• 한국물환경학회지
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• 제24권1호
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• pp.123-128
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• 2008

The Dissolved Organic Carbon (DOC) existing in a water includes both hydrophobic and hydrophilic substances however, most of the discussion focuses on hydrophobic substances. The hydrophobic fraction was easily removed by absorption or coagulation more than hydrophilic fraction. Therefore, control of the hydrophilic fraction is very important in water treatment process. This study is to determine the variation of DOC, the removal efficiency of DOC, and Trihalomethane formation potential (THMFP) after each stage of water treatment process by fractionating Natural Organic Matters (NOM) into hydrophobic and hydrophilic substance. DOC from raw water was fractionated at acidic pH (pH<2) using XAD 8 resin column, into two fraction : hydrophobic substance (i.e. humic substance) adsorbed on XAD 8 and hydrophilic substance which represent the organics contained in the final effluent. THMFP was carried out according to the following set condition: Cl2/DOC=4 mg/mg, incubation at $25^{\circ}C$ in darkness, pH 7 adjust with HCl or NaOH as necessary, and 72hour-contact time. THMs analyzed in this study were chloroform, bromodichloromethane, dibromochloromethan, and bromoform. Sewage was almost evenly split between the hydrophobic (56%) and hydrophilic fraction (44%). But, Aldrich humic substance (AHS) was found to contain less hydrophilics (14%) than hydrophobics (86%). The formation of THMs may depend on the source which is characterized by the composition of organic matters such as AHS and sewage. The THMFP yield of sewage and AHS were assessed as follows. The value of the THMFP reaction yield, AHS $172.65{\mu}g/mg$, is much higher than that of sewage $41.68{\mu}g/mg$. This illustrates possible significant difference in THMFP according to the component type and the proportion of organic matter existing in water source. Apparently AHS react with chlorine to produce more THMFP than do the smaller molecules found in sewage. Water treatment process may reduce THMFP, nevertheless residual DOC (the more hydrophilic substance) has significant THMFP. Further reduction in organic halide precursors requires application of alternative treatment techniques.

• Preventive Nutrition and Food Science
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• 제6권4호
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• pp.230-234
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• 2001

The extract of Ulmus davidiana var. japonica cortex has known as natural anti-inflammatory substance in East Asia. For the identification of antimicrobial substance, it was extracted by using methanol and fractionated by using different organic solvents. The fraction of butanol was represented the highest antimicrobial activities. Therefore, the butanol fraction was purified and identified the chemical structure by $^1$H and $^{13}$ C-NMR spectra, FT-IR and EI/MS spectroscopies. The isolated antimicrobial substance was identified as cis-2-[3,4-dihydroxy phenyl]-3,4-dihydro-2H-1-benzopyran-3,5,7-triol, which has commonly known as (-)epicatechin. Its minimum inhibitory concentrations (MICs) against Staphylococcus aureus and Listeria monocytogenes were shown as 100 $\mu\textrm{g}$/mL, respectively.

• 한국토양비료학회지
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• 제48권6호
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• pp.736-743
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• 2015

Organic matter plays important roles in soil ecosystem in terms of carbon and nitrogen cycles. Due to recent concerns on climate change, carbon sequestration in agricultural land has become one of the most interesting and debating issues. It is necessary to understand behavior of soil carbon for evaluating decomposition or sequestration of organic matter and analyzing potential carbon decomposition pattern about the kinds of organic matter sources to cope with well. In order to evaluate decomposition of soil carbon according to organic material during cultivating rice in paddy field, we treated organic material such as hairy vetch, rice straw, oil cake fertilizer, and manure compost at $50{\times}50{\times}20cm$ blocks made of wood board, and analyzed carbon contents of fulvic acid and humic acid fraction, and total carbon periodically in 2013 and 2014. Soil sampling was conducted on monthly basis. Four Kinds of organic matter were mixed with soil in treatment plots on 2 weeks before transplanting of rice. The treatment of animal compost showed the highest changes of total carbon, which showed $7.9gkg^{-1}$ in May 2013 to $11.6gkg^{-1}$ in October 2014. Fulvic acid fraction which is considered to easily decompose ranged from 1 to $2gkg^{-1}$. Humic acid fraction was changed between 1 to $3gkg^{-1}$ in all treatments until organic material had been applied in 2014. From May to August in the second year, the contents of humic acid fraction increased to about $4gkg^{-1}$. The average of humic fraction carbon at treatments of animal compost was recorded highest among treatments during two years, $2.1gkg^{-1}$. The treatment of animal compost has showed the lowest ratio of fulvic acid fraction, humic acid fraction compared with other treatments. The average ratio of fulvic fraction carbon in soil ranged from 16 to 20%, and humic fraction carbon ranged from 19 to 22%. In conclusion, animal compost including wood as bulking agent is superior in sequestrating carbon at agricultural land to other kinds of raw plant residue.

• 한국유기농업학회지
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• 제28권1호
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• pp.95-108
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• 2020

To develop an environment-friendly fungicide for controlling tomato wilt diseases, antifungal active substance was isolated Rheum australe D. Don roots against Fusarium oxysporum f. sp. lycopersici, a pathogen of tomato wilt, in this study. Methanol extract obtained from Rheum australe roots was successively fractionated with hexane, chloroform, ethyl acetate, butanol and water. The ethyl acetate fraction, which showed the highest antifungal activity, was separated by column chromatography, and 60 subfractions were obtained. The 60 subfractions were anlayzed for antifungal activities by bioassay. The active compound was identified as 5-[(E)-2- (3-hydroxy-4-methoxyphenyl)ethenyl]benzene-1,3-diol (rhapontigenin) by NMR and GC-MS analysis. As a result of testing antifungal activity of rhapontigenin against Fusarium oxysporum, EC₅₀ of rhapontigenin was showed strong antifungal activity at 7.48 mg/L. Therefore, this study showed that the Rheum australe roots extract can be a potential candidate which is a environment-friendly fungicide against Fusarium oxysporum.

• 한국환경농학회지
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• 제35권2호
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• pp.128-136
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• 2016

BACKGROUND: Hydrothermal carbonization reaction is the thermo-chemical energy conversion technology for producing the solid fuel of high carbon density from organic wastes. The hydrothermal carbonization reaction is accompanied by the thermal hydrolysis reaction which converse particulate organic matters to soluble forms (hydro-thermal hydrolysate). Recently, hydrothermal carbonization is adopted as a pre-treatment technology to improve anaerobic digestion efficiency. This research was carried out to assess the effects of hydro-thermal reaction temperature on the methane potential and anaerobic biodegradability in the thermal hydrolysate of organic sludge generating from the wastewater treatment plant of poultry slaughterhouse .METHODS AND RESULTS: Wastewater treatment sludge cake of poultry slaughterhouse was treated in the different hydro-thermal reaction temperature of 170, 180, 190, 200, and 220℃. Theoretical and experimental methane potential for each hydro-thermal hydrolysate were measured. Then, the organic substance fractions of hydro-thermal hydrolysate were characterized by the optimization of the parallel first order kinetics model. The increase of hydro-thermal reaction temperature from 170℃ to 220℃ caused the enhancement of hydrolysis efficiency. And the methane potential showed the maximum value of 0.381 Nm³ kg^-1-VS_added in the hydro-thermal reaction temperature of 190℃. Biodegradable volatile solid(VSB) content have accounted for 66.41% in 170℃, 72.70% in 180℃, 79.78% in 190℃, 67.05% in 200℃, and 70.31% in 220℃, respectively. The persistent VS content increased with hydro-thermal reaction temperature, which occupied 0.18% for 170℃, 2.96% for 180℃, 6.32% for 190℃, 17.52% for 200℃, and 20.55% for 220℃.CONCLUSION: Biodegradable volatile solid showed the highest amount in the hydro-thermal reaction temperature of 190℃, and then, the optimum hydro-thermal reaction temperature for organic sludge was assessed as 190℃ in the aspect of the methane production. The rise of hydro-thermal reaction temperature caused increase of persistent organic matter content.

• 한국물환경학회지
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• 제30권2호
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• pp.175-183
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• 2014

The influence of temperature on the treatment efficiency of chlorinated organic substances contained in groundwater by permeable reactive barrier which is composed of $Fe^{\circ}$ has been investigated by constructing the Pourbaix diagrams for Fe-$H_2O$ system at different temperatures based on thermodynamic estimation. In aerobic condition, the equilibrium potentials for $Fe^{\circ}/Fe^{2+}$ and $Fe^{2+}/Fe^{3+}$ were observed to increase, therefore, the dechlorination reaction for organic pollutants by $Fe^{\circ}$ was considered to decline with temperature due to the diminished oxidation of reactive barrier. The result for the variations of the ionization fraction of $Fe^{2+}$ and $Fe^{3+}$ ion in the pH range of 0 ~ 2.5 obtained by employing Visual MINTEQ program showed that the ionization fraction of $Fe^{2+}$ increased with pH, however, that of $Fe^{3+}$ decreased symmetrically and the extent of the variation of ionization fraction for both ions was raised as temperature rises. The equilibrium pH for $Fe^{3+}/Fe(OH)_3$ was examined to decrease with temperature so that the treatment efficiency of chlorinated organic substance was expected to decrease with temperature due to the enhanced formation of passivating film in aerobic condition. The change of the reactivity of a specific chemical species with temperature was defined quantitatively based on the area of its stable region in Pourbaix diagram and depending on this the reactivity of $Fe^{3+}$ was shown to decrease with temperature, however, that of $Fe(OH)_3$ was decreased monotonously as temperature is raised for $Fe^{3+}/Fe(OH)_3$ equilibrium system. In anaerobic condition, the equilibrium potential for $Fe^{\circ}/Fe^{2+}$ was observed to rise and the equilibrium pH for $Fe^{2+}/Fe(OH)_2$ were examined to decrease as temperature increases, therefore, similar to that for aerobic condition the efficiency of the dechlorination reaction for organic substances was considered to be diminished when temperature rises because of the reduced oxidation of $Fe^{\circ}$ and increased formation of $Fe(OH)_2$ passivating film.

• 한국해양학회지
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• 제29권2호
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• pp.171-182
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• 1994

황해 해역에서 해양 유기물의 생지화학적 특성을 파악하기 위하여 용존 자유 아미 노산 조성 및 추출된 유기물의 용존 가수분해 아미노산(DFAA) 조성 그리고 D/L alanine racemic ratio를 분석하였다. 용존 자유 아미노산의 농도는 평균 0.06 uM에서 0.26 uM의 범위를 보음, 우점하는 아미노산으로는 aspartate, glutamate, glycine, serine,alanin으로 나타났다. 각 기단별 물리·화학적 특성에 따라 분류한 아미노산 group 중 해수 중에 우점하는 것은 대부분 극성이 큰 hydrophilic group으로 나타났 다. 용존 가수분해 아미노산의 농도는 생거대유기물질의 경우 평균 2.05 uM에서 6.19uM의 범위를 보였고, 지구거대유기물질의 경우 평균 8.13 uM에서 24.46uM의 범위 를 보였다. 우점하는 아미노산의 group은 자유 아미노산과 유사한 경향을 보였다. 이 러한 용존 가수분해 아미노산은 생거대유기물질보다는 지구거대유기물질에서 상대적으 로 높은 농도를 보였다. 수괴가 성충화된 정점의 용존 가수분해 아미노산 농도는 저층 에 비해 표층이 상대적으로 높은 농도를 보였다. Alanine의 D/L racemic ratio는 생거 대 유기물질의 경우 0.126에서 0.146의 범위를 보였고 지구거대유기물질의 경우 0.309 에서 0.386의 범위를 보여 지구거대유기물질이 생거대유기물질보다 상대적으로 존재 연령이 오래된 것으로 나타났다. 이러한 자료들은 수괴의 특성 뿐만 아니라 생물활성 과 밀접하게 연관된 용존 유기 화합물의 중요한 생지화학적 지표를 이용될 수 있을 것 으로 사료된다.

• 한국유기농업학회지
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• 제23권4호
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• pp.951-962
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• 2015

본 연구는 균핵병의 원인균인 Sclerotinia sclerotiorum에 대해 항균활성을 갖는 친환경 유기농자재를 개발할 목적으로 이엽마두령(Aristolochia tagala Champ.)으로부터 활성물질 분리하였다. 이엽마두령을 MeOH로 추출하여 용매분획을 하였고, 용매분획 중에서 가장 강한 활성을 나타낸 $CHCl_3$ fraction을 column chromatography로 분리하여 43개의 subfraction을 얻었다. 43개의 subfraction을 bioassay한 결과 MYHS26 subfraction에서 강한 활성을 나타내었다. MYHS26 subfraction을 GC-MS로 분석하여 chromatogram 상의 주요 peak에 해당하는 mass spectrum과 Wiley library를 비교하여 profiling한 결과, 2,4-di-tetra-butyl-phenol, 2-monopalmitin, 1-mono-stearin이 주요 물질로 검출되었다. 항균활성물질로 추정되는 1-mono-stearin 화합물의 항균활성을 검정하기 위하여 표준품을 사용하여 생물검정한 결과 이 화합물이 강한 활성을 나타내었다. 따라서 이엽마두령으로부터 분리한 1-mono-stearin 화합물이 균핵병의 원인균인 Sclerotinia sclerotiorum에 대한 항균 활성물질인 것으로 추정되었다.

• 한국유기농업학회지
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• 제23권4호
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• pp.887-896
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• 2015

본 연구는 균핵병의 원인균인 Sclerotinia sclerotiorum에 대해 항균활성을 갖는 친환경 유기농자재를 개발할 목적으로 송라(Usnea longissima)로부터 활성물질을 분리하였다. 송라를 MeOH로 추출하여 용매분획을 하였고, 용매분획 중에서 강한 활성을 나타낸 $CHCl_3$ fraction을 column chromatography로 분리하여 40개의 subfractions을 얻었고 9개의 그룹으로 나누었다. 9개의 subfractions을 bioassay한 결과 G3 subfraction에서 강한 활성을 나타내었다. G3 subfraction을 GC-MS로 분석하여 chromatogram 상의 활성물질로 추정되는 peak의 mass spectrum과 Wiley library를 비교하여 profiling한 결과, Usnic acid가 주요 물질로 검출되었다. 항균활성물질로 추정되는 Usnic acid 화합물의 항균활성을 검정하기 위하여 표준품을 사용하여 생물검정한 결과 이 화합물이 강한 활성을 나타내었다. 따라서 송라로부터 분리한 Usnic acid가 균핵병의 원인균인 Sclerotinia sclerotiorum에 대한 항균 활성물질인 것으로 추정하였다.

• Fisheries and Aquatic Sciences
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• 제11권1호
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• pp.1-6
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• 2008

In an effort to discover an alternative therapeutic agent against methicillin-resistant Staphylococcus aureus (MRSA), several medicinal plants and seaweeds were evaluated for its antibacterial activity against MRSA. A methanolic extract of the Phaeophyta Ecklonia stolonifera exhibited significant antibacterial activity against MRSA. To perform more detailed investigation on antibacterial activity, the methanol extract of E. stolonifera was further fractionated with organic solvents such as hexane, dimethylchloride, ethyl acetate, and n-butanol. Among them, the hexane fraction showed the strongest antibacterial activity against MRSA strains with MIC from 500 to $600 {\mu}g/mL$. The fraction also exhibited a bactericidal activity against MRSA, indicating that E. stolonifera contains a bactericidal substance against MRSA.