing. Diesel-fuel removal efficiencies were 50% by SDS + NaI flushing and 90% by SDS + NaI foam flushing. Cd removal efficiency by the foam flushing reached to 80% which was higher than the result of the previous heavy metals onlycontaminated soil experiment. This result implied that diesel-fuel could act as a metal-solvent while it contacted to heavy metals present in the soil. This study clearly showed that surfactant foam flushing simultaneously removed heavy metals and diesel fuel from the soil column.

Determination of Heavy Metal Contents in Various Packaging Boards (지류 포장재 종류에 따른 중금속 함량 측정)

  • Kim, Jin-Woo;Seo, Joo-Hwan;Youn, Hye-Jung;Lee, Hak-Lae
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.41 no.2
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    • pp.55-63
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    • 2009
  • This study was performed to evaluate the heavy metal contents in various packaging board. Domestic and foreign OCC (old corrugated containers) and old duplex boards were used as raw materials. Tests were made for the printed and unprinted parts of the sample. Heavy metal contents of old food packaging boards made from virgin pulp fibers were also evaluated. The contents of heavy metals including lead (Pb), cadmium (Cd), barium (Ba), arsenic (As), antimony (Sb), selenium (Se), and mercury (Hg) were determined using ICP-AES (Inductively Coupled Plasma - Atomic Emission Spectrometer), and CV-AAS (Cold vapor-atomic absorption spectrometer) after digesting the samples in a microwave oven. The contents of heavy metals contained in domestic packaging board were higher than those in overseas samples, and OCC showed higher contents of heavy metals than old duplex boards. Printed parts gave greater heavy metal contents than unprinted parts. Results indicate that recycling of paper and paperboard products increases the heavy metal contamination of the paper packaging products and this derives mostly from the heavy metals contained in printing inks. Recycling processes that decrease heavy metals in recycled fibers and new printing inks that contains less heavy metals should be developed to solve the problem associated with the heavy metals in packaging paper products.

Removal of Heavy Metals by Sawdust Adsorption: Equilibrium and Kinetic Studies

  • Lim, Ji-Hyun;Kang, Hee-Man;Kim, Lee-Hyung;Ko, Seok-Oh
    • Environmental Engineering Research
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    • v.13 no.2
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    • pp.79-84
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    • 2008
  • Adsorption of heavy metals by sawdust was investigated to evaluate the effectiveness of using sawdust to remove heavy metals from aqueous solutions. Kinetic and isotherm studies were carried out by considering the effects of initial concentration and pH. The adsorption isotherms of heavy metals fitted the Langmuir or Freundlich model reasonably well. The adsorption capacity of metal was in the order $Pb^{2+}$ > $Cu^{2+}$ > $Zn^{2+}$. A high concentration of co-existing ions such as $Ca^{2+}$ and $Mg^{2+}$ depressed the adsorption of heavy metal. Adsorption data showed that metal adsorption on sawdust follows a pseudo-second-order reaction. Kinetic studies also indicated that both surface adsorption and intraparticle diffusion were involved in metal adsorption on sawdust. Column studies prove that sawdust could be effective biosorbent for the removal of heavy metals from aqueous phase.

The Concentrations of Heavy Metals in the Seawater, Sediment and Seaweed in Mokpo Coastal Region, Southwestern Coast of Korea (목포 연안해역의 해수, 퇴적물 및 해조류에 축적된 중금속 함량)

  • Park, Chan-Sun;Wi, Mi-Young;Hwang, Eun-Kyoung
    • Korean Journal of Environmental Biology
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    • v.26 no.4
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    • pp.303-310
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    • 2008
  • Heavy metal concentration of Fe, Zn, Cu, Cd and Pb were analysed from seaweeds (Ulva pertusa, Sargassum thunbergii, Caulacanthus okamurae), sediments and seawater at the two experimental sites of Daebul and Sabjin industrial complex in Mokpo coastal area with a control site (Heugsando). Highest values of heavy metals were found at two experimental sites influencing by various pollution sources such as industrial drains, sewage and harbours. In contrast, the lowest concentrations was observed at the control site without any pollution source. The concentration levels of accumulated heavy metals were in the following order: seaweeds > sediments > seawater. Similar spatial distribution patterns were observed at the seaweeds, sediments and seawater for the highest mean values of the different heavy metals. This result show that seaweeds could be used as a biomonitors of heavy metals at coastal region.

Concentrations of SPM and Ambient Hazardous Heavy Metals in an Industrial Complex Area in Daegu City (대구시 산단지역 대기 중 SPM과 유해중금속성분의 농도)

  • Song, Hee-Bong;Kwon, Jong-Dae;Park, Su-Kyoung;Kim, Eun-Kyung;Yoon, Hyun-Suk;Ju, Myeong-Hui;Bae, Gi-Soo
    • Journal of Environmental Health Sciences
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    • v.41 no.4
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    • pp.259-267
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    • 2015
  • Objectives: This study evaluated the regional and seasonal concentrations of ambient hazardous heavy metals in an industrial complex area in Daegu City. Methods: A total of 64 SPM (Suspended Particulate Matter) samples were collected in non-industrial and industrial areas during 2014 and were analyzed for hazardous heavy metals elements (As, Cd, Mn, Ni, Pb) with ICP after acid extraction. Results: SPM and hazardous heavy metals concentrations showed regional (industrial complex area>non-industrial complex area) and seasonal (spring, winter>fall, summer) variations. All of the hazardous heavy metals were influenced by anthropogenic sources. The pollution index of hazardous heavy metals was very low, showing roughly one-quarter of the level of the air quality guidelines of WHO. The correlation analysis among SPM and hazardous heavy metals indicated that components of non-industrial complex areas were more related to each other than those of industrial complex areas, and the correlation in the winter was higher than in other seasons. Conclusion: It is necessary to control air pollution sources and establish related policy because hazardous heavy metals from industrial areas can influence residential areas.

Crystallization of the Fly Ash from Municipal Incinerator (도시쓰레기 소각로 비산재 용융결정화 및 용출특성)

  • Lee, Hye-Mun;Kim, U-Hyeon;Lee, Jeong-Gyu
    • 연구논문집
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    • pp.5-14
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    • 2001
  • These days, interest in the leaching of hazardous heavy metals to consist of incinerator fly ash is increasing, because the heavy metals that leach from the incinerator fly ash pollute the soil and ground water. Therefore this study was undertaken to crystallize the fly ash and prevent the leaching of hazardous heavy metals from fly ash. The concentrations and the leaching concentration of hazardous heavy metals(Cd, Cr, Hg, Pb, Zn) in the law incinerator fly ash have been measured. The fly ash was melted with two kinds of flux($Na_2CO_3, CaCO_3$) and its add quantity(0, 1, 2, 3 wt%). The crystal structure of melting materials was analyzed by SEM(Scaning Electron Microscope) and X-RD(X-Ray Diffractometer). The leaching test of melting materials was undertaken. And the relation between crystallization of melting materials and flux and leaching concentration. These experiments indicate that the concentration and leaching concentration of heavy metals in incinerator fly ash was much higher than the regulatory standard for leachates in Korea and U.S.A and average concentration of heavy metals in soil. And the crystal structure was better.

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Risk assessment of heavy metals in soil based on the geographic information system-Kriging technique in Anka, Nigeria

  • Johnbull, Onisoya;Abbassi, Bassim;Zytner, Richard G.
    • Environmental Engineering Research
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    • v.24 no.1
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    • pp.150-158
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    • 2019
  • Soil contaminated with heavy metals from artisanal gold mining in Anka Local Government Area in Northwestern Nigeria was investigated to evaluate the human health risk as a result of heavy metals. Measured concentration of heavy metals and exposure parameters were used to estimate human carcinogenic and non-carcinogenic risk. GIS-based Kriging method was utilized to create a prediction maps of human health risks and probability maps of heavy metals concentrations exceeding their threshold limits. Hazard index calculation showed that 21 out of 23 locations are posing non-cancer risk for children. Adults and children are at high cancer risk in all locations as the total cancer risk exceeded $1{\times}10^{-6}$ (the lower limit CTR value). Kriging model showed that only a very small area in Anka has a hazard index of less than unity and cumulative target risk of less than $1{\times}10^{-4}$, indicating a significant carcinogenic and non-carcinogenic risks for children. The probability of heavy metals to exceed their threshold concentrations around the study area was also found to be high.

Ecological study on effects of heavy metal accumulation on pillbugs (토양 내 서식하는 공벌레의 중금속 축적에 따른 생태적 연구)

  • Lee, Sang-Don
    • Journal of Environmental Impact Assessment
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    • v.20 no.5
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    • pp.675-684
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    • 2011
  • In nature, the overall effect of heavy metals on the biota can be influenced by a number of environmental factors like soil characteristics and air pollution by elevated $CO_2$. Pillbugs (Isopoda, Armadillium vulgare) take up heavy metals with their food and store them mainly in the vesicles of hepatopancreas. They accumulate certain metals, occur in relatively large numbers, are easily collected and identified, and provide sufficient material for analysis. The species are decomposing litter well and soil impurities into N and P. Therefore, it has been suggested that total body concentration of metals in pillbugs could be positively correlated to the levels of environmental exposure and that pillbugs could be used as biological indicators of metal pollution and global change by $CO_2$. The aim of the study is to determine effects of heavy metal concentrations in soil and elevated $CO_2$ on pillbugs' body accumulation of heavy metal and growth rate. In this study, the concentrations of six metals (Fe, Mg Cu, Zn, Pb, Cd) have been determined. Pillbugs (N=287) were collected at five sites during Jul-Aug, 2006. Cu and Zn concentrations in the body were much higher than in the soils(1.39-41.70 times). This indicated that bioaccumulation of some of the heavy metals were increasing in the food-chain. The high bioconcentration of lead in Sangam may be partly associated with reclaimed land uses.

Convergence Process for the Removal of Heavy Metals in the Abandoned Mine (휴폐광산의 중금속제어를 위한 융합공정 개발)

  • Dho, Hyonseung
    • Journal of the Korea Convergence Society
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    • v.7 no.1
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    • pp.155-160
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    • 2016
  • The convergence process utilized both leaching and ion exchange techniques has been investigated for the heavy metals removal in the abandoned mine of Chungyang Province, Korea. The contaminated soil samples by heavy metals from Samkwang mine were analysed by statistical analyses. The highly contaminated soils was initially separated by the flotation process. The selectivity indices were increased with increasing flotation reagents. The selectivity of separation was then improved by the use of both leaching and ion exchange processes in order to extract the heavy metals. The results of this study showed that the higher the sulfuric acid concentration, the leaching rate of heavy metals was increased. The lecheate then was removed by the ion exchange method. The anticipating results might imply that convergence process utilized both leaching and ion exchange techniques would somehow apply for the removal of heavy metals in the abandoned mine.