• Korean Journal of Ecology and Environment
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• v.55 no.4
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• pp.376-389
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• 2022

Despite the consumption of disinfectants have been increased by COVID-19 pandemic, the fate of the chemicals in aquatic food webs are still unclear. In order to understand the trophic transfer of the chemicals, the concentration of disinfectants including six benzalkonium chloride (BACs) and five didecyldimethylammonium chlorides(DDACs) were measured at the Geum (2020), Han (2021), and Yeongsan River (2021), before and after rainfall. The highest concentration of ∑BACs (mainly C12 and C14) and ∑DDACs (mainly C10 and C14) were observed in the Han River, followed by Yeongsan River, Geum River Estuary, and Gapcheon. After rainfalls, both concentration and detection frequency were decreased in all sites. Although the BAC and DDAC seems to be accumulated in organisms, they were bio-diluted rather than magnified in the aquatic food web with the biomagnification factor(BMF) of less than 1, trophic magnification slope (TMS) from -0.236 to 0.001, and trophic magnification factor(TMF) from 0.85 to 1.01.

• Journal of Environmental Health Sciences
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• v.46 no.2
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• pp.159-169
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• 2020

Objectives: The purpose of this study was to investigate changes among the nine kinds of reduction chemical substances in Korea over the period of 2008-2017. We will define basic data for improving the management methods for reducing chemical substances. Methods: A survey of hazardous pollutant emissions for 2008-2017 was conducted through the pollutant Release and Transfer Register homepage. Nine kinds of designated reduction chemical substances (Benzene, Vinyl chloride, Trichloro ethylene, 1,3-butadiene, Dichloro methane, Tetrachloro ethylene, N,N-dimethylformamide, Acrylo nitrile, and Chloroform) provided the study subjects. The emission of hazardous chemicals and health effects used the National Health Statistics and Integrated Chemicals Information System (ICIS) as a reference. Results: Hazardous pollutant emissions increased by 1.2 times over the past decade, and nine types of reduction chemical substances increased by 1.6 times. By region, the emissions of reduction chemical substances over the last 10 years were in the order of Chungbuk, Gyeonggi, and Gyeongbuk. Emissions of Dichloro methane was the highest in Chungbuk and Gyeongbuk. N,N-dimethylformamide was the highest in Gyeonggi. Carcinogen pollutant emissions showed a tendency to increase continuously. In addition, group 1 carcinogen emissions showed a tendency to decrease. Conclusion: In the last decade, the amount of hazardous chemical emissions has been continuously increasing. Hazardous chemical emissions require facility improvement for continuous emissions reduction. More research on reduction of emissions is needed.

• Applied Chemistry for Engineering
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• v.30 no.5
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• pp.523-529
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• 2019

In this study, we investigated the pretreatment technologies of volatile organic compounds (VOCs) which is a problem as the semiconductor and display industry develops recently. The conventional concentrator used in the direct combustion system, is easily contaminated by the exhaust gas in the manufacturing process of the display, resulting in the low treatment efficiency of generated VOCs. Physical/Chemical analyses of the exhaust gas showed high boiling point and viscosity in addition to a large amount of molecular weight alcohols and oil components. In this study, we tried to treat degrading materials by using the heat exchanger in a pretreatment facility and some materials degrading the concentrator were condensed more than 90%. In addition, it was also confirmed that an auxiliary device of the grease filter could remove the redispersion polymer oil from the heat exchanger.

• Economic and Environmental Geology
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• v.37 no.1
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• pp.21-33
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• 2004

The objective of this study is to review of environmental assessment of heavy metals derived from various metalliferous mines in Korea. As a results of national wide research for heavy metal contaminations in the vicinity of metalleferous mines, the main contaminants are mine waste materials including tailings. From the materials, toxic elements including As, Cd, Cu, Pb and Zn can be dispersed into downstream through wind and water. Thus, soils around the mines contain elevated levels of those elements, which are over the guide values for environmental regulation of soils in Korea. Arsenic is one of the most important elements contaminated by mining activities, to a less extent, Cd, Cu, Pb and Zn. In spite of remediation works for some metal mines by the government, there are still lots of abandoned mines which are necessary for reclamation of mining sites. This study also includes that metal concentrations in soils and tailings can be varied upon various decomposition methods including 0.1N HC1 and aqua regia and sequential extraction scheme, with differences in each element, too. This may be due to geochemical characteristics of the elements, such as solubility, mobility and chemical forms in the geochemical environment. Finally, it is suggested that a certain organization should be runned by Korean government for management of abandoned mines.

• Journal of Environmental Health Sciences
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• v.44 no.1
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• pp.15-23
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• 2018

Objectives: The purpose of this study was to investigate the changes in hazardous pollutant emissions in Korea over the period of 2006-2015. Methods: A survey of hazardous pollutant emissions was conducted through the homepage for 2006-2015. The emission of hazardous chemicals and the health effect was examined using the Annual Report of Air Quality in Korea (2016) and National Health Statistics (2015) as references. Results: Hazardous pollutant emissions increased by 1.1 times over the past decade, and the circulation amount of chemicals was 15% compared to the previous year. $PM_{10}$ concentrations showed a tendency to decrease, but emissions have not declined. In addition, asthma and atopic dermatitis correlated with similar emissions, but allergic disease showed no connection. Conclusion: These results on hazardous pollutant emissions indicate that they have increased. However, no association between emissions and health effects was shown, so more research is needed.

• Korean Journal of Agricultural Science
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• v.32 no.1
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• pp.1-8
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• 2005

This study was carried out to examine the effect of heavy traffic on chemical properties of soil in roadside trees of Daejeon city. Soil samples at 0~10cm and 10~30cm depths were collected from soil of the roadside trees, Platanus occidentalis, and Ginko biloba, Soil pH in heavy traffic regions were around 7.0 at 0~10cm and 10~30cm soil depths because of spraying of calcium chloride for snow moving. The concentrations of Fe, Cd, Cu, Zn, and Pb in soil were higher in heavy traffic regions(Daejeon Station and Daehwa Industrial Complex) than in light traffic region (Chungnam National University). The result could be from rubbing and wear of car tire and metals when they travel.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.05b
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• pp.102-103
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• 2003

최근 고도 경제성장으로 인한 공업화와 그에 따른 업종이 다양해짐에 따라 여기에 수반되어 발생되는 대기오염물질이 증가할 뿐만 아니라 종류도 여러가지로 다양해지고 있다. 대부분 산업공정에서 배출되는 미세먼지 입자는 기존의 집진장치로 거의 포집제거가 불가능하여 대부분이 대기중으로 방출되고 있는 실정이다. 분진 중에서도 입경 l$\mu\textrm{m}$이하의 분진들은 침강 속도가 작아 거의 gas와 동일한 거동을 하기 때문에 기관 또는 폐포에 침착하여 호흡기에 영향을 미치므로 그 발생량과 화학적 성상이 문제화되고 있는 추세이다. (중략)

• Journal of the Korean Society of Propulsion Engineers
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• v.18 no.1
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• pp.73-84
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• 2014

The present paper includes recent research works on the estimation of physical properties like equivalence ratio and heat release rate of flame through chemiluminescence measurement. Modern combustion devices require a precise control to increase combustion stability as well as to suppress pollutant emissions. The determination of combustion characteristics from chemiluminescence provides practical advantages over other techniques. However, the technique is dependent on equivalence ratio, combustion pressure, inlet temperature, turbulent intensity and fuel type. The intensity ratio of $OH^*$ and $CH^*$ has a strong relation with an equivalence ratio for methane/air premixed flames. The global measurement of chemiluminescence is accepted as a good indicator for a global heat release rate.

• Journal of Korean Society of Environmental Engineers
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• v.38 no.11
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• pp.589-595
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• 2016

This study evaluated the environmental impacts for landfill treatment of the wastewater treatment sludge (WTS) from petrochemical firms by life cycle assessment (LCA) and reviewed the impact reduction by landfill gas (LFG) utilization. The functional unit was 'landfill of 1 ton of WTS', and the system boundary included the process of input and treatment for WTS in landfill site. The impacts were high at landfill process (LP) and leachate treatment process (LTP). Global warming (GWP) and photochemical oxidants creation (POCP) were high at LP, while abiotic depletion (ADP), acidification (AP), eutrophication (EP), ozone depletion (ODP) were high at LTP. The major substances of various impact categories were crude oil (ADP), $NO_X$ (AP, EP), $CH_4$ (GWP, POCP), $Cl_2$ (ODP), respectively. The major factor of ADP, AP, EP was attributed from the generation of electricity used in LTP, and the methane within uncollected LFG was main factor of GWP and POCP. Therefore, electricity consumption reduction is identified to be an impact improvement option, and the flaring system installation or enhanced LFG recovery could be an alternative to reduce impacts. Among the various categories, GWP accounted the highest impact (${\geq}90%$) followed by ADP, POCP. In the avoidance impact resulted from the utilization of LFG, to substitute B-C oil or LNG showed the impact reduction of 32.7% and 12.0%, respectively.

• Journal of Animal Environmental Science
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• v.1 no.1
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• pp.55-64
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• 1995

A wastewater purifying system using phototrophic bacterium, Rhodopseudomonas capsulata, is currently in operation in several countries, One of them, is a continuously aerated bioreactor(CABR) system, which treats concentrated swin wasterwater using small amounts of phototrophic bacteria as additive bacterial seeding. Using this plant, total biochemical oxygen demand was decreased to 13%, and most of volatile fatty acids were removed. About 40% of the wastewater(Influx) was evaporated during aerobic digestion for 24h, and 60% of that erupted in a decodorized foam(Efflux). The efflux had enough nutrients, N, P and K kor growing plant, as well as organic matters. When the efflux was applied to Italian ryegrass with high dose, fresh shoot and root weights were significantly greater, and $NO_3-N$ contents of the dried shoot were lower than those of control plant (CDU). These results indicate that the CABR plant is useful for reduction and deodorization of swine wastewater and the efflux from CABR can be used for crop production as an organic fertilizer.