• Journal of Korean Society of Environmental Engineers
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• v.34 no.4
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• pp.254-259
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• 2012

The discharge characteristics of Volatile Organic Compounds (VOCs) from seven wastewater treatment plants and two industry drains at Nakdong River basin were investigated. Four Sampling campaigns were conducted between May 2008 and November 2008, and tested for 17 VOCs. As results, eight VOCs were detected at some sampling sites, but their concentration levels were low; 0.19~3.41 ${\mu}g/L$, dependent on each sampling location and substance. However, proper management plans such as supervising and monitoring systems for VOCs are needed to control those pollutants since VOCs might affect human health as well as aquatic ecosystems with extremely low concentration levels.

• Asian Journal of Atmospheric Environment
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• v.4 no.1
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• pp.42-54
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• 2010

Automobile emissions have caused a major hydrocarbon pollution problem in the ambient air of many cities around the world. This study was conducted to measure the pollution status of volatile organic compounds (VOCs) in some urban residential areas in Seoul, Korea. A total of 20 VOCs (11 aromatic and 9 chlorinated species) were identified at 4 urban residential sites in Seoul, Korea from February 2009 to July 2009. Comparison of total VOC (TVOC) concentration data indicated the dominance of the aromatic species with the maximum (72.2 ppbC) at Jong Ro (JR) and the minimum at Yang Jae (33.4 ppbC). The peak concentration of TVOC occurred during spring at all sites with an exception at Gang Seo (GS), where it was recorded during winter. The distribution of individual VOCs at the study sites was characterized by high toluene concentration. A strong correlation of benzene was also observed with other VOCs and criteria pollutants at all sites (except YJ). The overall results of this study suggest that vehicular emissions have greatly contributed to the increase in VOC pollution at all the study sites.

• Asian Journal of Atmospheric Environment
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• v.12 no.2
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• pp.127-138
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• 2018

This study measured indoor and outdoor levels of hydrocarbon volatile organic compounds (VOCs), such as benzene, toluene, ethylbenzene, and xylene isomers (collectively referred to as BTEX), as well as 13 carbonyl compounds, at 20 homes in Seoul, South Korea. Along with the sampling of BTEX and carbonyls, indoor concentrations of the air pollutants nitrogen oxide (NO) and carbon dioxide ($CO_2$) were also measured at each home. These measurements were used to understand the characteristics of BTEX and carbonyls by calculating the various ratios and correlation coefficients between measured contaminant levels. We found that carbonyls were mostly originated from indoor sources, while BTEX were originated from both indoor and outdoor sources. A high correlation between indoor levels of NO and BTEX indicated that traffic emissions were also an important sources of BTEX.

• Journal of Korean Society of Water and Wastewater
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• v.31 no.6
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• pp.481-490
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• 2017

Water and wastewater treatment has always been a challenging task due to the continuous increase in amount and the change in characteristics of the poorly biodegradable and highly colored organic matters, as well as harmful micro-organisms. Advanced techniques are therefore required to successfully remove these pollutants from water before reuse or discharge to receiving water bodies. Application of ozone, which is a powerful oxidant and disinfectant, alone or as part of advanced oxidation process depends on the complex kinetic reactions and the mass transfer of ozone involved. Micro- and nano bubbling considerably improves gas dissolution compared to conventional bubbles and hence mass transfer. It can also intensify generation of hydroxyl radical due to collapse of the bubbles, which in turn facilitates oxidation reaction under both alkaline as well as acidic conditions. This review gives the overview of application of micro- and nano bubble ozonation for purification of water and wastewater. The drawbacks of previously considered techniques and the application of the hydrodynamic ozonation to synthetic aqueous solutions and various industrial wastewaters are systematically reviewed.

• Journal of the Society of Naval Architects of Korea
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• v.45 no.1
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• pp.101-107
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• 2008

According to the existing research result on the seabed organic sediment, pollutants from the land and the sea contaminate the coastal water and sediment on the seabed. To tackle this problem, we need to dredge organic sediment. In the present paper, the development of removing system of seabed sediment by the difference of water head is researched by experimental method. For the validation of the decompression system, computations for validation are carried out for sediment removing equipment. The performance of inhalation equipment is analysed by some model tests.

• Journal of Korean Society on Water Environment
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• v.22 no.4
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• pp.720-726
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• 2006

Long-term monitoring results of water qualities at major lakes in Korea showed COD (chemical oxygen demand) concentrations have been increasing while BOD (biochemical oxygen demand) concentrations have been decreasing during last decades. This was mainly due to refractory organic matters have been accumulated in the water body. In this study, the possible causes of COD concentration increase were evaluated. From the statistics, it can be understood that potent pollutant sources including fertilizer consumption, population, livestock, and carbon uptake have increased. Leaching tests were carried out with soils and biomasses sampled at agricultural-forestry area. From the leaching experiments, leachate qualities as a ratio of $COD_{Cr}/BOD$ were in the range of 2.5-5.0, implying that NOM (natural organic matters) discharged from the forestry area was mainly responsible for the COD accumulation. It can be understood from this research that diffuse pollutants from forestry areas should be controlled properly to reduce COD accumulation in the lakes.

• Asian-Australasian Journal of Animal Sciences
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• v.5 no.1
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• pp.113-121
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• 1992

An the livestock production in Japan is industrialized, a tremendous amount of animal wastes is being produced annually, resulting in serious environmental pollution problems. Animal wastes could be pollutants, but they are also important sources of fertilizer nutrients and organic matter. Composting is an effective way of promoting the increased utilization of animal wastes. The characterization of maturing process during composting is important in order to improve the composting technology and to develop and efficient method to estimate the degree of maturity. The rise and fall in temperature, and changes in the constituents of the compost, reflect the maturing process and may serve as indicators for maturation. In addition, the detection of nitrate by diphenylamine, the determination of cation-exchange capacity (CEC), and the germination test, are also recommended as the methods of estimating the degree of maturity. The heavy applications of animal manure and compost may cause an adverse effect on soils and crops. When excess manure is applied, the nitrogen will be accumulated in soil, resulting in accumulation of nitrate in crops and pollution of the groundwater. Guidelines for application rates are recommended, to maintain soil productivity and quality of crops, and to prevent the environmental pollution.

• Environmental Analysis Health and Toxicology
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• v.23 no.2
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• pp.67-77
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• 2008

It has been observed that the linear relationship between the logarithm of bioconcentration factor (log BCF) of highly hydrophobic chemicals and their log $K_{ow}$ breaks when log $K_{ow}$ becomes greater than 6.0. Consequently, super hydrophobic chemicals were not thought to cause baseline toxicity as a single compound. Researchers often call this phenomenon as "hydrophobicity cutoff" meaning that bioconcentration or corresponding baseline toxicity has a certain cutoff at high log $K_{ow}$ value of hydrophobic organic pollutants. The underlying assumption is that the increased molecular size with increasing hydrophobicity prohibits highly hydrophobic compounds from crossing biological membranes. However, there are debates among scientists about mechanisms and at which log $K_{ow}$ this phenomenon occurs. This paper reviews three hypotheses to explain observed "cutoff": steric effects, kinetic or physiological limitations, and chemical activity cutoff. Although the critical molecular size that makes biological membranes not permeable to hydrophobic organic chemicals is uncertain, size effects in combination with kinetic limitation would explain observed non-linearity between log BCF and log $K_{ow}$. Chemical activity of hydrophobic chemicals generally decreases with increasing melting point at their aqueous solubility. Thus, there may be a chemical activity cutoff of baseline toxicity if there is a critical chemical activity over which baseline effects can be observed.

• Journal of Korean Society of Water and Wastewater
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• v.7 no.2
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• pp.9-23
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• 1993

Emission of hazardous and volatile organic chemicals from solid waste landfill site was become to important issue because of environmental pollution and health risk by such chemicals. Laboratory batch and continuous experiments were conducted respectively to elucidate isothermal sorption behaviors and transport phenomena(by gas through unsaturated solid waste layer) in wet solid waste-gas system. Source separated and size reduced refuse(bulky waste) and incinerated ash were used after controlling water content, and trichloroethylene(TCE) was chosen among many such chemicals because of it's generality among those man-created pollutants. Isothermal TCE sorption equilibria wet solid waste-gas system can be described in linear equation and partition coefficient in this system can be estimated approximately by the simple equation derived from schematic structure of the system. Transport equation modified by instantaneous equilibrium sorption fraction and kinetic sorption rate(overall mass transfer capacity coefficient) simulated well the column experiment results.

• Journal of Korean Society for Atmospheric Environment
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• v.16 no.1
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• pp.79-87
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• 2000

This study analyzed the regulations concerning odor management or control in Korea, Japan, and developed countries such as USA and Germany. The Korean restriction standards and measurement methods for offensive odor substances are very similar to the Japanese standards and methods promulgated in 1976. Japan promulgated the odor control act and the specific measurement methods of the offensive odor substances in 1973. In Japan, currently, the local governments can establish their own odor restriction areas and proclaim their own standards suitable for their situations. Also, Japan has more strict regulations and more offensive odor substances to be monitored than Korea. The restriction standards of odor in German is quite similar to the permissible limits and standards of air pollutants at emission sources in Korea. Many states in USA are adopting their own restriction standards and measurement methods, e.q., the ambient air pollution standards, organic functionstest methods by dilation, and establishment and addition of air pollution control equipment at emission sources. Finally, this study analyzed the problems of the regulations, standards, and measurement methods concerning the Korean offensive odor management. Since the direct organic fuctions measurement(DOFMM) method is depending upon the personal sensitives of odor substances, the measurement odor value can be equivocal. That is, the odor measurement value by an examines can differ from that by the other examines. Also, there can be conflicts with the measured odor values depending upon the applied measurement methods, e.q., the DOFMM, the dilation method, and the instrumental analysis method.