• 한국산업보건학회지
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• 제16권3호
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• pp.254-263
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• 2006

Manganese has a role as both toxic and essential in humans. Manganese is also an essential component in the welding because it increases the hardness and strength, prevents steel from cracking of welding part and acts as a deoxidizing agent to form a stable weld. In this study, manganese generation rate and its content was determined in flux cored arc welding on stainless steel. Domestic two products and foreign four products of flux cored wires were tested in the well designed fume generation chamber as a function of input power. Welding fume was measured by gravimetric method and metal manganese was determined by inductively coupled plasma-atomic emission spectrophotometer. The outer shell of the flux cored wire tube and inner flux were analyzed by scanning electron microscopy to determine their metal compositions. Manganese generation rate($FGR_{mn}$) was increased as the input power increased. It was 16.3 mg/min at the low input power, 38.1 mg/min at the optimal input power, and up to 55.4 mg/min at the high input power. This means that $FGR_{mn}$ is increased at the work place if welder raise the current and/or voltage for the high productivity. The slope coefficient of $FGR_{mn}$ was smaller than that of the generation rate of total fume(FGR). Also, the correlation coefficient of $FGR_{mn}$ was 0.65 whereas that of FGR is 0.91. $FGR_{mn}$ was equal or higher in the domestic products than that of the foreign products although FGR was similar. From the electron microscopic analytical data, we concluded that outer shell of the wire was composed mainly of iron, chromium, nickel and less than 1.2 % of manganese. There are many metal ingredients such as iron, silica, manganese, zirconium, titanium, nickel, potassium, and aluminum in the inner flux but they were not homogeneous. It was found that both $FGR_{mn}$ and content of manganese was higher and more varied in domestic flux cored wires than those of foreign products. To reduce worker exposure to fumes and hazardous component at the source, further research is needed to develop new welding filler materials that improve the quality of flux cored wire in respect to these points. Welder should keep in mind that the FGR, $FGR_{mn}$ and probably the generation rate of other hazardous metals were increased as the input power increase for the high productivity.

• 대한토목학회논문집
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• 제35권3호
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• pp.533-544
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• 2015

해양환경에 노출된 콘크리트는 육상에서 건설되는 콘크리트와 달리 해풍, 조력, 파도, 파랑 등에 의한 물리적 작용과 해수의 $SO_4{^{2-}}$, $Cl^-$ 및 $Mg^{2+}$ 이온 등에 의한 화학적 침식작용 및 동결융해 등 가혹한 환경에 노출되어 콘크리트의 내구성을 크게 저하시킨다. 해중 콘크리트의 대규모 시공은 콘크리트의 강도손실은 물론 알칼리(pH) 및 중금속 등 환경유해물질이 용출될 수 있어 이에 대한 충분한 검토와 연구가 필요한 실정이다. 본 연구에서는 전기로 환원슬래그로부터 CSA 자극제를 개발하고 전기로 산화슬래그를 콘크리트용 골재로 활용하여 인공리프용 친환경콘크리트를 개발하였다. 초기강도는 Normal concrete보다 낮게 나타나 친환경콘크리트의 초기강도 품질향상을 위한 추가적인 연구가 필요하였으며, 친환경콘크리트의 해수저항성은 양생일 1년 대비 평균 강도손실이 8~9% 발생하였다. 고함량 고로슬래그 미분말과 고비중 전기로 산화슬래그 골재를 사용한 친환경콘크리트를 동결융해저항성 재료로써 충분히 활용할 수 있는 가능성을 확인하였다. 친환경콘크리트의 중금속 용출특성은 콘크리트의 수화반응을 통한 경화과정에서 중금속 성분은 화학적 결합을 통해 고정화되기 때문에 환경유해성 기준 이하이거나 검출되지 않아 유해물질 용출에 안전하다는 것을 확인하였다.

• 대한본초학회지
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• 제24권2호
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• pp.13-20
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• 2009

Objectives: To compare the contents of hazardous substances before/after a decoction. Methods : The heavy metal contents before/after a decoction were measured by Inductively Coupled Plasma Atomic Emission Spectrometer (ICP-AES) and mercury analyzer. In order to analyze pesticides in 6 samples we used simultaneous multi-residue analysis of pesticides by GC/ECD, which was followed by GC/MSD analysis to confirm the identity of the detected pesticide in each sample. In addition, the contents of sulfur dioxide (S02) were performed by Monier-Williams distillation method. Results : 1. The mean values of heavy metal contents (mg/kg) for the samples were as follows: Socheongryong-tang (before decoction - Pb; 1.115, Cd; 0.179, As; 0.069 and Hg; 0.028, after decoction - Pb; 0.110, Cd; 0.011, As; 0.005 and Hg; 0.002), Insampaedok-san (before decoction - Pb; 1.207, Cd; 0.148, As; 0.171 and Hg; 0.026, after decoction - Pb; 0.075, Cd; 0.006, As; not detected and Hg; O.OOD, Oryung-san (before decoction - Pb; 1.955, Cd; 0.430, As; 0.063 and Hg; 0.027, after decoction - Pb; 0.083, Cd; 0.013, As; 0.006 and Hg; 0.002), Hwangryunhaedok-tang (before decoction - Pb; 1.825, Cd; 0.210, As; 0.050 and Hg; 0.009, after decoction - Pb; 0.107, Cd; 0.010, As; 0.005 and Hg; O.OOD, Bangpungtongseong-san (before decoction - Pb; 1.740, Cd; 0.162, As; 0.585 and Hg; 0.018, after decoction - Pb; 0.041, Cd; 0.006, As; 0.022 and Hg; not detected) and Oyaksungi-san (before decoction - Pb; 1.199, Cd; 0.183, As; 0.321 and Hg; 0.031, after decoction - Pb; 0.096, Cd; 0.008, As; 0.021 and Hg; 0.0004). 2. Contents (mg/kg) of sulfur dioxide (S0$_2$) before a decoction in Socheongryong-tang, Insampaedok-san, Oryung-san, Hwangryunhaedok-tang, Bangpungtongseong-san and Oyaksungi-san exhibited 3.2, 5.7, 4.5, 49.8, 7.8 and 22.4, respectively. However, contents of sulfur dioxide after a decoction in all samples were not detected. 3. Contents (mg/kg) of residual pesticides before/after a decoction in all samples were not detected. Conclusions : These results will be used to establish a criterion of heavy metals, residual pesticides and sulfur dioxide.

• 융합정보논문지
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• 제10권12호
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• pp.208-215
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• 2020

본 연구는 SUKI를 활용하여 두피의 중금속 감소에 대해 미치는 영향에 대해 알아보았다. 연구대상자는 총 26명이었으며 실험군과 대조군 각각 13명이었다. SUKI 도구를 활용한 두피 중금속 배출에 대한 중재를 8주간 주 2회씩 실시하였고, 결과는 다음과 같다. 총 각각 8 종목의 실험군과 대조군의 비교에서 실험군에서 유의한 차이가 있었다. 실험군의 중금속인 Hg, Pb, Al, Cd, As, Ba, Ur, Cs 중에서 6가지 항목의 Hg, Al, Cd, As, Ba, Ur과 같은 중금속들에서 통계적으로 유의한 감소(p<.05)를 보여주었으며, Pb, Cs 는 유의하지 않았다. 그리고 해당 유해중금속 중에서 Al, Ba, Hg가 가장 큰 차이의 감소율을 나타냈다. 따라서 SUKI 도구의 중재가 일부 중금속 배출에 영향을 줄 수 있다는 것을 시사한다(p<.05). 결론적으로 향후 지속적인 연구를 통해 두피의 중금속 배출을 위한 기초자료로 활용될 수 있을 것으로 사료된다.

• 대한환경공학회지
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• 제30권2호
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• pp.213-217
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• 2008

본 연구는 지정폐기물에 함유된 미규제 중금속 Ni, Zn, Ba, Be, Sb, Se, V의 용출 특성을 조사한 것으로, 이들 항목의 배출 가능성이 높은 표본사업장을 선정하여 시료 108건을 채취 분석하였다. 중금속류의 용출시험은 선행연구과제에서 제시한 시험방법으로 분석하였다. 조사결과, Ni은 폐수처리오니, 분진에서 많이 검출되었으며, Zn은 대부분의 조사대상 시료에서 검출되었다. 석유 정제 공정에서 발생된 분진과 폐촉매에서는 V이 높은 농도로 검출되었다. Ba, Be, Sb, Se은 낮은 농도로 검출되었으나, 다양한 폐기물배출사업장에서 발생되는 폐기물을 추가 선정하여 용출특성을 파악하는 것이 필요하다고 판단되었다.

• 한국환경농학회지
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• 제15권4호
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• pp.494-500
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• 1996

To investigate the relationship between the atmospheric pollution level and the pollution level of soil adjacent to the roadside in Suwon suspended particles and soil samples were collected in August to October 1993, and analyzed by AAS and ICP. The Ca, K, Mg concentration in atmosphere were observed as high level and assumed that it was effected by the acid-rain originated from the erosion of concreate vicinity to the roadside, and the Pb, Zn concentration were higher at outer area than that of central area. Hazardous heavy metal (Cu, Pb, Zn) concentrations in soil were observed as high level at all sampling sites. The relationship between the heavy metal concentrations in the atmosphere and those in the soil were analyzed, by using the correlation coefficient value(r) and the result was appeared similarly. And this study indicated that the atmospheric pollution affect the level of the soil pollution adjacent to the road side.

• 한국염색가공학회:학술대회논문집
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• 한국염색가공학회 2012년도 제46차 학술발표회
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• pp.29-29
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• 2012

Rhodamine chromophore/fluorophore have been attracted to many researchers due to its excellent photophysical properties. In this study, we have designed and synthesized a strong emissive fluorescent dye chemosensor for toxic elements. A rhodamine-based sensor was prepared by incorporation the rhodamine fluorophore and several functional host groups with high affinity to hazardous metal and anion. This sensor shows a high selectivity and an excellent sensitivity and is a dual-responsive colorimetric and fluorescent metal/anion-specific sensor. In addition, the 1:1 binding mode was proposed based on Job's plot method. Finally, computational calculation was simulated and calculated to approach for HOMO/LUMO of this dye chemosensor.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.699-704
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• 2001

Until recently, disposal to landfill has been the most convenient way to deal with the increasing amount of residues the shredding industries produce. But the shortage of such disposal sites and the risk that liquid drained from these waste dusts may pollute ground water have increased the environmental pressures to find more effective solutions. The present study is an alternative approach that suggests identifying waste dusts characteristics and selecting an appropriate binder for hazardous materials to reduce the amount of contaminants (mainly lead) that were leaking into the soil. Investigations on the characteristics of automobiles waste dusts show that these materials are composed mainly of cottons and sponge like substances, plastics, rubber, glasses and gravel, metals, and electric wires. Besides, the percentage in weight of organic (inflammable) materials is about 70% and the lead contamination, which has not a ionic but a particulate nature, is particularly remarkable in cottons and sponge like materials. Binding additives such as K-20 and sodium carbonate were not effective but the addition of 5 % of cement (in weight of the investigated sample) followed by a 3-minute stirring and a 4-hour storage could drastically reduce the run off of lead below the maximum authorized level. No addition of water was necessary in this method.

• 한국환경농학회지
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• 제21권3호
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• pp.223-228
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• 2002

In addition to supplying the essential elements, Ca and S, phosphogypsum can have profound effect on both the physical and chemical properties of certain soils. However, no widespread use of by-product phosphogypsum will be made unless such uses pose no threat to the public health and soil contamination. In this study, the extractability of As, Cd, Cu, and Pb with water and DTPA solution from phosphogypsum samples of pH 3, 5, and 7 were investigated to estimate the availability of those metals. Contents of water extractable metals in ohosphogypsum were less than 5 mg/kg for all the heavy metals investigated. The extractability of metals in DTPA solution was not quite different but a little higher in comparison to the water extraction. And the extractability was decreased as the pH of phosphogypsum increased. In the phosphogypsum of pH 7, amounts of water extractable metals were nearly zero. There was no significant difference in the amount of extractable metals during the extraction period of 5 weeks. The length of extraction time did not affect heavy metal extractability. Therefore there may be small fractions of easily soluble or extractable forms of metals in the phosphogypsum and most of the metals would be present in very insoluble forms. These results suggest that the application of phosphogypsum at appropriate rates on agricultural lands appears of no concern in terms of hazardous element contamination in soil.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2014년도 추계학술대회 논문집
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• pp.698-698
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• 2014

According to the analysis of special medical examination and work environment monitoring data, the rate of C1 and D1 on noise hazard exceeded 90% among those of total hazardous factors. The rate of company exceeding noise exposure limit was also more than 90%. The analysis result shows that main ages diagnosed with C1 and D1 was age of 50s. The majority scale company having workers diagnosed with C1 and D1 was the companies employing 5~49 workers. Types of industries which have a large number of companies exceeding noise exposure limit were automobile and trailer manufacturing, metal processing industry and primary metal manufacturing. A large number of work processes exceeding noise exposure limit were forming and processing work, cutting and bending work and grinding. To reduce the number of company exceeding noise exposure limit, the reduction counterplan should be focused on the type of industry and the work process which exceeded noise exposure limit frequently. However, the reduction counterplan is preemptively necessary to the type of industry and the work process which exceeded noise exposure limit consecutively if the purpose of reduction counterplan is not to merely reduce the number of company exceeding noise exposure limit but to abate workers' suffering from noise.