• Journal of Korean Society for Atmospheric Environment
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• 제12권E호
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• pp.1-18
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• 1996

In this review, the significance of terrestrial ecosystems in the global sulfur budget has been reviewed based on the currently available databases covering the topic. In the section 1, we describe our current understanding of natural sulfur cycle in relation to most well-known natural reservoir, oceanic environment. The sections 2 and 3 provide the fundamental pictures of the rerrestrial sulfur cycle with respect to the relative importance of its individe the fundamental pictures of the terrestrial sulfur cycle with respect to the section 3, previously reported flux values for several major sulfur gases are presented for each reservoir and are intercompared to derive representative fluxes for the respective environment. In the section 4, source mechanisms for volatile sulfur species are dealt for both microscale and macroscale processes leading to their productions. In the section 5, environmental factors controlling the exchange of biogenic sulfur gases across the air-surface have been discussed. In the section 6, environmental fate of sulfur gases released into the atmosphere has been described. Finally in tie section 7, as concluding remarksm we discuss directions and suggestions to overcome various limitations encountered from previous measurement investigations of natural sulfur cycle in diverse natural ecological systems.

• Environmental Engineering Research
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• 제25권3호
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• pp.281-289
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• 2020

Environmental fate of ionizable organic pollutants such as perfluoroalkyl acids (PFAAs) are of increasing interest but has not been well understood because of uncertain values for parameters related with atmospheric interphase partitioning behavior. In the present study, not only the values for air-water partition coefficient (K_AW) and dissociation constant (pKa) of PFAAs were induced by adjusting to in situ measurements of air-water distribution coefficient between vapor phase and rainwater but also gas-particle partition coefficients were also estimated using three-phase partitioning model of ionizable organic pollutants, in situ measurements of PFAAs in aerosol and air vapor phase, and obtained parameter values. The pKa values of PFAAs we obtained were close to the minimum values suggested in literature except for perfluorooctane sulfonic acids, and COSMOtherm-modeled K_AW values were assessed to more appropriate among suggested values. When applying parameter values we obtained, it was predicted that air particle-associated fate and transport of PFAAs could be negligible and PFAAs could distribute ubiquitously along the transection from urban to rural region by pH-dependent phase transfer in air. Our study is expected to have some implications in prediction of the environmental redistribution of other ionizable organic compounds.

• Bulletin of the Korean Chemical Society
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• 제33권4호
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• pp.1183-1189
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• 2012

The KOrea Insecticide Exposure Model (KOIEM) was developed to facilitate ecological risk-based management of Korean insecticides. KOIEM, applied as a multimedia fate model, evaluates water, soil, air, and vegetation compartments based on three water-body types (streams, ditches, and ponds). Deltamethrin, a pyrethroid insecticide, was used to evaluate and create the model parameters. After exposure of both the stream and the ditch to deltamethrin, the KOIEM-predicted concentrations and the observed levels were in agreement. The model was also evaluated using the accuracy factor (AF), which was 4.32 and 0.35 for the stream and ditch, respectively. Ecological risk assessment was also performed to evaluate the application of KOIEM for four popular South Korean insecticides (cypermethrin, deltamethrin, diazinon, and permethrin). Despite the insecticides having low PECs in water, their risk quotients were typically above 1.0. Thus, KOIEM modification would be required in further studies to account for spatial variation.

• 한국지하수토양환경학회지:지하수토양환경
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• 제23권6호
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• pp.90-103
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• 2018

Although fluoride is an essential trace element, ingestion of excessive amount of fluoride could have detrimental effect on human health. Generally, the bioavailability of fluoride in soils was low, but it could be harmful to the environment depending on the soil properties. Therefore, it is necessary to understand the concentration distribution, and fate and transport characteristics of fluoride to establish a resonable management strategy for fluoride pollution. This study was conducted to evaluate nationwide fluoride distribution in soils in Korea, as well as its fate and transport characteristics. The average background concentration was 204.5 (15.3~504.8) mg/kg, which is lower than the values of foreign soils. For the three regions of different land use, the average concentration was 229.6 mg/kg in region 1, 195.7 mg/kg in region 2, and 273.4 mg/kg in region 3. The concentration of fluoride was the highest in soils from Youngnam block within tectonic structure derived from metamorphic rocks. The results of sequential extraction to access F bioavailability showed fluoride in soils mainly existed as a residual form, which suggests the bioavailability of fluoride was relatively low. Soil properties such as soil pH, CEC, and clay content were found to affect F bioavailability of soil.

• 펄프종이기술
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• 제37권3호
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• pp.74-80
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• 2005

The compositions of residual extractives in woodmeal, unbleached and oxygen-delignified aspen kraft pulps were investigated with gas chromatography(GC) and gas chromatography-mass spectrometry (GC-MS) with focus on fate of extractives in kraft pulping and oxygen delignification. Steryl esters and shorter retention time (shorter than palmitic acid) extractives were main extractives in aspen woodmeal. Shorter retention time extractives were well removed in kraft pulping. Sterol esters were hydrolyzed to sterols and fatty acids. Sterols and fatty acids were two major extractives classes in unbleached kraft pulps. Linoleic acid was main fatty acids in unbleached pulps compared with palmitic acid which is generally found in aspen woodmeal. Sterolsand fatty acids were also two major extractives classes in oxygen-delignified kraft pulps. However, linoleic acid was well removed in oxygen delignification.

• 한국환경독성학회:학술대회논문집
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• 한국환경독성학회 2004년도 Sharing Experience of Human and Ecological Risk Assessment and Management in Asia/Pacific Region
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• pp.62-62
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• 2004

• 한국환경독성학회:학술대회논문집
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• 한국환경독성학회 2003년도 춘계학술대회
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• pp.166-166
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• 2003

In terms of the risk assessment, qualitative and quantitative informations are needed to estimate the exposures of environmental pollutants, which may be potentiality of risks, and those are the information about the changes caused by the chemical transportation among environmental media and transformation in environmental media by duration. The various fate mechanism of chemical is possible for estimation of chemical concentration in environmental media. Since there are limitations in measuring the change of chemical concentration within all medium according to the time period, estimating method through modeling are developed.

• 대한환경공학회지
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• 제33권6호
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• pp.453-479
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• 2011

오늘날 전세계적으로 수환경에서의 잔류 의약물질들의 오염에 대한 연구결과들이 많이 보고되고 있다. 이들 잔류 의약물질들은 다양한 종류와 그들이 가지는 물리 화학적인 특성들로 인해 수환경에서의 거동, 오염현황, 영향 및 독성 등도 매우 다양하여 수환경 및 수처리 공정에서의 거동을 예측 평가하기가 어렵다. 선진 외국의 경우 환경 중에서의 오염 현황 및 사용량을 정량화하기 위한 조사를 이미 시작하였고, 잔류 의약물질들의 인체에 대한 잠재적 위험성뿐만 아니라 상수나 하수처리 공정에서의 제거기술에 관한 다양한 연구도 활발히 진행하고 있다. 그러나 국내의 경우 잔류 의약물질들에 대해 전국 주요하천과 상수원에 대한 모니터링 결과도 매우 부족한 실정이다. 우선 국내의 경우는 상수원으로 이용되는 전국 주요 하천과 호소에 대해 주기적이고 체계적인 오염현황 평가가 선행되어야 하며, 잔류 의약물질들이 비교적 고농도로 검출되는 상수원에 대해서는 주오염원에 대한 조사도 병행되어야 한다. 또한, 의약물질 사용량은 지속적으로 증가할 것으로 전망되기 때문에 하수처리 시설에 대한 부하도 지속적으로 증가할 것이다. 따라서 수환경에서의 유해도를 저감시키기 위해 효과적인 하수처리 공법의 도입이 절실하며, 상수에 대한 안전성 확보를 위해서도 잔류 의약물질들의 수환경중에서의 물리 화학적 거동에 대한 면밀한 연구가 요구된다.

• Toxicological Research
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• 제24권3호
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• pp.207-212
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• 2008

Pesticide residues play several key roles as environmental and food pollutants and it is crucial to develop a method for the rapid determination of pesticide residues in environments. In this study, a simple, effective, and sensitive method has been developed for the quantitative analysis of methoxyfenozide in water and soil when kept under laboratory conditions. The content of methoxyfenozide in water and soil was analyzed by first purifying the compound through liquid-liquid extraction and partitioning followed by florisil gel filtration. Upon the completion of the purification step the residual levels were monitored through high performance liquid chromatography(HPLC) using a UV absorbance detector. The average recoveries of methoxyfenozide from three replicates spiked at two different concentrations and were ranged from 83.5% to 110.3% and from 98.1% to 102.8% in water and soil, respectively. The limits of detection(LODs) and limits of quantitation(LOQs) were 0.004 vs. 0.012 ppm and 0.008 vs. 0.024 ppm, respectively. The method was successfully applied to evaluate the behavioral fate of a 21% wettable powder(WP) methoxyfenozide throughout the course of 14 days. A first-order model was found to accurately fit the dissipation of methoxyfenozide in water with and a $DT_{50}$ value of 3.03 days was calculated from the fit. This result indicates that methoxyfenozide dissipates rapidly and does not accumulate in water.

• 한국환경독성학회:학술대회논문집
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• 한국환경독성학회 2003년도 춘계학술대회
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• pp.149-149
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• 2003

To understand environmental paths of the transport and accumulation of endocrine disrupting chemicals (EDCs), a single cell multimedia fate model has been constructed and evaluated. The EDCs of concern were PAHs, Organochlorine Pesticides (OCPs), PCBs, Alkyl phenols, and phthalates. An evaluation model was designed for the multimedia distribution, including air, water, soil, sediment and vegetation. This model was verified using reported values and via monitoring data. Based on collected data, the distribution trends of EDCs with respect to environmental media were analyzed. Those results have applied to the model for the prediction of the spatial and temporal distribution of EDCs in Seoul. Especially, phenol compound, phthalates, PAHs, PCBs and organochlorine pesticides were estimated and the model was verified. This model was successfully conducted to environmental media, such as air (vapor and suspended particles), soils (forest soil, bare soil, and cement-concrete covered soil), water (dissolved and suspended solids), sediment, trees (deciduous and coniferous). The discrepancies between the model prediction and the measured data are approximately within or near a factor of 10 for the PAHs of three rings through that of six rings, implying that multimedia distribution of the PAHs could be predicted with a factor of 10. Concerning about the air equilibrium may be assumed, a fugacity at steady state is similar in all environmental media. Considering the uncertainties of this model, the use of equilibrium models may be sufficient for assessing chemical fates. In this study, a suggestion was made that modeling and estimation of chemicals in environmental multimedia be rigorously evaluated using the measured flux data. In addition, these data should be obtained, for example, from the precise and standardized inventory of the target chemicals. The model (EDC Seoul) will be refined in an on-going research effort and will be used to support decision-making concerning the management of EDCs.