• The Journal of Engineering Geology
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• v.16 no.4 s.50
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• pp.373-379
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• 2006

We investigated the relationship of the organic pollutant index in wastewater where the high percentages of an organic load to a water body was found. Measuring of TOC was to identify the relationship with COD and BOD which were used already. The correlation coefficient (r) of TOC/COD, BOD/COD and TOC/BOD were effected by the types of industry such as paper, textile, chemical, food and metal industries. In food industry it was found that the highest correlation coefficient (r) of TOC/COD, BOD/COD and TOC/BOD as 0.967, 0.969 and 0.990, respectively. There is low correlation coefficient in many cases. Hence it was impossible that the use of TOC for the water standard or monitoring instead of COD and BOD directly. However it can be used as alternative index to management a water process in the case of waste water where there was found high correlation coefficient of TOC/ COD, BOD/COD and TOC/BOD. It was sure that the water quality of river body can be protected if we use these the relationship among organic index.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.28 no.1
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• pp.108-116
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• 2018

Objectives: This study investigated to the analytical work environment, analyst's expert and status of analytical instrument in the designated organization's laboratory for measuring work environment, and carried out to ensure reliability of analytical results. Methods: This study was conducted by 114 analysts who work in designated organization's laboratory for measuring work environment. Information on the working environment and personal characteristics of the analysts were collected using a self-reported questionnaire and were analyzed using the SPSS program through analysis of frequency and t-test. Results: The speciality of subjects was occupational health(57.0%), environmental health(38.6%) and environmental engineering(4.4%), and they had a higher level of academic ability than workers in other industries. Analysts had to handle a large number of sample analysis and many tasks other than analytical work. The analysts answered that it was difficult to analyze organic substances than inorganic substances, and the difficult parts were the analytical methods setting of new substances(55.3%), instrument analysis(24.6%) and principle of analysis(23.7%). Analytical instruments mainly have legally required instruments. The difficulty of the analysis is solved from the senior analyst in the laboratory and analytical information is mainly exchanged through seminar organized by the Association of Occupational Health Analysts. The analysts who are planning to move or considering the company were 48.2%, and the reasons for moving the company were difficult to work(14.0%), low salary(9.6%), employment type(8.8%) and job stress(7.0%). Conclusions: The conclusions of our study were that it was possible to secure reliability by solving the problems such as implementing professional education to improve expertise of analysts, strengthening analytical instruments through institutional improvement and improving work environment.

• Journal of Microbiology and Biotechnology
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• v.29 no.7
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• pp.1043-1052
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• 2019

Active lipase-producing bacterium Burkholderia gladioli Bps-1 was rapidly isolated using a modified trypan blue and tetracycline, ampicillin plate. The electro-phoretically pure enzyme was obtained by purification using ethanol precipitation, ion-exchange chromatography, and gel filtration chromatography. The molecular weight was 34.6 kDa and the specific activity was determined to be 443.9 U/mg. The purified lipase showed the highest activity after hydrolysis with $p-NPC_{16}$ at a pH of 8.5 and $50^{\circ}C$, and the $K_m$, $k_{cat}$, and $k_{cat}/K_m$ values were 1.05 mM, $292.95s^{-1}$ and $279s^{-1}mM^{-1}$, respectively. The lipase was highly stable at $7.5{\leq}pH{\leq}10.0$. $K^+$ and $Na^+$ exerted activation effects on the lipase which had favorable tolerance to short-chain alcohols with its residual enzyme activity being 110% after being maintained in 30% ethanol for 1 h. The results demonstrated that the lipase produced by the strain B. gladioli Bps-1 has high enzyme activity and is an alkaline lipase. The lipase has promising chemical properties for a range of applications in the food-processing and detergent industries, and has particularly high potential for use in the manufacture of biodiesel.

• Journal of Life Science
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• v.28 no.12
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• pp.1545-1553
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• 2018

The International Society of Rare Sugars (ISRS) defines rare sugars as monosaccharides and their derivatives that rarely occur in nature. Rare sugars have recently received much attention because of their many uses including low-calorie sweeteners, bulking agents, and antioxidants, and their various applications including as immunosuppressants in allogeneic rat liver transplantation, as potential inhibitors of various glycosidases and microbial growth, in ischemia-reperfusion injury repair in the rat liver, and in segmented neutrophil production without detrimental clinical effects. Because they rarely exist in nature, the production of rare sugars has been regarded as one of the most important research areas and, generally, they are produced by chemical synthesis. However, the production of rare sugars by bioconversion using enzymes from microorganisms has been receiving increased attention as an environmentally friendly alternative production method. In particular, D-allulose, D-allose, and D-tagatose are of interest as low-calorie sweeteners in various industries. To date, D-tagatose 3-epimerase, D-psicose 3-epimerase, and D-allulose 3-epimerase have been reported as D-allulose bioconversion enzymes, and L-rhamnose isomerase, Galactose 6-phosphate isomerase, and Ribose 5-phosphate isomerase have been identified as D-allose production enzymes. Elsewhere, D-tagatose has been produced by L-arabinose isomerase from various microorganisms. In this study, we report the production of D-allulose, D-allose, and D-tagatose by microorganism enzymes.

• Journal of Life Science
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• v.28 no.12
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• pp.1523-1528
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• 2018

This study investigated the chemical composition of four Korean cultivated Chrysanthemum indicum L. (Gamguk 1 ho, Gamguk 2 ho, Gamguk 3 ho, and Wonhyang) which are used in the food and fragrance industries to identify their volatile flavor compounds. These compounds were analyzed using headspace GC-MS from plant samples cultivated in the same region of Korea (Sancheong-gun, Gyeongsangnam-do). A total of 23 compounds were identified, eight of which were common across the four cultivars. The major flavor components in the three Gamguk plants were identified as 3-carene, camphene, ${\beta}$-phellandrene, eucalyptol and (+)-camphor. Eleven compounds, including (+)-camphor at 31.40%, were identified in Gamguk 1 ho. Gamguk 2 ho was found to contain 12 flavor compounds, predominant of which was camphene at 25.60%. Thirteen compounds including (+)-camphor (26.88%) were identified in Gamguk 3 ho, while 17 were detected in the Wonhyang cultivar, including trans-piperitol (47.33%), sabinene, and ${\gamma}$-terpinyl acetate. These results indicate differences in the type and ratio of functional volatile flavor ingredients in Chrysanthemum indicum L. cultivars which is highly valuable as material for fragrance product development.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.2
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• pp.237-243
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• 2019

Floating platforms made of PE (PolyEthylene) are often located in shallows of seas, rivers or lakes. They are widely used for marine pensions, marine pontoons, marine bridges, etc. These products are characterized by good flexibility, recyclability, chemical resistance and weatherability with corrosion resistance. Existing PE floating platforms have a simple structure in which one pipe is fastened to one bracket, but this has limited application, even if a user modifies the arrangement. Therefore, we developed a structure that allows buoyancy pipes of various sizes to be fastened to one bracket and verified the structural safety of the product using the finite element method. From the results of structural analysis for buoyancy pipes of different diameters, the maximum stress ratio was 0.78 compared with allowable criteria of 1.0, which represented sufficient safety for a model with 500 mm diameter pipes. Based on the results of this study, further research to evaluate the structural safety of various floating platforms can be carried out in the further; it will also be necessary to establish related evaluation criteria.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.12
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• pp.62-70
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• 2018

In this study, we synthesized Oligo Peptide (Lys-Val-Ala-Arg-Pro: KVARP) and peptide derivatives using Solid Phase Peptide Synthesis(SPPS). KVARP was commonly known to improve whitening of skin. We measured bio-activity of the synthesized compounds. The whitening effect was measured in tyrosinase inhibition and the result showed to be highly effective with 93% inhibition rate at $5000{\mu}g/m{\ell}$ of Geranic-KVARP, on the other hand the IC50 value was $68{\mu}g/m{\ell}$. The wrinkle-reducing effect was measured by elastase inhibition at a concentration of 63% at $400{\mu}g/m{\ell}$ of Salicylic-KVARP, and the IC50 value was $253{\mu}g/m{\ell}$. In the DPPH assay, Caffeic-KVARP showed more than 95% antioxidant activity at $400{\mu}g/m{\ell}$ with high concentration and IC50 value was $31{\mu}g/m{\ell}$. The anti-inflammatory effect of Nitric Oxide inhibition was 67% at $400{\mu}g/m{\ell}$ of Lipoic-KVARP. Therefore, the four types of KVARP derivative that were synthesized from various experiments has shown that it could have potential to be used to develop new medicines, cosmetics as well as in various industries.

• Journal of Korea Society of Waste Management
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• v.35 no.7
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• pp.670-682
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• 2018

Engineered nanomaterials (ENMs) can be released to humans and the environment through the generation of waste containing engineered nanomaterials (WCNMs) and the use and disposal of nano-products. Nanoparticles can also be introduced intentionally or unintentionally into waste streams. This study examined WCNMs in domestic industries, and target nanomaterials, such as silicon dioxide, titanium oxide, zinc oxide, nano silver, and carbon nanotubes (CNTs), were selected. We tested 48 samples, such as dust, sludge, ash, and by-products from manufacturing facilities and waste treatment facilities. We analyzed leaching and content concentrations for heavy metals and hazardous constituents of the waste. Chemical compositions were also measured by XRD and XRF, and the unique properties of nano-waste were identified by using a particle size distribution analyzer and TEM. The dust and sludge generated from manufacturing facilities and the use of nanomaterials showed higher concentrations of metals such as lead, arsenic, chromium, barium, and zinc. Oiled cloths from facilities using nano silver revealed high concentrations of copper, and the leaching concentrations of copper and lead in fly ash were higher than those in bottom ash. In XRF measurements at the facilities, we detected compounds such as silicon dioxide, sulfur trioxide, calcium oxide, titanium dioxide, and zinc oxide. We found several chemicals such as calcium oxide and silicon dioxide in the bottom ash of waste incinerators.

• Journal of Korean Society of Water and Wastewater
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• v.35 no.6
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• pp.533-544
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• 2021

Ion exchange (IX) performance on the exchanger bed is essentially evaluated for the generation of ultrapure water in electronics and chemical industries and for the corrosion control in nuclear power plants. The breakthrough characteristics of IX bed with multi-component were investigated with both cation- and mixed-IX beds of H- and ETAH-form for four kinds of cation exchange resins by using the combined solution of ethanolamine (ETA) and ammonia (NH₃) at trace NaCl. Unlike major components (ETAH⁺ and NH₄⁺ ), the phenomena of breakthrough and overshooting at bed outlet were not observed by Na⁺ over the test period (> 3 times theoretical exchange capacity of IX bed). The breakthrough from H-form resin bed was sequentially reached by ETAH⁺ and NH₄⁺, while the overshooting was observed for ETAH⁺ at the breakthrough of NH₄⁺. NH₄⁺ was 51.5% higher than ETAH⁺ in terms of the relative selectivity determined with the width of breakthrough zone. At the increased concentration of Na⁺ at bed inlet, the selectivity and the overshooting were decreased and increased, respectively. Na⁺ leakage was higher from ETAH-form resin bed and was not identical for four kinds of cation-exchange resins, which may be reduced by improving the intrinsic property of IX resin.

• Microbiology and Biotechnology Letters
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• v.50 no.2
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• pp.211-217
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• 2022

Sodium hypochlorite (NaClO) is a disinfectant widely used in hospitals and food industries because of its antimicrobial activity against not only bacteria but also fungi and virus. The antibacterial activity of NaClO lies in the maintenance of a stable hypochlorous acid (HClO) concentration, which is regulated by pH of the solution. HClO can easily penetrate bacterial cell membrane due to its chemical neutrality and the antibacterial activity of NaClO is thought to depend on the concentration of HClO in solution rather than hypochlorite ions (ClO^-). In this study, we investigated the antibacterial activity of NaClO according to pH adjustment by means of time kill test and assays of Reactive Oxygen Species (ROS) and adenosine triphosphate (ATP) concentration changes before and after NaClO treatment. We also investigated that the degree of cell wall destruction through field emission scanning electron microscopy (FE-SEM). Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) exposed to 5 ppm NaClO at pH 5 exhibited 99.9% mortality. ROS production at pH 5 was 48% higher than that produced at pH 7. In addition, the ATP concentration in E. coli and S. aureus exposed to pH 5 decreased by 94% and 91%, respectively. As a result of FE-SEM, it was confirmed that the cell wall was destroyed in the bacteria by exposing to pH 5 NaClO. Taken together, our results indicate that the antibacterial activity of 5 ppm NaClO can be improved simply by adjusting the pH.