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Municipal solid waste incinerators (MSWIs) have long been the major contributors of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) to ambient air in Taiwan. After stringent MSWI emission standards were introduced in 2001, the long-term continuous monitoring of flue gas and ambient air quality became necessary to ensure the effectiveness of the related control strategies. Three MSWIs and the surrounding ambient air were investigated in the current study for PCDD/F characteristics during 2006 to 2011. The average concentrations in the flue gas ranged from 0.008 ~ 0.0488 ng I-TEQ/Nm(3), which is much less than the emission standard in Taiwan (0.1 ng I-TEQ/Nm(3)) (I-TEQ is the abbreviation of International Toxic Equivalent). This led to extremely low levels in the ambient air, 0.0255 pg I-TEQ/Nm(3), much less than the levels seen in most urban areas around the world. Additionally, the results obtained using the Industrial Source Complex Short-Term Dispersion Model (ISCST3) indicate that the PCDD/F contributions from the three MSWIs to the ambient air were only in the range from 0.164 ~ 0.723 %. Principal component analysis (PCA) showed that the PCDD/Fs in the air samples had very similar characteristics to those from mobile sources. The results thus show that stringent regulations have been an effective control strategy, especially for urban areas, such as Taipei City.

This study introduced a self-developed wet scrubber/plasma reactor (WSB/PR) system to treat cooking fumes, and measured the changes in the optical emissions spectra (OES), before and after treatment using OES, in order to understand the changes of OES in a gaseous phase from waste gas. In terms of operational parameters of the experiment, the scrubbing solution used in WSB was tap water and an enzyme scrubbing solution, and atmospheric pressure plasma was applied inside PR. Furthermore, five different output powers (0.112 kJ/m^3, 0.129 kJ/m^3, 0.138 kJ/m^3, 0.146 kJ/m^3, and 0.156 kJ/m^3) were utilized to conduct experiments. The experimental results showed that, through the operations of five different plasma output powers, active species C, C_2, CH, N, H_γ, N_2, N_2^+, NO, C^+, NH, O_2^+, H_2, and O can be tested under the following three situations: (i) start PR (plasma background value) without importing cooking fumes; (ii) cooking fumes pass through WSB/PR; and (iii) cooking fumes pass through ESB/PR. When cooking fumes are treated with WSB/PR, light emission intensity intensifies with increased plasma power, from 0.112 kJ/m^3 to 0.146 kJ/m^3. The same tendency occurs in the situation of cooking fumes treated with ESB/PR, which increases plasma power from 0.112 kJ/m^3 to 0.138 kJ/m^3. In addition, the number of active species is reduced when plasma power is increased. This indicates that, electron energy is reduced due to the H_2O decomposition function in the plasma reaction, which results in a decrease in the number of active species.

This study investigated the emissions of polychlorinated dibenzo-p-dioxins, dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs) from 45-hr cold start-up operations (from the ambient temperature) of two municipal solid waste incinerators (MSWIs). Fifteen samples were collected during the whole process, while the sampling period was divided as follows: (1) the initial stage (25-250°C); (2) the second stage (250-850°C), and the final stage (850-1000°C). The peak of total (PCDD/F + PCB) (WHO_(2005)-TEQ) concentration occurred during the second stage of the cold start-up. This could because the temperature in the combustion chamber reached 295-359°C, within the temperature window (250-450°C) of PCDD/F reformation by de novo synthesis. However, both PCDD/F and PCB (WHO_(2005)-TEQ) concentrations were still 2.8-3.8 times higher than the regulated standards in Taiwan 45 hours after the cold start-up began, demonstrating significant memory effects. Higher PCB/(PCDD/F + PCB) TEQ fractions were observed during the initial stage of cold start-up. This is probably due to the higher volatilities of memorized PCB-126 and -169 than PCDD/F congeners, thus making them more easily released into the flue gas. On the other hand, the total (PCDD/F + PCB) emissions during 45-hr cold start-up were estimated at 46-68 mg WHO_(2005)-TEQ.The annual (PCDD/F + PCB) emissions from normal conditions are generally estimated by the normal operating emissions factor without the cold start-up. The normal annual (PCDD/F + PCB) emission rates of the two MSWIs were 70.7-101 mg WHO_(2005)-TEQ, including once cold start-up emission, and these increased to 142-480 mg WHO_(2005)-TEQ, up by 65-458%, if one to eight times of cold start-up were included. Therefore, reducing unnecessary start-ups could be more important with regard to controlling the PCDD/F and PCB emissions than only attempting to increase the pollutant removal efficiency in the steady operations of MSWIs.

Atmospheric deposition, including dry and wet deposition, is a primary pathway for the transfer of POPs to terrestrial and aquatic ecosystems. In this study (that is, the part I.), the characteristics of PCDD/Fs and PCBs in the ambient air of Tainan City were simulated by the PM_(10) versus PCDD/Fs concentration regression analysis, gas-particle partition modeling, and the simulation of dry deposition. Dry deposition fluxes are obtained from the combination of the PCDD/F and PCB concentrations, meteorological information, dry deposition velocities, and scavenging ratios. The dry deposition fluxes of PCDD/F-TEQ2005 increase with decreasing temperature, while increase with a higher degree of chlorine numbers on PCDD/F homologues. In this study (that is, the part I.), the average PCDD/F dry deposition fluxes in spring, summer, fall and winter were 69.3, 28.2, 129 and 246 pg WHO-TEQ/m^2-month during 2012, respectively. As for 2013, the average PCDD/F dry deposition fluxes in spring, summer, fall and winter were 67.0, 29.8, 102 and 377 pg WHO-TEQ/m^2-month, respectively. The average PCB dry deposition fluxes in spring, summer, fall and winter were 2.16, 1.99, 5.70 and 11.9 pg WHO-TEQ/m^2-month during 2012, respectively. As for 2013, the average PCB dry deposition fluxes in spring, summer, fall and winter were 2.11, 1.27, 4.49 and 8.88 pg WHO-TEQ/m^2-month, respectively. The minimum simulated value occurred in summer, while the maximum dry deposition fluxes, which were about 4-5 times higher than the minimum values, occurred in winter. The lower values observed in summer may be caused by the atmospheric diffusion of SVOCs and high rainfall intensity.

The wet deposition flux increased with stronger rainfall intensity. From the congener profiles of PCDD/F and PCB WHO-TEQ2005 total deposition fluxes, 2,3,4,7,8-PeCDF, 2,3,4,6,7,8-HxCDF, 1,2,3,4,7,8-HxCDF and 1,2,3,7,8-PeCDD dominate the deposition fluxes. PCB-126 and PCB169 are the two most significant congeners that dominate the PCB WHO-TEQ2005. The simulated results show that the monthly PCDD/F and PCB wet deposition fluxes during 2012 were in the range of 9.26–265 pg WHO-TEQ2005/m2-month and 0.205–9.38 pg WHO-TEQ/m2-month, respectively. The monthly PCDD/F and PCB wet deposition fluxes during 2013 were 0.152–211 pg WHO-TEQ2005/m2-month and 0.00823–6.84 pg WHO-TEQ/m2-month, respectively. Wet deposition mainly occurs in the high rainfall intensity seasons, such as summer. The simulated results indicate that wet deposition is dominated by the particulate phase. Regarding the annual PCDD/F and PCB total (dry + wet) WHO-TEQ2005 deposition fluxes, dry deposition fluxes account for 68.0–73.9%. Among these, PCDD/Fs dominate the total deposition (95.9–96.1%) and PCBs contribute only 3.9–4.1%. The average total PCDD/F and PCB-TEQ2005 deposition (dry + wet) flux in winter (317–429 pg WHO-TEQ/m2-month) was 1.46–2.63 times higher than that in summer (163–216 pg WHO-TEQ/m2-month).

Dry deposition is one of the major routes by which air pollutants enter the ecosystem, and thus this study investigated the dry deposition characteristics of polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs) and biphenyls (PCBs) in the ambient air of industrial, urban, and rural areas in southern Taiwan from November 2010 to May 2011. Average dry deposition fluxes of total PCDD/Fs and PCBs in the ambient air of four sites were 157-544 pg/m2-day (8.30-27.5 pg ITEQ/ m^2-day) and 289-1010 pg/m^2-day (0.540-1.94 pg WHO-TEQ/m^2-day), respectively. The results showed that particle phase depositions dominated the dry deposition processes for the removal of PCDD/Fs and PCBs from the atmosphere, and the atmospheric deposition flux in the cold season tended to be higher than that during the warm season. The dry deposition velocity of individual PCDD/Fs (0.031-0.546 cm/s) increased as the number of chlorinated substitutes increased, which were similar to those measured or predicted in other Asian countries. Similar patterns of dry deposition velocities were observed for individual PCBs (0.069-3.38 cm/s), due to the fact that low chlorinated PCBs are predominant in gas phase and have lower deposition velocities.

The CO2 emissions and energy flows of a steel mill A (mill A) and petro-chemical industry B (PCI B) in southern Taiwan were investigated in this study. And the feasibility of integrating the energy flows of mill A and nearby waste management plant E (WMP E) was also evaluated in order to improve the energy efficiency and reduce the CO2 emission. The results show that the annual energy consumption of mill A and PCI B were 6,045,518 and 11,957,543 KLOE (kiloliter of crude oil equivalent), respectively. Mill A utilized less than 5% of Taiwan's total annual energy consumption, but it used high CO2 emission coefficient fuels and accounted for 8-9% of Taiwan's total CO2 emission inventory. However, the energy efficiency was improved, and at least 15% of total steam produced in mill A came from waste heat recycling. By recovering waste heat in mill A, 63,420 tonnes of heavy fuel oil (HFO) consumption was prevented, and thus 177,513 tonnes of CO2 were not emitted. Furthermore, WMP E is able to produce about 578,993 tonnes of process steam (17.6 kg/cm^2G × 275°C) annually. These results show that creating a steam-network between mill A and WMP E can not only reduce the amount of energy consumed by the industrial park, but also brought an extra benefit of 95 million NTD/yr for WMP E. This is the first study of an innovative steam-network at an industrial park in Taiwan, and the results of this work can further be applied in other locations to improve energy efficiency and reduce CO2 emissions.

PBDES are used as the flame retardants and have adverse effects on human health. Electric arc furnaces (EAF) are one of major emission source of PBDEs. The PBDE contents in the fly ashes of an EAF (29.3 ng/g) examined in this study were one to three orders higher than those in environmental soils. EAF fly ash treatment plants are established to resolve the disposal of this material, and also to recover the remaining iron or zinc from it. However, very little is known about the fate of PBDEs in EAF fly ash treatment plants. The EAF fly ash treatment plant investigated in this work can be divided into three sub-systems, including a pelletizer, reducing furnace and submerged arc furnace (SAF). The fly ash generated from the pelletizer process exhibited the highest PBDE content (7.69 ng/g), and contributed about 91% of the total PBDE inputs (4.40 g/day). The total PBDE concentrations in the stack flue gases of the pelletizer, reducing furnace and SAF were 24.5, 2.88 and 4.71 ng/Nm^3, respectively. The high PBDE concentrations of the pelletizer resulted from not only the thermal desorption of lighter brominated congeners, but also fugitive particles of EAF fly ashes. Together, the three stacks accounted for 40.8% of the total PBDE outputs, revealing that the air pollution control devices deployed in the current study were not very effective with regard to removing PBDEs from the flue gas. The PBDE output/input ratio of the EAF fly ash treatment plant was 0.0378, and thus most PBDEs introduced into the system were decomposed. The EAF fly ash treatment plant examined in this work is thus a reliable facility with regard to the disposal of this material.

In this study, the concentrations of five volatile organic compounds (VOCs), including BTEX and methyl tertiary-butyl ether (MTBE), were investigated in five different traffic tunnels (including Liangshan, Yueguangshan, Zoying, Guogang and Zhongliao tunnels) in southern Taiwan. Results showed that Guogang Tunnel was the most polluted with the highest average levels of both MTBE and BTEX while ethylbenzene had the lowest levels. The range of measured concentration of toluene in Liangshan, Yueguangshan, Zoying, Guogang and Zhongliao tunnels were from 5.6 to 6.2 (mean = 1.6), from 0.0 to 62.3 (mean = 17.6), from 2.7 to 26.7 (mean = 13.1), from 15.2 to 125.5 (mean = 57.5), and from 43.7 to 197.1 (mean = 115.8) μg/m 3 , respectively. In Guogang Tunnel, the average MTBE–BTEX ratios at two peak rush periods were (5.0:1, 5:3, 4:1, 0:1, 5:1.1) and (5.7:1, 3:3, 2:1, 0:1, 4:1.1). From morning till night, the ratios at different sampling periods in the five different tunnels suggest the existence of both different traffic flow and variations in traffic fleet type in different tunnels. T/B ratio ranged from 0 to 2.3, from 0 to 1.9, from 0.6 to 2.5, from 0.9 to 2.6 and from 0 to 10.5 in Liangshan, Yueguangshan, Zoying, Guogang and Zhongliao tunnels, respectively. We also observed a wide range of (m+p+o)-xylenes/ethylbenzene (ΣX/E) or m,p-X/E ratio in all five tunnels. The m,p-xylene/ethylbenzene ratio ranged from 2.2 to 5.7, from 1.4 to 3.3, from 2.0 to 7.7, from 1.4 to 1.5 and from 5.5 to 8.1 in Liangshan, Yueguangshan, Zoying, Guogang and Zhongliao Tunnels, respectively. Notably, those high ΣX/E ratios in all tunnels reflect a fresh air parcel in the tunnels due to the enclosed/half-enclosed environment. Nevertheless, it is important that the characteristics of X/E in different traffic tunnels are explored.

This study investigated the distribution of 21 target polycyclic aromatic hydrocarbons (PAHs) in the bio-oils, which were produced during the induction-heating pyrolysis of three different food-processing sewage sludges. The total concentrations of these priority PAHs ranged from 298 to 336 mg L −1 . The levels of PAHs are relatively high in low molecular weight fractions such as naphthalene, acenaphthylene, acenaphthene, fluorene and pyrene, and high molecular weight fractions such as indeno[ 1 , 2 , 3-cd ]pyrene and dibenz( a , h )anthracene. However, in consideration of carcinogenic potency, it was found that dibenz( a , h )anthracene comprised a significant proportion of toxic equivalency values for target PAHs present in the bio-oils as a basis for using toxic equivalency factor method.

1 Department of Bioenvironmental Engineering, Chung Yuan Christian University, 200, Chung-Pei Road, Chung-Li 320, Taiwan 2 Department of Environmental Engineering and Science, Chia-Nan University of Pharmacy and Science, Tainan 717, Taiwan 3 Department of Environmental Engineering and Management, Chaoyang University of Technology, Wufong, Taichung 413, Taiwan 4 Department of Tourism Management, Chia-Nan University of Pharmacy and Science, Tainan 717, Taiwan

Emissions of polycyclic aromatic hydrocarbons (PAHs, 2–7 ring) and regulated air pollutants (CO, HC, NO x , PM) from 2-stroke carburetor (2-Stk/Cb), 4-stroke carburetor (4-Stk/Cb) and 4-stroke fuel injection (4-Stk/FI) motorcycles were investigated by testing these vehicles on a chassis dynamometer. Exhaust samplings were carried out on diluted exhausts in a dilution tunnel connected to a constant volume sampling system. Measurements were performed on a standard driving cycle. The results reveal that low molecular weight PAHs (especially naphthalene) dominated in the exhaust gas. The averages of soluble organic fractions were 86.4%, 46.3% and 48.9% for the 2-Stk/Cb, 4-Stk/Cb and 4-Stk/FI motorcycles, respectively. PAH emissions are greater from cold-start driving than those from hot-start driving cycle for all these three kinds of motorcycles. Total PAH emission factors were 8320, 5990 and 3390 μg km −1 for the in-used 2-Stk/Cb, 4-Stk/Cb and 4-Stk/FI motorcycles, respectively. PAH emission factors were the largest for the 2-Stk/Cb motorcycles. Besides, the 2-Stk/Cb motorcycle had the largest total BaP equivalent emission factor of 10.8 μg km −1 , indicating that the emission exhaust from the 2-Stk/Cb motorcycle was most carcinogenic. HC, PM and PAH emissions were the lowest for the 4-Stk/FI motorcycles. The correlation coefficient between CO and total PAH emissions for all the test motorcycles was 0.51, indicating that CO and PAH emissions are not highly correlated.

This study was set out to assess the characteristics and significance of metal contents emitted from diesel engines. We found that the emitted concentrations of crust elements (including Al, Ca, Fe, Mg, and Si) were much higher than those of anthropogenic elements (including Ag, Ba, Cd, Co, Cr, Cu, Mn, Mo, Ni, Pb, Sb, Sr, Ti, V, and Zn) from diesel vehicle engine exhausts under the transient-cycle condition. The emission concentrations of particulate matters from diesel vehicle engine were inversely proportional to the specified engine speeds. To the contrary, the increase of engine speeds resulted in increase of fractions of metal contents in particulate matters. We conducted simple linear regression analysis to relate the emission rates of the metal contents in vehicle exhaust to the consumption rates of metal contents in diesel fuel. This study yielded R2=0.999 which suggests that the emission of the metal contents in vehicle exhaust could be fully explained by the consumption of metal contents in diesel fuel. For illustration, we found that the annual emission rates of both crust and anthropogenic elements from all diesel engine vehicles (=269 000 and 58 700 kg yr−1, respectively) were significantly higher than those from the coal power plant, electrical arc furnace, and coke oven (=90 100 and 1660 kg yr−1, 2060 and 173 kg yr−1, and 60 500 and 3740 kg yr−1, respectively) in Taiwan area. The relatively high amount of metal contents emitted from diesel engines strongly suggests that the measurement on the control of metal contents in diesel fuel should be taken in the future.

PAH emissions from a municipal waste incinerator stack in central Taiwan were sampled and analyzed by gas phase and particulate phase samples. A modified Gaussian atmospheric dispersion model, industrial sources complex (ISCST3), was used to simulate the PAH concentration in ambient air, which was compared with the measured PAH concentration in the ambient air. Total-PAH emission factor for the municipal waste incinerator ranged between 748 and 992 mg/ton-waste and averaged 871 mg/ton-waste, while the total-PAH emission rate ranged between 21,000 and 27,900 mg/hr and averaged 24,500 mg/hr. The results of dispersion modeling indicated that the contribution of PAHs to the ambient air by the municipal waste incinerator only reached 0.98% of the background concentration. Consequently, other emission sources, especially mobile sources, impact air quality more significantly.

In order to explore the emission characteristics of particulate and its particle-bound metal elements, eight construction sites in southem Taiwan were investigated during the period between Dec. 1996 and May 1997. Total suspended particulate (TSP) samples were collected with PS-1 samplers, and the dry deposition particles were sampled by dry deposition plates with smooth surfaces. The emission factors of particulate matter from construction sites were estimated using a dispersion model. Twenty elements, including Al, Ca, Fe, Mg, Na, Pb, Zn, Ni, V, Ba, Mn, Cr, Cu, Cd, Sr, Ag, Mo, Sb, As, and Ti, were analyzed in this study． The results indicated that dry deposition fluxes of TSP ranged between 762 and 3,760 mg/m(superscript 2)-day with an average of 2,230 mg/m(superscript 2)-day． The dry deposition velocities (V(subscript d)) of TSP varied in a narrow range between 2.63 to 5.55 cm/s with an average of 4.31cm/s and a standard deviation of l.21 cm/s. The major elemental components of particulate matter in the ambient air at construction sites were found to be crustal elements including Al, Ca, Fe, Mg and Na. These compositions were similar to those of road dust. Dry deposition fluxes of crustal metals were much higher than those measured at urban and suburban sites.

Our objective in this study was to assess the effect of using two kinds of lead-free gasoline [including 92-lead-free gasoline (92-LFG) and 95-lead-free gasoline (95-LFG), rated according to their octane levels] to replace the use of premium leaded gasoline (PLG) on the emissions of polycyclic aromatic hydrocarbons (PAHs) and their corresponding benzo[a]pyrene equivalent (BaP(eq)) amounts from the gasoline-powered engine. The results show that the three gasoline fuels originally contained similar total PAHs and total BaP(eq) contents; however, we found significant differences in the engine exhausts in both contents. The above results suggest that PAHs originally contained in the gasoline fuel did not affect the PAH emissions in the engine exhausts. The emission factors of both total PAHs and total BaP(eq) obtained from the three gasoline fuels shared the same trend: 95-LFG > PLG > 92-LFG. The above result suggests that when PLG was replaced by 95-LFG, the emissions would increase in both total PAHs and total BaP(eq), but when replaced by 92-LFG would lead to the decreased emissions of both contents. By taking emission factors and their corresponding annual gasoline consumption rates into account, we found that both total PAH and total BaP(eq) emissions increased from 1994 to 1999. However, the annual increasing rates in total BaP(eq) emissions were slightly higher than the corresponding increasing rates in total PAHs.

A manganese-based additive was used in this study to investigate the effects on the polycyclic aromatic hydrocarbons (PAHs) emission from a natural-aspirated heavy-duty diesel-powered engine. A similar turbocharged engine was tested and compared with the natural-aspirated one for the PAH emission. The concentrations of 21 individual PAHs (gas + particle phases) and the metal element (Mn) of the particulate from the engine exhaust and in the diesel fuel, respectively, were determined. Engine exhaust (PAHs and Mn) was collected over the modified JAMA J-13 mode by a PAH sampling system. By adding 400 mg/kg of Mn-based additive in the diesel, the reduction fraction of mean total-PAH (gas plus particle phase) emission was 37.2%, while for the 10 higher molecular weight (HMW) PAHs, the mean reduction fraction was 64.5%. These results indicate that the Mn-based additive in the diesel engine can act as a catalyst enhancing the oxidation process and reducing a considerable amount of PAH emission. In addition, the amount of 10 HMW PAH emission from the turbocharged engine averaged 92.4% of magnitude lower than that of the natural-aspirated engine. This result revealed that the turbocharged engine has higher pressure and temperature and thus makes a more complete combustion of the fuel.

A gasoline powered engine operated on a dynamometer was used to investigate the PAH (Polycyclic Aromatic Hydrocarbons) emission. A 95‐leadfree gasoline (95‐LFG) and a premium leaded gasoline (PLG) were used as power‐fuels. The engine was simulated for the idling condition and for the cruising speeds at 40, 80 and 110 km/hr. The concentrations of 21 individual PAHs in the engine exhaust, gasolines, and the ambient air were determined. Engine exhaust samples were collected by a PAH sampling system, while the ambient air sample was collected by using a standard PS‐1 sampler. Twenty one individual PAHs were analyzed primarily by a gas chromatography/mass spectrometer (GC/MS). Naphthalene (Nap) has the highest concentration in the liquid phase of both 95‐LFG and PLG, in which it accounts for respectively 98.3% and 76.6% of the total PAH. In term of the mean fraction of the total PAHs entering the 95‐LFG and PLG engines, the ambient air contributed less than 0.108% and 0.012%, respectively. Gasoline is...

A batch-type, controlled-air incinerator was used for the treatment of oily sludge and polyethylene (PE) plastic mixtures. The concentration and composition of 21 individual PAHs (polycyclic aromatic hydrocarbons) in the raw wastes, flue gas (gas and particle phases) and ash were determined. Stack flue-gas samples were collected by a PAH stack-sampling system. Twenty one individual PAHs were analyzed primarily by a gas chromatograph and a gas chromatography/mass spectrometer. Due to incomplete combustion, PAH content in the feeding wastes have a strong influence on PAH emission in both stack flue gas and ash residue. With the oily sludge in the feeding waste mixtures, the input mass of lower molecular weight PAHs — Nap, AcPy, Acp, Flu, PA, Ant and FL — was contributed mainly by liquid diesel, while the input mass of higher molecular weight PAHs — Pyr, CYC, CHR, BbF, BkF, BeP, BaP, PER, IND, DBA, BbC, BghiP and COR — was primarily contributed by the oily sludge. For the distribution of individual PAH mean output mass, lower molecular weight PAHs — Nap, AcPy, Acp and Flu — have > 87% of their mass discharged by the stack flue gas. However, the higher molecular weight PAHs — Ant, FL, CHR, BbF, BeP, BaP, PER, IND, DBA, BbC, BghiP and COR — have significant mass fractions (>18%) discharged by the ash residue. The total-PAH output/input mass ratios were between 0.00103 and 0.00360 and averaged 0.00203. This result indicated that the depletion of PAH mass in the combustion process was very significant. The PAH content in the fuel during the combustion process is the control factor of PAH emission. The co-combustion of oily sludge with plastic is a potential method of reducing the PAH emission and of saving the consumption of auxiliary fuel.

The aim of this work was to prepare the bio-crudes from agricultural wastes (i.e., rice straw, rice husk, sugarcane bagasse and coconut shell) by using induction-heating pyrolysis at specified conditions. The quantitative analysis of 21 priority pollutant polycyclic aromatic hydrocarbons (PAHs) in bio-crudes examined using gas chromatography/mass spectrometry (GC/MS) revealed that the PAHs in bio-crudes were primarily dominant in the low molecular weight (LMW) PAHs, including naphthalene (1.10-2.45 mg/L) and acenaphthene (0.72-7.61 mg/L). However, by considering carcinogenic potency, the bio-crudes from rice husk and sugarcane bagasse contained higher contents of benzo[a]pyrene (BaP) (0.52 and 0.92 mg/L, respectively) as compared to those from rice straw and coconut shell.

Sulfate-containing aerosol (SCA) dry deposition at the highway intersection, coastal location, and suburban area in Taiwan were analyzed and compared. Sampling was accomplished with a surrogate surface technique. Samples particles were coated with barium chloride (BaCl 2 ) in a vacuum evaporator and then exposed to a relative humidity of 85% for 2 h to form distinctive products of SCAs. Treated samples were examined by a scanning electron microscopy. SCA dry deposition fluxes were 10.2, 4.1, 3.4 μg m −2 s −1 and nonsulfate-containing aerosol (NSCA) dry deposition fluxes were 23.3, 8.2, 13.5 μg m −2 s −1 at the highway intersection, coastal, and suburban areas. At the highway intersection, both SCA and NSCA dry deposition fluxes were much higher than those at the other two sites. The dry deposition of particles was also analyzed with a traditional technique. The number median diameters (NMDs) of SCA were 0.41, 0.82, and 1.2 μm at the highway intersection, coastal, and suburban sites, respectively. The highway intersection site had a small NMD, which showed that most sulfate-containing deposited aerosols existed in fine diameter range. The mass median diameters (MMDs) of SCA were 8.8, 19.5, and 14.9 μm at the highway intersection, coastal, and suburban sites, which were much higher than NMDs. Average numbers of SCAs in total particulate were 33%, 33%, and 22% at the highway intersection, coastal and suburban areas Most deposited particulates were nonsulfate-containing at the three sampling sites. SCAs less than 10 μm contributed 29%, 8%, and 7% to the total dry deposition at the highway intersection, coastal, and suburban areas, respectively. The contribution of fine particulate was significantly higher at the highway intersection site.

Polycyclic aromatic hydrocarbons (PAHs) emission tests for a heavy-duty diesel engine fueled with blend base diesel fuel by adding batch fractions of poly-aromatic and mono-aromatic hydrocarbons, Fluorene and Toluene, respectively, were simulated to five steady-state modes by a DC-current dynamometer with fully automatic control system. The main objective of this study is to investigate the effect of total aromatic content and poly-aromatic content in diesel fuels on PAH emission from the HDD engine exhaust under these steady-state modes. The results of this study revealed that adding 3% and 5% (fuel vol%) Fluorene in the diesel fuel increases the amount of total-PAH emission by 2.6 and 5.7 times, respectively and increases the amount of Fluorene emission by 52.9 and 152 times, respectively, than no additives. However, there was no significant variation of PAH emission by adding 10% (vol%) of Toluene. To regulate the content of poly-aromatic content in diesel fuel, in contrast to the total aromatic content, will be more suitable for the management of PAH emission.

Polycyclic aromatic hydrocarbons (PAHs) emitted from 25 industrial boilers were investigated. The fuels used for these 25 boilers included 21 heavy oil, two diesel, a co-combustion of heavy oil and natural gas (HO+NG) and a co-combustion of coke oven gas and blast furnace gas (COG+BFG) boilers. PAH samples from the stack flue gas (gas and particle phases) of these 25 boilers were collected by using a PAH stack sampling system. Twenty one individual PAHs were analyzed primarily by a gas chromatography/mass spectrometer (GC/MS). Total-PAH concentration in the flue gas of 83 measured data for these 25 boiler stacks ranged between 29.0 and 4250 microg/m(3) and averaged 488 microg/m(3). The average of PAH-homologue mass (F%) counted for the total-PAH mass was 54.7%, 9.47% and 15.3% for the 2-ring, 3-ring and 4-ring PAHs, respectively. The PAHs in the stack flue gas were dominant in the lower molecular weight PAHs. The emission factors (EFs) of total-PAHs were 13,300, 2920, 2880 and 208 microg/kg-fuel for the heavy oil, diesel, HO+NG and COG+BFG fueled-boiler, respectively. Nap was the most predominant PAH occurring in the stack flue gas. In addition, the EF of 21 individual PAHs in heavy-oil boiler were almost the highest among the four various fueled-boilers except for those of FL and BkF in the diesel boiler. Furthermore, the EF of total-PAHs or BaP for heavy oil were both one order of magnitude higher than that for the diesel-fueled boiler.

PAH emission from the powered engines fueled by a 95 leadfree gasoline (95-LFG), a 92 leadfree gasoline (92-LFG) and a Premium leaded gasoline (PLG) with two gasoline additives (SA and SB) were collected using a PAH sampling system with a particulate interception device. Twenty one PAHs were analyzed primarily by an GC/MS, while eight metal elements were determined mainly by an ICP-AES. This investigation showed that the gasoline additives contain more amounts of carcinogenic PAHs than gasolines do. Blending these additives do raise the PAH content in the gasolines, simultaneously, will emit more amount of PAHs from the tailpipe of engine exhaust. It is suggested that before a gasoline additive is commercialized, an assessment on its PAH emission should be evaluated to make sure that the additive will not emit more PAHs and cause adverse effect on public health.