• Title/Summary/Keyword: $PbCl_2$

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Extraction and Separation of Ruthenium(III) from Hydrochloric Acid Solution Using TBP and Cyanex923 (염산용액(鹽酸溶液)에서 TBP 및 Cyanex923을 이용(利用)한 루테늄(III)의 유출(抽出).분리(分離)에 관한 연구(硏究))

  • Ahn, Jae-Woo;Lee, Ki-Woong
    • Resources Recycling
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    • v.20 no.2
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    • pp.60-66
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    • 2011
  • Solvent extraction experiments were carried out to recover and separate Ru(III) from aqueous hydrochloric acid media using TBP and Cyanex923. The efficiency of the extraction was studied under various experimental conditions, such as concentration of HCl and NaCl, concentration of extractant in the organic phase and temperature. The extraction behavior of metal impurities, such as Pt, Bi, Sn, Fe, Pb and Cu in mixed solutions was examined. From the experimental studies, it was found that the Cyanex923 resulted in higher extraction percentage of Ru than TBP. However TBP was more effective for the separation of Ru and Pt, Bi, Sn in mixed solutions than Cyanex923.

A Study on the Chemical characteristics of Anion Components and Metallic Elements of PM10 in Miryang and Changwon (밀양·창원지역의 PM10 중 음이온 성분 및 금속성분의 화학적 특성에 관한 연구)

  • Suh Jeong-Min;Jeon Bo-Kyung;Choi Kum-Chan
    • Journal of Environmental Science International
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    • v.13 no.12
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    • pp.1049-1058
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    • 2004
  • PM10 concentration of total 48 samples collected from 4 sites (the root of Miryang University, Sangnam township Office in Miryang. the root of Changwon elementary school, and Junam reservoir in Changwon) turned out to range from 42.29 to 69.49{\mu}g/m^{3}$, and the average concentration was the root of Changwon elementary school $(69.49{\mu}g/m^{3})$>the root of Miryang university $(58.59{\mu}g/m^{3})$>Junam reservoir $(43.56{\mu}g/m^{3})$>Sangnam township Office $(42.29{\mu}g/m^{3}).> In particular, Junam reservoir, the Clean Area, had a slightly higher value than Sangnam township Office. It was thought although the site was plane and windy without pollutants around. it had a higher concentration value influenced by external factors including bigger population and a northeasterly wind due to a newly-established industrial complex nearby. As for water-soluble ions among PM10 particle collected in Miryang and Changwon area, SO42- accounted for $50{/%}$ and NO3-, was $35{\%}$, and the concentration order was S042->N03->Cl->F-. As for the average concentration of metallic components among PM10 particle collected in Miryang and Changwon area. the root of Changwon elementary school had the AI concentration, Fe concentration and Zn concentration 4 times, 3 times and 1.5 times that of Junam reservoir, respectively. The root of Miryang University had the AI concentration 2 times that of Sangnam township Office, and had Fe concentration and Zn concentration $1.2\~1.5$ times those of Sangnam township Office. When it comes to the relation between metallic elements and meteorological factors in Changwon area, the highest coefficient of correlation was between temperature and humidity with 0.92, and temperature and wind speed turned out in the reverse correlation. The coefficient of correlation between Al and Cr was as high as 0.78. Among metallic elements, the coefficient of correlation between Cu and Pb, Cd, Al were 0.84, 0.85, 0.79, respectively. It is thought that the high coefficient of correlation between Cu and Pb is ascribed to busy traffic and wind in the urban areas, Sammun-dong and Gagok-dong in Miryang. Meanwhile, the coefficients of correlation between Fe and Cu, Al, Zn, Cd, Pb were in the reverse correlation. These coefficients of correlation are attributed to the difference in pollutant sources, rather than difference in pollutant and non-pollutant.

Composition and pollution characteristics of PM10 and PM2.5 particles at Gosan site of Jeju Island in 2008 (PM10, PM2.5 미세먼지의 조성 및 오염 특성: 2008년 제주도 고산지역 측정 결과)

  • Lee, Soon-Bong;Jung, Duk-Sang;Cho, Eun-Kyung;Kim, Hyeon-A;Hwang, Eun-Yeong;Kang, Chang-Hee
    • Analytical Science and Technology
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    • v.24 no.4
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    • pp.310-318
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    • 2011
  • The collection of atmospheric $PM_{10}$ and $PM_{2.5}$ particle samples was made at Gosan site of Jeju Island, which is one of the most representative background sites in Korea. Their chemical compositions have been analyzed to explore the pollution characteristics and emission sources. The mass concentrations of $PM_{10}$ and $PM_{2.5}$ particles were $37.6{\pm}20.1$ and $22.9{\pm}14.3{\mu}g/m^3$, respectively, with the content of $PM_{2.5}$ to $PM_{10}$ as 61%. The $PM_{2.5}/PM_{10}$ ratios of nss-$SO_4^{2-}$, $NO_3^-$, and $NH_4^+$ were 0.94, 0.56, 1.02, respectively, indicating that these components were distributed mostly in the fine fractions. Based on the factor analysis, it was found that the compositions of fine particles were mainly influenced by anthropogenic sources, followed by soil or marine sources. The results of the backward trajectory analysis indicate that the concentrations of nss-$SO_4^{2-}$, $NO_3^-$, $NH_4^+$, nss-$Ca^{2+}$, and Pb were high when the air parcels moved from the China continent, while relatively low with the air parcels coming from North Pacific Ocean and/or East Sea.

The Behavior of Dissolved and Particulate Phases of Trace Elements within the Watershed of Juam Reservoir (주암호 집수유역 내 용존 및 입자상 미량원소의 거동 특성)

  • Lee, Pyeong-Koo;Chi, Se-Jung;Youm, Seung-Jun
    • Economic and Environmental Geology
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    • v.41 no.4
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    • pp.405-425
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    • 2008
  • In order to investigate the amounts of trace elements flowing into reservoir, and to elucidate the relationship between trace element mobility and fraction size, the stream water and sediment samples were collected from thirty-two sites of the 3rd or 4th order stream within watershed surrounding the Juam reservoir. Chemical analyses of trace elements (As, Cd, Cr, Cu, Ni, Pb and Zn) for all samples were completed, and additionally cationi and anion for stream water samples. Considering the distribution of rocks and contamination sources in watershed, the eight stream sediments were selected from typical sites representing study areas, and we determined the concentrations of trace elements according to size fractions ($2\;mm{\sim}200\;{\mu}m$, $200{\sim}100\;{\mu}m$, $100{\sim}50\;{\mu}m$, $50{\sim}20\;{\mu}m$ and < $20\;{\mu}m$). The correlation relationships between concentrations and size fractions of stream sediments were important to identify the hydro-geochemical behavior of trace elements that flow into Juam reservoir. Stream waters showed four water types (Ca-Mg-$HCO_3$, Ca-Na-$HCO_3$-Cl, Ca-Na-$HCO_3-SO_4$, Ca-Na-$HCO_3$) depending on pollution sources such as coal mine, metal mine, farm-land and dwellings. Concentrations of trace elements increased clearly with the decrease in size fractions of stream sediments. Concentrations of Cu, Pb and Zn increased dramatically in silt size (< $20\;{\mu}m$) fraction, while As had high concentrations in sand size ($2\;mm{\sim}100\;{\mu}m$) fraction in downstream sediments of metal mines. These indicate that Cu, Zn, and Pb moved into Juam reservoir easily in the adsorbed form on silt size grain in sediments, and As was transported as As-bearing mineral facies, resulting in its less chance to reach into Juam reservoir.

Hydrochemical Characteristics and Changes by Rainfall in the Jungrang River (강우에 의한 중랑천의 수질 특성 변화 연구)

  • Kim, Youn-Tae;Kim, Yu Lee;Woo, Nam-Chil;Hyun, Seung Gyu
    • Journal of Korean Society on Water Environment
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    • v.22 no.4
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    • pp.666-671
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    • 2006
  • Effects of a rainfall event (July 28, 2005) on the hydrochemical characteristics of the Jungrang river, the biggest tributary of the Han river, was investigated. Significant spatial variations in the hydrochemical characteristics were observed. At JR2 location, concentrations of T-N and T-P were relatively low indicating occurrence of active oxidation in the stepped drop structure. At JR3 location, concentrations of Na, K, Cl, $NH_4-N$ and EC were elevated suggesting increased discharge from the nearby waste-water treatment plant and tributaries. The rain event diluted major dissolved ion concentrations in the river by 12~52%. The $NO_3-N$ levels were preserved during the rain then increased about twofold after rainfall, suggesting increased discharge of nitrate-contaminated groundwater. Heavy metals including Cd, Co, Cr, Cu and Pb were not detected in all water samples and the leachates from surface sediment samples. Concentrations of Fe, Mn, Al and Zn were below the Korean Drinking Water Guideline. Results of this study suggested that establishment of water-quality monitoring protocols describing temporal and spatial variations in parameters sensitive to rainfall events, relatively steady factors, and contaminant sources is required.

Chitosan-Cu-salen/Carbon Nano-Composite Based Electrode for the Enzyme-less Electrochemical Sensing of Hydrogen Peroxide

  • Jirimali, Harishchandra Digambar;Saravanakumar, Duraisamy;Shin, Woonsup
    • Journal of Electrochemical Science and Technology
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    • v.9 no.3
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    • pp.169-175
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    • 2018
  • Cu-Salen complex was prepared and attached into chitosan (Cs) polymer backbone. Nanocomposite of the synthesized polymer was prepared with functionalized carbon nano-particles (Cs-Cu-sal/C) to modify the electrode surface. The surface morphology of (Cs-Cu-sal/C) nanocomposite film showed a homogeneous distribution of carbon nanoparticles within the polymeric matrix. The cyclic voltammogram of the modified electrode exhibited a redox behavior at -0.1 V vs. Ag/AgCl (3 M KCl) in 0.1 M PB (pH 7) and showed an excellent hydrogen peroxide reduction activity. The Cs-Cu-sal/C electrode displays a linear response from $5{\times}10^{-6}$ to $5{\times}10^{-4}M$, with a correlation coefficient of 0.993 and detection limit of $0.9{\mu}M$ (at S/N = 3). The sensitivity of the electrode was found to be $0.356{\mu}A\;{\mu}M^{-1}\;cm^{-2}$.

Total Phenolic Contents, Radical Scavenging Capacities and Inhibitory Effects on Lipid Peroxidation and LDL Oxidation of Prunus persica Branch

  • Yi, Hyo-Seung;Park, Won-Hwan;Lim, Sun-Hee;Moon, Jin-Young
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.22 no.5
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    • pp.1309-1314
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    • 2008
  • This study was undertaken to elucidate the antioxidant activity of the ethanol (EEPB) and water (WEPB) extracts of Prunus persica branches. The extracts contained a high phenolic content and revealed a potent hydrogen donating activity in DPPH scavenging assay. Compared to $\alpha$-tocopherol, EEPB (p < 0.001) and WEPB (p < 0.05) significantly inhibited $FeCl_2$-ascorbic acid-induced lipid peroxidation, and also exhibited potent antiradical activities against hydroxyl radical, superoxide anion, nitric oxide and peroxynitrite. In copper- and AAPH-mediated human low-density lipoprotein (LDL) oxidation systems, the extracts demonstrated a strong antioxidant function by metal chelating, rather than direct scavenging, action. Furthermore, EEPB at 5 ${\mu}g/mL$ concentration showed 80.77% inhibition of the electrophoretic mobility of LDL, compared to 77.69% for ascorbic acid and 76.92% for BHT. These results suggest that PB branch extracts may protect against oxidative stress-induced diseases.

Synthesis and Characterization of Bandgap-modulated Organic Lead Halide Single Crystals

  • Park, Dae Young;Byun, Hye Ryung;Lee, A Young;Choi, Ho Min;Lim, Seong Chu;Jeong, Mun Seok
    • Journal of the Korean Physical Society
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    • v.73 no.11
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    • pp.1716-1724
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    • 2018
  • Single crystal of organic lead halide ($CH_3NH_3PbX_3$; $CH_3NH^+_3$ = methylammonium (MA), $X=Cl^-$, $Br^-$, $I^-$) is the best candidate for material intrinsic property studies due to no grain boundary and high crystal quality than the film having a lot of grain boundary and surface defects. The representative crystallization methods are inverse temperature crystallization (ITC) and anti-solvent vapor assisted crystallization (AVC). Herein, we report bandgap modulated organic lead halide single crystals having a bandgap ranging from ~ 2.1 eV to ~ 3 eV with ITC and AVC methods. The bandgap modulation was achieved by controlling the solvents and chloride-to-bromide ratio. Structural, optical and compositional properties of prepared crystals were characterized. The results show that the crystals synthesized by the two crystallization methods have similar properties, but the halide ratios in the crystals synthesized by the AVC method are controlled more quantitatively than the crystals synthesized by ITC.

Size Distributions of Trace Elements in Airborn Particulates Collected using Drum impactor at Gosan, Jeju Island : Measurements in Springtime 2002 (DRUM impactor를 이용한 대기 입자상 물질 중 원소성분의 입경분포 특성 : 제주도 고산지역의 2002년 봄철 (3.29-5.30) 측정 연구)

  • 한진석;문광주;류성윤;안준영;공부주;홍유덕;김영준
    • Journal of Korean Society for Atmospheric Environment
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    • v.20 no.4
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    • pp.555-569
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    • 2004
  • Size -segregated measurements of aerosol composition using 8-stage DRUM impactor are used to determine the transport of natural and anthropogenic aerosols at Gosan site from 29 March to 30 May in 2002. Separation of ambient aerosols by DRUM impactor offers many Advantages over other standard filtration techniques. Some of the most important advantages are the ability to segregate into details by particle tire, to better preserve chemical integrity since the air stream doesn't pars through the deposit, to collect samples as a function of time, and to have a wide variety of impaction surfaces available to match analytical needs. Although the transport of Yellow sand is a well-known phenomenon in springtime, the result of measurement shows that not only soil dust but also anthropogenic aerosols, including sulfur, enriched trace metals such as Pb, Ni, Zn. Cu, Cr, As, Se, Br, are transported to Gosan in springtime. This study combines the size- and time-resolved aerosol composition measurements with isentropic, backward air-mass trajectories in order to identify some potential source regions of anthropogenic aerosols. As a result, during the NYS period, the average concentration of PM$_{10}$ was 46$\mu\textrm{g}$/㎥, Si, Al. S, Fe, Cl, K, Ca were higher than 1,000 ng/㎥ and Ti was about 100 ng/㎥. The concentrations of Zn, Mn, Cu. Pb, Br, Rb, V, Cr, Ni. At, Se ranged between 1 and 70 ng/㎥. More than 50% typical soil elements, tuck as Al, Si, Fe, Cd. Ti, Cr, Cu, Br. were distributed in a coarse particle range(5.0-12${\mu}{\textrm}{m}$). In other hand, anthropogenic pollutants, luck as S, N, Vi, were mainly distributed in a fine particle range (0.09-0.56${\mu}{\textrm}{m}$). During the YS period, PM$_{10}$ increased about 8 times than NYS period, and main soil elements, such as Al, Si, S, K, V, Mn, Fe also doubled in coarse particle range (1.15-12${\mu}{\textrm}{m}$). But Zn, As, Pb, Cu and Se, which distributed in the time aerosols (0.09-0.56${\mu}{\textrm}{m}$), were on the same level with or decreased than NYS period. Finally. except the YS Period, coarse particles (2.5-12${\mu}{\textrm}{m}$) are inferred to be influenced by soil, coal combustion, waste incineration, ferrous and nonferrous sources through similar pathways with Yellow Sand. But fine particles have different sources, such as coal combustion, gasoline vehicle, biomass burning, oil or coal combustion, nonferrous and ferrous metal sources, which are transported from China, Korea peninsula and local sources.ces.

Study on Chemical Characterization of PM2.5 based on Long-term Database (1990 ~ 2012) and Development of Chemical Species Profiles During Haze Days and Asian Dust Days in Yongin-Suwon Area (장기간 (1990 ~ 2012) 측정자료를 이용한 용인-수원지역에서의 PM2.5의 화학적 특성연구 및 헤이즈와 황사 현상 시 화학성분별 질량분율표의 개발)

  • Lim, Hyoji;Lee, Tae-Jung;Kim, Dong-Sool
    • Journal of Korean Society for Atmospheric Environment
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    • v.31 no.3
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    • pp.223-238
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    • 2015
  • The $PM_{2.1}$ was collected by LVCI (low volume cascade impactor) during Group-A Period (September 1990 to December 2012) and the $PM_{2.5}$ was collected by HVAS (high volume air sampler) during Group-B Period (September 2009 to April 2012) at Kyung Hee University, Global Campus located on the boarder of Yongin and Suwon. The 8 water-soluble ions ($Na^+$, $NH_4{^+}$, $K^+$, $Mg^{2+}$, $Ca^{2+}$, $Cl^-$, $ NO_3{^-}$, and $SO_4{^{2-}}$) were analyzed by IC, and the 14 inorganic elements (Al, Mn, Si, Fe, Cu, Pb, Cr, Ni, V, Cd, Ba, Zn, Ti, Ag) were analyzed by XRF and ICP-AES after performing proper pre-treatments of each sample filter. The average total mass fractions of $SO_4{^{2-}}$, $NO_3{^-}$, and $NH_4{^+}$+ to $PM_{2.5}$ samples during Group-B Period were 0.39 in normal days, 0.44 in haze days, and 0.27 in Asian dust days, respectively; however, the average total mass fractions of Al, Fe, and Si to $PM_{2.5}$ mass were 0.043 in normal days, 0.021 in haze days, and 0.036 in Asian dust days, respectively. Especially the concentration of Pb was significantly decreased during Group-B Period rather than during Group-A Period, while Cr and Ni was increased during Group-B Period. In this study, we intensively compared the annual and seasonal patterns of major chemical species among normal days, haze days, and Asian dust days. Further we developed mass fraction profiles by collecting episode cases of haze days and Asian dust days, which were consisting of 22 chemical species. Those profiles are considered to be useful when applying various receptor models and establishing air quality management plans near future.