• 한국환경과학회지
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• 제16권1호
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• pp.9-19
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• 2007

Comparing predicted PCDF isomer patterns with those obtained from a municipal waste incinerator assessed the role of two-phenol condensation pathways in the formation of PCDFs. Complete PCDF homologue and isomer distributions were obtained from a Fluidized Bed Incinerator (FBI). Two-phenol condensation model, dependent only on the distributions of phenols, was developed to predict the PCDF congeners produced from phenol precursors. R-squared values from linear correlations are presented for the dichlorinated through hexa-chlorinated isomer distributions between measured and predicted. They range from 0.00: to 0.1 far the di-chlorinated through hexa-chlorinated isomer sets. Agreement between predicted and measured PCDF isomer distributions was very poor for all homologues. Two-phenol condensation pathways are not likely to be the pre-dominant pathways in the formation of PCDF in a FBI. However, dibenzofuran (DF) is likely to be produced from a condensation of two phenols. This work demonstrates the use of PCDF homologue and isomer patterns for testing PCDF formation mechanism from two-phenol condensation pathways in municipal waste incinerators.

• 한국대기환경학회지
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• 제22권6호
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• pp.842-850
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• 2006

The role of chlorination reactions in the formation of polychlorinated dibenzofurans (PCDFs) in a municipal waste incinerator was assessed using a chlorination model for predicting PCDF isomer distributions. Complete distributions of PCDF congeners were obtained from a stoker-type municipal waste incinerator operated under 13 test conditions. Samples were collected from the flue gas prior to the gas cleaning system. While total PCDF yields varied by a factor of five to six, the distributions of congeners were similar. A chlorination model, dependent only on the observed distribution of monochlorinated isomers, was developed to predict the distributions of poly-chlorinated isomers formed by chlorination of dibenzofuran (DF). Agreement between predicted and measured PCDF isomer distributions was high for all homologues, supporting the hypothesis that DF chlorination can play an important role in the formation of PCDF byproducts.

• Environmental Engineering Research
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• 제11권4호
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• pp.217-231
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• 2006

The gas-phase formation of polychlorinated naphthalenes (PCNs) and dibenzofurans (PCDFs) was experimentally investigated by slow combustion of the three chlorophenols (CPs): 2-chlorophenol (2-CP), 3-chlorophenol (3-CP) and 4-chlorophenol (4-CP), in a laminar flow reactor over the range of 550 to $750^{\circ}C$ under oxidative condition. Contrary to the a priori hypothesis, different distributions of PCN isomers were produced from each CP. To explain the distributions of polychlorinated dibenzofuran (PCDF) and PCN congeners, a pathway is proposed that builds on published mechanisms of PCDF formation from chlorinated phenols and naphthalene formation from dihydrofulvalene. This pathway involves phenoxy radical coupling at unsubstituted ortho-carbon sites followed by CO elimination to produce dichloro-9, 10-dihydrofulvalene intermediates. Naphthalene products are formed by loss of H and/or Cl atoms and rearrangement. The degree of chlorination of naphthalene and dibenzofuran products decreased as temperature increased, and, on average, the naphthalene congeners were less chlorinated than the dibenzofuran congeners. PCDF isomers were found to be weakly dependent to temperature, suggesting that phenoxy radical coupling is a low activation energy process. Different PCN isomers, on the other hand, are formed by alternative fusion routes from the same phenoxy radical coupling intermediate. PCN isomer distributions were found to be more temperature sensitive, with selectivity to particular isomers decreasing with increasing temperature.

• 분석과학
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• 제15권2호
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• pp.142-148
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• 2002

우리 나라에서 많이 소비되고 있는 생선류인 고등어, 명태, 조기, 오징어에 포함되어 있는 다이옥신을 HRGC/HRMS를 사용하여 분석하였다. 시료는 서울, 춘천, 대전, 광주, 부산 5개 대도시의 각 3곳에서 수집되었으며 모두 20개의 시료를 분석하였다. PCDDs는 고등어에서 0.032 pgTEQ/g으로 가장 높은 값을 나타냈고, PCDFs는 명태가 0.010 pgTEQ/g으로 가장 낮은 값을 나타냈다. 또 생선중에 포함된 총 다이옥신 농도 중에서 PCDDs가 PCDFs보다 높은 비율을 차지하고 있는 것으로 조사되었다.

• Environmental Engineering Research
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• 제11권4호
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• pp.232-240
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• 2006

Polychlorinated naphthalenes (PCNs) formed along with dibenzo-p-dioxin and dibenzofuran products in the slow combustion of dichlorophenols (DCPs) at $600^{\circ}C$ were identified. Each DCP reactant produced a unique set of PCN products. Major PCN congeners observed in the experiments were consistent with products predicted from a mechanism involving an intermediate formed by ortho-ortho carbon coupling of phenoxy radicals; polychlorinated dibenzofurans (PCDFs) are formed from the same interemediate. Tautomerization of the intermediate and $H_2O$ elimination produces PCDFs; alternatively, CO elimination to form dihydrofulvalene and fusion produces naphthalenes. Only trace amounts of tetrachloronaphthalene congeners were formed, suggesting that the preferred PCN formation pathways from chlorinated phenols involve loss of chlorine. 3,4-DCP produced the largest yields of PCDF and PCN products with two or more chlorine substituents. 2,6-DCP did not produce tri- or tetra-chlorinated PCDF or PCN congeners. It did produce 1,8-DCN, however, which could not be explained.

• 분석과학
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• 제24권6호
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• pp.484-492
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• 2011

우리나라 주요 하천수계의 대표적인 지점 한 곳씩 선정하여 이곳에 서식하는 붕어에 대한 PCDDs, PCDFs 및 DL-PCBs의 체내 축적 정도를 분석하고 분포특성을 살펴보았다. 회수율은 PCDDs 및 PCDFs는 50.6%~88.3%, DL-PCBs는 52.3%~93.2%이었으며, 붕어 체내에 축적된 PCDDs, PCDFs 및 DL-PCBs를 모두 합한 ${\sum}$dioxins은 평균 0.39 pg TEQ $g^{-1}$ wet wt., 중앙값 0.14 pg TEQ/g wet wt., 그리고 농도 범위는 0.047-1.0 pg TEQ/g wet wt.으로 나타났다. PCDDs 및 PCDFs는 일부 시료에서 검출된 반면, DL-PCBs는모든 시료에서 검출되었으며 ${\sum}$dioxins에 대한 기여도가 83.6%로서 가장 높았다. 다음으로 PCDFs와 PCDDs가 각각 ${\sum}$dioxins의 12.7%와 3.7%를 기여하고 있었다.

• 대한환경공학회지
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• 제28권5호
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• pp.511-521
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• 2006

페놀류 전구물질로부터 형성된 polychlorinated dibenzo-p-dioxins(PCDDs)와 dibenzofurans(PCDFs)의 모든 동족체와 이성질체의 경향을 페놀과 19개의 염화페놀류의 분포를 이용하여 연구하였다. 실험은 $400^{\circ}C$(particle-mediated formation)와 $600{\sim}700^{\circ}C$(gas-phase formation)에서 각각 행하여 졌으며, 운반가스로 사용된 가스의 조성은 92%의 질소와 8%의 산소를 사용하였다. 염소기가 없는 dibenzo-p-dioxin(DD)와 dibenzofuran(DF)를 포함한 모든 종류의 PCDDs와 PCDFs의 동족체와 이성질체들이 20개의 페놀류를 혼합하여 사용한 본 실험으로부터 얻어졌다. 가스상 실험은 PCDFs가 많이 생성하였고, 입자상 실험에서는 PCDDs를 많이 생성 하였다. 가장 많이 생성된 동족체는 각각 DD와 DF였으며, 염소기의 숫자가 증가할수록, 동족체의 생성량은 감소하였다. 하지만 가스상과 입자상 실험에서 얻어진 PCDDs와 PCDFs의 동족체와 이성질체의 분포는 거의 항상 일정하였다. 고농도로 존재하는 페놀과 적은수의 염소기를 가지고 있는 염화 페놀류의 농도가 가스상과 입자상에서 발생하는 PCDDs와 PCDFs의 분포에 아주 중요한 역활을 하였다.

• 분석과학
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• 제14권6호
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• pp.504-509
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• 2001

우리 나라 사람들의 체지방 조직과 초유중에서, 다이옥신의 잔류 농도를 HRGC/HRMS를 이용하여 동위원소희석법으로 측정하였다. 체지방 조직 시료는 서울에 있는 모병원에서 채취하였으며, 체지방 조직에서의 PCDFs의 총농도와 TEQ 농도는 각각 5.812 pg/g, 1.485 pgTEQ/g 이었고, PCDDs의 총농도와 TEQ 농도는 각각 26.648 pg/g, 1.176 pgTEQ/g 이었다. 서울대학 병원으로부터 받은 산모 20명의 초유에 함유된 다이옥신의 잔류농도는 PCDFs의 총 농도가 7.019 pg/mL, TEQ 농도로 환산하면 0.177 pgTEQ/mL 이었고, PCDDs의 총 농도와 TEQ 농도는 각각 14.224 pg/mL, 0.693 pgTEQ/mL이었다. 체지방 조직과 모유에서의 다이옥신 이성질체들의 분포는 PCDDs가 PCDFs보다 상대적으로 높게 나타났으며, 그중 OCDD가 가장 높은 농도로 포함되어 있다.

• 한국대기환경학회:학술대회논문집
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• 한국대기환경학회 1999년도 추계학술대회 논문집
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• pp.225-228
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• 1999

The formation of dioxin (term used here to refer to both polychlorinated dibenzo-p-dioxins, PCDDS, and dibenzofurans, PCBFs) in combustion processes is of concern because of the extreme toxicities of some of these compounds and because of their resistance to degradation in the environment. The number and location of chlorine substituents differentiate dioxin homologues and isomers, respectively. There are a total of 75 PCDD congeners and 135 PCDF congeners.(omitted)

• 한국환경과학회:학술대회논문집
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• 한국환경과학회 2005년도 봄 학술발표회지 제14권(제1호)
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• pp.298-300
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• 2005

다이옥신 29종을 분석한 결과 PCDD/PCDFs는 검출빈도가 3/4(붕어), 0/4(황소개구리)였으며, co-PCBs는 검출빈도가 4/4(붕어), 3/4(황소개구리)를 나타내었다.