• 한국환경보건학회지
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• 제30권3호
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• pp.264-271
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• 2004

An aquatic food chain was constructed to provide information of bioaccumulation of DEHP as followed: phytoplankton(Scenedesmus subspicatus) ${\rightarrow}$ zooplankton(Daphnia magna) ${\rightarrow}$ fish(Oryzias latipes). After 10 days of exposure to DEHP, the fish and culture water were analyzed for residual concentration of DEHP and BAF(Bioaccumulation Factor) was determined. In addition, BCF(Bioconcentration Factor) was calculated in exposure tank in which fish were only exposed DEHP by culture water. These experiments provide the relative importance between BAF and BCF. In this study, BCF and BAF did not show any significant difference. Another work in this study was model construction and application to investigate the effect of food chain structure to BAF in higher organism (fish). The model constructed in this study considered the biological characteristics of DEHP such as metabolic parameters, as well as the chemical characteristics such as solubility. This model could be used in prediction of bioaccumulation level in dependent of various food chain structures, when the target organisms or chemicals would be changed.

• 환경영향평가
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• 제8권2호
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• pp.83-93
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• 1999

ASPEN PLUS, a steady-state simulator, was used in this study for predicting emissions of VOCs and tracing the fate of all compounds in biodegradation processes. Mathematical models for the processes such as volatilization, reaction and clarification were adopted from literatures. Unlike most previous simulations that various pollutants were considered as a single component, COD or BOD, four components of water, biomass, VOCs and COD were included in this simulation. Sensitivity analysis of several physical parameters on the performance of the WWTP was conducted. Model predictions of VOCs emissions agreed well with the plant data. The simulator could provide design conditions for a future WWTP as well as monitoring/control regimes to an existing WWTP.

• 한국환경과학회지
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• 제11권7호
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• pp.737-742
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• 2002

Sorption and desorption is an important phenomenon to determine the fate of halogenated aliphatic hydrocarbons in the aqueous phase. This study was conducted to develope a predictive equation capable of estimating the sorption and desorption potentials of halogenated aliphatic hydrocarbons onto the sludge from activated process, sediment, and clay. It has shown that the sorption and desorption parameters can be accurately estimated using Quantitative Structural Activity Relationship(QSAR) models based on molecular connectivity indexes of test compounds. The QSAR model could be applied to predict the sorption and desorption capacity of the other halogenated aliphatic hydrocarbons. The QSAR modeling would provide a useful tool to predict the sorption and desorption capacity without time-consuming experiments.

• 한국환경보건학회:학술대회논문집
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• 한국환경보건학회 2002년도 춘계 국제 학술대회
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• pp.9-12
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• 2002

Diffusive transport of volatile organic compounds(VOCs) and their degradation by bacteria in unsaturated soils are couple by poorly understood mass transfer kinetics at the gas/water interface. Determination of the fate of VOCs in unsaturated soil is necessary to evaluate the feasibility of natural attenuation as a VOC remediation strategy. The objective of this study was to develop a mechanistically based mathematical model that would consider the interdependence of VOC transport, microbial activity, and sorptive interaction in a moist, unsaturated soil. Because the focus of the model was on description of natural attenuation, the advective VOC transport that is induced in engineered remediation processes such as vapor extraction was not considered. The utility of the model was assessed through its ability to describe experimental observations form diffusion experiments using toluene as a representative VOC in well-defined soil columns that contained a toluene degrading bacterium, Pseudomonas Putida, as the sole active microbial species. The coefficient for gas-liquid mass-transfer, K$\sub$LA/, was found to be a key parameter controlling the ability of bacteria to degrade VOCs. This finding indicates that soil size and geometry are likely to be important parameters in assessing the possible success of natural attenuation of VOCs in contaminated unsaturated soils.

• 한국지하수토양환경학회지:지하수토양환경
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• 제10권4호
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• pp.13-17
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• 2005

암모늄의 질산화 반응, 질소산화물의 탈질 반응, 그리고 유기물의 산화반응을 고려한 SAT 모델링 시스템에 대해서, 현장조건의 변화에 따른 모델 결과를 비교하기 위해 6가지 모델 조건에 대한 가상의 수직 2차원상 모델 시뮬레이션을 하였다. 시뮬레이션 조건에서 수리전도도, 주입수 주입율, 지표 피복 여부, 그리고 운영 계획과 같은 4가지 영향 인자들이 고려되었다. 시뮬레이션 결과, 모든 조건에서 모델 개발 과정에서 고려한 반응 영향들이 잘 모사되었다.

• Environmental Analysis Health and Toxicology
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• 제16권3호
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• pp.139-142
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• 2001

Acetanilide is a High Production Volume Chemical, which is produced about 2,300 tons/year in Korea as of 1998 survey. Most is used as an intermediate for synthesis of pharmaceuticals and dyes, and the chemical is one of seven chemicals of which human and environmental risk are being assessed by National Institute of Environmental Research under the frame of OECD SIDS program. The Atmospheric Oxidation Program for Microsoft Windows (AOPWIN) is used to estimates the rate constant for the atmospheric, gas－phase reaction between photochemically produced hydroxyl radicals and organic chemicals. It is also used to estimates the rate constant for the gas－phase reaction between ozone and olefinic/acetylenic compounds. The rate constants estimated by the program are then used to calculate atmospheric half－lives for organic compounds based upon average atmospheric concentrations of hydroxyl radicals and ozone. AOPWIN requires only a chemical structure to make these predictions. Structures are entered into AOPWIN by SMILES (Simplified Molecular Input Line Entry System) notations. In this study, one of environmental fate/distribution of the chemical elements, photodegradation of acetanilide was estimated using AOPWIN model based on SMILES notation and chemical name data.

• 한국환경과학회지
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• 제4권1호
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• pp.19-28
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• 1995

본 연구에서는, 골프장에서 사용되는 농약의 강우유출특성과 인테의 건강에 대한 risk assessment를 행하였다. 골프장에 살표되는 농약으니 강우시의 강우유출큭성을 모델화하여, 지표농약의 강우유출특성을 구하였다. 이 유충계수를 이용하여 하류 하천에서의 농약의 온도를 예측하여, 인체의 건강에 대한, risk를 평가하였다. 농약의 강우유출특성을 파악하기 위하여 온약이 유입되는 저정연목의 유역을 선정하여 강우시의 농약의 강우유출특성을 조사하였다. 지표농약으로 선정한 농약의 츄출계수(1/mm)는, Flutolanil가 0.0054, Isoprothiolane이 0.0019, Chlorpyrifos가 0.0003, Simazine이 0.0044 였다. 이 유출계수를 지역수계의 특성을 고려하여 설정한 지역수계모델의 재현능력을 확인하였다. 또, 이 지역수계모델을 이용하여 하류 하천에서의 농약ㅢ 농도를 예측하여 농약에 오염된 하천수를 이용하는 하류주민에 대한 건강 risk의 평가를 행하였다. 폴로경로로서는 음료수로서의 섭휘만을 고려하였으며, risk의 평가시표로서는 10% ADI(Acceptable Daily Intake) 와 VSD(Virtually Safe Dose)를 이용하였다. 인체의 건강에 대한 risk는 발암risk로서 Simazine의 경우 $10^{-7}$~$10^{-9}$로 비교적 낮은 risk수준인 것으로 판단되었다

• 한국환경독성학회:학술대회논문집
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• 한국환경독성학회 2003년도 추계국제학술대회
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• pp.91-93
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• 2003

It has been estimated that the equivalent of approximately $US 50 billion has been spent on research on the behavior and fate of pesticides in the environment since Rachel Carson published “Silent Spring” in 1962. Much of the resulting knowledge has been summarized explicitly in computer algorithms in a variety of empirical, deterministic, and probabilistic simulation models. These models describe and predict the transport, degradation and resultant concentrations of pesticides in various compartments of the environment during and after application. In many cases the known errors of model predictions are large. For this reason they are typically designed to be “conservative”, i.e., err on the side of over-prediction of concentrations in order to err on the side of safety. These predictions are then compared with toxicity data, from tests of the pesticide on a series of standard representative biota, including terrestrial and aquatic indicator species and higher animals (e.g., wildlife and humans). The models' predictions are good enough in some cases to provide screening of those compounds which are very unlikely to do harm, and to indicate those compounds which must be investigated further. If further investigation is indicated a more detailed (and therefore more complicated) model may be employed to give a better estimate, or field experiments may be required. A model may be used to explore “what if” questions leading to possible alternative pesticide usage patterns which give lower potential environmental concentrations and allowable exposures. We are currently at a maturing stage in this research where the knowledge base of pesticide behavior in the environmental is growing more slowly than in the past. However, innovative uses are being made of the explosion in available computer technology to use models to take ever more advantage of the knowledge we have. In this presentation, current developments in the state of the art as practiced in North America and Europe will be presented. Specifically, we will look at the efforts of the ‘Focus’ consortium in the European Union, and the ‘EMWG’ consortium in North America. These groups have been innovative in developing a process and mechanisms for discussion amongst academic, agriculture, industry and regulatory scientists, for consensus adoption of research advances into risk management methodology.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 총회 및 춘계학술발표회
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• pp.25-39
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• 2003

Risk and exposure assessment for subsurface environment is very important for both aspects of health and environmental protection as well as making decision of remedial goal for engineering activities. Exposure due to hazardous chemicals in the subsurface environment is essential to assess risk lev121 to individual person, especially from soil and groundwater environmental media. In this paper, the status of soil and groundwater contamination is presented to discuss on the problem for environmental risk assessment. The methodologies of fate and exposure models are also discussed by conducting the case studies of exposure assessment for heavy metals, organic compounds, and dioxin compounds. In addition, the structure of exposure models and available data for model calculation are examined to make clear more realistic exposure scenarios and the application to the practical environmental issues. Three kinds of advanced remediation techniques for soil and groundwater contamination are described in this paper, The most practical method for VOCs is the bio-remediation technique in which biological process due to consortium of microorganisms can be applied. For more effective remediation of soil contaminated by heavy metals we have adopted the soil flushing technique and clean-up system using electro-kinetic method. We have also developed the advanced techniques of geo-melting method for soil contaminated by DXNs and PCB compounds. These techniques are planed to introduce and to apply for a lot of contaminated sites in Japan.

• 한국환경과학회지
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• 제12권11호
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• pp.1173-1179
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• 2003

Laboratory sorption isotherm batch studies have been attempted to elucidate interaction of synthetic pyrethroids (bifenthrin and permethrin) with sediments and their fractions. As a nonlinear isothermal model, the Freundlich equation was applied to sorption results obtained from sediments to investigate the relationship between synthetic pyrethroids and sediments containing different amounts of organic carbon. Results demonstrated that the sorption capabilities of bifenthrin and cis- and trans-permethrin was in the order of bifenthrin, cis-permethrin and trans-permethrin, respectively, indicating that adsorbed bifenthrin was the most stable followed by cis- and trans-permethrin in all sediments. Their sorption capability was closely related to organic carbon contents in sediments. Higher sorption was observed in sediments containing higher organic carbon contents. Sorption study extended into the fractions, clay and humic acids, extracted from a sediment, indicated that higher sorption capacity in humic acids occurred than in the clay of both examined bifenthrin and permethrin. This study demonstrates the sorption of synthetic pyrethroids with sediments, and will help in the understanding of the transport and fate of synthetic pyrethroids existing in field sediments.