• 한국습지학회지
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• 제17권2호
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• pp.146-154
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• 2015

국내의 철도 산업은 친환경적 지속가능한 교통으로 많은 관심을 받으며 지속적인 산업발전을 이루어왔다. 하지만 철도운영 시 발생하는 중금속 오염물질에 대한 처리 및 예방이 미흡하다. 철도 운영 시에 발생하는 중금속은 강우 시 강우유출수와 함께 흘러나온다. 특히 철도 교량의 경우 강우 시 중금속이 강우 유출수와 함께 수계로 직접 유입되어 하천 및 호소 등 오염의 원인으로 작용한다. 이러한 중금속 유출을 예방하기 위해선 철도 노반 재료의 흡착능이 중요하다. 본 연구에서는 기존에 철도 노반의 주 재료로 사용되는 자갈과 고로슬래그의 흡착능에 대하여 분석하였으며, Freundlich와 Langmuir 등온흡착식을 이용하여 고로슬래그의 흡착 특성에 대한 연구를 수행하였다. 그 결과 고로슬래그의 흡착양이 Cd와 Cu는 초기에 자갈보다 높게 나타났고, Pb와 Zn은 자갈의 흡착양이 높게 나타났다. 하지만 시간이 지남에 따라 고로슬래그의 흡착양이 기존에 철도 노반 재료로 쓰이는 자갈에 비하여 높게 나타났다. 흡착 특성은 Freundlich 등온흡착식에 비하여 Langmuir 등온흡착식에서 중금속의 결정계수가 더 높은 것으로 분석되었다. 또한 모델링을 이용하여 철도 노반 재료로서의 안전성을 평가하였다. 또한 모델링을 통해 기존 노반재료와의 안전성 비교 분석을 실시하였다. 그 결과 기존 노반재료인 자갈에 비하여 변형율이 약 10%정도 낮은 것으로 나타났다. 이는 중금속의 수계 유출을 예방 및 안전성 확보 측면에서 철도 노반 재료로 고로슬래그를 적용할 수 있을 것으로 판단된다.

• 한국수산과학회지
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• 제50권4호
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• pp.343-351
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• 2017

Sanitary evaluation of seawater and Pyropia sp. laver collected from the five major laver growing areas in Korea was performed four times over the course of a year. The seawater quality in four of these five areas was regarded as the clean area according to Korean criteria, but the seawater at one investigation site in Seoheon area was found to exceed the standard for fecal coliform. In the bacteriological safety analysis of laver (raw source), the percentages of samples not conforming to Chinese criteria at the five sites were 55.6% (Seocheon), 70.0% (Shinan), 81.8% [Jindo (Haenam)], 63.6% (Wando), and 28.6% [Goheung (Jangheung)]. Pathogenic bacteria were not detected in all laver samples. The food safety of laver (raw source) based on heavy metal concentration was confirmed using Korean criteria; the concentrations of heavy metals in laver samples collected from the major laver growing areas were 0.008-0.632 mg/kg wet weight (ww) lead, 0.024-0.137 mg/kg ww cadmium, 0.908-2.892 mg/kg ww total arsenic, and 0.003-0.013 mg/kg ww total mercury. Therefore, pollution source management and periodic monitoring of heavy metals may be required to improve the food safety of laver produced in these laver growing areas.

• 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.

• Mass Spectrometry Letters
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• 제13권4호
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• pp.166-176
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• 2022

Banana peels are also widely used as bio-adsorbent in the removal of chemicals contaminants and heavy metals from water and soil. GC-MS plays an essential role in the phytochemical analysis and chemo taxonomic studies of medicinal plants containing biologically active components. Intrinsically, with the use of the flame ionization detector and the electron capture detector which have very high sensitivities, Gas chromatography can quantitatively determine materials present at very low concentrations and most important application is in pollution studies. In the present study banana peels were used as bio-adsorbent to remediate the heavy metal contaminated water taken from three different stations located around the industrial belts of Ranipet, Tamilnadu, India. The AAS analysis of the samples shows a decrement of chromium concentration of 98.93%, 96.16% and 96.5% in Station 1, 2 and 3 respectively which proves the efficiency of the powdered peels of Musa paradisiaca. The GC-MS analysis of the control and treated peels of Musa paradisiaca reveals the presence of phytochemicals like Acetic Acid, 1-Methylethyl Ester, DL-Glyceraldehyde Dimer, N-Hexadecanoic Acid, 3-Decyn-2-Ol, 26-Hydroxy, Cholesterol, Ergost-25-Ene-3,5,6,12-Tetrol, (3.Beta.,5.Alpha.,6.Beta.,12.Beta.)-, 1-Methylene-2b-Hydroxymethyl-3, and 3-Dimethyl-4b-(3-Methylbut-2-Enyl)-Cyclohexane in the control banana peels. The banana peels which were used for the treatment reveals the changes and alteration of the phytochemicals. It is concluded that the alteration in phytochemicals of the experimental banana peels were due to adsorption of chromium heavy metal from the sample.

• 광물과 암석
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• 제33권4호
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• pp.391-405
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• 2020

본 연구에서는 안동댐 퇴적물의 일반항목과 중금속의 용출 특성에 대해 조사하였다. 용출 실험은 카드뮴, 구리, 납, 크롬, 아연, 수은, 비소, 철, 망간 등 중금속 9개 및 pH, 총인, 총질소등 일반 3개 항목에 대해 혐기성과 호기성 조건에서 60일간 실험을 수행하였다. 총질소와 총인은 호기성 조건에 비해 혐기성 조건의 용출이 높게 나타났으며, 일부 시료에서 높은 농도가 검출되었다. 대부분의 중금속의 용출율은 아주 낮았으며, 퇴적물에서 함유량이 높은 비소와 카드뮴도 최대 용출량이 각각 0.028 mg/L, 0.003 mg/L로 낮은 값을 나타낸다. 5단계 연속추출연구에서는 쉽게 용출될 수 있는 이온교환형태나 흡착한 형태의 분율이 전체 함유량의 10% 미만으로 낮게 나타났다. 대부분의 중금속은 왕수에 용해되는 잔류(residual)형태로 존재하고 있으며, 특히 독성이 높고 오염도가 높은 비소와 카드뮴의 경우 잔류형태로 존재하는 비율이 각각 80%와 95%로 오염도에 비해 짧은 시간에 용출되어 유해성을 일으킬 가능성은 낮은 것으로 판단된다.

• 한국물환경학회지
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• 제20권5호
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• pp.525-533
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• 2004

The object ofthis study was to test for STORMSYS process that composed Catch Basin and Stormsys(three units: vortex solids separator, filter media bed and vegetated filter strips). It could be applied to treat the first-flush non-point pollution materials on the road(especially, motorway). This study investigated that the runoff characteristics of non-point pollutions containing the heavy metal(Fe, Zn and Cu) by rainfall showed relatively high pollution concentration in the early-stage storm runoff on the road, which seems to be caused by the vehicular traffic, and showed the rapid reduction of pollution concentration on the basis of about 5mm rainfall volume. As the number of the non-rainy days were increased, the pollution concentration by storm runoff was increased, also. As a test result of this process, the average removal efficiency of BOD, $COD_{mn}$, SS, T-N and T-P over the testing period were 92.7%,88.6%,97.4%,93.0% and 93.3%, respectively. Also, the average removal efficiency of n-Hexane, Fe, Zn and Cu were 86.7%, 96.1%, 84.4% and 78.4%, respectively. As shown in the characteristics of storm runoff, the non-point pollution materials have high pollution concentration in the early-stage storm runoff on the road, the installation of STORMSYS process is expected to reduce considerable amount of non-point pollutions.

• 한국세라믹학회지
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• 제35권2호
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• pp.163-171
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• 1998

Continuously contacting with camshaft the face of Valve Lifter made of cast iron brings about abnormal wear such as unfairwear or earlywear because it is heavily loaded in the valve train systems as the engine gets more powered. This abnormal wear becomes a defet namely over-clearance when the valve is lifting so that the fuel gas imperfectly combusted by unsuitable open or close aaction of the engine valve in the combustion chamber. The imperfect combustion in the end results in the major cause of air pollution and combustion chamber. The imperfectly combusted by unsuitable open or close action of the engine valve in the combustion chamber. The imperfect combustion in the end results in the major causes of air pollution and decrease of the engine output. Consequently to prevent this wear this study was to develop the valve lifter which is joined by brazing process with SCM435H and a tip by manufacturing the face as a superhardened which is joined by brazing process with SCM435H and a tip by manufacturing the face as a superhardened ceramics alloy which has high wear resistance. Having the excellent surface hardness with Hv1100-1200 the sintered body developed with superhardened alloy(WC) can endure the severe face loading in the valve train system. We experienced with various brazing alloys and obtained the excellent joining strength to the joint had 150MPa shear strength. Interface analysis and microstructure in a joint were examined through SEM & EDS Optical microscope. Also 2,500 hours high speed(3,000-4,000 rpm) and continuous (1step 12hr) engine dynamo testing was carried out to casting valve liter and ceramics-metal joint valve lifter so that the abnormal wears were compared and evaluated.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.977-980
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• 2004

Metalworking fluids (MWFs) are fluids used during machining and grinding to prolong the life of the tool, carry away debris, and protect the surfaces of work pieces. These fluids reduce friction between the cutting tool and the work surface, reduce wear and galling, protect surface characteristics, reduce surface adhesion or welding and carry away generated heat. Workers can be exposed to MWFs by inhaling aerosols (mists) and by skin contact with the fluid. Skin contact occurs by dipping the hands into the fluid, splashes, or handling workpieces coated with the fluids. The amount of mist generated (and the resulting level of exposure) depends on many factors. To reduce the environmental pollution wastes and the potential health risks associated with occupational exposures to MWFs, it is required to establish optimum MWFs supply method and condition with minimum quantity in all over the mechanical machining field including high-speed type heavy cutting process.

• 환경위생공학
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• 제12권2호
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• pp.65-74
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• 1997

The purpose of this study was to investigate the removal effect and variation of contaminated water by various water treatment processes using sediment filter, activated carbon, photocatalysis, reverse osmosis, ultra violet sterilizer and ultra filtration. The removal effect of chloride and trace metal was low by activated carbon and ultra filter but high in reverse osmosis. The removal effect of bacteria and E. coli was low by activated carbon and membrane filter system using activated carbon but high in impregnated activated carbon. The removal effect of TCE was low in sand and ultra filter system as compared with activated carbon. Ultra filtration process was effective for purify agricultural water without E.coli. Reverse osmosis was effective to remove heavy metal and activated carbon was effective to remove halogenated organic chemical compound. The flux and the removal effect of COD in spiral wound ultrafilter were higher than the hollow fiber ultrafilter.

• 한국환경보건학회:학술대회논문집
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• 한국환경보건학회 2004년도 International Conference Current Challenges and Advances in Environmental Health
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• pp.63-68
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• 2004

Immunohistochemical and ultrastructural experiments were conducted to find out heavy metal accumulation in some selected organs such as the kidney, the digestive gland, and the gill of the Antarctic clam Laternula elliptica and R. philippinarum. According to the immunohistochemical study the subject organs of the clam showed reactions indicating the presence of MT (metallothionein), a metal-binding protein involved in metal detoxifying process. Examination under the transmission electron microscope also revealed that other ligands may play a role in metal accumulating and detoxifying process in L. elliptica and R. philippinarum. In the artificial exposure of the clam to Cd, the clams showed immediate subcellular responses. The level of the anti-MT reactions became higher in the proportion to the degree of pollution of their habitat and to the period of Cd exposure. These suggest that the two species can be used as efficient biomarkers for Cd exposure in the natural environment.