• 대한환경공학회지
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• 제27권3호
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• pp.293-301
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• 2005

재생골재를 교각안정용 쇄석으로 재활용하기 위하여 다양한 용출방법을 이용하여 미량원소를 포함한 무기이온들의 용출특성을 연구하였다. 본 연구에 적용한 방법은 연속 회분식 용출시험(Continuous batch leaching test: DIN 38414-S4), 가용용출시험(Availability test, NEN 7341), pH 유지 시험(pH-stat test: CEN/TC 292/WG6) 그리고 탱크 확산시험(Tank diffusion test: NEN 7345)등 이다. 기존에 많이 적용되온 EPA의 TCLP와 국내 공정시험법의 경우 빠르고 경제적인 방법으로 고형폐기물의 단기간 용출특성을 파악할 수 있으나 다양한 용출환경에서 장기간 일어나는 용출특성을 판단하기 어려운 점이 있었다. 본 시험에 적용된 방법들은 이러한 제한을 극복하고 보다 다양한 환경에서 일어날 수 있는 용출특성을 평가하고자 하였다. 본 연구에 적용된 시험들은 별도의 위해성 판단 기준이 없다. 그러나 본 시험의 결과들을 위해성 판단을 위해 많이 쓰이는 TCLP와 국내폐기물 공정시험방법의 기준에 비교할 때 접촉시간, pH 조건 등의 용출조건이 더 가혹한 조건에서 이루어졌음에도 두 시험의 위해성 기준에 훨씬 못 미치고 있다. 이는 재생골재를 교각안정용 쇄석으로 활용할 경우 환경위해 정도가 우려할 수준 이하일 것임을 시사한다. 특히 교각안정용 쇄석이 사용될 하천은 물이 정지되지 않고 늘 흐르는 곳으로써 용출된 원소들은 그 자리에 축적되지 않고 분산, 희석되어 그 영향정도는 더 낮아질 것으로 생각된다.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2002년도 Proceedings of the International Welding/Joining Conference-Korea
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• pp.450-455
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• 2002

Cu-cored Sn-Ag solder balls were fabricated by coating pure Sn and Ag on Cu balls. The melting behavior and the solderability of the BGA joint with the Ni/Au coated Cu pad were investigated and were compared with those of the commercial Sn-Ag and Sn-Ag-Cu balls. DSC analyses clarified the melting of Cu-cored solders to start at a rather low temperature, the eutectic temperature of Sn-Ag-Cu. It was ascribed to the diffusion of Cu and Ag into Sn plating during the heating process. After reflow soldering the microstructures of the solder and of the interfacial layer between the solder and the Cu pad were analyzed with SEM and EPMA. By EDX analysis, formation of a eutectic microstructure composing of $\beta$-Sn, Ag$_3$Sn, ad Cu$_{6}$Sn$_{5}$ phases was confirmed in the solder, and the η'-(Au, Co, Cu, Ni)$_{6}$Sn$_{5}$ reaction layer was found to form at the interface between the solder and the Cu pad. By conducting shear tests, it was found that the BGA joint using Cu-cored solder ball could prevent the degradation of joint strength during aging at 423K because of the slower growth me of η'-(Au, Co, Cu, Ni)$_{6}$Sn$_{5}$ reaction layer formed at the solder, pad interface. Furthermore, Cu-cored multi-component Sn-Ag-Bi balls were fabricated by sequentially coating the binary Sn-Ag and Sn-Bi solders on Cu balls. The reflow property of these solder balls was investigated. Melting of these solder balls was clarified to start at the almost same temperature as that of Sn-2Ag-0.75Cu-3Bi solder. A microstructure composing of (Sn), Ag$_3$Sn, Bi and Cu$_{6}$Sn$_{5}$ phases was found to form in the solder ball, and a reaction layer containing primarily η'-(Au, Co, Cu, Ni)$_{6}$Sn$_{5}$ was found at the interface with Ni/Au coated Cu pad after reflow soldering. By conducting shear test, it was found that the BGA joints using this Cu-core solder balls hardly degraded their joint shear strength during aging at 423K due to the slower growth rate of the η'-(Au, Cu, Ni)$_{6}$Sn$_{5}$ reaction layer at the solder/pad interface.he solder/pad interface.

• 한국토양비료학회지
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• 제29권3호
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• pp.275-281
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• 1996

정수장슬러지를 건물중 기준으로 10a당 0, 1, 3, 5톤의 비율로 토양에 시용한 후. 대두 및 당근에 대한 몇가지 화학성분의 흡수와 수량을 조사한 결과는 다음과 같다. 1. 정수장슬러지의 화학적 특성상 pH, OM 및 CEC면에서 미미하나마 농업적인 이익을 기대할 수 있을 것으로 판단된다. 2. 슬러지 시용은 토양중 유기물과 CEC 수준을 다소 증가시켰다. 3. 10a당 1톤과 같은 낮은 수준의 슬러지 시용량은 대조구에 비해 대두의 수량을 증가시킨 반면, 계속적인 시용량의 증가는 역으로 대두의 수량을 감소시켰다. 그러나 당근의 지하부는 슬러지의 시용량이 증가할수록 높은 수량효과가 인정되었다. 4. 대두 및 당근의 두 작물에서 공히 슬러지 시용량의 증가로 인산의 흡수억제가 관찰된 반면에 슬러지의 시용이 작물에 대한 Al의 흡수를 증가시키지는 않았다. 5. 정수장슬러지의 시용으로 대두 종실의 충실도는 향상된 반면 영양학적으로 중요한 질소 또는 인산과 같은 몇가지 무기성분의 함유량이 낮았고, 당근에 대한 슬러지 시용에서는 유효성분인 ${\beta}$-carotene의 함량을 증진 시켰으나, 외관적인 품질을 떨어뜨리는 결과를 가져왔다. 이로써 정수슬러지는 대두 및 당근의 품질에 이익과 유해한 효과를 동시에 가져다 주는 것으로 보인다.

• 한국토양비료학회지
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• 제49권4호
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• pp.293-299
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• 2016

The chemical properties of paddy fields in Gangwon province were monitored every 4 years from 2003 to 2015 in order to provide basic information for soil fertility management of paddy fields. In 2015, the soil chemical properties of paddy fields were 5.9 in pH, $22g\;kg^{-1}$ in organic matter (OM), and $123mg\;kg^{-1}$ in available (Avail.) phosphate $P_2O_5$. Exchangeable (Exch.) potassium (K), calcium (Ca) and magnesium (Mg) were 0.39, 4.8 and $0.9cmolc\;kg^{-1}$, respectively, and Avail. $SiO_2$ was $170mg\;kg^{-1}$. In the long-term analysis, the contents of Avail. $SiO_2$, Exch. K and pH of paddy soils showed increasing tendency. However, Avail. $P_2O_5$, Exch. Ca and Mg tended to decrease, and there were no significant changes in the contents of OM. Soil OM, Avail. $P_2O_5$ and $SiO_2$ were not different among the different topographical sampling sites. However, the mean value of Exch. K and Ca were different among the different topographical sampling sites, and exceeded optimal values in the fluvio-marine plains. Different soil texture resulted in different soil pH, while no difference for OM, Avail. $P_2O_5$ and $SiO_2$. Paddy soil samples within appropriate pH range increased from 65% in 2003 to 77% in 2007, 68% in 2011, and 71% in 2015. In case of Avail. $SiO_2$, soil samples within appropriate range increased from 20% in 2003, to 37% in 2007, 29% in 2011, and 45% in 2015. Meanwhile, Cd and Pb were distributed to less than 5% of soil pollution standards. Cu, As and Zn were distributed to less than 10%, 15% and 20%, respectively. Therefore, paddy soil in Gangwon Province was judged to be safe. As a result, paddy fields with more or less in nutrient level need to be fertilized based on the soil analysis. And the application of silicate fertilizer is strongly recommended to those of paddy fields in need. In addition, soil management including the cultivation of green manure crop or application of rice straw is necessary to increase the organic matter content of paddy soil.

• 한국패류학회지
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• 제28권3호
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• pp.225-232
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• 2012

갯벌어장에 서식하는 패류의 성분원소 함량 및 연안 생태계의 퇴적물의 지화학적 특성의 연관성을 조사하기 위하여 서해연안을 연구지역으로 선정하였다. 연구지역내 갯벌어장 표층퇴적물의 COD, AVS, IL의 지화학적특성은 다소 오염된 지역이 나타나지만 대부분 양식장 오염니 기준에 비하여 매우 낮은 농도를 보이며 패류의 성장에 영향이 적은 것으로 생각된다. 그리고 중금속에 대한 농축비(Ef) 와 농집지수 (Igeo) 의 결과는 연구지역이 오염원이 적은 자연적인 상태를 유지하여 서식하는 패류에 대한 오염이 적은 것으로 평가되었다. 또한 연구지역내에 서식하는 패류의 성분원소 함량을 분석한 결과에 따르면 퇴적물과 패류의 원소함유량의 상관관계는 연관성 있는 것으로 평가되었다. 패류의 무기원소 및 중금속의 농축은 Mn, Zn에 대해서만 상관관계가 반영되는 것으로 사료된다. 한편 갯벌어장의 패류 및 저서생물들이 서식하기에 좋은 조간대 퇴적물 상태를 유지하기 위하여 어장관리를 위한 중금속 오염에 대한 기준설정이 필요하며, 오염경로와 퇴적물의 오염원을 관리할 수 있는 체계적인 정책이 요구된다.

• 한국환경생태학회지
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• 제22권3호
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• pp.241-248
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• 2008

본 연구는 대한민국 서해안 새만금 갯벌지역에서 $1999{\sim}2000$년에 도래한 섭금류 3종의 간에서 철(Fe), 아연(Zn), 구리(Cu), 납(Pb) 그리고 카드뮴(Cd) 농도를 측정하여 비교하고, 각 원소 사이의 상관관계를 분석하였다. 연구결과 철(ANOVA, p=0.018), 구리(ANOVA, p=0.043), 납(ANOVA, p<0.001) 그리고 카드뮴(ANOVA, p=0.016)은 종간에 유의한 차이가 나타났지만 아연에서는 유의한 차이가 나타나지 않았다. 본 연구에서 나타난 철, 아연 그리고 구리와 같은 필수원소는 조류의 체내 신진대사에 필요한 정상범위 내의 농도로 생각된다. 오염원소인 납 농도는 붉은어깨도요 Calidris tenuirostris $(5.76{\pm}2.14{\mu}g/dry\;g)$는 비오염수준이었지만 좀도요 Calidris ruficollis$(29.4{\pm}10.6{\mu}g/dry\;g)$와 뒷부리도요 Xenus sinereus$(15.9{\pm}11.9{\mu}g/dry\;g)$는 오염수준이었으며, 특히 좀도요는 중독수준에 근접하였다. 카드뮴 농도는 뒷부리도요$(0.82{\pm}12{\mu}g/dry\;g)$와 붉은어깨도요$(0.45{\pm}0.53{\mu}g/dry\; g)$는 비오염수준의 농도였으나, 좀도요$(17.5{\pm}22.1{\mu}g/dry\;g)$는 오염기준$(3{\mu}g/dry\;g)$을 초과하였다. 원소간의 상관관계에서는 납과 카드뮴에서만 유의한 관계가 나타났고 (r=0.067, p<0.01), 다른 원소는 상관관계가 나타나지 않았다.

• Bulletin of the Korean Chemical Society
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• 제35권11호
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• pp.3289-3293
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• 2014

Femtosecond laser ablation (fs LA) was used in this study to identify pollution by heavy metals and the distribution of elemental nutrients at different rice milling ratios. Polished rice (degrees of milling of 3, 5, 7, 9, and 11) was collected from major Korean supermarkets and one sample thereof was selected. An internal quality control experiment was conducted using a rice flour certified reference material from the Korea Research Institute of Standards and Science (KRISS CRM) for the evaluation of the efficacy. To assess the effectiveness of the analysis method, the reliability was validated using a food analysis performance assessment scheme (FAPAS), with chili powder serving as an external quality control. The results of the analysis of the inorganic elements Ti, Ca, Al, Fe and Mn in white and brown rice with degrees of milling of 3, 5, 7, 9 and 11 using ICP-MS, ICP-OES and AAS revealed contents of 0.40, 49.2, 2.43, 5.36 and 10.3 mg/kg in white rice and 0.59, 78.0, 7.52, 11.0 and 18.5 mg/kg in brown rice, respectively. Among the elements, there were remarkable differences in the measured contents. By comparing the contents of the elements at different degrees of milling, Ti, Co, As, Ca, Al, Cu, Fe, and Mn were determined to be distributed on the surface of the rice grains, whereas the contents of Cd and Pb increased toward the center of the rice grains, and Si was evenly distributed. After the quantitative analysis of rice samples polished to different degrees of milling, Ca and Al, which were contained in large amounts, and Si were analyzed with specificity by fs LA. The results show that Ca and Al were distributed in the rice husk (protective covering of rice) and Si was distributed in all parts of the rice.

• 한국환경보건학회지
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• 제21권1호
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• pp.56-67
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• 1995

This study was carried out to observe how composting reaction proceed in the optimum composting condition and to understand the characteristics of final compost, when swine feces was amended with different bulking material. Sawdust, rice straw, and rice hull were selected as bulking materials and each of these was mixed with swine feces to obtain the optimum range of moisture contents and C:N ratio. To grasp the influence of newspaper on cornposting reaction when it flew into the composting site intentionally or accidentally, another composting reaction using newspaper as a bulking material was studied. In this experiment, raw material mixes containing the same amount of organic materials were put into 4 composting reactors and composted in the same environmental condition for 3 weeks from Aug. 1, 1994 to Aug. 22, 1994. The followings are the main results of this study. 1. The maximum temperatures reached at during cornposting reaction were 53.8$\circ$C, 51.9$\circ$C, 52.7$\circ$C, and 52.1$\circ$C in the reactor using sawdust, rice straw, rice hull, and newspaper as a bulking material respectively: Thermophilic temperatures were maintained for 72, 108, 108, and 111 hours in each reactor. Mean temperatures of reactors using sawdust, rice straw, rice hull, or newspaper as a bulking materials were 39.7$\circ$C, 39.5$\circ$C, 41.3$\circ$C, and 40.3$\circ$C, but no significant difference between these mean temperatures was observed(p>0.05). Each composter showed significant difference from room temperature(p<0.01), and the mean difference between them was 9.4$\circ$C. 2. Ash contents of each reactor increased rapidly in order of rice straw, rice hull, newspaper, and sawdust according to the pattern of second order function. This rate of increase seemed to result from structural characteristics of a bulking material. The absolute values of second order coefficient of these regression functions were 0.0199, 0.0159, 0.0157, and 0.0144 in each reactor using rice straw, rice hull, newspaper, or sawdust as a bulking material. 3. C:N ratio decreased as the reaction proceeded. Degree of decrease was in order of rice straw, rice hull, newspaper, and sawdust. This sequence was consistent with the increase rate of ash content. The ratios of initial C:N ratio to final C:N ratio were 0.45, 0.53, 0.64, and 0.75 in each reactor using rice straw, rice hull, newspaper, and sawdust as a bulking material respectively. From this ratios, it was possible to infer that all the composting reactions were completed. 4. Fertilizer content containing in the final compost was 1.61~2.20% of N, and 0.35~0.54% of P in dry weight base. According to the classification standard for compost constituent by Higgins, all composts had the intermediate grade of N, but below the low grade of P excepting the newspaper amended compost(fall into the range of the low grade). 5. Heavy metal contents contained in the composts were analyzed. In case of Cd, the range of 0.58~1.11 $\mu$g/g was observed, and in case of Pb, the range of 24.76~39.53 $\mu$g/g was observed(in wet weight base). These values are below the permissible heavy metal level for compost of foreign countries.

• 한국축산시설환경학회지
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• 제18권3호
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• pp.201-206
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• 2012

말의 성장단계별 분뇨의 시료를 채취하여 비료성분 및 오염물질 성분을 채취하여 분석하여 본 결과 다음과 같았다. 1. 말의 분뇨의 수분함량은 각각 76.1%, 96.0%로 조사되었다. 2. 또한 말의 분 중 유기물함량은 21.3%로 조사되었으며, 뇨는 약 2.0%로 조사되었다. 3. 또한 말의 분뇨 중 비료성분인 T-N, T-P, T-K의 성분이 각각 0.18%, 0.10% 및 0.23% 이며, 뇨는 각각 2.88%, 0.0015% 및 0.84%로 조사되었다. 4. 말 분뇨의 오염물질을 조사한 결과, 말의 분뇨의 pH는 각각 7.10, 8.48이며, BOD는 분이 26,906.2 $mg/{\ell}$, 뇨는 14,298.9 $mg/{\ell}$, COD는 분이 36,642.3 $mg/{\ell}$, 뇨는 7,484.3 $mg/{\ell}$, SS (Suspended Solid, 부유물질)은 분에서 89,375.0 $mg/{\ell}$, 뇨에서 6,987.0 $mg/{\ell}$로 조사되었다. 5. 말의 분과 뇨의 중금속함량 중 Cr은 각각 2.65 mg/kg, 1.52 mg/kg으로 조사되었으며, Cu 성분도 7.05 mg/kg, 1.62 mg/kg 으로 조사된 반면에 Ni 성분은 말의 분뇨에서 각각 1.24 mg/kg, 0.0 mg/kg으로 조사되었다. 6. 따라서 말의 분뇨는 퇴비원료물로 사용이 가능한 것으로 조사 분석되었으며, 향후 승마사업의 급격한 발전으로 말의 분뇨 발생량이 증가될 것으로 전망되며, 이를 적정 처리하기 위해서는 퇴비화 방법으로 자원화가 가능 할 것으로 조사되었다.

• 한국환경농학회지
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• 제33권2호
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• pp.78-85
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• 2014

BACKGROUND: Recent studies using various industrial wastes for heavy metal stabilization in soil were conducted in order to find out new alternative amendments. The acid mine drainage sludge(AMDS) contains lots of metal oxides(hydroxides) that may be useful for heavy metal stabilization not only waste water treatment but also soil remediation. The aim of this study was to investigate the applicability of acid mine drainage sludge for heavy metals stabilization in soils METHODS AND RESULTS: Alkali soil contaminated with heavy metals was collected from the agricultural soils affected by the abandoned mine sites nearby. Three different amounts(1%, 3%, 5%) of AMDS were applied into control soil and contaminated soil. For determining the changes in the extractable heavy metals, $CaCl_2$ and Mehlich-3 were applied as chemical assessments for metal stabilization. For biological assessments, lettuce(Lactuca sativa L.) and chinese cabbage(Brassica rapa var. glabra) were cultivated and accumulation of heavy metals on each plant were determined. It was revealed that AMDS reduced heavy metal mobility and bioavailability in soil, which resulted in the decreases in the accumulation of As, Cd, Cu, Pb, and Zn in each plant. CONCLUSION: Though the high level of heavy metal concentrations in AMDS, any considerable increase in the heavy metal availability was not observed with control and contaminated soil. In conclusion, these results indicated that AMDS could be applied to heavy metal contaminated soil as an alternative amendments for reducing heavy metal mobility and bioavailability.