• Title/Summary/Keyword: Ni 함량

Search Result 575, Processing Time 0.028 seconds

Absorption of Heavy Metals of Waste Leachate Using by Fast Growing Trees(II) (속성수를 이용한 쓰레기 매립지 침출수의 오염물질 흡수제거(II))

  • 우수영
    • Korean Journal of Agricultural and Forest Meteorology
    • /
    • v.5 no.1
    • /
    • pp.36-42
    • /
    • 2003
  • To identify the rapacity of waste leachate absorption in Populus euramericana and Betula platyphylla var, japonica, four different treatments were applied to seedlings: leachate solution (100% leachate), 50% dilution (50% leachate: 50% water, v/v) and 25% dilution, (25% leachate: 75% water, v/v) were applied to these two species. After the experiment, concentrations of heavy metals in tree parts were analyzed by an Inductively Coupled Plasma emission spectrometer (ICP). treatment with waste leachate significantly stimulated both Populus euramericana and Betula platyphylla var. japonica biomass production relative to the water control. In addition, these species showed good absorption capacity of As, Co, Hg and Ni elements. The results of this study suggested that these two species can absorb the toxic materials through their roots and transport them to stems or leaves.

Determination of Arsenic in Human Scalp Hair by Hydride Generation-Inductively Coupled Plasma Spectrometry (수소화물 생성-유도 결합 플라즈마 분광법에 의한 머리카락 중 비소의 분석)

  • Park, Hyung-Shin;Kim, Sun-Tae;Jin, Hyoun-Chul;Ryoo, Si-Saeng;Choi, Beom-Suk
    • Analytical Science and Technology
    • /
    • v.5 no.1
    • /
    • pp.51-56
    • /
    • 1992
  • A method to determine the trace level of arsenic in scalp hair by the hydride generation(HG)-inductively coupled plasma(ICP) spectrometry is described. The optimum conditions for the generation of arsine($AsH_3$), and the interference effects from the concomitant ions were studied. Severe interference effect from Ni(II) is circumvented by the coprecipitation of arsenic with $La(OH)_3$. The detection limit of arsenic is 0.3ppm and the arsenic contents in scalp hair ranged 10~20ppb.

  • PDF

Effects of Retained Austenite on Mechanical Properties of 2.3%C-26%Cr-1%Ni-0.5%Mo White Cast Iron

  • Yu, Sung-Kon
    • Journal of Korea Foundry Society
    • /
    • v.18 no.6
    • /
    • pp.586-592
    • /
    • 1998
  • 2.3%C-26%Cr-1%Ni-0.5%Mo 조성의 아공정 백주철을 여러형태로 열처리를 한 후 잔류오스테나이트함량(Vr), 거시 및 미소경도 그리고 내마찰마모성사이의 상호관계를 연구하였다. 주방상태에서의 Vr가 70.2%인 반면 열처리시편들의 경우 0.3-65.4%의 분포를 나타내었다. 초기마모구간 이외에는 마찰마모량과 마모시간과의 사이에 직선적 관계가 얻어졌으며 그 직선의 기울기(Rw)를 내마모성의 비교시 지표로 사용하였다. Rw는 주방상태에서 $2.77{\times}10^{-2}\;mg/s$로 가장 낮았으며 l173k에서 18ks동안 균질화 열처리만 한 시편의 경우 $4.12{\times}10^{-2}\;mg/s$로 내마모성이 가장 열악하였다. 주방상태에서 내마모성이 가장 좋은 이유는 마찰마모시 오스테나이트가 가공경화를 일으켜 마르텐사이트로 변태되었기 때문으로 여겨진다. 미소경도는 HV 358-HV 756, 거시경도는 이 보다 높은 HV 529-HV 785의 분포를 나타내었는데 이는 거시경도의 측정시 공정탄화물인 $M_7C_3$가 포함되었기 때문이다. 가장 높은 미소 및 거시경도는 1323k에서 7.2ks동안 오스테나이화열처리한 시편에서 얻어졌으며 주방상태의 시편이 가장 낮은 경도치를 나타내었다.

  • PDF

Distribution of Heavy Metal Contents in Sediment of the Lower Kumho River (금호강하류의 저니중 중금속 함량분포)

  • 권오억
    • Journal of Environmental Health Sciences
    • /
    • v.20 no.4
    • /
    • pp.45-52
    • /
    • 1994
  • This study was performed to investigate the contents of six heavy metals (Cd, Cr, Cu, Ni, Pb and Zn) with respect to the particle sizes and depths in sediment collected at nine sites of the lower Kumho river. The mean Cd, Cr, Cu, Ni, Pb and Zn contents in sediment of all sites ranged from 1.59~5.32 mg/kg, 17.4~301.7 mg/kg, 23.2~399.9 mg/kg, 9.48~116.8 mg/kg, 31.1~294.1 mg/kg and 74.2~964.3 mg/kg, respectively. The highest heavy metal contents was generally found to be Zn and lowest was Cd. The mean contents of heavy metal by particle sizes (1.0~0.5, 0.5~ 0.25, <0.25 mm)was the highest in particle sizes less than 0.25 mm, but the coefficients of variation was lowest in particle sizes less than 0.25 mm. Mean contents and coefficient of variation by depths (0~5 cm, 5~10 cm, 10~15 cm) were generally found to be higher in the upper parts of sediment than in the lower parts of sediment. Organic substances were found to be higher as the particle sizes become more small. Moreover, contents of heavy metal increased with the amounts of organic substances in sediment.

  • PDF

Effects of Cr Content and Volume Fraction of δ-Ferrite on Thermal Cycling Fatigue Properties of Overlay Welded Heat-Resistant 12%Cr Stainless Steels (내열용 오버레이 12%Cr계 스테인레스강의 열피로 특성에 미치는 Cr 함량과 델타-페라이트의 영향)

  • Jung, J.Y.
    • Transactions of Materials Processing
    • /
    • v.26 no.6
    • /
    • pp.356-364
    • /
    • 2017
  • In this study, submerged arc cladded Fe-Cr-Ni-Mo-CuWNbV-C stainless steels containing various Cr contents between 11.2 wt.% and 16.7 wt.% were prepared with fixed C content at about 0.14 wt.%. Using these alloys, changes in microstructure, tensile property, and thermal fatigue property were investigated. Phase fraction of delta-ferrite was increased gradually with increasing Cr content. However, tensile strength, hardness, and thermal fatigue resistance appeared to be decreased. When the microstructure of delta-ferrite was observed, it was revealed that the mesh structure retained up to about 15% Cr content. Although thermal fatigue resistance was almost the same for Cr contents between 11.0 and 14.5 wt.%, it was significantly decreased at higher Cr contents. This was evident from mean value of crack lengths of 10 largest ones. Evaluation of thermal fatigue resistance on alloys with various Cr contents revealed the following important results. First, the reproducibility of ranking test was excellent regardless of the number of cycles. Second, thermal fatigue resistance was increased in proportion to true tensile fracture strength values of overlay materials. Finally, the number of thermal fatigue cracks per unit length was increased with increasing true tensile fracture strength.

Geochemistry of Heavy Metals and Rare Earth Elements in Core Sediments from the Korea Deep-Sea Environmental Study (KODES)-96 Area, Northeast Equatorial Pacific (한국심해환경연구(KODES) 지역 주상 퇴적물중 금속 및 희토류원소의 지구화학적 특성)

  • Jung, Hoi-Soo;Park, Sung-Hyun;Kim, Dong-Seon;Choi, Man-Sik;Lee, Kyeong-Young
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
    • /
    • v.2 no.2
    • /
    • pp.125-137
    • /
    • 1997
  • To study the vertical variation of heavy metal and Rare Earth Element (REE) contents in deep-sea sediments, eighteen cores were sampled from the Korea Deep-sea Environmental Study (KODES)-96 area in the C-C zone (Clarion-Clipperton fracture zone), northeast equatorial Pacific. Sediment columns can be divided into three units based on sediment colors and geochemical characters; uppermost Unit I with brown color, middle Unit II with pale brown color and smaller Ni/Cu ratio than the ratio in Unit I, and lowermost Unit III with dark (brown) colors and higher contents of Mn, Ni, Cu, and REEs than those in Unit I and II. Unit II can be divided more into two layers of upper Unit IIa and lower Unit IIb. Unit IIb is characterized by high contents of Cu, 3+REEs (REEs except Ce), smectite, and severely deteriorated fossil tests. Unit III can also be divided into two units; upper Unit IIIa with dark brown color, and lower Unit IIIb with black color and enriched Mn and Fe. The KODES area was located near from the East Pacific Rise (EPR) When Unit III Sediments were deposited, considering the hiatus between Unit II and III (Quaternary-Tertiary boundary) and the spreading rate (10 cm/yr) and direction (north southern west) of the Pacific plate from the EPR. High contents of Mn and Fe in Unit IIIb may be related with hydrothermal influence from the EPR. Meanwhile, Unit IIb (about 2~3 Ma) and Unit III (11~30 Ma) layers were probably formed near (or under) the equatorial high productivity zone, and accordingly received a lot of organic materials. As a result, Cu and 3+REEs, closely associated with organic materials, are enriched in smectite and/or Ca-P composites (fish bone debrise, biogenic apatite) after decomposition and reprecipitation on the sea floor. Higher contents of Cu and 3+REEs in Unit IIb and III are suggested to be the result of abundant supply of organic substances in the equatorial high productivity zone.

  • PDF

The Absorption and Purification of Air Pollutants and Heavy Metals by Selected Trees in Kwangju (광주지역(光州地域)에서 주요(主要) 수목(樹木)의 대기오염물질(大氣汚染物質)과 중금속(重金屬) 흡수(吸收) 정화기능(淨化機能)에 관(關)한 연구(硏究))

  • Cho, Hi Doo
    • Journal of Korean Society of Forest Science
    • /
    • v.88 no.4
    • /
    • pp.510-522
    • /
    • 1999
  • The air pollutants ; $SO_2$, $SO{_4}^{-2}$, $NO{_3}^-$, $Cl^-$ are absorbed into soils through falling with dusts and rain from the atmosphere. The sources of heavy metal contaminants in the environments are agricultural and horticultural materials, sewage sludges, fossil fuel combustion, metallurgical industries, electronics and waste disposal etc.. The soils and hydrosphere can be polluted on the way of the circulation of these heavy metals. Studied pollutant anions are $SO{_4}^{-2}$, $NO{_3}^-$ and $Cl^-$ and heavy metals are Se, Mo, Zn, Cd, Pb, Mn, Cr, Co, V, As, Cu and Ni which are the elements to be concerned with the essentials for plants, with animal and human health. This study is with the aim of selecting the species of roadside trees and green space trees which have excellent absorption of air pollutants and heavy metals from the atmosphere and the soils in the urban area. Two areas are designated to carry out this study : urban area ; Kwangju city and rural area ; the yard of Forest Environment Institute of Chollanam-do, at Sanje-ri, Sampo-myum, Naju city, Chollanam-do (23km away from Kwangju). This study is carried out to understand the movement of anions and heavy metals from the soils to the trees in both areas, the absorption of anions and heavy metals from atmosphere into leaves and the amounts of anions and heavy metals in leaves and fine roots(< 1mm dia.) of roadside trees and green space trees in Kwangju and trees in the yard of Forest Environment Institute of Chollanam-do. The tree species selected for this study in both areas are Ginkgo biloba, Quercus acutissima, Cedrus deodara, Platanus occidentalis, Robinia pseudoacacia, Alnus japonica. Metasequoia glyptostroboides. Zekova serrata. Prunus serrulata var. spontanea, and Pinus densiflora. The results of the study are as follows : 1. $SO{_4}^{-2}$, $NO{_3}^-$ and $Cl^-$ concentrations are higher in the soils of the urban area than in those of the rural area, and $NO{_3}^-$ and $SO{_4}^{-2}$ are higher in the leaves than in the roots due to the absorption of the these pollutants through the stomata. 2. Ginkgo biloba, Robinia pseudoacacia. Zekova serrata, Quercus acutissima, and Platanus occidentalis can be adequated to the roadside trees and the environmental trees due to their good absorption of $NO{_3}^-$ and $SO{_4}^{-2}$. 3. Heavy metals in the soils of both areas are in the order of Mn > Zn > V > Cr > Pb > Ni > Cu > Mo> Cd, and in the leaves and roots of the trees in the both areas are in the order of Mn>Zn>Cr>Cu>V>Ni. Both orders are similar ones except V. There are more in the urban soils than in the rural soils in amount of Mn, Zn, Pb, V, Cu. 4. It is supposed that there is no antagonism between Mn and Zn in this study. 5. Se, Co and As are not detected in the soils, the leaves and the roots in both areas. Sn, Mo, Cd and Pb are also not detected in the leaves and roots in spite of considerable amount in the soils of both areas.

  • PDF

Mechanical Properties of Monodisperse Polymer Particles and Electroless Ni Plated Monodisperse Polymer Particles (단분산 가교고분자 미립자 및 그의 무전해 니켈도금체의 기계적 물성 연구)

  • Kim Dong-Ok;Jin Jeong-Hee;Shon Won-IL;Oh Seok-Heon
    • Polymer(Korea)
    • /
    • v.30 no.4
    • /
    • pp.332-337
    • /
    • 2006
  • Monodisperse polymer particles were prepared via one-step seeded polymerization using PMMA seed particles and HDDA (or EGDMA) as crosslinking monomer. For the study, the effects of 1) the ratio of the absorbed monomer or monomer mixture to the seed polymer particles (swelling ratio), 2) the ratio of EGDMA in absorbed monomer mixture, 3) the dosage of initiator, and 4) electro less Ni plating on the variation of mechanical properties of monodisperse polymer particles, such as recovery rate, K-values, breaking strength and breaking displacement, were investigated by using MCT (micro compression test). It was observed that monomer swelling ratio influenced only breaking strength, but EGDMA ratio in monomer mixture, dosage of initiator and electroless Ni plating affected both K-values and breaking strength.

Effect of Cr/Ni equivalent ratio on ductility-dip cracking in AISI 316L austenitic stainless steel weld metals ($Cr_{eq}/Ni_{eq}$ 당량비에 따른 AISI 316L 스테인리스강의 연성저하균열 특성에 대한 연구)

  • Jang, A.Y.;Lee, D.J.;Kim, Y.H.;Choi, C.H.;Lee, S.H.;Byun, J.C.;Jung, G.H.;Lee, H.W.
    • Proceedings of the KWS Conference
    • /
    • 2009.11a
    • /
    • pp.56-56
    • /
    • 2009
  • AISI 316L 스테인리스강에 새롭게 디자인한 서로 다른 3가지 응고모드를 가진 와이어로 FCAW(Flux Cored Arc Welding)을 하였다. 각각의 3가지 와이어는 Pseudobinary phase diagram에 따라 AF, FA, F모드를 가졌다. 미세조직은 $Cr_{eq}/Ni_{eq}$이 증가할수록 델타 페라이트 함량이 증가하였으며, 초정 상의 경우 초정 오스테나이트에서 초정 페라이트로 변태하였고, 연성저하균열의 민감도가 감소하였다. 연성저하균열은 이동결정립계의 형상에 따라 좌우되며, 미량의 페라이트를 함유한 오스테나이트에서는 페라이트가 핀(Pin) 역할을 제대로 하지 못하여 직선형태의 이동 결정립계 따라 입계 미끄러짐의 메커니즘을 통해 전파되었으며, 곡선형태의 이동 결정립계에서는 델타 페라이트가 핀 역할을 하여 역할을 하여 구속 상태에서 응력집중을 막고 응력을 분산시켜 균열이 전파되는 것을 방해하여 균열이 발생되지 않았다.

  • PDF

Ecological Study on Aquatic Plant Communities in the Stream of Thermal Wastewater (온배수 유입하천에 형성된 수생식물군집의 생태학적 연구)

  • 길봉섭;유현경
    • Korean Journal of Environmental Biology
    • /
    • v.17 no.2
    • /
    • pp.139-146
    • /
    • 1999
  • The seasonal changes of the flora at three samples sites such as Sockchong, Wang-gung and Chukrim hot spring by drained thermal waters were investigated from 1997 to 1998. Monthly occurrence of plant species in February and October showed more abundantly control site than that of heavy and/or light polluted sites. This trend demonstrated similarly in terms of seasonal changes of leaf area and plant growths, both fresh and dry weight, too. Cu, Zn, Ni and Pb content including plants from Sockchong hot spring site were increased from April to September at test area than that of control, while that was decreased in October. But Zn and Pb content holding plants from Wang-gung hot spring site represented higher test site than that of control. In short impacts on aquatic plants communities by thermal wastewater of sampled area have happened in the season of low temperature, and their restorations have done in summer season.

  • PDF