• Journal of Korean Society for Atmospheric Environment
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• v.24 no.E1
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• pp.1-11
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• 2008

Mercury (Hg), which is mainly emitted from coal-fired power plants, remains one of the most toxic compounds to both humans and ecosystems. Hg pollution is not a local or regional issue, but a global issue. Hg compounds emitted from anthropogenic sources such as coal-fired power plants, incinerators, and boilers, can be transported over long distances. Since the last decade, many European countries, Canada, and especially the United States, have focused on technology to control Hg emissions. Korea has also recently showed an interest in managing Hg pollution from various combustion sources. Previous studies indicate that coal-fired power plants are one of the major sources of Hg in Korea. However, lack of Hg emission data and feasible emission controls have been major obstacles in Hg study. In order to achieve effective Hg control, understanding the characteristics of current Hg sampling methods and control technologies is essential. There is no one proven technology that fits all Hg emission sources, because Hg emission and control efficiency depend on fuel type, configuration of air pollution control devices, flue gas composition, among others. Therefore, a broad knowledge of Hg sampling and control technologies is necessary to select the most suitable method for each Hg-emitting source. In this paper, various Hg sampling methods, including wet chemistry, dry sorbents trap, field, and laboratory demonstrated control technologies, and international regulations, are introduced, with a focus on coal-fired power plants.

• Environmental Engineering Research
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• v.12 no.5
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• pp.203-210
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• 2007

Since the emissions composition from the household products have potentially been associated with health risks for building occupants, the chemical composition emitted from the products should be surveyed. The current study identified the emission composition for 42 liquid household products, using a purge-and-trap method. This evaluation was done by classifying the household products into five product classes (deodorizers, household cleaners, color removers, pesticides, and polishes). Nineteen compounds were chosen on the basis of selection criteria. The quality control program for purge-and-trap and analytical systems included tests of laboratory blank Tenax traps and blank water samples, and the determination of calibration equation, measurement precision, method detection limit (MDL), and recovery. The number of chemicals varied according to the product categories, ranging from 4 for the product category of bleaches to 12 for the product categories of air fresheners and nail color removers. For all product categories, the emission composition and concentrations varied broadly according to product. It is noteworthy that most household products emit limonene: 19 of 25 cleaning products; 5 of 6 deodorizers; 1 of 3 pesticides; 3 of 3 color removers; and 4 of 5 polishes. It was suggested that the use of household products sold in Korea could elevate the formation of secondary toxic pollutants in indoor environments, by the reaction of limonene with ozone, which entered indoor environments or might be generated by indoor sources such as electronic air cleaning devices and copying machines.

• Journal of the Korean Ceramic Society
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• v.47 no.2
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• pp.189-194
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• 2010

Compared with organic fluorophores, semiconductor quantum dots (QDs) have the better properties such as photostability, narrow emission spectra coupled to tunable photoluminescent emissions and exceptional resistance to both photo bleaching and chemical degradation. In this work, CdSe/ZnS QDs nanobeads were prepared by the incorporation of CdSe/ZnS QDs with mesoporous silica to use as the optical probe for detecting toxic and bio- materials with high sensitivity, CdSe/ZnS core/shell QDs were synthesized from the precursors such as CdO and zinc stearate with the lower toxicity than pyrotic precursors. The QD-nanobeads were characterized by transmission electron microscopy, FL microscopy, UV-Vis and PL spectroscopy, respectively.

• Applied Chemistry for Engineering
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• v.3 no.2
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• pp.201-206
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• 1992

Annual amount of plastics waste including rubber and leather waste, generated in 1990 was about 2,600,000 tons. Amount of generation of plastics waste has rapidly increased, but fractions of recycling and incineration have gradually decreased. Recently, two-stage incinerator, consisting of gasifier and gas combustor, draws much attention in Korea. Plastics are gasified in the starved air condition in the gasifier and produced gas is fired in the combustor. Combustion of produced gas is much easier than that of solid plastics, and produces a little pollutants. Standardzation of technology and process automation are still needed, but this incineration technology is in the commercial stage. Next topic concerned with this two-stage incineration will be how to treat complex plastics waste including toxic substances generated from automobiles and household appliances. Pyrolysis, realized by indirect heating in inert atmosphere, can provide high-quality products with minimum emissions. Many plastics are easily decomposed into oil in pyrolysis conditions, which can be utilized as chemical feedstocks, or gasoline or kerosene depending on feed materials and operating conditions. This has been demonstrated in several pilot-scale tests performed in Japan, Germany, etc. Easy removal of HCl from PVC is one of the most decisive merits of pyrolysis process. But in general, further efforts should be made for the process to obtain marketability. The future of pyrolysis process depends on public concern about environmental problems and oil prices.

• KSBB Journal
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• v.26 no.5
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• pp.471-476
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• 2011

Nowadays biodiesel (fatty acid methyl ester, FAME) has been becoming an important issue as a desired alternative of energy products because of non-toxic, biodegradable properties, and lower exhaust emissions. During esterification of fatty acids or transesterification of oils and fats with short chain alcohols by the alkali-catalyzed methanolysis, FAME and unrefined glycerol are generated. Quantification of glycerol as a by-product is important because of a determinant of biodiesel quality. However, the glycerol analysis by gas chromatography (GC) method has laborious works with sample preparation, long time and cost of sample analysis. Thus, there is a need to analyze glycerol more simply. Herein we demonstrate that the colorimetric assay for glycerol analysis conducted by UV-vis spectrophotometer at the wavelength 617 nm whose peak is maximum intensity of malachite green, resulting in the red-shift occurred proportionally as a function of glycerol amount. Thus, it is considered the solvent media for malachite green fading for biodiesel production: (1) water, (2) MeOH, and (3) EtOH. The resulting findings show that the peak intensity at 617 nm in glycerol-malachite green mixture had a relationship between glycerol concentration and degree of peak shift as increase in pure glycerol concentration approximately at pH 7.0. However, when it was measured the unrefined glycerol concentration by diluting and adjusting with water to buffer (pH 7.0), it was not observed the absorption peak at 617 nm because of impurities and OH ions. In case of glycerol from biodiesel production factories, glycerol concentration could be successfully measured.

• Environmental Analysis Health and Toxicology
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• v.25 no.1
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• pp.41-55
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• 2010

The aims of this study were to develop the suitable "system software" in chemical ranking and scoring (CRS) for the food hazardous chemicals associated with environmental emission and to suggest the priority lists of food contamination by environmental-origined pollutants. Study materials were selected with reference to the priority pollutants list for environment and food management from domestic and foreign research and the number of study materials is 103 pollutants (18 heavy metals, 10 PBTs, 10 EDs, and 65 organic compounds). The Food-CRS-Korea system consisted of the environmental fate model via multimedia, transfer environment to food model, and health risk assessment by contaminated food intake. We have established that health risks of excess cancer risks, hazard quotients (HQs) by chronic toxicity and HQs by reproductive toxicity convert to score, respectively. The creditable scoring system was designed to consider uncertainty of quantitative risk assessment based on VOI (Value-Of-Information). The predictability of the Food-CRS-Korea model was evaluated by comparing the presumable values and the measured ones of the environmental media and foodstuffs. The priority lists based on emissions with background-level-correction are 15 pollutants such as arsenic, cadmium, and etc. The priority lists based on environmental monitoring date are 17 pollutants including DEHP, TCDD, and so on. Consequently, we suggested the priority lists of 13 pollutants by considering the several emission and exposure scenarios. According to the Food-CRS-Korea system, arsenics, cadmium, chromes, DEHP, leads, and nickels have high health risk rates and reliable grades.

• Bulletin of the Korean Chemical Society
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• v.34 no.12
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• pp.3755-3761
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• 2013

This study aims to assess the ecological risk of the hazardous air pollutants (HAPs) emitted in the semiconductor manufacturing processes in Korea by using Quantitative Structure Activity Relationship (QSAR, EPA, US, EPI $Suite^{TM}$ 4.1). Owing to the absence of environmental standards of hazardous air pollutants in the semiconductor manufacturing processes in Korea, 18 HAPs in the semiconductor field included in both the US EPA NESHAPs and the hazardous air pollutant list of Ministry of Environment in Korea were selected. As a results 8 chemicals (44.4%) of the selected 18 HAPs were VOCs. Cyanides (cyanides) and ethylene oxides (epoxy resins), and tetrachloro-ethylene (aliphatic compounds, halides) showed long half-lives. Cyanide HAPs especially had the highest half-life with the estimated value of 356.533 days. Nickel compounds (heavy metal compounds) possessed the highest water solubility followed by acetaldehyde (aldehyde compounds), ethylene oxides, and 1,4-dioxanes. The halides, including tetrachloro-ethylenes, carbon tetra-chlorides, benzene (aromatic compounds), and lead (heavy metals), are estimated to take the longest time for biodegradation. Tetrachloroethylene, with the acute toxicity end point of 3.685-7.033 mg/L, was assessed to be the most highly toxic substance among the 18 HAPs. However, considering the absence of the HAPs in the common category of log $K_{ow}{\geq}4$and $BCF{\geq}500$, which indicates the standard of bioconcentration potentials, potentials of the bioconcentration are considered to be low.

• Analytical Science and Technology
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• v.31 no.1
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• pp.14-22
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• 2018

After signing the WHO FCTC in 2003, South Korea ratified the FCTC in 2005. This study was conducted to provide data on toxic constituents that can be used as useful information for the level of exposure to Korean smokers. Emissions data from five brands of cigarettes were tested under the ISO and "Canadian Intense (HCI)" smoking regimes, respectively. We conducted an analysis of 25 compounds containing nicotine, tar, carbonyls, phenolics, volatile organic compounds (VOCs), and semi-VOC cigarette smoke. Tar and nicotine showed levels of 4.3 to 5.8 mg/cig and 0.4 to 0.5 mg/cig, respectively, which are within the range of tolerance presented in ISO 8243. In the case of carbonyls, formaldehyde was detected within a range of 8.2 to $14.3{\mu}g/cig$, and acetaldehyde was present within a range of 224.7 to $327.2{\mu}g/cig$ under the ISO smoke regime. Crotonaldehyde was not detected under the ISO regime, and all of the carbonyls showed values 2.3 to 4.5 times higher under the HCI regime than those under the ISO regime. Catechol, which showed a level of 47.0 to $80.5{\mu}g/cig$ under the ISO regime and 117.5 to $184.7{\mu}g/cig$ under the HCI regime, was the highest constituent among the phenols. The amount of isoprene was 91.7 to $158.3{\mu}g/cig$ under the ISO regime and 221.0 to 377.0 under the HCI regime. To summarize, most of the constituents showed a tendency to be detected at levels 2 to 4 times higher under the HCI regime than under the ISO regime. Above all, these results represent the first analysis in Korea from an independent institute of tobacco companies under accreditation of ISO 17025.

• Korean Chemical Engineering Research
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• v.56 no.4
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• pp.479-495
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• 2018

This study was carried out to research the multimedia fate modeling, concentration distribution and impact assessment of polycyclic aromatic hydrocarbons (PAHs) emitted from automobiles, which are known as carcinogenic and mutation chemicals. The amount of emissions of PAHs was determined based on the census data of automobiles at a target S-city and emission factors of PAHs, where multimedia fugacity modeling was conducted by the restriction of PAHs transfer between air-soil at the impervious area. PAHs' Concentrations and their distributions at several environmental media were predicted by multimedia fugacity model (level III). The residual amounts and the distributions of PAHs through mass transfer of PAHs between environment media were used to assess the health risk of PAHs at unsteady state (level IV), where the sensitivity analyses of the model parameter of each variable were conducted based on Monte Carlo simulation. The experimental result at S-city showed that Fluoranthene among PAHs substances are the highest residual concentrations (60%, 53%, 32% and 34%) at all mediums (atmospheric, water, soil, sediment), respectively, where most of the PAHs were highly accumulated in the sediment media (more than 80%). A result of PAHs concentration changes in S-city over the past 34 years identified that PAHs emissions from all environmental media increased from 1983 to 2005 and decreased until 2016, where the emission of heavy-duty vehicle including truck revealed the largest contribution to the automotive emissions of PAHs at all environment media. The PAHs concentrations in soil and water for the last 34 years showed the less value than the legal standards of PAHs, but the PAHs in air exceeded the air quality standards from 1996 to 2016. The result of this study is expected to contribute the effective management and monitoring of toxic chemicals of PAHs at various environment media of Metropolitan city.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.05a
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• pp.281-284
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• 2011

Recently, many drivers was the damage caused by similar oil product sales and gas station by not using quantitative gas. so, these damages is expected to rise damages by increasing these problem. By using similar oil products, caused damage in the fuel lines' working of lubrication and self-cleaning function for the occurred trouble in the part of the early obsolescence and the accumulation of impurities in the fuel lines, combustion rate due to the difference between retail gasoline engine, the burden of weight, Toxic substances in exhaust emissions, engine oil and unresolved issue is the chemical reaction can occur. to prevent these damages, using the system use in-vehicle state data with OBD-II protocol and measure quantitative gas and similar oil. In this paper, there implement similar oil identification and quantitative gas system through OBD-II scanner to provide WiFi communcation by using WinCe development Board.