• 한국안전학회지
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• 제4권1호
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• pp.75-81
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• 1989

The aim of this study is, by the Lime-Stabilization of decayed Organic Wastes, in preventing the reclaimed Waste from being another pollution due to reclaiming those things. 1. A perfect reaction is possible by the addition of poor Stabilization-Lime of 5 percent in a short time of 5 minute. 2. PH of the Stabilization-handled Wastes rise over 12. 3. Malodorant of Stabilized Wastes is slight because malodorant Volatilize in the course of the Stabilization or is captured in the handled subetance. 4. The second pollution scarcely brings about because a rapid decomposition is impossible on account of the coating of Alkali Substance.

• Ocean and Polar Research
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• 제29권2호
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• pp.87-99
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• 2007

This study was conducted to understand the source and behavior of organic matter using the fluorescent technique (excitation-emission matrix) as a part of environmental monitoring program in the Korea manganese nodule mining site in the Northeastern Pacific Ocean. Water samples were collected at $0^{\circ},\;6^{\circ}N$, and $10.5^{\circ}N$ along $131.5^{\circ}W$ in August 2005. The concentration of total organic carbon (TOC) ranged from 58.01 to $171.93\;{\mu}M-C$. The vertical distribution of TOC was characterized as higher in the surface layer and decreased with depth. At $6^{\circ}N$, depth-integrated (from surface to 200 m depth) TOC was $337.1\;gC/m^2$, which was 1.4 times higher value than other stations. The exponential decay curve fit of vertical profile of TOC indicated that 59% of organic carbon produced by primary production in the surface layer could be decomposed by bacteria in the water column. Dissolved organic matter is generally classified into two distinctive groups based on their fluorescence characteristics using three-dimensional excitation/emission (Ex/Em) fluorescence mapping technique. One is known as biomacromolecule (BM; protein-like substance; showing max. at Ex 280/Em 330), mainly originated from biological metabolism. The other is geomacromolecule (GM; humic-like substance; showing max. at Ex 330/Em 430), mainly originated from microbial degradation processes. The concentration of BM and GM was from 0.42 to 7.29 TU (tryptophan unit) and from 0.06 to 1.81 QSU (quinine sulfate unit), respectively. The vertical distribution of BM was similar to that of TOC as high in the surface and decreased with depth. However, the vertical distribution of GM showed the reverse pattern of that of BM. From these results, it appeared that BM occupied a major part of TOC and was rapidly consumed by bacteria in the surface layer. GM was mainly transformed from BM by microbial processes and was a dominant component of TOC in the deep-sea layer.

• 한국산업보건학회지
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• 제29권1호
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• pp.1-12
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• 2019

Objective: Significant concerns have been raised over chemical exposure and potential health risks such as increased cancer mortality among laboratory workers. The aim of this study was to investigate the overall exposure and unit task exposure levels of researchers in organic synthesis laboratories at universities. Methods: Seventy-seven personal Time-weighted average(TWA) samples and 139 task-based samples from four organic synthesis laboratories at two universities were collected over three days. The concentrations of acetone, chloroform, dichloromethane(DCM), diethyl ether, ethyl acetate, n-hexane, tetrahydrofuran(THF), benzene, toluene, and xylene were determined using the GC-FID. Results: The most frequently used chemicals in the laboratories were acetone, DCM, n-hexane, methanol, and THF. Carcinogens such as benzene, chloroform, and DCM were used in one or more laboratories. The TWA full-shift exposures of researchers to acetone was the highest(ND-59.3 ppm). Benzene was observed above the occupational exposure limit in 18-40% of the samples. The levels of exposure to organic solvents were statistically different by task(p<0.05), while washing task was the highest. Washing was not perceived as a part of the real lab tasks. Rather it was considered as simple dish-washing or experimental preparation and performed in an open sink where exposure to organic solvents was unavoidable. TWAs and task-based concentrations were compared by substance, which suggests that TWA-based assessment could not reflect short-term and high concentration exposures. Conclusions: Laboratory workers may be exposed to various organic solvents at levels of concern. TWA-based measurement alone cannot guarantee holistic exposure assessment among lab workers as their exposures are very dependent on their tasks. Further investigation and characterization for specific tasks and overall chronic exposures will help protect lab workers from unnecessary exposure to chemicals while they perform research.

• 한국지하수토양환경학회지:지하수토양환경
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• 제27권5호
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• pp.10-17
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• 2022

Inorganic acids such as HCl, HNO₃, and H₂SO₄ have been commonly applied to soil washing of heavy metals-contaminated soil due to their cost-effectiveness. However, implementing the 'Chemical Substance Control Act' requires off-site risk assessment of the chemicals used in the soil washing. Therefore, in this study, organic acids or Fe(III)-based washing agents were evaluated to replace commonly used inorganic acids. Ferric removed heavy metals via H⁺ generated by hydrolysis, which is similar to the HCl used in the control group. Oxalic acid and citric acid were effective to remove Cu, Zn, and Cd from soil. Organic acids could not remove Pb because they could form Pb-organic acid complexes with low solubility. Furthermore, Pb could be adsorbed onto the iron-organic acid complex on the soil surface. Ferric could remove exchangeable-carbonate, Fe-Mn hydroxide, and organic matter and sulfides bound heavy metals (F1, F2, and F3). Organic acids could remove the exchangeable-carbonate and Fe-Mn hydroxide bound metals (F1&F2). Therefore, this research shows that the fractionation of heavy metals in the soil and the properties of washing agents should be considered in the selection of agents in the process design.

• KIEAE Journal
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• 제4권3호
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• pp.129-136
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• 2004

Recently, indoor air pollution has been seriously apprehended, and became a striking issue, due to the airtightness of buildings or the misuse of building materials. Especially, SHS(Sick House Syndrome) and MCS(Multi Chemical Sensitivity) which can have bad influences on the resident in an existing apartment house as well as newly constructed apartment house start to attract public attention. The emission rates of VOCs is sensitively affected by the indoor/outdoor condition, construction materials, construction method, and character of ventilation facilities. Therefore, in this study, by measuring the indoor air pollution substance of the existing apartment house, the problem over this tends to be grasped and it is going to secure an improvement methods.

• Biotechnology and Bioprocess Engineering:BBE
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• 제7권1호
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• pp.31-37
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• 2002

This paper was investigated to clarify the possibility of a biodegradation of materials adsorbed on different porous granular-activated carbons (GACs) such as coal-& coconut-based GAC. Total organic carbon, humic substance and ammonia were used to compare their removal efficiencies. The objective of this study is to determine the adsorption capacity of bioregenerated GAC. When raw water reacted with chloride, the yield of THMs increased as a function of the input amount of chloride. The formation of trihalomethanes (THMs) was investigated in water treated with chlorine when humic acid was used as THM precursor. As the input amount of chloride in raw water increased by two or five-fold to remove the $NH_3$, the chloroform of the THMs significantly increased also five or ten-fold. It was found that the chloroform was significantly removed by the treatment of biological activated carbon (BAG) in comparison with the ozone treatment, and the removal efficiency of THMs in coal-typed GAC was $10-30\%$ better than coconut-typed GAC due to the biological degradation on the surface of the activated carbons.

• 산업기술연구
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• 제27권B호
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• pp.109-114
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• 2007

Humic substances generally comprise 30-50% of the dissolved organic carbon in water. They can affect water quality adversely in several ways and they are important from a water treatment perspective due to their role as precursors for the formation of chlorination by-products such as trihalomethanes. The objectives of this research are to investigate the characteristics of organic matter using raw water of Chuncheon area, to isolate the humic substance fractions from natural water samples, and characterize the extracted humic substances. Humic substances were fractionated according to "isolation of IHSS aquatic humic and fulvic acids" using XAD resin adsorption technique. Characteristics of humic substances were analyzed through DOC, $UV_{254}$, $SUVA_{254}$, FT-IR spectra, fluorescence analysis.

• 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.

• 펄프종이기술
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• 제47권2호
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• pp.70-79
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• 2015

This study was carried out to analyze deterioration characteristics of color-pigments painted Hanji to preserve and restore the cultural properties. On the traditional painting technique, glue was used with pigments in various ways for painting, but it eventually caused the deterioration of paintings. Thus, five colors were selected and analyzed for this study for investigating their characteristics of deteriration. Three kinds of glues (Wugyo, Nokgyo, and Togyo) and two kinds of pigments (Chinese and Gilsang) were painted on the Hanji for the accelerated aging test. And then color fastness of pigments and tensile strength of painted Hanji were measured for the estimation of deterioration degree. The results of SEM-EDS showed that Chinese pigments including blue, yellow, green, and red were composed of inorganic substances but the brown was organic substance. Gilsang pigments were composed mainly of Si and Ti ions. Color fastness of the Gilsang pigment blue, yellow, green, and brown were better than those of Chinese. Chinese pigment brown with organic substance showed the worst color fastness. Generally, Chinese pigments painted Hanji showed higher tensile strength than Gilsang in the accelerated aging test. Hanji treated with Chinese pigment and Nokgyo (antler glue) blends and Gilsang pigment and Togyo (rabbit pelt glue) blends showed higher tensile strength than the others. And Andong Hanji showed the highest tensile strength.