• 해양환경안전학회지
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• 제20권5호
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• pp.504-510
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• 2014

본 연구에서는 2014년 03월에 인천 H항의 5개 정점(S1~S5)에서 채취된 표층 퇴적물의 물리화학적 특성을 조사하고, COD, AVS, IL 및 중금속(Cd, Cu, Ni, Pb, Zn, Cr, Hg)을 분석하여 오염도를 평가하였다. 입도분석, 비표면적분석, XRD 및 XRF 분석을 통하여 채취된 퇴적물 시료 모두 거의 동일한 산화물과 광물로 구성되었음을 확인하였다. 국내기준으로 COD, AVS 및 IL 세 항목의 총점에 대한 오염도는 S2, S3, S5 지점은 2등급으로 S1, S4 지점은 3등급으로 평가되었다. 중금속 오염의 경우 Cd, Ni, Pb은 USEPA 기준으로 중간오염에 해당하였고, Cu, Zn 및 Cr은 심한오염으로 분류되었다. 농집지수를 이용한 오염도 평가결과 Cd가 Class 3으로 평가되었고, 농축계수를 이용한 평가결과 모든 지점에서 Cd, Pb, Zn의 경우 1보다 큰 것으로 나타났다. 또한 총농축계수는 S4지점이 3.1로 가장 높은 것으로 나타났다.

• Nuclear Engineering and Technology
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• 제54권6호
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• pp.2230-2243
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• 2022

The tin tailing processing industry in Malaysia has operated with minimal regard and awareness for material management and working environment safety, impacting the environment and workers in aspects of radiation and heavy metal exposure. RIA was conducted where environmental samples were analyzed, revealing concentrations of ²²⁶Ra, ²³²Th and ⁴⁰K between the range of 0.1-10.0, 0.0-25.7, and 0.1-5.8 Bq/g respectively, resulting in the AED exceeding UNCEAR recommended value and regulation limit enforced by AELB (1 mSv/y). Ra_eq calculated indicates that samples collected pose a significant threat to human health from gamma-ray exposure. Assessment of heavy metal content via pollution indices of soil and sediment showed significant contamination and enrichment from processing activities conducted. As and Fe were two of the highest metals exposed both via soil ingestion with an average of 4.6 × 10^-3 mg/kg-day and 1.4 × 10^-4 mg/kg-day, and dermal contact with an average of 5.6 × 10^-4 mg/kg-day and 6.0 × 10^-4. mg/kg-day respectively. Exposure via accidental ingestion of soil and sediment could potentially cause adverse non-carcinogenic and carcinogenic health effect towards workers in the industry. Correlation analysis indicates the presence of a relationship between the concentration of NORM and trace elements.

• 한국농공학회논문집
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• 제58권3호
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• pp.39-46
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• 2016

This study investigated the potential use and the effectiveness of biomass ashes for the stabilization of heavy metals in soil through a series of experiments. The ashes used for the experiments were obtained from the gasification of biomass including miscanthus and woodchips. The amounts of nickel and chromium released from the soil and ash mixture were analyzed. Chemical analysis showed that the ash contained unburned carbon as well as silica and alkali metals. Miscanthus ashes have C (83.400 %) > Si (9.040 %) > K (3.180 %) > Ca (1.800 %), and woodchip ashes have C (93.800 %) > Ca (2.220 %) > Fe (1.370 %) > K (1.200 %). KSLT and TCLP test results implied that the heavy metal concentrations were below the environmental standards and would not impose the risks. The results also showed that Ni releases were more limited as more ashes were mixed with the soil due to the increases in exchangeable, carbonate, and oxide nikels. Both miscanthus and woodchip ahses were effective in stabilizing nickel and chromium through mixing with the soil. It could be seen that ashes produced from biomass gasification can be used to stabilize the heavy metals in soils.

• ALGAE
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• 제20권2호
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• pp.157-166
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• 2005

Uptake kinetics of Cd and Zn by leaves and rhizome of the seagrass Zostera marina were examined in controlled laboratory radiotracer experiments. Subsequently, acute toxicity of Cd, Cu and TBT on photosynthetic quantum yield (ΔF/Fm’ of Z. marina were determined, and the differential sensitivities of rapid light curve (RLC) to those harmful substances were also compared. All measurements on photosynthetic activity were determined by chlorophyll a fluorescence method using pulse amplitude modulation (PAM). Metal uptake by Z. marina was saturated with increasing exposure time in leaves and rhizomes. Uptake of Zn by Z. marina was faster than that of Cd. Metal uptake rates in Z. marina decreased with the increase of dissolved metal concentrations and also with the increase of biomass. The adverse effect of TBT on effective quantum yield was stronger than other pollutants. Average acute toxicity on the RLC of the seagrass exposed to TBT and two heavy metals (Cd and Cu) was going to decrease as follows: TBT > Cd > Cu. Our preliminary results in this study suggested that Z. marina potentially can be used as a biomonitor of harmful substances contamination in coastal waters.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2000년도 창립총회 및 춘계학술발표회
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• pp.28-32
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• 2000

There are many different chemical pollutants that originate from atmospheric deposition and transportational activities along roads. This paper review the characteristics of heavy metal pollution, relationships between land use and pollutant load in urban area. Four land use areas in Seoul were selected for sampling and study with different characteristics during the period from April 1998 and February 2000. A series of studies have been carried out concerning the physicochemical characteristics of the sediments settling down in a gully pot to evaluate the contamination for heavy metals. The sediment samples from gully pots were characterized by the chemical extraction experiments. Sediments are characterized by very high concentrations of heavy metals, probably because of a long-term accumulation of vehicle- and industrial-related pollutants. The characteristics of heavy metal pollution show that each land use has different sources of contaminations. Mean Zn concentration in Yeouido and Junggu areas is 2-3 times higher than those in Dobonggu area. This suggests that Zn may be derived from the source of automobile traffic. The mean concentrations of Cu and Cr are very significantly high in Junggu and Gurogu areas and indicate that the industrial activities may contribute to the accumulation of Cu and Cr in sediments. The low Pb levels throughout the whole study areas in Seoul can be accounted for the use of unleaded gasoline since 1987.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.133-133
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• 2013

For both oxygen reduction (ORR) and hydrogen oxidation reactions (HOR) of proton electrolyte membrane fuel cells (PEMFCs), alloying Pt with another transition metal usually results in a higher activity relative to pure Pt, mainly due to electronic modification of Pt and bifunctional behaviour of alloy surface for ORR and HOR, respectively. However, activity and stability are closely related to the preparation of alloy nanoparticles. Preparation conditions of alloy nanoparticles have strong influence on surface composition, oxidation state, nanoparticle size, shape, and contamination, which result from a large difference in redox priority of metal precursors, intrinsic properties of metals, increasedreactivity of nanocrystallites, and interactions with constituents for the synthesis such as solvent, stabilizer, and reducing agent, etc. Carbon-supported Pt-Ni alloy nanoparticles were prepared by the borohydride reduction method in anhydrous solvent. Pt-Ru alloy nanoparticles supported on carbon black were also prepared by the similar synthetic method to that of Pt-Ni. Since electrocatalytic reactions are strongly dependent on the surface structure of metal catalysts, the atom-leveled design of the surface structure plays a significant role in a high catalytic activity and the utilization of electrocatalysts. Therefore, surface-modified electrocatalysts have attracted much attention due to their unique structure and new electronic and electrocatalytic properties. The carbon-supported Au and Pd nanoparticles were adapted as the substrate and the successive reduction process was used for depositing Pt and PtM (M=Ru, Pd, and Rh) bimetallic elements on the surface of Au and Pd nanoparticles. Distinct features of the overlayers for electrocatalytic activities including methanol oxidation, formic acid oxidation, and oxygen reduction were investigated.

• 환경영향평가
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• 제10권2호
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• pp.85-98
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• 2001

This study was conducted to investigate the geochemical factors governing the distribution of heavy metals(Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) in the marine surface sediment samples collected from the Samcheonpo coal-fired power plant. Variations of absolute metal concentrations were related to those in textural and/or carbonate and organic matter content. Most elements, except for Pb, showed generally lower contents compared with the average shale concentration, and the effect of anthropogenic input appeared to be minimal in the sediments. Computations of LF%(labile fraction) and EF(enrichment factor) based on all trace metal data indicated the presence of mineralogical control for Co, Cr, Cu, Ni, and Zn, and anthropogenic contamination for Pb, which needs to be considered in the design of long term monitoring programmes.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 추계 학술발표회 제17권2호
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• pp.743-747
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• 2005

In South Korea, about 900 metal mines have been abandoned, and about 88 million-t metal mine wastes have been discarded in recent years. The treatment of the tailings which are the main wastes in the abandoned metal mines becomes a social problem because they cause environmental pollution such as acidic waste water generation, groundwater contamination, and dust generation. Since almost whole quantities of the tailings have disposed by landfill now, the development of effective recycling methods for the tailings are strongly requested. It is expected that the fine tailings obtained by centrifugal separation process among the tailings can be utilized as admixture for cement. The purpose of this study is to evaluate the micro-structure of cement mortar admixed with fine tailing. Various admixtures were made of Fine tailings and 2 Types of OPC, fly-ash and blast furnace slag. The hydration reactivity of cement mortar with FT was examined by Porosity, XRD and SEM morphology analysis. The anolytical result about hardened hydrates shows that waste fine tailing help hydrates none densified due to it,s filling-space, These densified effect is concluded with improving the resistance to attack of cement mortar including waste fine tailing.

• 대한치과기공학회지
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• 제23권2호
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• pp.203-210
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• 2002

This test is to conduct applied research the reaction area of the Ti-cast metal body which is made use of Dental Phosphate-silica alumina bonded investment material selling at a market, and the cooling method is how to effect on the acicular. The experimentation is as followings, 1. Experimental specimens After invest with Dental Phosphate-silica alumina bonded investment material, the $10{\times}10{\times}1.0mm^3$ wax pattern was casted by Dental high vacuum argon centrifugal casting machine. 2. Test We can analyze SEM/EDS, XRD utilize the fractography(an optical microscope). 3. Conclusion The pure cast metal body constituted of reaction products layer, stability layer and contamination layer. This pure cast have no connection with the cooling condition. The pure Titanium shows difference in a component distribution according to the cooling condition. Through this experimentation we can establish that acicular in the pure Ti-cast metal is consist of Hexagonal structure a=2.9505$\AA$, c=4.6826$\AA$.

• 한국환경보건학회지
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• 제45권6호
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• pp.561-568
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• 2019

Objectives: The most commonly detected heavy metals in rocks and soils, including Pb, Cd, Cu, Fe, Mn and As, are representative pollutants discharged from abandoned mines and have been listed as potential sources of contamination in drinking water. This study focused on increasing the removal efficiency of heavy metals from drinking water resources by surface modification of natural adsorbents to reduce potential health risks. Methods: Iron oxide coating and graft polymerization with zeolites and talc was conducted for bipolar surface modification to increase the combining capacity of heavy metals for their removal from water. The removal efficiency of heavy metals was measured before and after the surface modification. Results: The removal efficiency of Pb, Cu, and Cd by surface modified zeolite showed 100, 92, and 61.5%, respectively, increases compared to 64, 64, and 38% for non-modified zeolite. This implies that bipolar surface modified natural adsorbents have a good potential use in heavy metal removal. The more interesting finding is the removal increase for As, which has both cation and anion characteristics showing 27% removal efficiency where as non-modified zeolite showed only 2% removal. Conclusions: Zeolite is one of the most widely used adsorptive materials in water treatment processes and bipolar surface modification of zeolite increases its applicability in the removal of heavy metals, especially As.