• Clean Technology
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• v.29 no.2
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• pp.135-144
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• 2023

Pseudomonas aeruginosa and Staphylococcus aureus are the two most frequently encountered pathogens responsible for chronic wound infections, often coexisting in such cases. These infections exhibit heightened virulence compared to single infections, leading to unfavorable patient outcomes. The interaction among microorganisms within polymicrobial infections has been shown to exacerbate disease progression. Polymicrobial infections, prevalent in various contexts such as the respiratory tract, wounds, and diabetic foot, typically involve diverse microorganisms, with Pseudomonas aeruginosa and Staphylococcus aureus being the most commonly identified pathogens. This study aimed to compare the growth patterns of bacteria under a concentration gradient of toxic chemicals, focusing on a Gram-negative strain of Pseudomonas aeruginosa and a Gram-positive strain of Staphylococcus aureus. The minimum inhibitory concentration (MIC), which signifies the concentration at which bacterial growth is inhibited, was determined by performing broth microdilution and assessing the bacteria's growth curves. The growth curves of both Pseudomonas aeruginosa and Staphylococcus aureus were confirmed, and the exponential growth phases were applied to calculate the doubling times of bacteria. The MIC value for each toxic chemical was determined through broth microdilution. These results allowed for the identification of disparities in growth rates between Gram-positive and Gram-negative bacteria, as well as differences in resistance to individual toxic substances. We expect that this approach has a strong potential for further development towards the innovative treatment of bacteria-associated infections.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.spc
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• pp.23-29
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• 2022

To detect harmful chemical substances in seawater, we fabricated a prototype sensor and evaluated its performance. The prototype sensor consisted of a detector, housing, and driving circuit. We built the detector by printing an Indium-Tin-Oxide (ITO) nanoparticle film on a flexible substrate, and it had two detection parts for simultaneous detection of temperature and HNS concentration. The housing connected the detector and the driving circuit and was made of Teflon material to prevent chemical reactions that may affect sensor performance. The driving circuit supplied electric power, and display measured data using a bridge circuit and an Arduino board. We evaluated the sensor performances such as response (ΔR), the limit of detection (LOD), response time, and errors to confirm the specification.

• KSBB Journal
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• v.22 no.3
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• pp.151-156
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• 2007

Increasing public concerns over odors and air regulations necessitates the remediation of a wide range of odorous compounds for industrial purpose. Currently, wet scrubbing technique by neutralization using essential oils is utilized to treat methyl mercaptan odor. The chemical analysis is performed to analyze the composition of an essential oil by GC-MS. The objective of this study is to clarify the possibility of the neutralization of odors sprayed in the fixed bed and determine the removal efficiencies in the misty aerosol by different input odor concentration. It is found that methyl mercaptan is significantly removed in the wet scrubber, and their removal efficiency of methyl mercaptan is obtained by 98%.

• Fire Science and Engineering
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• v.31 no.1
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• pp.81-88
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• 2017

This study analyzed chemical accidents each year according to the status, type of accident, accident place, business size, and chemical substance. The results of the chemical accident investigation were 16 cases in 2013, 27 cases in 2014, 46 cases in 2015, and 23 cases in 2016. According to the type of chemical accident, number of accidents, and casualty accidents, leakage was found to be the major cause. As a result of accidents and casualties caused by chemical accidents, workplaces had the highest numbers in all survey items. An examination of the top 10 accident materials revealed 9 substances to be hazardous chemicals. These materials were accident preparedness substances, and toxic substances.

• Journal of Korean Society on Water Environment
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• v.40 no.1
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• pp.1-10
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• 2024

Algal blooms occur seasonally in the eutrophicated rivers or reservoirs, and some harmful cyanobacteria species produce toxic substances, which are directly or indirectly harmful to the ecosystem and terrestrial animals. So, the monitoring and control of harmful cyanobacteria occurrence and toxins residual in the aquasystem are important to preserve the water environment and secure public health. In this study, the four harmful cyanobacteria occurrences and toxic substance concentrations of two agricultural reservoirs in the southern part of Gyeonggi Province were investigated from August to October 2022. Among four harmful cyanobacteria (Microcystis sp., Anabaena sp., Oscillatoria sp., Aphanizomenon sp.), three kinds of cyanobacteria except Oscillatoria sp. were observed, and Microcystis sp. was the dominant cyanobacteria except for Anabaena sp. dominant result of a sample collected on October at reservoir B. The cell density of cyanobacteria was influenced by season and weather due to the length of daytime and concentrations of organic carbon and nitrogen. Three kinds of microcystin and anatoxin-a were quantitatively analyzed as total (in the cell body and water) and extracellular (in water) concentrations. The maximum total concentrations of anatoxin-a, microcystin-LR, microcystin-RR, and microcystin-YR were 0.1291 ㎍/L, 0.2776 ㎍/L, 0.3721 ㎍/L, and 0.0306 ㎍/L, respectively, in reservoir A and 0.3274 ㎍/L, 0.1495 ㎍/L, 0.2037 ㎍/L, and 0.0153 ㎍/L, respectively, in reservoir B.

• Proceedings of KOSOMES biannual meeting
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• 2006.11a
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• pp.221-237
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• 2006

Domestic laws such as Korea Marine Pollution Prevention Law which has been made and amended according to the conclusions and amendments of various international conventions, especially by MARPOL 73/78, were reviewed and compared with major contents of international conventions, and several alternative measures for legislating new laws or amending existing laws such as Korea Marine Pollution Prevention Law in accordance with new contents and recent amendments of existing and new international conventions were proposed. Annex VI of MARPOL 73/78 has been recently accepted in Korea Marine Pollution Prevention Law which should be applied to ships which are the moving point sources of air pollution at Sea rather than in Korea Air Environment Conservation Law which should be applied to automobiles and industrial installations which are the line and/or point sources of air pollution in land. International Convention for Ship's Ballast Water/Sediment Management should be accepted in Korea Marine Pollution Prevention Law or by a new law in order to prevent domes marine ecosystem and costal environment from the invasion of harmful exotic species through the discharge of ship's ballast water. International Convention for the Control of Harmful Anti-Fouling Systems on the Ships should be accepted in Korea Marine Pollution Prevention Law which should be applied to ships which are navigating in open sea and coastal waters rather than in Korea Noxious Chemicals Management Law. Basel Convention which shall regulate and prohibit inter-nations movements of noxious chemical substances should be accepted in Korea Marine Pollution Prevention Law in order to prevent the movement and transfer of scrap-purpose tanker ships containing bilge water of oil/water mixtures and chemicals remained on board from advanced countries to developing and/or underdeveloped countries and to conserve global marine environment after all.

• Geotechnical Engineering
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• v.11 no.4
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• pp.87-98
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• 1995

Laboratory tests were performed on modeling of in situ remediation of contaminated soils by aqueous solution extraction, thus investigating the feasibility of in situ treatments of soil to promote desorption of organic hazardous wastes. The investigation was conducted using phenol, aniline, quinoline, and 2-napthol adsorbed onto a UH40 soil, and various aqueous solutions were used to desorb, or otherwise remove, these organic contaminants. Decontaminants consisted of deionized water as a reference, hydrogen peroxide, acidy, bases, and surfactants. In situ conditions were modeled in the laboratory by permeating potential extracting liquids through reconstituted, contaminated soil specimens under controlled hydraulic gradients and stress condition through flexible wall permeameter tests. Sodium hydroxide desorbed phenol effectively. Aniline was effectively descorbed by nonionic surfactant. Anionic surfactant remediated quinoline and 2-napthol.

• Korean Journal of Hazardous Materials
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• v.6 no.2
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• pp.13-22
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• 2018

Recently, social crimes using chemicals at home and abroad are increasing. These chemicals are readily available in the internet. Therefore, the NICS(national institute of chemical safety) runs a 'Chemical Cyber Surveillance' to help the public take control of the internet and create a healthy cyberspace through voluntary participation of the public. The study analyzed more than 1,000 sites suspected illegal hazardous information or blocked among cyber surveillance 3,500 case reports in the past yeas. And, the number of illegal hazardous information reported in the past three years is analyzed by type and substance. They want to examine the characteristics of hazardous chemical information on the internet and use it as a basic data to establish illegal information management measures that spread over cyberspace.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.11
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• pp.781-790
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• 2014

Contaminants such as organic matters, nutrients and toxic chemicals in rivers and lakes with a weak flow rate are first removed from the water and accumulated in the sediments. Subsequently, they are released into the water column again, posing direct/indirect adverse effects on the water quality and aquatic ecosystems. In particular, phosphorus is known to accelerate the eutrophication phenomenon when it is released into the water column via physical disturbance and biological/chemical actions as one of important materials that determine the primary production of aquatic ecosystems and an element that is stored mainly in the sediments in the process of material circulation in the body of water. In this study, the effect on reducing phosphorus release in sediments was analyzed by applying different capping materials to lake water, where the effect of aquatic microorganisms is taken into account, and to distilled water, where the effect of microorganisms is excluded. The experimental results showed that capping with chemical materials such as Fe-gypsum and $SiO_2$-gypsum further reduced the phosphorus release by at least 40% compared to the control case. Composite materials like granule gypsum+Sand showed over 50% phosphorus release reduction effect. Therefore, it is determined that capping with chemical materials such as granule-gypsum and eco-friendly materials such as sand is effective in reducing phosphorus release. The changes in phosphorus properties in the sediments before and after capping treatment showed that gypsum input helped to change the phosphorus that is present in lake sediments into apatite-P, a stable form that makes phosphorus release difficult. Based on the above results, it is expected that the application of capping technology will contribute to improving the efficiency of reducing phosphorus release that occurs in river and lake sediments.

• Korean Journal of Hazardous Materials
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• v.6 no.2
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• pp.1-6
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• 2018

The use of chemicals to enhance and improve life is a widespread practice worldwide. But alongside the benefits of these products, there is also the potential for adverse effects to people or the environment. Thus, If anyone handles hazardous chemicals, they should adhere to specific criteria for hazardous chemicals. This study used hazard statement(H-code) and precautionary statement(P-code) to set specific criteria for handling chemicals. According to the UN GHS, hazard statement means a statement assigned to a hazard class and category that describes. And a precautionary statement is a phrase which describes recommended measures that should be taken to minimize or prevent adverse effects resulting from exposures to a hazardous product, or improper storage or handling of a hazardous product. The study suggests the treatment criteria(Public Notice) of 785 types of hazardous chemicals managed by the Chemical Control Act.