• Advances in environmental research
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• 제9권3호
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• pp.175-189
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• 2020

Municipal solid waste disposal is considered as one of the most important risks for environmental contamination which necessitates the development of strategies to reduce destructive consequences on the ecosystem as related especially to heavy metal accumulation. This study investigates heavy metal (i.e., As, Cd, Co, Cr, Cu, Mn, Ni, Pb, Zn) accumulation in the Tonekabon region, NW of Iran that is related to city waste disposal and evaluates the environmental impact in the Caspian Sea coastal region. For this purpose, after performing field studies and collecting 50 soil specimens from 5 sites of the study area, geochemical tests (i.e., inductively coupled plasma mass spectrometry, atomic absorption spectroscopy and x-ray fluorescence) were conducted on the soil specimens collected from the 5 sites (named as Sites A1, A2, A3, A4 and A5) and the results were used to estimate the pollution indices (i.e., geo-accumulation index, normalized enrichment factor, contamination factor, and pollution load index). The obtained indices were utilized to assess the eco-toxicological risk level in the landfill site which indicated that the city has been severely contaminated by Cu, Mn, Ni, Pb and Zn. These levels have been developed along the stream towards the nearshore areas indicating uptake of soil degradation. The heavy metal contamination was classified to range from unpolluted to highly polluted, which indicated serious heavy metal pollution in the study area as related to municipal solid waste disposal in Tonekabon.

• Journal of Microbiology and Biotechnology
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• 제27권10호
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• pp.1885-1891
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• 2017

In this study, we evaluated the inhibitory effect of a rice bran mixture extract (RBE) on Brucella abortus pathogenesis in professional (RAW 264.7) and nonprofessional (HeLa) phagocytes. We fermented the rice bran mixture and then extracted it with 50% ethanol followed by gas chromatography-mass spectrometry to identify the components in RBE. Our results clearly showed that RBE caused a significant reduction in the adherence of B. abortus in both cell lines. Furthermore, analysis of phagocytic signaling proteins by western blot assay revealed that RBE pretreatment resulted in inhibition of phosphorylation of JNK, ERK, and p38, leading to decline of internalization compared with the controls. Additionally, the intensity of F-actin observed by fluorescence microscopy and FACS was remarkably reduced in RBE-pretreated cells compared with control cells. However, the intracellular replication of B. abortus within phagocytes was not affected by RBE. Taken together, these findings suggest that the phagocytic receptor blocking and suppressive effects of RBE on the MAPK-linked phagocytic signaling pathway could negatively affect the invasion of B. abortus into phagocytes.

• 생약학회지
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• 제48권1호
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• pp.56-62
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• 2017

The aim of this study was to screen the contamination by ochratoxin A of mycotoxins in various medicinal herbs. We conducted a survey of ochratoxin A in medicinal herb on the retail market in Incheon in 2016. 116 medicinal herb samples were evaluated for the ochratoxin A contamination. They were analyzed for ochratoxin A using immunoaffinity column and high-performance liquid chromatography(HPLC)-fluorescence detection and the positive samples were confirmed using HPLC-tandem mass spectrometry. Ochratoxin A was detected in 4 medicinal herb samples; the concentrations of ochratoxin A were containing between 20.11 and $372.90{\mu}g/kg$. This study shows that in general, this kind of commodity may be contaminated by mycotoxins. Also this contamination is not limited to only aflatoxin of mycotoxins.

• 보존과학회지
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• 제35권4호
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• pp.295-307
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• 2019

In the process of the conservation treatment of the glass eyes of the stone standing Maitreya of Daejosa temple, Buyeo (Treasure No. 217), a blackish material, expected to be the adhesive for fixing the glass eyes, was collected and analyzed. Infrared spectroscopy and pyrolysis/gas chromatography/mass spectrometry (pyrolysis/GC/MS) were employed to identify the organic material in the sample. The IR analysis revealed the presence of materials such as apatite or bone black. The pyrogram of the sample was similar to that of Asian lacquer, among traditional adhesives. In particular, the pyrolysis/GC/MS analysis with online methylation detected 1,2-dimethoxy-3-pentadecylbenzene, methyl 7-(2,3- dimethoxyphenyl) heptanoate, and methyl 8-(2,3-dimethoxyphenyl)octanoate. These are known to be the pyrolysis products of catechol and its oxidation product, which indicated the presence of Asian lacquer in the sample. X-ray diffraction, X-ray fluorescence, and thermal gravimetry analysis showed that the sample contained ca. 60% inorganic substances, including apatite. Radiocarbon dating of the sample suggested that the blackish material was applied between the late 13^th and early 15^th century, revealing some discrepancy with the art-historical manufacturing time of the Maitreya. From the above analysis, it was concluded that Asian lacquer and bone ash were used to attach the glass eyes by forming a thick blackish lacquer layer.

• 한국광물학회지
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• 제17권1호
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• pp.23-35
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• 2004

울산시 사연댐 상류에 위치하여 주기적으로 침수되는 퇴적암의 풍화특징을 연구하였다. 현장조사, 전자현미분석기, Χ-선 회절분석기 및 Χ-선 형광분석기를 이용하여 암석의 풍화조직 및 광물의 조성변화 조사를 통해 주기적으로 침수되는 암석의 기계적 및 화학적 풍화양상을 연구하였다. 수장암석의 풍화작용은 퇴적층리와 수직방향으로 발달한 파쇄대 및 균열과 박리현상과 같은 기계적 풍화작용이 현저하다. 이러한 물리적인 풍화현상은 물과 암석과의 접촉면적을 넓혀 화학적 풍화작용을 가속화시킨 결과 풍화대와 약풍화대에서 석영을 제외한 거의 모든 광물이 용해작용 또는 변질작용을 받았으며, 특히, 탄산염광물의 용해작용이 현저하여 약풍화대에서 조차 방해석이 완전히 용해되어 빈 공간으로 남아있다. 그러나 점토광물과 같은 이차광물의 형성은 미약한 특징을 보인다. 이 지역의 암석은 일정기간 동안 물에 잠긴 상태로 유지되고, 동결과 해빙이 반복됨으로써 물리적 풍화작용이 상대적으로 빠르게 진행되어 물의 침투가 용이한 투수성 구조를 형성하였고, 그 결과 탄산염광물의 용해작용이 급속하게 일어났다. 자유로운 물의 순환으로 인하여 용해된 원소들이 점토광물과 같은 풍화광물로 침전되지 않고 용탈됨으로써 암석조직이 이완되어 풍화작용이 가속되었다. 퇴적암중 풍화에 극히 약한 탄산염광물의 높은 함량이 강한 화학적 풍화작용의 주 요인으로 보인다.

• 한국환경보건학회지
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• 제40권2호
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• pp.147-156
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• 2014

Objectives: This study was carried out to examine whether the apparent photolysis with or without sensitizers [NaOH and humic acid (HA)] was prompted photodegradation of polychlorinated biphenyl (PCB) in aqueous solution. Methods: PCBs photodegradation occurred using fluorescence black lamps at ${\lambda}_{max}=300nm$. PCB congeners were exposed in 10 ppm HA or 0.05N NaOH solutions, to investigate the decreasing profile of PCB concentration with time. The PCBs were then analyzed by gas chromatography/mass spectrometry (GC-MS). Reductive degradation profile of PCB congeners in the presence of both sensitizers under oxygen-saturated protic conditions was described using the wind-rose diagrams. Results: Use of HA or NaOH decreased PCB concentration with time in the dark and on irradiation, indicating that photolysis underwent through reductive dechlorination through energy transfer and possibly with reactive oxygens. The dechlorination was marked by a chromatographic shift, observed in the GC-MS plots. Therefore it is logical to assume that increasing the dose of sensitizers would increase the photodegradation rates of PCBs. The half-lives of pentachloro-PCB (penta-3) in 0.05N NaOH and 10 ppm HA were estimated at about 47 hours and 39 hours, respectively, under the same experimental conditions of photolysis. It was found that the rate of photolysis of pentachloro-PCB in aqueous solution followed apparent first-order kinetics compared to other congeners. Conclusion: Photochemical degradation (using 328 nm UV light) of penta- and hexa-PCBs in HA or alkaline solution is a viable method for pretreatment method. The results are helpful for the further comprehension of the reaction mechanism for photolytic dechlorination of PCBs in aquatic system.

• Membrane and Water Treatment
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• 제11권4호
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• pp.257-274
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• 2020

There are many previous review articles are available to summarize either the characterization methods of effluent organic matter (EfOM) or the individual control treatment options. However, there has been no attempt made to compare in parallel the physicochemical treatment options that target the removal of EfOM from biological treatments. This review deals with the recent progress on the characterization of EfOM and the novel technologies developed for EfOM treatment. Based on the publications after 2010, the advantages and the limitations of several popularly used analytical tools are discussed for EfOM characterization, which include UV-visible and fluorescence spectroscopy, Fourier transform infrared spectroscopy (FTIR), size exclusion chromatography (SEC), and Fourier transform-ion cyclotron resonance-mass spectrometry (FT-ICR-MS). It is a recent trend to combine an SEC system with various types of detectors, because it can successfully track the chemical/functional composition of EfOM, which varies across a continuum of different molecular sizes. FT-ICR-MS is the most powerful tool to detect EfOM at molecular levels. However, it is noted that this method has rarely been utilized to understand the changes of EfOM in pre-treatment or post-treatment systems. Although membrane filtration is still the preferred method to treat EfOM before its discharge due to its high separation selectivity, the minimum requirements for additional chemicals, the ease of scaling up, and the continuous operation, recent advances in ion exchange and advanced oxidation processes are greatly noteworthy. Recent progress in the non-membrane technologies, which are based on novel materials, are expected to enhance the removal efficiency of EfOM and even make it feasible to selectively remove undesirable fractions/compounds from bulk EfOM.

• 대한화학회지
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• 제61권5호
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• pp.238-243
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• 2017

본 연구에서, 400도에서 탄화시킨 정수 슬러지를 수중의 납과 카드뮴의 제거를 위한 흡착제로서 시험하였다. 탄화된 슬러지는 열중량 분석, 주사 전자 현미경, X-선 형광분광기, 표면적 분석에 의해 특성화 하였다. 탄화 슬러지는 정수 슬러지 자체보다도 대단히 높은 비표면적과 총 세공부피를 나타내었다. 회분식 흡착 과정에서 탄화 슬러지는 카드뮴보다는 납에 대하여 더 나은 흡착성능을 보였으며, 실험에서 행한 농도에서 90~98%의 흡착 능력을 달성하였다. 흡착의 평형 데이터는 Freundlich와 Langmuir와 흡착등온선 모델을 이용하여 평가하였고, Freundlich와 Langmuir 흡착 등온선 둘 다 0.95보다 큰 상관계수($R^2$) 값을 나타내었다. 연구의 결과들은 열처리 된 탄화 정수 슬러지가 수중으로부터 납과 카드뮴을 제거하는데 효율적인 흡착제로 사용될 수 있다는 것을 보였다.

• Journal of the korean society of oceanography
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• 제33권4호
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• pp.178-184
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• 1998

To elucidate contamination levels and distribution of methyl mercury (Me-Hg) in Korean coastal areas, 126 sediment samples were collected from Kyeonggi Bay, Namyang Bay, Chinhae Bay, and Lake Shihwa during 1995-1996, and the Me-Hg concentrations were determined by cold vapor atomic fluorescence spectrometry (CVAFS). Contamination levels of Me-Hg in sediments from Kyeonggi Bay, Namyang Bay, Chinhae Bay, and Lake Shihwa were 274 ${\pm}$ 990, 108 ${\pm}$ 24, 294 ${\pm}$ 342, and 1080 ${\pm}$ 760 pg/g, respectively. Concentrations of Me-Hg in sediments were significantly correlated with total organic carbon and sulfur contents, but were independent of mud contents and mean grain size. The highest concentration of Me-Hg (7100 pg/g) was observed at Incheon North Harbor (Site Kl9) in Kyeonggi Bay. This Me-Hg concentration was one or two orders of magnitude higher than those in other Kyeonggi Bay sediments were. The average concentration of Me-Hg in sediments from Lake Shihwa was higher than in those from other study areas. The three peaks of Me-Hg concentrations were observed on three sites (55, 56,and 510) in Lake Shihwa and gradually decreased in distance-dependent manner around these sites. High concentrations of Me-Hg at surface and 10-cm sediment depth in Chinhae Bay maybe due to higher rates of methylation process by active sulfate-reducing bacteria or higher concentrations of total mercury available to sulfate-reducing bacteria.

• 분석과학
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• 제13권2호
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• pp.179-188
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• 2000

대기환경시료인 도시분진시료와 인공적으로 준비한 휠터상 도시분진시료중의 미량원소를 중성자방사화분석법을 사용하여 비파괴 분석하였다. 분석정도관리를 위하여 미국 표준기술원의 인증표준시료 (Urban Dust, NIST SRM 1648)를 이용하였다. 37종의 검출된 원소의 상대오차와 상대 표준편차를 계산하였으며 각각 10%와 15%이내이었다. 도시분진시료로부터 29종의 원소, 휠터상 도시분진시료로부터 21종의 원소를 정량하였다. 측정결과의 신뢰도 및 숙련도 평가를 위하여, 중성자방사화분석법, 하전입자유도 X-선방출분광법, X-선 형광분석법과 원자흡수분광법을 이용한 세계 39개 실험실이 참여한 실험실간 비교시험에 참여하였으며 수집된 결과를 통계처리하였다. 평균값과 표준편차로 계산한 z-score는 몇개의 원소를 제외하고 모두 -1