- Formation and emission status of PCDDS/PCDFS in municipal solid waste incinerators in korea
-
This study was carried out to examine the formation and the emission status of polychlorinated dibenzo-p-dioxins/ polychlorinated dibenzofurans (PCDDs/PCDFs) in the flue gases of commercial-scale municipal solid waste (MSW) incinerators, and thus to provi
- Kim, Sam-Cwan,Jeon, Sung-Hwan,Jung, Il-Rok,Kim, Ki-Heon,Kwon, Myung-Hee,Kim, Jae-Hyung,Yi, Jun-Heung,Kim, Seung-Jin,You, Jae-Cheon,Jung, Dong-Hee
-
p. 701 - 707
(2007/10/03)
-
- Mechanistic studies on the role of PAHs and related compounds in PCDD/F formation on model fly ashes
-
Model fly ashes containing Florisil , CuCl2 · 2H2O and PAHs with structures similar to dibenzo-p-dioxin or dibenzofuran were heated at 250°C in He/O2 with regard to a supposed intramolecular reaction mechanism for oxygen incorporation. Highest reactivities in PCDF formation could be found for model compounds containing a biphenyl structure, while condensed π-systems lead to a decrease in reactivity for such compounds. Biphenyl is almost completely converted to dibenzofuran. PCDD formation from six-membered rings like xanthene/9,10-dihydroanthracene is of minor importance. 18O-labeling of gaseous oxygen reveals no common reaction step for oxygen incorporation using 9-fluorenone, xanthene, diphenyl ether and diphenyl-2-carboxylic acid as model compounds. Pre-existing oxygen in reactants is a major source for ether groups in PCDD and PCDF. Determination of labeled and unlabeled CO and CO2 besides He/O2 reflects higher reactivities towards oxidation for model compounds containing ether groups than for compounds with carbonyl groups.
- Wilhelm,Stieglitz,Dinjus,Will
-
p. 797 - 802
(2007/10/03)
-
- Dioxins from thermal and metallurgical processes: Recent studies for the iron and steel industry
-
In thermal metallurgical processes such as iron ore sintering and metal smelting operations, large flows of off-gases are generated. Mainly due to residue recycling in such processes, chlorine and volatile organics are always present in the feed. As a consequence of de novo formation, the off-gases from such processes typically contain dioxins in the range 0.3-30 ng I-TEQ/Nm3. So far there are only very few studies about the mechanisms of dioxin formation and destruction in these metallurgical processes. In an European Union (EU) research project Minimization of dioxins in thermal industrial processes: mechanisms, monitoring and abatement (MINIDIP) , integrated iron and steel plant has been selected as one of the industrial sectors for further investigation. A large number of particulate samples (feed, belt siftings, electrofilter) were collected from the iron ore sintering installations from various steel plants and analyzed for their organochlorocompound contents. Measurable amounts of PCDD/F, PCBz, PCB were found for all samples. The various parameters influencing their de novo synthesis activity were also evaluated in laboratory experiments, and such activity was found to be moderate for samples from the ore sinter belt, but extremely high for some ESP dusts. Fine dust is active in a wide range of temperatures starting at 200°C and declining above 450°C; the optimal temperature for de novo synthesis was found to be around 350°C; some inhibitors, such as triethanolamine, may reduce de novo activity by 50%, and lowering the O2 concentration in the gas stream leads to a much lower amount of PCDD/F formation. On the basis of their relative mass, typical operating conditions and specific activity of the different samples, the regions in the sintering plant where de novo synthesis may take place were tentatively established.
- Buekens,Stieglitz,Hell,Huang,Segers
-
p. 729 - 735
(2007/10/03)
-
- Effects of oxygen on formation of PCB and PCDD/F on extracted fly ash in the presence of carbon and cupric salt
-
The effect of oxygen-nitrogen atmosphere (N2 + 10%O2, N2 + 1%O2 and 99.999% N2) on the formation of PCB, PCDD and PCDF by the de novo synthetic reactions in the system consisting of extracted fly ash
- Pekarek,Grabic,Marklund,Puncochar,Ullrich
-
p. 777 - 782
(2007/10/03)
-
- Determination of polychlorinated dibenzo-p-dioxins and dibenzo-furans in solid residues from wood combustion by HRGC/HRMS
-
PCDD/PCDF were determined in solid samples from wood combustion. The samples included grate ashes, bottom ashes, furnace ashes as well as fly and cyclone ashes. The solid waste samples were classified into bottom and fly ash from native wood and bottom and fly ash from waste wood. For each of the four classes concentration distribution patterns from individual congeners, the sums of PCDD/PCDF and the international toxicity equivalents (I-TEQ) values are given. The I-TEQ levels of fly ash from waste wood burning can be approximately up to two thousand times higher than the values from fly ashes of natural wood. The I-TEQ levels in bottom ashes from waste wood combustion systems are as low as the corresponding ashes from the combustion of native wood. Grate ash samples from waste wood combustion systems with low carbon burnout show high levels of PCDD/PCDF.
- Wunderli, Samuel,Zennegg, Markus,Dolezal, Ivan Samuel,Gujer, Erika,Moser, Urs,Wolfensberger, Max,Hasler, Philip,Noger, Dominik,Studer, Christoph,Karlaganis, Georg
-
p. 641 - 649
(2007/10/03)
-
- Estimation of dioxin emission from fires in chemicals
-
The formation of the 17 toxic 2,3,7,8-substituted-PCDDs and PCDFs during combustion of selected chemicals were measured by high-resolution GC/MS. The 16 chemicals studied were commonly used chlorinated pesticides, industrial chemicals, and PVC. In a series of experiments carried out in a DIN 53,436 furnace, 2.5 g of these compounds were burned at 500°C and 900°C, respectively. The resultant yields ranged from 740 ng ITEQ/g for pentachlorophenol, to below 0.01 ng ITEQ/g for PVC and dichlobenil. The results show that some chemicals generate PCDD/F in very high - possibly dangerous - amounts during burning, whereas others generate insignificant amounts. The influence of scale were studied for chlorobenzene and 4-chloro- 3-nitro-benzoic acid in additional experiments, carried out in a cone calorimeter burning 20 g substance, and in ISO 9705 room test burning about 50 kg. A good agreement between the results for large and small scale indicated that formation of PCCD/F during a fire may be estimated from laboratory experiments. This suggest laboratory test may be used to screen for chemicals posing a hazard for release of PCDD/F during fires.
- Vikelsoe,Johansen
-
p. 165 - 175
(2007/10/03)
-
- Comparison of 2,4,6-trichlorophenol conversion to PCDD/PCDF on a MSWI- fly ash and a model fly ash
-
We performed experiments on two different matrices with 2,4,6- trichlorophenol as precursor to Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD)/F. A municipal solid waste incinerators (MSWI) and a model fly ash were spiked in two different ways. The experiments demonstrated a three times higher formation potential of the trichlorophenol to PCDD on MSWI fly ash compared with the model fly ash used. For both fly ashes the PCDD yield was higher when gaseous trichlorophenol was fed continuously compared to mixing the fly ashes prior to the experiments with the total amount of the precursor. Despite dilution of the fly ashes tenfold with an inactive matrix the conversion of the chlorophenol was very high. (C) 2000 Elsevier Science Ltd.
- Hell,Altwicker,Stieglitz,Addink
-
p. 995 - 1001
(2007/10/03)
-
- The effect of oils on PAH, PCDD, PCDF, and PCB emissions from a spark engine fueled with leaded gasoline
-
The effect of synthetic and mineral oils on the formation of polyaromatic hydrocarbons (PAHs), polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and biphenyls (PCBs) in emissions from a spark ignition engine was studied on a Skoda Favorit engine fueled with leaded gasoline. The test cycle simulated urban traffic conditions on a chassis dynamometer, in accordance with the ECC 83.00 test. The data for selected PAHs as well as PCDDs, PCDFs, and PCBs congener profiles are presented. PCDD/Fs emissions for an unused oil and the oil after 10 000-km operation varied from 300 to 2000 fmol/m3, PCBs emissions from 75 to 178 pmol/m3, and PAHs emissions from 150 to 420 μg/m3. The content of PCBs in oils varied from 2 to 920 mg/kg.
- Broz, Jan,Grabic, Roman,Kilian, Juraj,Lojkasek, Milan,Marklund, Stellan,Ocelka, Tomas,Pekarek, Vladimir,Pribyl, Josef,Tydlitat, Vratislav,Vyska, Jan
-
p. 1905 - 1911
(2007/10/03)
-
- Copper-catalyzed chlorination and condensation of acetylene and dichloroacetylene
-
The chlorination and condensation of acetylene at low temperatures is demonstrated using copper chlorides as chlorinated agents coated to model borosilicate surfaces. Experiments with and without both a chlorine source and borosilicate surfaces indicate the absence of gas-phase and gas-surface reactions. Chlorination and condensation occur only in the presence of the copper catalyst. C2 through C8 organic products were observed in the effluent; PCDD/F were only observed from extraction of the borosilicate surfaces. A global reaction model is proposed that is consistent with the observed product distributions. Similar experiments with dichloroacetylene indicate greater reactivity in the absence of the copper catalyst. Reaction is observed in the gas-phase and in the presence of borosilicate surfaces at low temperatures. The formation of hexachlorobenzene is only observed in the presence of a copper catalyst. PCDD/F were only observed from extraction of the borosilicate surfaces. A global reaction model is proposed for the formation of hexachlorobenzene from dichloroacetylene. (C) 2000 Elsevier Science Ltd.
- Taylor, Philip H.,Wehrmeier, Andreas,Sidhu, Sukh S.,Lenoir, Dieter,Schramm,Kettrup
-
p. 1297 - 1303
(2007/10/03)
-
- Study of evolution of PCDD/F in sewage sludge-amended soils for land restoration purposes
-
The evolution of polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF) in sewage sludge-amended soils used in the restoration of degraded lands, like quarries, has been studied. Two experiments were performed: one in the lab, under controlled conditions, and another in a quarry. Two different doses of sewage sludge were applied in both experiments (with two types of application in the quarry experiment) and the evolution of the amended soils were compared with that of the respective control soils (without addition of sewage sludge). The samples were analyzed with a previously validated method by HRGC-HRMS after the extraction and the necessary clean-up steps. The results reveal that polluted sewage sludge increases PCDD/F concentration in soils and that these compounds are persistent in the matrix after long periods of time. (C) 2000 Elsevier Science Ltd. The evolution of polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF) in sewage sludge-amended soils used in the restoration of degraded lands, like quarries, has been studied. Two experiments were performed: one in the lab, under controlled conditions, and another in a quarry. Two different doses of sewage sludge were applied in both experiments (with two types of application in the quarry experiment) and the evolution of the amended soils were compared with that of the respective control soils (without addition of sewage sludge). The samples were analyzed with a previously validated method by HRGC-HRMS after the extraction and the necessary clean-up steps. The results reveal that polluted sewage sludge increases PCDD/F concentration in soils and that these compounds are persistent in the matrix after long periods of time. Laboratory and field experiments were conducted in Spain to examine the evolution of PCDDs and PCDFs in sewage-sludge-amended soils. The PCDD/F concentrations were measured in the original sewage sludge and in soil samples over time. Results from the laboratory showed that the PCDD/F concentration in amended soils was related directly to the sewage-sludge dose applied. After 1 yr, however, no evolution of PCDD/Fs was observed in any sample. In the field, high dispersion was observed, which did not allow establishment of a concentration trend over time. (from Eighteenth Symp on Halogenated Environ Organic Pollutants-Dioxin '98, Stockholm, Sweden (Aug 17-21, 98)).
- Molina,Diaz-Ferrero,Coll,Marti,Broto-Puig,Comellas,Rodriguez-Larena
-
p. 1173 - 1178
(2007/10/03)
-
- Influence of combustion conditions on the PCDD/F-, PCB-, PCBz- and PAH- concentrations in the post-combustion chamber of a waste incineration pilot plant
-
Experiments at a pilot scale waste incinerator (0.5 MW thermal power) showed that the conditions in the postcombustion chamber (650-900°C) are strongly influencing the formation of chlorinated and non-chlorinated aromatics. Non-optimal combustion conditions resulted in increased concentrations of mono- to trichlorinated dibenzo-p-dioxins (PCDD), dibenzofurans (PCDF) and polycyclic aromatic hydrocarbons (PAH), while chlorinated benzenes (PCBz), polychlorinated biphenyls (PCB) and the higher chlorinated PCDD/F are only weakly affected or even decrease. The changes in concentration of the compounds investigated over a time span of hours gave hints on 'memory effects' in this combustion zone. For mono- and dichlorinated benzenes, a high correlation (r2 = 0.80) with the international toxicity equivalent (I-TEQ) value of PCDD/F was observed. As recently has been demonstrated, this correlation can be utilized for an indirect on-line measurement of the I-TEQ by a novel laser mass spectrometric technique (REMPI-TOFMS). (C) 2000 Elsevier Science Ltd.
- Blumenstock,Zimmermann,Schramm,Kettrup
-
p. 987 - 993
(2007/10/03)
-
- Peroxidase-catalyzed in vitro formation of polychlorinated dibenzo-p-dioxins and dibenzofurans from chlorophenols
-
Chlorophenols (CP) are transformed in vitro to polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) by a peroxidase-catalyzed oxidation. This is shown for 2,4,5-tri-, 2,3,4,6-tetra- and pentachlorophenol with plant horseradish peroxidase and with myeloperoxidase recovered from human leukocytes, each in the presence of hydrogen peroxide. The yield, the reaction and the PCDD/F-pattern found are dependent on the CP. The amounts of PCDD/F formed within 4 or 24 h are in the μmol/mol-range for all substrates and both peroxidases. The experiments suggest that biochemical formation of PCDD/F from precursors such as CPs can take place in the human body and that this metabolic pathway may lead to a higher inner exposure to PCDD/F than up to now assumed based on intake data for PCDD/F. Copyright (C) 1999 Elsevier Science Ireland Ltd.
- Wittsiepe, Juergen,Kullmann, Yvonne,Schrey, Petra,Selenka, Fidelis,Wilhelm, Michael
-
p. 191 - 200
(2007/10/03)
-
- Influence of variation in combustion conditions on the primary formation of chlorinated organic micropollutants during municipal solid waste combustion
-
The aim of this study was to investigate the influence of variation in combustion conditions on the primary formation of organic micropollutants (OMPs). The flue gas samples were taken at a relatively high flue gas temperature (650°C), to enable mechanistic studies on the high temperature formation (primary formation). Eleven experiments were performed in a laboratory scale fluidized bed reactor fed with an artificial municipal solid waste (MSW). The samples were analyzed for mono- to octachlorinated dibenzo- p-dioxins and dibenzofurans (CDDs/Fs), tri- to decachlorinated biphenyls (CBs), di- to hexachlorinated benzenes (CBzs), and di- to pentachlorinated phenols (CPhs). In addition to chlorinated OMPs, nonchlorinated dibenzo-p- dioxin (DD), dibenzofuran (DF), and biphenyl (BP) were analyzed. The experiments show that variations in the CE influence the degree of chlorination of the organic micropollutants. A correlation between low CE and formation of non- and low-chlorinated DMPs was seen and a distinct relationship of higher chlorinated homologues and efficient combustion condition. Thus, the DiCDFs and DiCBzs are formed during low combustion efficiency (CE), while the PeCDF and PeCBzs formation take place at higher CE. The distribution between primary and secondary air is important for the formation of higher CDD/Fs and CBzs. The primary formation of CDDs and CDFs is through different mechanisms. The CDDs are mainly formed by condensation of CPhs, while the CDFs are formed through a non- or a low-chlorinated precursor followed by further chlorination reactions.
- Wikstroem,Tysklind,Marklund
-
p. 4263 - 4269
(2007/10/03)
-
- Reactions of dibenzofuran and 1,2,3,4,7,8-hexachlorodibenzo-p-dioxin on municipal waste incinerator fly ash
-
Dibenzofuran (DF) on fly ash can be converted to polychlorinated dibenzofurans (PCDF)in a N2/O2/HCl atmosphere, yielding especially 2,3,7,8- substituted congeners. This is consistent with an electrophilic aromatic substitution mechanism. 1,2,3,4,7,8-Hexa-chlorodibenzo-p-dioxin (1,2,3,4,7,8- H6CDD) on fly ash can be chlorinated by HCl both in N2 and O2 atmospheres. Dechlorination and decomposition reactions are not important under these conditions, and isomerization reactions do not take place either. 1,2,3,4,7,8-H6CDD dechlorinates or decomposes on fly ash when no HCl is present. Only a limited number of dechlorination products are formed. Chlorination and dechlorination are separate processes, not occurring simultaneously.
- Addink, Ruud,Antonioli, Mischa,Olie, Kees,Covers, Harrie A. J.
-
p. 833 - 836
(2007/10/03)
-