- Regioselective arene homologation through rhenium-catalyzed deoxygenative aromatization of 7-oxabicyclo[2.2.1]hepta-2,5-dienes
-
Combined use of oxorhenium catalysts with triphenyl phosphite as an oxygen acceptor allowed efficient deoxygenative aromatization of oxabicyclic dienes. The reaction proceeded under neutral conditions and was compatible with various functional groups. Combining this deoxygenation with regioselective bromination and trapping of the generated aryne with furan resulted in benzannulative π-extension at the periphery of the PAHs. This enabled direct use of unfunctionalized PAHs for extension of π-conjugation. Iteration of the transformations increased the number of fused-benzene rings one at a time, which has the potential to alter the properties of PAHs by fine-tuning the degree of π-conjugation, shape, and edge topology.
- Murai, Masahito,Ogita, Takuya,Takai, Kazuhiko
-
supporting information
p. 2332 - 2335
(2019/02/27)
-
- Bismuth-catalyzed synthesis of polycyclic aromatic hydrocarbons (PAHs) with a phenanthrene backbone via cyclization and aromatization of 2-(2-arylphenyl)vinyl ethers
-
The reaction of 2-(2-arylphenyl)vinyl ethers in the presence of a catalytic amount of bismuth(III) triflate gave substituted phenanthrenes in excellent yields under mild reaction conditions. The reaction was also applied to the construction of other polycyclic aromatic hydrocarbons (PAHs), such as chrysene, helicene, and pyrene having a phenanthrene backbone, via regioselective cyclization. This method has the advantages of easy availability of the cyclization precursors, operational simplicity, and high reaction efficiency.
- Murai, Masahito,Hosokawa, Naoki,Roy, David,Takai, Kazuhiko
-
supporting information
p. 4134 - 4137
(2014/09/30)
-
- Synthesis of 13C4-labelled oxidized metabolites of the carcinogenic polycyclic aromatic hydrocarbon benzo[a]pyrene
-
Polycyclic aromatic hydrocarbons (PAHs), such as benzo[a]pyrene (BaP), are ubiquitous environmental contaminants that are implicated in causing lung cancer. BaP is a component of tobacco smoke that is transformed enzymatically to active forms that interact with DNA. We reported previously development of a sensitive stable isotope dilution LC/MS method for analysis of BaP metabolites. We now report efficient syntheses of 13C4-BaP and the complete set of its 13C4-labelled oxidized metabolites needed as internal standards They include the metabolites not involved in carcinogenesis (Group A) and the metabolites implicated in initiation of cancer (Group B). The synthetic approach is novel, entailing use of Pd-catalyzed Suzuki, Sonogashira, and Hartwig cross-coupling reactions combined with PtCl2-catalyzed cyclization of acetylenic compounds. This synthetic method requires fewer steps, employs milder conditions, and product isolation is simpler than conventional methods of PAH synthesis. The syntheses of 13C4-BaP and 13C4-BaP-8-ol each require only four steps, and the 13C-atoms are all introduced in a single step. 13C4-BaP-8-ol serves as the synthetic precursor of all the oxidized metabolites of 13C-BaP implicated in initiation of cancer. The isotopic purities of the synthetic 13C 4-BaP metabolites were estimated to be ≥99.9%.
- Wu, Anhui,Xu, Daiwang,Lu, Ding,Penning, Trevor M.,Blair, Ian A.,Harvey, Ronald G.
-
p. 7217 - 7233
(2012/09/05)
-
- Role of temperature and hydrochloric acid on the formation of chlorinated hydrocarbons and polycyclic aromatic hydrocarbons during combustion of paraffin powder, polymers, and newspaper
-
Formation of chlorinated hydrocarbons and polycyclic aromatic hydrocarbons (PAHs) were determined using a laboratory-scale incinerator when combusting materials at different temperatures, different concentrations of hydrochloric acid (HCl), and when combusting various types of polymers/newspaper. Polychlorobenzenes (PCBz), polychlorophenols (PCPhs), polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) and their toxic equivalency (TEQ) and PAHs were highlighted and reported. Our results imply maximum formation of chlorinated hydrocarbons at 400°C in the following order; PCBz≥PCPhs?PCDFs>PCDDs>TEQ on a parts-per-billion level. Similarly, a maximum concentration of chlorinated hydrocarbons was noticed with an HCl concentration at 1000 ppm with the presence of paraffin powder in the following order; PAHs>PCBz≥PCPhs?PCDFs>PCDDs>TEQ an a parts-per-billion level. PAHs were not measured at different temperatures. Elevated PAHs were noticed with different HCl concentrations and paraffin powder combustion (range: 27-32 μg/g). While, different polymers and newspaper combusted, nylon and acrylonitrile butadiene styrene (ABS) produced the maximum hydrogen cyanide (HCN) concentration, concentrations of PCDD/FS, dioxin-like polychlorinated biphenyls (DL-PCBs), and TEQ were in a decreasing order: polyvinylchloride (PVC)newspaperpolyethyleneterephthalate (PET) polyethylene (PE) polypropylene (PP) ABS = blank. Precursors of PCBs were in a decreasing order: PPnylonPEnewspaperABSPVCblankPET. Precursors of PCDD/Fs were in a decreasing order: newspaper PP= nylonPEABSPVC= blankPET. BTX formation was in a decreasing order; PEnylonnewspaperABSPP. PAHs formation were elevated with parts-per-million levels in the decreasing order of PPnylonPE newspaperblankABS PETPVC.
- Takasuga, Takumi,Umetsu, Norihito,Makino, Tetsuya,Tsubota, Katsuya,Sajwan, Kenneth S.,Kumar, Kurunthachalam Senthil
-
-
- Emission factors for carbonaceous particles and polycyclic aromatic hydrocarbons from residential coal combustion in China
-
Emission factors of carbonaceous particles, including black carbon (BC) and organic carbon (OC), and polycyclic aromatic hydrocarbons (PAHs) were determined for five coals, which ranged in maturity from sub-bituminous to anthracite. They were burned in the form of honeycomb briquettes in a residential coalstove, one of the most common fuel/stove combinations in China. Smoke samples were taken through dilution sampling equipment, with a high volume sampler that could simultaneously collect emissions in both particulate and gaseous phases, and a cascade impactor that could segregate particles into six fractions. Particulate BC and OC were analyzed by a thermal-optical method, and PAHs in emissions of both phases were analyzed by GC-MS. Burning of bituminous coals produced the highest emission factors of particulate matter (12.91 g/kg), BC (0.28 g/kg), OC (7.82 g/kg), and 20 PAHs (210.6 mg/kg) on the basis of burned dry ash-free (daf) coal, while the anthracite honeycomb-briquette was the cleanest household coal fuel. The size-segregated results show that more than 94% of the particles were submicron, and calculated mass median aerodynamic diameters (MMAD) of all particles were under 0.3 μm. Based on the coal consumption in the residential sector of China, 290.24 Gg (gigagrams) of particulate matter, 5.36 Gg of BC, 170.33 Gg of OC, and 4.72 Gg of 20 PAHs mass were emitted annually from household honeycomb-briquette burning during 2000. Anthracite coal should be selected preferentially and more advanced burning conditions should be applied in domestic combustion, from the viewpoint of both climate change and adverse health effects.
- Chen, Yingjun,Sheng, Guoying,Bi, Xinhui,Feng, Yanli,Mai, Bixian,Fu, Jiamo
-
p. 1861 - 1867
(2008/12/21)
-
- Emission factors and importance of PCDD/Fs, PCBs, PCNs, PAHs and PM 10 from the domestic burning of coal and wood in the U.K.
-
This paper presents emission factors (EFs) derived for a range of persistent organic pollutants (POPs) when coal and wood were subject to controlled burning experiments, designed to simulate domestic burning for space heating. A wide range of POPs were emitted, with emissions from coal being higher than those from wood. Highest EFs were obtained for particulate matter, PM10, (～ 10 g/kg fuel) and polycyclic aromatic hydrocarbons (～ 100 mg/ kg fuel for ΣPAHs). For chlorinated compounds, EFs were highest for polychlorinated biphenyls (PCBs), with polychlorinated naphthalenes (PCNs), dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) being less abundant. EFs were on the order of 1000 ng/kg fuel for ΣPCBs, 100s ng/ kg fuel for ΣPCNs and 100 ng/kg fuel for ΣPCDD/Fs. The study confirmed that mono- to trichlorinated dibenzofurans, Cl1,2,3DFs, were strong indicators of low temperature combustion processes, such as the domestic burning of coal and wood. It is concluded that numerous PCB and PCN congeners are routinely formed during the combustion of solid fuels. However, their combined emissions from the domestic burning of coal and wood would contribute only a few percent to annual U.K. emission estimates. Emissions of PAHs and PM 10 were major contributors to U.K. national emission inventories. Major emissions were found from the domestic burning for Cl1,2,3DFs, while the contribution of PCDD/F-ΣTEQ to total U.K. emissions was minor.
- Lee, Robert G. M.,Coleman, Peter,Jones, Joanne L.,Jones, Kevin C.,Lohmann, Rainer
-
p. 1436 - 1447
(2007/10/03)
-
- Experimental study on the removal of PAHs using in-duct activated carbon injection
-
This paper presents the incineration tests of municipal solid waste (MSW) in a fluidized bed and the adsorption of activated carbon (AC) on polycyclic aromatic hydrocarbons (PAHs). An extraction and high performance liquid chromatography (HPLC) technique was used to analyze the concentrations of the 16 US EPA specified PAHs contained in raw MSW, flue gas, fly ash, and bottom ash. The aim of this work was to decide the influence of AC on the distribution of PAHs during the incineration of MSW. Experimental researches show that there were a few PAHs in MSW and bottom ash. With the increase of AC feeding rate, the concentrations of three- to six-ring PAHs in fly ash increased, and the concentration of two-ring PAH decreased. The total-PAHs in flue gas were dominated by three-, and four-ring PAHs, but a few two-, five-ring PAHs and no six-ring PAHs were found. PAHs could be removed effectively from flue gas by using in-duct AC injection and the removal efficiencies of PAHs were about 76-91%. In addition, the total toxic equivalent (TEQ) concentrations of PAH in raw MSW, bottom ash, fly ash, and flue gas were 1.24 mg TEQ kg-1, 0.25 mg TEQ kg-1, 6.89-9.67 mg TEQ kg-1, and 0.36-1.50 μg TEQ N m-3, respectively.
- Zhou, Hong-Cang,Zhong, Zhao-Ping,Jin, Bao-Sheng,Huang, Ya-Ji,Xiao, Rui
-
p. 861 - 869
(2007/10/03)
-
- Emissions of air pollutants from household stoves: Honeycomb coal versus coal cake
-
Domestic coal combustion can emit various air pollutants. In the present study, we measured emissions of particulate matter (PM) and gaseous pollutants from burning a specially formulated honeycomb coal (H-coal) and a coal cake (C-coal). Flue gas samples for PM2.5, PM coarse (PM 2.5-10), and TSP were collected isokinetically using a cascade impactor; PM mass concentrations were determined gravimetrically. Concentrations of SO2, NOx, and ionic Cr(VI) in PM were analyzed using spectrometric methods. Fluoride concentrations were measured using a specific ion electrode method. PM elemental components were analyzed using an X-ray fluorescence technique. Total (gas and particle phase) benzo[a]pyrene (BaP) concentration was determined using an HPLC/fluorescence method. Elemental and organic carbon contents of PM were analyzed using a thermal/optical reflectance technique. The compositional and structural differences between the H-coal and C-coal resulted in different emission characteristics. In generating 1 MJ of delivered energy, the H-coal resulted in a significant reduction in emissions of SO2 (by 68%), NOx (by 47%), and TSP (by 56%) as compared to the C-coal, whereas the emissions of PM2.5 and total BaP from the H-coal combustion were 2-3-fold higher, indicating that improvements are needed to further reduce emissions of these pollutants in developing future honeycomb coals. Although the H-coal and the C-coal had similar emission factors for gas-phase fluoride, the H-coal had a particle-phase fluoride emission factor that was only half that of the C-coal. The H-coal had lower energy-based emissions of all the measured toxic elements in TSP but higher emissions of Cd and Ni in PM2.5.
- Ge, Su,Xu, Xu,Chow, Judith C.,Watson, John,Sheng, Qing,Liu, Weili,Bai, Zhipeng,Zhu, Tan,Zhang, Junfeng
-
p. 4612 - 4618
(2007/10/03)
-
- Semivolatile and volatile compounds in combustion of polyethylene
-
The evolution of semivolatile and volatile compounds in the combustion of polyethylene (PE) was studied at different operating conditions in a horizontal quartz reactor. Four combustion runs at 500 and 850°C with two different sample mass/air flow ratios and two pyrolytic runs at the same temperatures were carried out. Thermal behavior of different compounds was analyzed and the data obtained were compared with those of literature. It was observed that α,ω-olefins, α-olefins and n-paraffins were formed from the pyrolytic decomposition at low temperatures. On the other hand, oxygenated compounds such as aldehydes were also formed in the presence of oxygen. High yields were obtained of carbon oxides and light hydrocarbons, too. At high temperatures, the formation of polycyclic aromatic hydrocarbons (PAHs) took place. These compounds are harmful and their presence in the combustion processes is related with the evolution of pyrolytic puffs inside the combustion chamber with a poor mixture of semivolatile compounds evolved with oxygen. Altogether, the yields of more than 200 compounds were determined. The collection of the semivolatile compounds was carried out with XAD-2 adsorbent and were analyzed by GC-MS, whereas volatile compounds and gases were collected in a Tedlar bag and analyzed by GC with thermal conductivity and flame ionization detectors.
- Font, Rafael,Aracil, Ignacio,Fullana, Andrés,Conesa, Juan A.
-
p. 615 - 627
(2007/10/03)
-
- A Convenient New Synthesis of Benzo[a]pyrene
-
A convenient new synthesis of the ubiquitous environmental carcinogen benzo[a]pyrene (BaP) is described. In the key step, the method entails Suzuki coupling of naphthalene 2-boronic acid with 2-bromobenzene-1,3-dialdehyde and requires only three steps. It is considerably shorter and simpler than the older methods and provides BaP in higher overall yield.
- Harvey, Ronald G.,Lim, Keunpoong,Dai, Qing
-
p. 1372 - 1373
(2007/10/03)
-
- Relationship between pressure fluctuations and generation of organic pollutants with different particle size distributions in a fluidized bed incinerator
-
The hydrodynamic behaviors of fluidization perhaps significantly influence the uniformity of fluidization in fluidized bed incinerator. Good uniformity of fluidization expressed the air across uniformly through the bed and the particles being distributed well in the fluid stream. The aggregates, flocs and channels of particles do not happen during fluidization. The Good uniformity will maintain high heat and mass distribution to improve reaction efficiency. These parameters include the height of static bed, gas velocity, mixing and distribution of bed particle, which have rarely been studied in previous investigations. Consequently, this study examines how the hydrodynamic parameters affect the generation of organic pollutants (BTEXs and PAHs) during incineration. The statistical and power spectral analysis of the measured pressure fluctuation during incineration are used to elucidate the relationship between behaviors of fluidization and generation of pollutants during incineration. Experimental results show the organic concentration does not increase with uniformity of fluidization decreasing. The reason may be the explosion of the gas and the consequent thermal shock destroy the coalescent bubbles to form small bubbles again and enhance the efficiency of transfer of oxygen to increase combustion efficiency. Additionally, the mean amplitude and fluidized index of pressure fluctuation similarly vary with the concentration of organic pollutants. These two indices can be used to assess the efficiency of combustion. The four particle size distributions could be divided into two groups by statistical analysis. The Gaussian and narrow distributions belong to one group and the binary and flat the other. The organic concentration of the Gaussian and narrow distributions are lower than that of the other distributions. Consequently, the bed materials should maintain narrow or Gaussian distributions to maintain a good combustion efficiency during incineration.
- Lin, Chiou-Liang,Wey, Ming-Yen,Cheng, Han-Tsung
-
p. 911 - 922
(2007/10/03)
-
- Characterization of emissions during the heating of tyre contaminated scrap
-
In order to characterize the compounds (type and quantities) emitted during melting of organic contaminated scrap and to investigate the mechanism of their formation, an experimental set-up has been designed and built to study precisely the influence of temperature and gas atmosphere in the conditions of an electric arc furnace. These experiments lead to the determination of mass balances (C, H, O, S) and to the quantification of unburnt compounds (tars, carbon monoxide, volatile organic compounds (VOCs), benzene, toluene, ethylbenzene and xylenes (BTEX), polyaromatic compounds (PAHs)). Degradation conditions (gas atmosphere and temperature) corresponding to different areas in the electric furnace have also been investigated. Such experiments lead to a better understanding of degradation mechanisms; this interpretation is not possible from investigations performed in an industrial furnace since there are many uncontrolled parameters (large dispersion of the results).
- Arion,Baronnet,Lartiges,Birat
-
p. 853 - 859
(2007/10/03)
-
- Pah and soot emissions from burning components of medical waste: Examination/surgical gloves and cotton pads
-
This is a laboratory investigation on the emissions from batch combustion of representative infectious ( red bag ) medical waste components, such as medical examination latex gloves and sterile cotton pads. Plastics and cloth account for the majority of the red bag wastes by mass and, certainly, by volume. An electrically heated, horizontal muffle furnace was used for batch combustion of small quantities of shredded fuels (0.5-1.5 g) at a gas temperature of ≈1000°C. The residence time of the post-combustion gases in the furnace was ≈1 s. At the exit of the furnace, the following emissions were measured: CO, CO2, NOx, particulates and polynuclear aromatic compounds (PACs). The first three gaseous emissions were measured with continuous gas analyzers. Soot and PAC emissions were simultaneously measured by passing the furnace effluent through a filter (to collect condensed-phase PACs) and a bed of XAD-4 adsorbent (to capture gaseous-phase PACs). Analysis involved soxhlet extraction, followed by gas chromatography-mass spectrometry (GC-MS). Results were contrasted with previously measured emissions from batch combustion of pulverized coal and tire-derived fuel (TDF) under similar conditions. Results showed that the particulate (soot) and cumulative PAC emissions from batch combustion of latex gloves were more than an order of magnitude higher than those from cotton pads. The following values are indicative of the relative trends (but not necessarily absolute values) in emission yields: 26% of the mass of the latex was converted to soot, 11% of which was condensed PAC. Only 2% of the mass of cotton pads was converted to soot, and only 3% of the weight of that soot was condensed PAC. The PAC yields from latex were comparable to those from TDF. The PAC yields from cotton were higher than those from coal. A notable exception to this trend was that the three-ring gas-phase PAC yields from cotton were more significant than those from latex. Emission yields of CO and CO2 from batch combustion of cotton were, respectively, comparable and higher than those from latex, despite the fact that the carbon content of cotton was half that of latex. This is indicative of the more effective combustion of cotton. Nearly all of the mass of carbon of cotton gasified to CO and CO2, while only small fractions of the carbon in latex were converted to CO2 and CO (20% and 10%, respectively). Yields of NOx from batch combustions of latex and cotton accounted for 15% and 12%, respectively, of the mass of fuel nitrogen indicating that more fuel nitrogen was converted to NOx in the former case, possibly due to higher flame temperatures. No SO2 emissions were detected, indicating that during the fuel-rich combustion of latex, its sulfur content was converted to other compounds (such as H2S) or remained in the soot.
- Levendis, Yiannis A,Atal, Ajay,Carlson, Joel B.,Del Mar Esperanza Quintana, Maria
-
p. 775 - 783
(2007/10/03)
-
- Removal of dioxins and related aromatic hydrocarbons from flue gas streams by adsorption and catalytic destruction
-
The dioxin removing capacity of the shell dedioxin system (SDDS a - Ti/V oxidative type catalyst) has been tested using the Umefa lab-scale incinerator over the temperature range 100 -230°C and at space velocities of 8000 and 40,000 h-1. Other analogous organic compounds, such as PCBs, PAHs, chlorobenzenes and chlorophenols have also been investigated. Results show a high degree of dioxin removal already at 100°C (82%), which occurs mainly by adsorption. When the temperature is raised a transition towards destruction is seen and at 150°C, gas hour space velocity (GHSV) 8000 and at 230°C, GHSV 40,000 virtually all removal is by destruction. High PCDD/F destruction efficiencies are reported (> 99.9%, based on I-TEQ); the other dioxin-related species and PAHs are also removed and destroyed to a significant extent. The SDDS has proved to be an effective means of destroying organic compounds in the gas phase, particularly dioxins, at temperatures as low as 150°C.
- Liljelind, Per,Unsworth, John,Maaskant, Onno,Marklund, Stellan
-
p. 615 - 623
(2007/10/03)
-
- Evaluation of acute toxicity and genotoxicity of liquid products from pyrolysis of Eucalyptus grandis wood
-
Slow pyrolysis of Eucalyptus grandis wood was performed in an oven laboratory, and smoke was trapped and condensed to yield liquid products. Polycyclic aromatic hydrocarbons (PAHs) and phenolic fractions were isolated from the former liquid products using adsorption column chromatography (ACC) and identified by GC/MS. Concentrations of PAH and phenolic fractions in total pyrolysis liquids were respectively 48.9 μg/g and 8.59% (w/w). Acute toxicity of total samples of pyrolysis liquids and the phenolic fraction was evaluated by means of two bioassays, namely, 24-h immobilization bioassay with Daphnia magna and Microtox(TM) bioassays, the latter employing the luminescent bacteria Photobacterium phosphoreum. Total pyrolysis liquids and the PAH fraction were evaluated for genotoxicity by the Microtox(TM) bioassay conducted using rehydrated freeze-dried dark mutant of the luminescent bacteria Vibrio fisheri strain M169. Total pyrolysis liquids and the phenolic fraction, respectively, in concentrations of 170 and 68 mg/L were able to immobilize 50% (EC50) of the D. magna population following 24-h exposure. Concentrations of 19 and 6 mg/L, respectively, for total pyrolysis liquids and phenolic fraction were the effective concentrations that resulted in a 50% (EC50) reduction in light produced by bacteria in the Microtox(TM) bioassay. Accordingly, the Microtox(TM) bioassay was more sensitive to toxic effects of both kind of samples than the D. magna bioassay, particularly for the phenolic fraction. Regarding to the genotoxicity evaluation, the results achieved by Microtox(TM) bioassay showed that total pyrolysis liquids had no genotoxic effects with and without exogenous metabolic activation using rat liver homogenate (S9). However, the PAH fraction showed toxic effects with rat liver activation and had a dose-response number (DRN) equal to 1.6, being in this way suspected genotoxic. The lowest detected concentration (LDC) of the PAH fraction able to cause genotoxic effects was 375 μg/L.
- Pimenta,Bayona,Garcia,Solanas
-
p. 169 - 175
(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)
-
- 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)
-
- Fine particle and gaseous emission rates from residential wood combustion
-
Residential wood combustion emissions were analyzed to determine emission rates and to develop chemical emissions profiles that represent the appliances and woods typically used in wood-burning-communities. Over 350 elements, inorganic compounds, and organic compounds were quantified. A range of 4-9 g/kg dry fuel of particulate matter(a dilution stack sampler equipped with a 2.5-μm particle selective cyclone. Emissions were diluted 20-70 times, cooled to ambient temperature, and allowed 80 s for condensation prior to collection. Wood type, wood moisture, burn rate, and fuel load were varied for different experiments. Fine particle and se mivolatile organic compounds were collected on filter/PUF/XAD/PUF cartridges. Inorganic samples and mass were collected on Teflon and quartz filters. Volatile organic carbon compounds were trapped with Tenax (C8- C20), canister (C2-C12), and 2,4-dinitrophenylhydrazine impregnated cartridges (carbonyl compounds). Analysis of particle and semivolatile organic species was conducted by gas chromatography/mass spectrometry. Teflon filters were analyzed for mass by gravimetry, trace elements were analyzed by X-ray fluorescence and ammonium was analyzed by automated colorimetry. Quartz filters were analyzed for organic and elemental carbon by thermal/optical reflectance, and forts were analyzed by ion chromatography. Select quartz filters were analyzed by accelerator mass spectrometry for carbon-12 and carbon-14 abundance. Canister and Tenax samples were analyzed by gas chromatography with a flame ionization detector, and carbonyl compounds were analyzed by high-performance liquid chromatography. Residential wood combustion emissions were analyzed to determine emission rates and to develop chemical emissions profiles that represent the appliances and woods typically used in wood-burning communities. Over 350 elements, inorganic compounds, and organic compounds were quantified. A range of 4-9 g/kg dry fuel of particulate matter (a dilution stack sampler equipped with a 2.5-μm particle selective cyclone. Emissions were diluted 20-70 times, cooled to ambient temperature, and allowed 80 s for condensation prior to collection. Wood type, wood moisture, burn rate, and fuel load were varied for different experiments. Fine particle and semivolatile organic compounds were collected on filter/PUF/XAD/PUF cartridges. Inorganic samples and mass were collected on Teflon and quartz filters. Volatile organic carbon compounds were trapped with Tenax (C8-C20), canister (C2-C12), and 2,4-dinitrophenylhydrazine impregnated cartridges (carbonyl compounds). Analysis of particle and semivolatile organic species was conducted by gas chromatography/mass spectrometry. Teflon filters were analyzed for mass by gravimetry, trace elements were analyzed by X-ray fluorescence, and ammonium was analyzed by automated colorimetry. Quartz filters were analyzed for organic and elemental carbon by thermal/optical reflectance, and ions were analyzed by ion chromatography. Select quartz filters were analyzed by accelerator mass spectrometry for carbon-12 and carbon-14 abundance. Canister and Tenax samples were analyzed by gas chromatography with a flame ionization detector, and carbonyl compounds were analyzed by high-performance liquid chromatography.
- Mcdonald, Jacob D.,Zielinska, Barbara,Fujita, Eric M.,Sagebiel, John C.,Chow, Judith C.,Watson, John G.
-
p. 2080 - 2091
(2007/10/03)
-
- Analysis of hydrocarbons and ash particles formed from contaminated industrial biowaste under combustion-like conditions
-
A concept of multizone combustion of pulp and paper-generated biowaste was investigated. The biowaste was initially fed into the low-temperature region (1250 K) and then subjected to the high-temperature treatment (1770 K), which was followed by sudden quenching in a second lowtemperature zone (1250 K). This type of burning is called the low-high-low temperature process (LHL). It was found that destruction of selected polycyclic aromatic compounds occurred during the LHL process before they were emitted into the atmosphere. The biowaste material underwent dramatic morphological changes, which influenced segregation of metals within ash particles and their leachability. The heavy metals (Cr, Cd, Pb) were encapsulated and immobilized within the ash particle core surrounded by a compact shell consisting of condensed layers of light nonhazardous metals (Si, Al, Na, K). It seems that the multizone combustion of biowaste may be an attractive and useful way for the clean and efficient disposal of contaminated biowastes.
- Kozinski, Janusz A.,Zheng, Guohui,Uloth, Vic,Gangli, Peter,Hutny, Wes
-
p. 4318 - 4325
(2007/10/03)
-
- Combustion of high calorific value waste material: Organic atmospheric pollution
-
Waste tire combustion in an atmospheric fluidized-bed (AFB) reactor (7 cm i.d., 76 cm height) has been performed in a laboratory plant with the aim of studying the polycyclic aromatic hydrocarbon (PAH) emissions as a function of combustion temperature. The main aim has been to compare these organic emissions with the ones obtained when coal is burned at the same combustion conditions. PAH emissions have been analyzed in solids collected in two cyclons at the exit of the reactor and in a trap system formed by a condenser, a filter (20 μm), and an adsorbent. After PAH extraction with dimethylformamide (DMF) by sonication, fluorescence spectroscopy in the synchronous mode (FS) has been used as an analytical technique to quantify the PAHs emitted. It could be concluded that higher PAH emissions are generated when this waste material is burnt at the same conditions used for coal atmospheric fluidized-bed combustion (AFBC).
- Mastral, Ana M.,Callen, Maria S.,Murillo, Ramon,Garcia, Tomas
-
p. 4155 - 4158
(2007/10/03)
-
- Characterization of the combustion products of polyethylene
-
Polyethylene (PE) was burned in a tube-type furnace with an air flow at a temperature of 600~900°C. Combustion products were collected with glass wool, glass fiber filter, and XAD-2 adsorbent. The analysis of the products was performed with GC-FID and GC-MSD. At low temperature, hydrocarbons were the major components, while at higher temperature the products were composed of polycyclic aromatic hydrocarbons. With the high performance of the Hewlett-Packard 6890GC-5973MSD, more compounds were identified in comparison with previous studies.
- Piao, Mingjun,Chu, Shaogang,Zheng, Minghui,Xu, Xiaobai
-
p. 1497 - 1512
(2007/10/03)
-
- Supercritical water oxidation of 2-chlorophenol effected by Li+ and CuO/zeolites
-
Catalytic oxidation of 2-chlorophenol (2CP) in supercritical water was investigated. Experimentally, conversion of 2CP in supercritical water oxidation (SCWO) process is effectively enhanced in the presence of Li+ that also reduces the formation of higher chlorinated phenols and PAHs. The global reaction rate of SCWO of 2CP in the presence of Li+ is expressed as: 92.5 exp (-10.5/RT)[2CP]0.95[O2]0.56[H2O]0.45. The undesired by-products in the SCWO of 2CP are also extensively reduced in the channels of zeolite catalysts. By EXAFS spectroscopy, Cu-O and Cu-Cu are identified as the main oxidation active species in the zeolite channels. Cl-bonded CuO species in zeolite Y are not observed.
- Lin, Kuen-Song,Wang, H. Paul,Yang
-
p. 1385 - 1396
(2007/10/03)
-
- The impact of turbulent mixing on the oxidation of a chlorinated hydrocarbon
-
Combustion of chlorinated wastes can lead to the formation of hazardous byproducts. Rates of mixing of fuel and air in combustion systems can have an impact on the composition of the byproducts. Methyl chloride and methane were burned in a turbulent diffusion flame in a combustion wind tunnel with a coflow of air. Reynolds numbers were varied from 3500 to 7200. A water- cooled sampling probe was used to obtain gas samples from within the flame at a number of locations and at various Reynolds numbers. The postflame gases and particulate matter were trapped above the flames with sorbent tubes and filters. The samples were desorbed and analyzed for aromatic species and other trace products of incomplete combustion. Destruction of the methyl chloride was essentially complete for all the Reynolds numbers that were studied. Small amounts of low molecular weight chlorinated compounds were fOUnd within the flame and in the postflame gases. The major chlorinated species in the postflame gases was chloronaphthalene. Low Reynolds number flames were found to Yield larger amounts of aromatic and chlorinated aromatic species than the high Reynolds number flames. Fluoranthene was present in greater amounts on the soot particles at lower Reynolds numbers, suggesting that the rate of mixing of reactants could have an impact on the toxicity of the combustion byproducts. Combustion of chlorinated wastes can lead to the formation of hazardous byproducts. Rates of mixing of fuel and air in combustion systems can have an impact on the composition of the byproducts. Methyl chloride and methane were burned in a turbulent diffusion flame in a combustion wind tunnel with a coflow of air. Reynolds numbers were varied from 3500 to 7200. A water-cooled sampling probe was used to obtain gas samples from within the flame at a number of locations and at various Reynolds numbers. The postflame gases and particulate matter were trapped above the flames with sorbent tubes and filters. The samples were desorbed and analyzed for aromatic species and other trace products of incomplete combustion. Destruction of the methyl chloride was essentially complete for all the Reynolds numbers that were studied. Small amounts of low molecular weight chlorinated compounds were found within the flame and in the postflame gases. The major chlorinated species in the postflame gases was chloronaphthalene. Low Reynolds number flames were found to yield larger amounts of aromatic and chlorinated aromatic species than the high Reynolds number flames. Fluoranthene was present in greater amounts on the soot particles at lower Reynolds numbers, suggesting that the rate of mixing of reactants could have an impact on the toxicity of the combustion byproducts.
- Yang, Gosu,Jones, A. Daniel,Kennedy, Ian M.
-
p. 1265 - 1268
(2007/10/03)
-
- Effects of an oxidation catalytic converter and a biodiesel fuel on the chemical, mutagenic, and particle size characteristics of emissions from a diesel engine
-
This study was conducted to obtain additional information on exhaust emissions with potential health importance from an indirect injection diesel engine, typical of those in use in underground mines, when operated using a soy-derived, fatty-acid mono-ester (or biodiesel) fuel and an oxidation catalytic converter (OCC). Compared to emissions with the diesel fuel without the OCC, use of the diesel (D2) and biodiesel fuel with the OCC had similar reductions (50-80%) in total particulate matter (TPM). The solid portion of the TPM was lowered with the biodiesel fuel. Particle-associated polynuclear aromatic hydrocarbon and 1-nitropyrene emissions were lower with use of the biodiesel fuel as compared to the D2 fuel, with or without the OCC. Vapor- phase PAH emissions were reduced (up to 90%) when the OCC was used with either fuel. Use of the OCC resulted in over 50% reductions in both particle and vapor-phase-associated mutagenic activity with both fuels. No vapor- phase-associated mutagenic activity was detected with the biodiesel fuel; only very low levels were detected with the D2 fuel and the OCC. Use of the OCC caused a moderate shift in the particle size/volume distribution of the accumulation mode particles to smaller particles for the diesel fuel and a reduction of particle volume concentrations at some of the tested conditions for both fuels. The nuclei mode did not contribute significantly to total particle volume concentrations within the measured particle size range (~0.01-1.0 μm). The biodiesel fuel reduced total particle volume concentrations. Overall, use of this OCC for the engine conditions tested with the biodiesel fuel, in particular, resulted in generally similar or greater reductions in emissions than for use of the D2 fuel. Use of the biodiesel fuel should not increase any of the potentially toxic, health- related emissions that were monitored as part of this study. Detailed information necessary to evaluate impact of using a biodiesel fuel on potentially health-related emissions from a diesel engine typical of those used in many underground mining operations are provided. Compared to emissions with the diesel fuel without the oxidation catalytic converter (OCC), use of the diesel (D2) and biodiesel fuel with the OCC had a similar reductions in total particulate matter (TPM). The solid portion of the TPM was lowered with the biodiesel fuel. Particle-associated polynuclear aromatic hydrocarbon and 1-nitropyrene emissions were lower with use of the biodiesel fuel as compared to the D2 fuel, with or without the OCC.
- Bagley, Susan T.,Gratz, Linda D.,Johnson, John H.,McDonald, Joseph F.
-
p. 1183 - 1191
(2007/10/03)
-
- Spectrometry and reactivity of benzanthrenyl and 1-hydroperylenyl anions
-
Charge distribution and reactivity of benzanthrenyl (1-) and 1-methyl-1-hydroperylenyl anion (2-) are examined by means of semiempirical calculations, NMR spectroscopy and reactions with electrophiles. Highest charge density and reactivity are located at position 7 of 1- and the comparable position 12b of 2-. A small degree of reactivity is located at positions 4 and 6 of 1-, as shown by reactions. Generally, a good correlation between calculated charge distribution and charge distribution obtained from 13C NMR is observed.
- Van Dijk, Joost T. M.,Van De Panne, Berit J.,Bleeker, Annemarie C.,Lugtenburg, Johan,Cornelisse, Jan
-
p. 2647 - 2662
(2007/10/03)
-
- Enantioselective Synthesis of the (+)-anti-7,8-Dihydrodiol-9,10-epoxide of the Potent Carcinogen Benzopyrene
-
The title compound, the most important genotoxic metabolite of benzopyrene, has been prepared efficiently in a synthesis which capitalized on Jacobsen-type enantioselective epoxidation of 9,10-dihydrodibenzopyrene, cleavage of the epoxide by KOH-Me2SO to give the tetrahydro-trans-7,8-diol, and formation of the dibenzoate from which the contaminating antipode was removed by crystallization.
- Huang, Xiaoming,Harris, Thomas M.
-
p. 1699 - 1700
(2007/10/02)
-
- Radical Cations of Benzopyrene and 6-Substituted Derivatives: Synthesis and Reaction with Nucleophiles
-
Radial cations of benzopyrene (BP) and 6-substituted derivatives were synthesized by two methods: reaction of the hydrocarbon with I2 and AgClO4 in benzene, and reaction of the hydrocarbon with NOBF4 in CH3CN/CH2Cl2.Both the radical cation perchlorates and tetrafluoroborates were stable for prolonged periods of time when stored under argon at subzero temperatures.The radical cations were reacted with nucleophiles of various strengths, namely H2O, AcO(1-) and F(1-), as a means of best characterizing these intermediates, as well as determining their chemical properties.Reaction of BP, 6-FBP, 6-ClBP, and 6-BrBP radical cation perchlorates with H2O produced BP 1,6-, 3,6-, and 6,12-dione, whereas the radical cation derived from 6-CH3BP yielded 6-CH2OHBP.When BP(.1+)ClO4(1-) and 6-FBP(.1+)ClO4(1-) were reacted with NaOAc in H2O/CH3CN (9:1), 6-OAcBP was formed, in addition to the quinones. 6-ClBP(.1+)ClO4(1-) formed a small amount of 1-OAc-6-ClBP and 3-OAc-6-ClBP, in addition to the diones, whereas for 6-BrBP(.1+)ClO4(1-) and 6-CH3BP(.1+)ClO4(1-) the reaction products were BP diones and 6-CH2OHBP, respectively.Reactions conducted under anhydrous conditions, using tetramethylammonium acetate in CH3CN, gave similar results, except that no quinones were formed.These results confirm the reactivity of nucleophiles at the postions of high charge localization in the BP(.1+), i.e.C-6, followed by C-1 and C-3.
- Cremonesi, Paolo,Stack, Douglas E.,Rogan, Eleanor G.,Cavalieri, Ercole L.
-
p. 7683 - 7687
(2007/10/02)
-
- Superoxide Oxidation: A Novel Route to Aromatic 1,2-Dicarboxylic Acids
-
Potassium superoxide in aprotic media, in the presence of 18-crown-6 ether, effects a novel and mild oxidative cleavage of quinones, cyclic alcohols, and ketones fused to various aromatic hydrocarbons.Aromatic 1,2-dicarboxylic acids are obtained as major products, with highest yields in dimethylformamide, under oxygen or air.For example, the yield of pyrene-1,2-dicarboxylic acid is 82percent from 9,10-dihydrobenzopyren-7(8H)-one and 88percent from benzopyrene-7,8-dione.Minor side products include aromatic tetrones and 3-(2-carboxyaryl)propionic or 3-(2-carboxyaryl)propenoic acid, which provide mechanistic insights.
- Sotiriou, Chariklia,Lee, Wenni,Giese, Roger W.
-
p. 2159 - 2164
(2007/10/02)
-
- Friedel-Crafts alkylation of pyrene in carbon disulfide; 1H NMR spectroscopy of pyrene derivatives
-
Friedel-Crafts alkylation of pyrene with 2,5-dichloro-2,5-dimethylhexane and 2,4-dichloro-2,4-dimethylpentane in carbon disulfide yields 7,7,10,10-tetramethyl-7,8,9,10-tetrahydrobenzopyrene and 7,7,9,9-tetramethyl-8,9-dihydro-7H-cyclopentapyrene, respectively, both in 99percent yield.Alkylation with 1,4-dichlorobutane, followed by aromatization, yields benzopyrene in a facile two-step synthesis in 8percent yield.A mechanism is proposed which rationalizes the fact that only one ring of pyrene undergoes substitution.The 1H-1H NMR coupling constants of the pyrene derivatives are discussed.
- Rodenburg, L.,Block, R. de,Erkelens, C.,Lugtenburg, J.,Cornelisse, J.
-
p. 529 - 535
(2007/10/02)
-
- DEOXYGENATION OF TERTIARY AMINE N-OXIDES AND ARENE OXIDES BY IRON (II) PORPHYRIN AS A MODEL OF CYTOCHROME P-450 DEPENDENT REDUCTION
-
Tetraphenylporphiratoiron (II), a model complex of reduced cytochrome P-450, reduces several substrates such as tertiary amine N-oxides and arene oxides at room temperature in anaerobic conditions.A process for the direct oxene transfer from oxide to reduced iron porphyrin is suggested.KEYWORDS - cytochrome P-450; reduction; deoxygenation; tertiary amine N-oxide; tetraphenylporphinatoiron (II); oxene transfer; arene oxide; ferryl oxide
- Miyata, Naoki,Santa, Tomofumi,Hirobe, Masaaki
-
p. 377 - 380
(2007/10/02)
-
- Synthesis of Polycyclic Aromatic Hydrocarbons via a Novel Annelation Method
-
A new general synthetic approach to polycyclic aromatic hydrocarbons is described.The method is based on the convenient availability of o-lithioarylamides from regiospecific metalation of N,N-diethylarylamides with alkyllithium-amine reagents.Addition of the o-lithioarylamide to an aryl ketone or aldehyde affords a lactone.Reduction of the latter with zinc and alkali or HI generates the free acid which undergoes cyclization with ZnCl2 and Ac2O and reduction with zinc and alkali or HI to furnish the fully aromatic polyarene.Compounds synthesized via this route include 3-methylcholanthrene, benzanthracene, dibenzanthracene, dibenzanthracene, benzopyrene, and their methyl derivatives.Overall yields are generally good.Competitive enolate anion formation depresses the yield in the initial step in the reactions of enolizable ketones.However, this pathway can be suppressed with substantial improvement in yield through deuterium exchange of the hydrogens α to the carbonyl.The last three steps of the general method can be condensed to only one step through reductive cyclization of the lactone intermediates with hydriodic acid in acetic acid.While tertiary lactones are resistant to HI under these conditions, the corresponding free acids undergo reductive cyclization under similar conditions.
- Harvey, Ronald G.,Cortez, Cecilia,Jacobs, Stephen A.
-
p. 2120 - 2125
(2007/10/02)
-
- Temperature Effects on Electrode Processes. I. The Entropy of the Reversible Oxidation and Reduction of Alternant Aromatic Hydrocarbons
-
The temperature dependence of the reversible electrode potentials for the oxidation and reduction of alternant aromatic hydrocarbons (AAH) was determined using phase selective second harmonic a.c. voltammetry.The value of dErev/dT, which is equal to ΔS, was found to vary for the reduction of planar AAH in a manner predictable from the distribution of charges in the ions.Triphenylene, the ions of which have disperse charge showed a very low temperature dependence of Erev for the reduction process while anthracene reduction was accompained by the highest value.The charges in the ion radicals of anthracene are concentrated in the 9,10-positions.Substitution of phenyl groups on the 9- or 9,10-positions of anthracene brought about essentially no effect on dErev/dT for the reduction processes.It was proposed that the entropy of solvation is greater the more localized the charge is.The oxidation processes were less amenable to study but it was possible to draw conclusion for the processes involving the phenyl substituted anthracenes.Oxidation of 9,10-diphenylanthracene was accompained by a temperature effect of similar magnitude as for the reduction process while the entropy effect was greater for the oxidation of 9-phenylanthracene.The interpretation of these data is that in the case of the 9-phenylanthracene cation radical, solvation is strongest at the unsubstituted 10-position.The results indicate that entropy studies can give added detail to the study of electrode processes.
- Svaan, Morten,Parker, Vernon D.
-
p. 559 - 566
(2007/10/02)
-
- Evidence for Single Electron Transfer in the Reactions of Alkali Metal Amides and Alkoxides with Alkyl Halides and Polynuclear Hydrocarbons
-
Evidence for single electron transfer as the major pathway in reactions previously considered to be classic SN1 and SN2 pathways has been obtained.In this connection, the reaction of KOBu-t with trityl bromide has been shown to proceed through the trityl radical, and the reaction of LiN(i-Pr)2 with a primary alkyl iodide probe gave evidence of proceeding by single electron transfer, as indicated by the cyclized nature of the product as a result of a radical intermediate.
- Ashby, E. C.,Goel, A. B.,DePriest, R. N.
-
p. 2429 - 2431
(2007/10/02)
-
- Evidence of Single Electron Transfer in the Reduction of Various OrganicSubstrates by Lithium Tetrakis(N-dihydropyridyl)aluminate
-
Aromatic ketones, polynuclear hydrocarbons, and alkyl halides with LiAl(PyH)4 by a single electron transfer process.
- Ashby, E.C.,Goel, A.B.
-
p. 3934 - 3936
(2007/10/02)
-
