• Title, Summary, Keyword: dioxins

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Optimization of Incinerator Controllers using Artificial Neural Networks

  • Mackin, Kenneth J.;Fukushima, Ryutaro;Fujiyoshi, Makoto
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • pp.334-337
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    • 2003
  • The emission of dioxins from waste incinerators is one of the most important environmental problems today, It is known that optimization of waste incinerator controllers is a very difficult problem due to the complex nature of the dynamic environment within the incinerator. In this paper, we propose applying artificial neural networks to waste incinerator controllers. We show that artificial neural networks can project the emission of dioxins with a fair degree of accuracy.

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DFT Calculation on the Electron Affinity of Polychlorinated Dibenzo-p-dioxins

  • Lee, Jung-Eun;Choi, Won-Yong;Mhin, Byung-Jin
    • Bulletin of the Korean Chemical Society
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    • v.24 no.6
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    • pp.792-796
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    • 2003
  • Polychlorinated dibenzo-p-dioxins (PCDDs) are extremely toxic and persistent environmental pollutants. Their chemical reactivities and other physicochemical/biological properties show a strong dependence on the chlorination pattern. With increasing the number of chlorines, dioxin congeners become more electronegative and gain higher electron affinities. The vertical electron affinities (VEA) are related with the LUMO energies of neutral molecules. LUMO energies of all PCDD congeners were calculated at the B3LYP/6-31G** level and those of some selected congeners at the level of B3LYP/6-311G**//B3LYP/6-31G** and B3LYP/cc-pvtz/ /B3LYP/6-31G**. The total energies of neutral and anionic species for dibenzo-p-dioxins (DD), 1469-TCDD, 2378-TCDD, and OCDD were calculated at the level of B3LYP/6-31G**, B3LYP/aug-cc-pvdz, and B3LYP/ aug-cc-pvtz//B3LYP/6-31G**. By using the four congeners with D2h symmetry as reference molecules, we could estimate VEA (B3LYP/aug-cc-pvdz) of 75 PCDD congeners based on the linear correlations between LUMO energy and VEA (B3LYP/6-31G**) and between VEA (B3LYP/6-31G**) and VEA (B3LYP/aug-ccpvtz// B3LYP/6-31G**). Results show that all PCDDs with the number of Cl ≥ 3 have positive electron affinities. The PCDD electron affinity values provided in this work can be a useful data set in understanding the congener-specific reactivities of dioxins in various environmental media.

Evaluation for Concentration of Residual PCDD/Fs in Pig Feed (돼지사료 중의 다이옥신 잔류 평가)

  • Ahn, Yun-Gyong;Shin, Jeoung-Hwa
    • The Korean Journal of Community Living Science
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    • v.23 no.2
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    • pp.129-136
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    • 2012
  • Dioxins are chemical substances that are not properly decomposed degradation under natural photochemical, biological and chemical conditions in the environment, and bio-accumulate through the food chain, so pose a risk of causing adverse effects to human health and the environment. Ninety seven percent of human exposure to dioxins comes through meat, fish, dairy consumption and so on. Pork is the largest proportion meat aspect of daily intake in the Korean food. Pigs are three times more than Cattle in terms of breeding population and production amount in the world, and the amount is increasing every year. Therefore, it is necessary to monitor the exposure level of dioxins in pig's body. Also, it is required to evaluate the presence of these chemical substances in the pig's feed grain such as corn, soybeans, and tallow. The purpose of this study was to evaluate PCDD/Fs in pig's feed to search the origin of PCDD/Fs. Feed samples obtained were wheat from East Europe, corn from South America and America, soybean meal from Korea, America, South America and India and tallow from Korea. The preparation of samples was based on the EPA method 1613. Instrumental analysis was based on the use of high resolution gas chromatography coupled to high resolution mass spectrometry (HRGC/HRMS). The concentrations of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and 1,2,3,7,8-pentachlorodibenzo-p-dioxin (PCDD), which are the most toxic potent dioxins, were not observed in any of the samples. However OCDD was detected in most of the samples. The TEQs in the feed samples were ranged from 0 pg TEQ/g to 0.09841 pg TEQ/g. Especially, the high level of TEQs was observed in the samples of wheat from East Europe and soybean meal from Korea.

Metal Recycling Technologies from Fly-Ashes by the Metal Mining Agency of Japan

  • Kazuyuki, Kikuta;Nobuyuki, Masuda;Nobuyuki, Okamoto;Eiichi, Arai;Junichi, Kobayashi
    • Proceedings of the IEEK Conference
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    • pp.659-663
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    • 2001
  • In Japan, the municipal solid waste, which amounts to 50 million tons, is generated every year and most of it is incinerated. The bottom and fly ashes are disposed to the registered disposal areas under the provisions of The Waste Disposal and Public Cleaning Law. Especially, as the fly ash from the municipal waste incineration (the primary fly ash) contains heavy metals (lead, zinc, etc) and dioxins, it cannot be disposed directly without decontamination, such as moiling, cementation, chelating and dissolving processes provided in the law. However, these procedures for decontamination, except melting, are not enough for dioxins. Even in case of melting, the fly ash from the process (the secondary fly ash) contains high concentration of heavy metals (e.g., Zn; 1-20%, Pb; 1-10%). For these reasons, Metal Mining Agency of Japan (MMAJ), a governmental organization, started a four-year project to develop the treatment technologies of these fly ashes in 1999. The purpose of the project is to establish the integrated technologies to recover the valuable metals from, and to decontaminate, the primary and secondary fly-ashes in the practical scale by utilizing the existing metallurgical processes and facilities, along with the energy saving and the reduction of the environmental impact.

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Comparative risk analysis for priority ranking of environmental problems in Seoul

  • Kim, Ye-Shin;Lee, Yong-Jin;Park, Hoa-Sung;Lim, Young-Wook;Shin, Dong-Chun
    • Proceedings of the Korea Society of Environmental Toocicology Conference
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    • pp.169-169
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    • 2003
  • In Korea, there is no CRA studies and has not well known CRA and not well established their methodologies. Therefore, objectives of this study is to establish the framework of CRA consisting of health risk, economic risk and perceived risk and the detail methodologies of three main component of estimating and comparing those risks for on the three environmental problems of air pollution, indoor air pollution and drinking water contamination which being subjective to the eight sub-problems of hazardous ai. pollutants (HAPs), regulated pollutants (representative as PM10) and Dioxins (PCDDS/ PCDFs) in air pollution, and indoor ai. pollutants (IAPs) and Radon in indoor air pollution, and drinking water pollutants (DWPs), disinfection-by- products(DBPs) and radionuclides in drinking water contamination in Seoul, Korea. And then, their problems set priorities by individual and integrated risk. As a results, ranking of health risk were the following order of indoor air pollution, air pollution and then drinking water contamination, in three environmental problems and of radon, PM10, IAPs, HAPs, DWPs, Dioxins, DBPs, and then radionuclides in eight sub-problems. And that of economic risk were the same order. In the contrary, ranking of perceived risk were the following order of air pollution, drinking water contamination, and then indoor air pollution, and of HAPs, Dioxins, radionuclides, PM10, DWPs, IAPs, Radon and then DBPs.

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Potential Dioxin and Furan Sources from Hospital Solid Waste Streams : A Pilot Study

  • Lee, Byeong-Kyu;Fraso, Rafael-Moure;M
    • Journal of Korean Society for Atmospheric Environment
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    • v.11 no.E
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    • pp.13-21
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    • 1995
  • This Pilot study identifies potential dioxin and furan sources and medical plastic wastes produced from hospital solid waste streams. In this study, air emissions of dioxins and furans from sources in the U.S., which were estimated by the U.S. Environmental Protection Agency (EPA), were summarized. Potential loading routes of dioxins and furans to the U.S.-Canada Great Lakes region have also been identified in trcent surveys. In addition, medical and hospital solid wastes produced in typical large city hospitals were characterized as important potential sources of dioxins and furans. Plastic contents in medical Plastics Characterization Survey (MMPCS), plastics composition data were obtained from a survey of five Massachusetts Hospitals and Medical Centers. By identifying plastic wastes as a percentage of total hospital wastes, we were able to use data from a preliminary study that analyzed the waste stream of 16 major New York City hospitals (NYCMWS) characterizing the plastic content of the wasters. This study determined the types of plastic wastes included in each medical waste stream (regulated medical waste or non regulated medical waste) and it discussed the potential for recyclibility of hospital plastic wastes. The combination of the NYCMWS and the MMPCS surveys provides for the first overview of the size of the recycling task of hospital plastic wastes and the potential of dioxin elimination if dioxin generating plastics were to be eliminated from hospital use.

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Comparative Risk Analysis for Priority Ranking of Environmental Problems (환경 문제의 우선 순위 도출을 위한 비교 위해도 분석에 관한 연구)

  • 김예신;임영욱;남정모;장재연;이동수;신동천
    • Environmental Analysis Health and Toxicology
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    • v.17 no.4
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    • pp.285-298
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    • 2002
  • In Korea, no CRA (comparative risk analysis) studies have been undertaken, nor have their methodologies of such studies been established. Therefore, the objectives of this study were to establish the framework of CRA consisting of health risk, economic risk and perceived risk, and to estimate and compare these risks among the three environmental problems of air pollution, indoor air pollution and drinking water contamination, which are themselves subject to the eight sub -problems of hazardous air pollutants (HAPs), regulated pollutants (representative as PM 10) and dioxins (PCDDs/PCDFs) in air pollution, indoor air pollutants (IAPs) and radon in indoor air pollution, and drinking water pollutants (DWPs), disinfection by -products (DBPs) and radionuclides in drinking water contamination in Seoul, Korea. After which, the priorities of these problems were set by individual and integrated risk. From the results, the rankings of both health risk and economical risk were in the following order: radon, PM10, IAPs, HAPs, DWPs, dioxins, DBPs, and radionuclides among the eight sub problems. On the contrary, the ranking of perceived risk was in the following order: HAPs, dioxins, radionuclides, PM10, DWPs, IAPs, Radon and then DBPs among the eight sub-problems.

Formation of Polybrominated Dibenzo-p-dioxins/Furans (PBDDs/Fs) by the Pyrolysis of 2,4-Dibromophenol, 2,6-Dibromophenol, and 2,4,6-Tribromophenol

  • Na, Yun-Cheol;Hong, Jong-Ki;Kim, Kang-Jin
    • Bulletin of the Korean Chemical Society
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    • v.28 no.4
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    • pp.547-552
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    • 2007
  • This study examined the thermal reactions of 2,4-dibromophenol (diBP), 2,6-diBP and 2,4,6-triBP. The products obtained under pyrolytic conditions were analyzed by gas chromatography/mass spectrometry (GC/MS). 2,7-dibromodibenzo-p-dioxin (diBDD) was the major compound produced from the thermal reaction of 2,4-diBP. In addition, monoBDD and triBDDs were obtained through a process of debromination and bromination, respectively. The pyrolysis of 2,6-diBP and 2,4,6-triBP produced two major brominated dioxin isomers through direct condensation and a Smiles rearrangement. The two ortho-Brs in 2,6-diBP and 2,4,6-triBP mainly led to the production of dioxins, whereas in addition to 2,7-diBDD, 2,4-diBP produced two furans as minor products, 2,8-dibromodibenzofuran (diBDF) and 2,4,8-triBDF, through the intermediate dihydroxybiphenyl (DOHB). The maximum yield of the major dioxins was obtained at 400 oC, and decomposition by debromination at 500 oC resulted in less substituted bromodioxins.

Exposure assessment of dioxins through foods (식품을 통한 다이옥신류의 노출 평가)

  • Oh, Keum-Soon;Suh, Jung-Hyuck;Paek, Ock-Jin;Kim, Mee-Hye;Lee, Kwang-Ho
    • Analytical Science and Technology
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    • v.23 no.6
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    • pp.595-606
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    • 2010
  • A total 221 samples of the retailed foods collected from 2004 to 2007 was examined to estimate the level of dioxins(29 congeners) by the isotopic dilution method, and the exposure of population of Korean to dietary of dioxins was performed. Dioxins levels were calculated using TEF values established in 1998 and 2005, respectively. The average levels (pg TEQ/g) were less than 0.01 for polished rice, 0.04 (poultry)-0.13 (beef) for meats, 0.04 (milk)-0.05(cheese) for milk and dairy products, 0.13 for egg (york, only) and 0.11 (alaska pollack)-1.35 (pacific mackerel) for fishes. The estimated daily intake of Korean through foods was 0.47 pg TEQ/kg bw/day, and it was estimated as about 11% to tolerable daily intake (TDI; 4 pg TEQ/kg bw/day) of Korea and Japan. Consequently, it was concluded that there was no health risk.

Investigation on Polychlorinated Dibenzo-p-dioxins, Polychlorinated Dibenzofurans and Dioxin-like Polychlorinated Biphenyls of Grains and Estimation of Dietary Intake for Korean (국내생산 주곡작물의 Polychlorinated Dibenzo-p-dioxins, Polychlorinated Dibenzofurans와 Dioxin-like Polychlorinated Biphenyls 잔류량 및 섭취노출량 평가)

  • Choi, Geun-Hyoung;Choi, Dal-Soon;Hong, Su-Myeong;Kwon, Oh-Kyoung;Eun, Hee Soo;Kim, Jung Han;Kim, Jin Hyo
    • Journal of Applied Biological Chemistry
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    • v.55 no.4
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    • pp.253-261
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    • 2012
  • Dioxin contamination on agroproducts is one of the most important issue in food safety. Herein, we measured concentration of 17 dioxins polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) and 14 dioxin like-polychlorinated biphenyls (DL-PCBs) in the main grain (rice and barley) that were produced in Korea. The 36 rice samples were collected from rice processing complex at eight provinces, and the average concentrations of each province were ranged from 2.98 pg/g wet weight (w.w) to 4.98 pg/g w.w. as total PCDD/Fs and DL-PCBs. The seven barley samples were collected from Jeon-nam and Jeon-buk provinces, and their average total concentrations of PCDD/Fs and DL-PCBs were 3.00 pg/g w.w. and 3.24 pg/g w.w. respectively. The residual amounts and toxic equivalent (TEQ) of DL-PCBs in rice and barley were higher than PCDD/Fs. The average total TEQ of rice and barley were 0.0056 pg-TEQ/g and 0.0092 pg-TEQ/g on lower bound estimation respectively. Estimated daily intake of dioxins from rice and barley were calculated 1.03 pg-TEQ/day/person and 0.0534 pg-TEQ/day/person respectively. These were estimated 0.46% and 0.03% of Korean TDI based on 55 kg body weight.