• 한국환경과학회지
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• 제10권4호
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• pp.299-304
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• 2001

For the remediation of the contaminated soil with heavy metals, Cd, Cr, Cu, and Pb, the reaction parameters were optimized. Tartaric acid (TA) and oxalic acid(OA) as a washing agent and recovery of metals, The optimum washing conditions of TA and OA were in the ratio of 1 : 20 between soil and acid solution during 2hr reaction under unbuffered pH solutions. At the optimized reaction conditions, the removal efficiencies were compared with that of 0.1 M HCl and ethylenediamine tetraacetic acid(EDTA). TA showed higher efficiency on the removal of Pb than that of EDTA, which established for the remediation of contaminated soil with Pb and Cd metals. The recovery of metal ions from washing solution was achieved by adding calcium hydroxide and sodium sulfide by forming the precipitation of metal hydroxide and metal slfied. Optimum amounts of sodium sulgide and calcium hydroxide were Cd = 25g/$\ell$, Cu = 5~10g/$\ell$ and Pb = 5~10g/$\ell$ for the washing solution of OA and 2~5g/$\ell$ for the washing solution of TA, respectively. The amounts of $Na_2S$ and $CA(OH)_2$ for the tartaric acid was less than that of oxalic acid.

• 분석과학
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• 제11권3호
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• pp.222-228
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• 1998

15종의 분자량이 낮은 휘발성 유기용매 물질류를 사용하여 에탄올에 대한 분리분석 등을 검토하기 위하여 5가지 충진 칼럼과 2가지 모세관 칼럼을 이용한 기체 크로마토그래피 실험에서 Gaskuropack 54 와 DB-1 column이 좋은 분리능을 보여 주었다. GC 기화평형법에 의한 생체물 시료의 알코올 농도 측정에서 0.6N 과염소산, 1M 메타인산 및 염화나트륨 포화용액을 이용한 salt-effect 첨가실험은 그 중 염화나트륨 포화 용액이 알코올 농도값을 얻는데는 가장 안정된 값을 보였다. 혈액 및 각 조직의 시료들에서 시간에 따른 농도변화 실험에서 에틸알코올 농도 변화, 무게 변화, 함수분 변화, 헤마토크리트 변화치 영향을 함께 실험한 결과, 용기의 직경에 따르는 알코올 농도의 감소 변화를 1차 함수로 제안 할 수 있었으며, NISI에 조사 의뢰된 25 부검 사례에서 각 장기별 에틸알코올 분배농도에 대한 실험에서 뇌, 혈액, 신장, 비장, 간장, 폐장의 순으로 분포율이 낮아지는 결과를 얻을 수 있었다.

• 환경생물
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• 제22권1호
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• pp.184-191
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• 2004

To investigate bacteria with algalytic activities against Anabaena cylindrica when water blooming occurs and to study enzyme profiles associated with alga-lytic activity, various bacterial strains were isolated from surface waters and sediments in eutrophic lakes or reservoirs in Korea. Among 178 isolates, only nine isolates exhibited lytic abilities against A cylindrica on the agar plates, and then the isolate AK-13 was selected as the strongest in lysing the cyanobacterium A. cytindrica. The strain AK-13 was characterized and identified as Sinorhizobium sp. based on fatty acid methyl ether profiles and 16S rDNA sequence. According to the results of the enzyme assays, in the strain An-13 of Sinorhizobium sp., alginase, amylase, proteinase (caseinase and gelatinase), carboxymethyl-cellulase (CMCase), laminarinase, and lipase was produced, namely CMCase, laminarinase and protease were highly active. None of glycosidase was produced. Therefore, enzyme systems of Sinorhizobium sp. AK-13 were very complex to degrade cell walls of A. cylindrica. The peptidoglycans of A. cylindrica mat be hydrolyzed and metabolized to a range of easily utilizable monosaccharides or other low molecular weight organic substances by Sinorhizobium sp. AK-13.

• 한국자기공명학회논문지
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• 제26권3호
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• pp.24-33
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• 2022

The browning phenomenon of fruits can be easily observed when fruits or vegetables (apples, pears, bananas, potatoes, etc.) are cut with a knife and the part turns brown. When this browning occurs, changes in taste, color, and nutrients usually are introduced. The cause of this browning phenomenon has been well studied for a long time, but these studies have mainly focused on preventing deterioration of processed foods during food processing or storage. Resultantly, there are few studies on how much changes in nutrients (saccharides, amino acids, fats, water-soluble low molecular weight ammonium ions, etc.) are caused by browning. The purpose of this study is to determine the change in nutrients during browning using apple as a model fruit. We conducted a comparative study on how much the nutrient fluctuations differ depending on the presence or absence of pretreatment such as the application of heat. All analysis was conducted using ¹H NMR. The ANOVA analysis showed that the concentrations of 4 amino acids (alanine, asparagine, isoleucine, and valine), 3 types of sugars (fructose, glucose, and xylose), 1 type of organic acid (lactate) and choline were significantly increased in samples showing browning. In addition, the groups before and after browning were clearly separated using multivariate statistical analysis methods (PCA, PLS-DA), which was greatly contributed by two sugar components (fructose and glucose) present in high concentrations in apples.

• 청정기술
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• 제28권3호
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• pp.232-237
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• 2022

해조류 바이오매스 중 갈조류의 주요 구성 성분인 알긴산은 다양한 산업에서 널리 사용되어지며, 촉매적 저분자화를 통해 당, 당알코올, 퓨란계, 그리고 유기산과 같은 고부가가치 화합물로 전환할 수 있다. 본 연구에서는 루테늄 담지 활성탄과 마그네시아를 혼합하여 알긴산 저분자화 반응에 적용하고자 하였다. 이러한 불균일계 촉매 시스템은 생성물에 대한 분리가 용이하고 정제 과정의 간소화가 장점으로 작용한다. 반응 결과, 탄소 수 5개 이하의 저분자량 알코올 및 유기산이 생성되었으며, 최적의 반응 조건 탐색을 통해 최종적으로 1 wt% 알긴산 수용액 30 mL, 루테늄 담지 활성탄 100 mg, 마그네시아 100 mg, 반응 온도 210 ℃, 반응 시간 1 h의 반응 조건에서 29.8%의 알코올에 대한 탄소 수율과 43.8%의 알코올 포함 액상 생성물에 대한 총 탄소 수율을 확보하였다.

• Korean Chemical Engineering Research
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• 제54권6호
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• pp.806-811
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• 2016

오르가노솔브를 이용한 전처리는 목질계 바이오매스의 주요성분을 분별하고 전처리 바이오매스의 효소당화를 효과적으로 유도할 수 있는 공정이다. 이에 사용되는 오르가노솔브는 증류와 재순환공정으로 쉽게 재사용이 가능하고 고형성분에서 리그닌을 화학적으로 분별시킬 수 있다는 장점이 있다. 경제적인 이유로서 낮은 분자량의 알코올(에탄올, 메탄올 등)이 사용되어 왔으며, 무기산(염산, 황산, 인산 등)이 촉매로 첨가되었을 경우 탈리그닌 효과 및 자일로스 성분의 수율을 증대시킬 수 있다. 본 연구에서는 오르가노솔브로는 에탄올을 사용하였고 소량의 황산 촉매를 첨가해 전처리를 수행하였다. 바이오매스는 침출식반응기에서 40~50 wt%의 에탄올을 이용해 20~60분 동안 $170{\sim}180^{\circ}C$에서 전처리가 되었다. 전처리를 마친 바이오매스에 대해서는 전처리 효과를 알아보기 위하여 72시간 동안 효소당화를 수행하였다. 그 결과 $180^{\circ}C$에서 50 wt% 에탄올을 이용한 리기다의 2단 전처리에서 당화율은 40.6%로 나타났지만 같은 조건에서의 1단 전처리에서는 55.4%로 가장 높게 나타나는 것을 보았을 때, 용매와 촉매를 균일하게 섞는 것이 전처리에 효과적이라는 것을 알 수 있었다.

• Journal of Ginseng Research
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• 제45권6호
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• pp.726-733
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• 2021

Background: Panax notoginseng is a highly valued medicinal herb used widely in China and many Asian countries. Its root and rhizome have long been used for the treatment of cardiovascular and hematological diseases. Imaging the spatial distributions and dynamics of metabolites in heterogeneous plant tissues is significant for characterizing the metabolic networks of Panax notoginseng, and this will also provide a highly informative approach to understand the complex molecular changes in the processing of Panax notoginseng. Methods: Here, a high-sensitive MALDI-MS imaging method was developed and adopted to visualize the spatial distributions and spatiotemporal changes of metabolites in different botanical parts of Panax notoginseng. Results: A wide spectrum of metabolites including notoginsenosides, ginsenosides, amino acids, dencichine, gluconic acid, and low-molecular-weight organic acids were imaged in Panax notoginseng rhizome and root tissues for the first time. Moreover, the spatiotemporal alterations of metabolites during the steaming of Panax notoginseng root were also characterized in this study. And, a series of metabolites such as dencichine, arginine and glutamine that changed with the steaming of Panax notoginseng were successfully screened out and imaged. Conclusion: These spatially-resolved metabolite data not only enhance our understanding of the Panax notoginseng metabolic networks, but also provide direct evidence that a serious of metabolic alterations occurred during the steaming of Panax notoginseng.

• 생명과학회지
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• 제30권12호
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• pp.1128-1139
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• 2020

최근 기후의 급속한 변화에 따라서 식품과 농산물에 Aspergillus, Fusarium 및 Penicillium속에 해당하는 곰팡이에 의한 오염이 빈번하고 이들에 의해 생성되는 aflatoxins, fumonisins, ochratoxins, patulin, trichothecenes, zearalenone등의 곰팡이 독소로 인해서 인간의 건강에 위해를 끼치고 또한 경제적인 손실을 가져오게 하고 있다. 최근 건강에 대한 소비자의 관심으로 인하여 기존에 사용되고 있는 프로피온산 및 소브산과 같은 보존료에 대한 거부감이 증가하고 있어 천연의 소재로부터 이를 대체할 만한 항진균제의 개발이 필요한 상황이다. 본 총설에서는 곰팡이의 생육 및 독소 생성을 제어하기 위한 생물학적 방법으로 유산균의 역할에 대하여 살펴보고자 하였다. 최근의 연구에 의하면 유산균은 저분자 화합물인 유기산, reuterin, 단백질 유래 화합물, 하이드록시 지방산, 페놀 화합물과 같은 다양한 대사산물을 통하여 곰팡이의 생육을 효과적으로 억제시키고 있으며, 또한 유산균의 세포벽 구성성분과의 흡착, 곰팡이 독소의 분해 및 곰팡이 독소의 생산 저해 등을 통하여 곰팡이 독소의 생산을 감소시키고 있는 사실이 제시되고 있다. 유산균은 다양한 종류를 포함하고 있으며 다양한 대사산물을 생산하고 있으므로 이를 바탕으로 효과적으로 곰팡이의 생육 및 독소 생산을 제어할 수 있는 잠재력 갖추고 있으므로, 유산균은 식품에 있어서 곰팡이의 생육을 조절하는 소재로서 주목 받을 것으로 기대된다.

• 대기
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• 제31권3호
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• pp.267-282
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• 2021

Characteristics of carbonaceous components and organic compounds in PM_2.5 over the atmosphere of the Yellow Sea were investigated. PM_2.5 samples were collected onboard the meteorological research vessel, GISANG 1, over the Yellow Sea during the YES-AQ campaign in 2018 and 2019, respectively. The average concentrations of carbonaceous components in this region were 2.59 ± 1.59 ㎍ m^-3 for the OC, 0.24 ± 0.10 ㎍ m^-3 for the EC, 2.14 ± 1.30 ㎍ m^-3 for the WSOC and 1.17 ± 0.94 ㎍ m^-3 for the HULIS-C, respectively. The total concentration of 56 organic compounds (ΣOCs) accounts for 10% of OC. The main group among organic compounds were dicarboxylic acids which account for 57% of ΣOCs, followed by n-alkanoic acids accounting for 34% of ΣOCs. In n-alkanoic acid distribution, hexanoic (C_6:0) and octanoic (C_8:0) acids which are low molecular weight n-alkanoic acids and known as emitted from marine biogenic activities were dominant in this region. Furthermore, non-HULIS-C fraction increased when the air mass originated from the marine region rather than the continental region. When the Asian dust episode was observed, the WISOC concentrations along with the levoglucosan were increased, while the haze episodes caused the increase of WSOC, HULIC-S and DCAs. In this study, we found that the components of carbonaceous and organic aerosols in PM_2.5 over the Yellow Sea were changed with the specific air pollution episodes. It indicates that the physicochemical properties of PM_2.5 can be changed by the air pollution episodes in this region.

• 한국물환경학회지
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• 제21권5호
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• pp.484-489
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• 2005

In order to determine the removal rate of non-biodegradable substances and the change of their structural properties, this study was carried out by an ozone-treatment experiment on leachate collected from the landfill area of D City in Chung chung nam-do and examined the change of the chemical properties of non-biodegradable substances. The main elements of non-biodegradable substances in landfill leachate were benzene, toluene, trichloroethane, trichloroethylene, xylene, etc. and the concentration of toluene was 15.7 mg/L on the average, benzene 7.2 mg/L, trichloroethane 1.1 mg/L, trichloroethylene 0.75 mg/L and xylene 0.5 mg/L. When leachate was treated with ozone for 10 min, 30 min and 60 min, UV absorbance was reduced with the increase of reaction time, and the reduction rate was 38.6% at 60 min. TOC was removed by 13.2% at 60 min. The low reduction rate of TOC may be because TOC reacts indirectly with OH radical produced from reaction with ozone while UV absorbance usually relies on direct reaction between organic matters and ozone molecules. Color was removed by up to 97%, which suggests that ozonation is highly effective in removing coloring elements in leachate. Sixteen kinds of non-biodegradable compounds were found in the leachate and most of them had the characteristic of aromatic hydrocarbon. Among them dibutyl phthalate was identical with a substance included in the list of US EPA, which is classified as a mutagen that may cause the mutation of genes and disorders in chromosomes. In addition, 2,5-Cyclohexadiene-1,4-dione, 1,2-Benzenedicarboxylic acid and butyl octyl ester were found to be similar to substances listed by USEPA. According to the result of analyzing structural changes before and after ozonation using GC-MS, cyclic compounds and aromatic compounds were observed in the original water and aliphatic compounds were newly observed after ozonation. In addition, through ozonation, humic substances of high molecular weight were oxidized and decomposed and produced low-molecular compounds such as aldehyde, ketone and carboxyl acid and highly biodegradable aliphatic carbon, which suggests the bio-degradability of non-biodegradable substances.