EVALUATION OF GAS/PARTICLE PARTITIONING OF PCDD/FS
FROM STACK GAS OF MSW INCINERATOR AND AMBIENT AIR
IN NORTHERN TAIWAN
ABSTRACT
K. H. Chi, S. H. Chang and M. B. Chang
Graduate Institute of Environmental Engineering, National Central University, Chungli,
Taiwan 320, R.O.C.
In this study evaluation of the PCDD/F congener distribution at the stack gas of
municipal waste incinerator (MWI) and ambient air in northern Taiwan is conducted
via stack and ambient air sampling and analysis. Ambient air samples were taken
concurrently in the vicinity area of a large-scale MWI for measuring polychlorinated
dibenzo-p-dioxin and furan (PCDD/Fs) concentrations and then partitioning in
gas/particle phase from November 1999 through Jan 2001 in northern Taiwan. In
the meantime stack gas sample of MWI was taken during the period of ambient air
sampled. The ambient air PCDD/F concentrations measured at all sampling sites in
this study are considerably lower than the ambient air standards proposed in Japan
(600 fg-I-TEQ/m3). The PCDD/F concentrations measured in fall and winter
seasons are significantly higher than those measured in summer times. In both of
stack gas and ambient air sample, the highly (hexa- to octa-) chlorinated PCDD/Fs
exist mainly in the particle phase while majority of the lowly (tetra- to penta- )
chlorinated PCDD/Fs exist in the gas phase. In addition, the results obtained on
gas/particle partitioning of ambient PCDD/F samples indicate that the particle phase
account for more than 80% of the total concentration. On the contrary, the
gas/particle partitioning of stack gas PCDD/F sample was complete different with
ambient sample. According to the results in this study, we find out that the gas phase
account for more than 80% of the total concentration. We speculate that may be
cause by the variation of temperature between ambient air and stack gas. In addition,
the temperature in ambient air might also affect the percentage of particle-bound
dioxins. When the temperature in ambient air decreases 10℃, the percentage of
PCDD/Fs in particle phase increases 15% to 25% (especially the highly chlorinated
PCDD/F congeners). On the other hand, PCDFs accounts for around 80% of the
I-TEQ concentrations for each stack gas and ambient air sample, among them the
2,3,4,7,8-PeCDF is the major contributor (especially in gas phase), accounting for 30
to 55% of total I-TEQ.
1. INTRODUCTION
The Taiwan government has implemented “The Wastes Management Plan for
1
Taiwan Area” Since 1998 all 17 large-scale MWIs in Taiwan municipal waste
incinerators (MWIs) islandwide to solve the emerging municipal waste
treatment/disposal problem. However, previous study indicates that dioxin in
ambient air originates mainly from waste incineration processes (Gotoh and
Nakamura, 1999). Emission of PCDD/Fs from various industrial processes has
become a public concern in Taiwan. PCDD/Fs are distributed over ambient air in
gas phase and particle phase after emitting from pollution sources. Besides the
distribution of gas/particle phase of PCDD/Fs in ambient air was effected by three
mechanisms of vaporizing, deposition and photo-degradation (Lohmann and Jones,
1998).
Around 70 to 80% of the seventeen 2,3,7,8-substituted PCDD/F
concentrations (not for I-TEQ) in the atmosphere are bounded to particles (Oh et al.,
2001), which are brought into the atmosphere through wind blowing, and eventually
settle to water bodies or other receptors in the environment either via dry or wet
deposition mechanism, then through food chain to enter human body and effect
human a lot. To date none comprehensive measurement of PCDD/F concentrations
in ambient air has been documented in Taiwan. This study was initiated to address
this important issue. We focus on the understanding of the partitioning of PCDD/Fs
in gas/particle phase of MWI stack gas and ambient air by measuring seventeen most
noxious PCDD/F congeners via seasonal samplings.
2. EXPERIMENTAL
2.1 Sampling sites
In this study, the large-scale MWI started to operate in 1995. It consists of
three incinerating units, each with its own heat recovery system. In addition, MWI
is equipped with cyclones, dry lime sorbent injection systems (DSI) and fabric filters
(FF) as air pollutant control devices (APCDs). The operating conditions of this
MWI are listed in Table 2. As highly as 4.5 ng-I-TEQ/Nm3 of PCDD/F
concentrations were measured in the stack gas of this MWI in 1998 (Chang and Lin,
2001). For better controlling the dioxin emissions from large-scale MWIs, the
Taiwan government was prompted to set up guidelines for regulating the dioxin
emissions from MWIs to environment.
In 1999, the Taiwan government
promulgated the dioxin emission limits for existing large-scale MWIs (0.1
ng-I-TEQ/Nm3). The activated carbon injection (ACI) technology was retrofitted in
this MWI for reducing PCDD/F emission to meet the stringent standards in March
1999.
To sample the ambient air PCDD/Fs and obtain gas/particle distribution of
2
PCDD/F in northern Taiwan., four sampling sites (A, B, C, and D) were set up based
on the meteorological information and relative locations to existing MWI. All air
samples were taken on seasonal basis from November 1999 through Jan 2001 at four
sampling sites in northern Taiwan. Description and location of four sampling sites
are given at Table1 and Figure 1. To obtain meteorological conditions in the vicinity
area near the sampling sites, a meteorological station was set up in sampling site B,
and has been operating since November 1999. The meteorological parameters
recorded in this study include wind speed, wind direction, rainfall, humidity and
temperature.
2.2 Sample collection
The flue gas sampling was conducted with the Graseby Anderson Stack
Sampling System complying with USEPA Method 23. The gas-phase sample was
collected by XAD-2 resin while the particle bound samples were collect by the glass
fiber filter and the rinse of the sampling probe. To avoid the error and bias caused
by sampling of dioxins bound to the particulate matter, isokinetic sampling had to be
conducted in order to collect a representative sample. In addition, the temperature in
stack gas of MWI was between 120℃ and 130℃. To avoid the particle phase
PCDD/Fs vaporized from fiber filter, the temperature of probe and filter holder in this
study were set up below 120℃. The flue gases were sampled after APCDs, the flue
gas flow sheets and PCDD/F sampling points of MWI is schematically shown in
Figure 2.
All air samples were taken on seasonal basis from November 1999 through
January 2001 at four sampling sites in northern Taiwan. The ambient air samples
were collected with PS-1 air samplers (Tisch PS-1) complying with USEPA TO-9A.
The PS-1 sampler is equipped with a Whatman glass fiber filter collecting
particle-bound PCDD/Fs and a polyurethane (PU) foam plug retaining PCDD/F
compounds in the gaseous phase. The total volume of the air sampled was more
than 1,500 m3 for a typical sampling duration of 4-5 days. Once the sampling was
completed, the samples were brought back to the laboratory under refrigeration.
Finally, the ambient air sample was analyzed for seventeen 2,3,7,8-substituted
PCDDF congeners with high resolution gas chromatography (HRGC) /high resolution
mass spectrometer (HRMS) equipped with a fused silica capillary column DB-5 MS.
2.3 Sample analysis
Once the sampling was completed, the samples were brought back to the
laboratory under refrigeration. They were then spiked with known amounts of
USEPA Method 23 internal standard solution which contains nine
13
C12-2,3,7,8-substituted PCDD/F congeners, i.e., 2,3,7,8-TeCDF, 1,2,3,7,8-PeCDF,
3
1,2,3,6,7,8-HxCDF,
2,3,4,6,7,8-HxCDF,
1,2,3,4,6,7,8-HpCDF,
2,3,7,8-TeCDD,
1,2,3,7,8-PeCDD,
1,2,3,6,7,8-HxCDD,
1,2,3,4,6,7,8-HpCDD
and
OCDD.
Thereafter, the PU foam and filter sample were Soxhlet extracted with toluene for
twenty four hours. The toluene extract was then concentrated to about 1ml by rotary
evaporation and was replaced by 5ml hexane for pretreatment process. Having been
treated with conc. sulfuric acid, the sample was then subjected to a series of clean-up
columns including sulfuric acid silica gel column, acidic aluminum oxide column and
Celite/Carbon column. Finally, the cleaned up solution was spiked with known
amounts of M23 recovery standard solution, and then analyzed for seventeen
2,3,7,8-substituted PCDDF congeners with high resolution gas chromatography
(HRGC) (Hewlett Packard 6890 plus)/high resolution mass spectrometer (HRMS)
(Auto Spec Ultima) equipped with a fused silica capillary column DB-5 MS (60m x
0.25 mm x 0.25μm, Supelco). The mass spectrometer was operated with a
resolution greater than 10,000 under positive EI conditions, and data were obtained in
the selected ion monitoring (SIM) mode.
3. RESULTS AND DISCUSSION
3.1 Average ambient dioxin concentrations in four seasons in northern Taiwan
Table 3 indicates that the average PCDD/F I-TEQ concentrations in ambient air
sampled in the vicinity areas are 245, 169, 162, 91, 196 and 271 fg-I-TEQ/m3,
respectively, during November 1999 to January 2001. In some Asian countries (like
Korea and Japan), the PCDD/F concentrations in ambient air near the area of MWI
ranged from 280 to 2,500 fg-I-TEQ/m3 (Makiya, 1999). The PCDD/F concentrations
measured at all sampling sites in this study are considerably lower than the
concentrations measured in Korea and Japan countries and the ambient air standards
proposed in Japan (600 fg-I-TEQ/m3). Besides, the PCDD/F concentrations
measured in winter seasons are significantly higher than those measured in summer
times. The trend matches with the results compiled in other countries (Lohmann and
Jones, 1998). The ambient air PCDD/F concentration may be closely correlated with
the meteorological conditions (Yunje and Jaehoon, 1999). In addition, local rainfall
is mainly from plum rains in spring, and typhoons and afternoon showers in summer.
During the winter season, the continental cold front moves to south, and only will the
cold front bring small amount of rainfall. As a result, the rainfall during the summer
time is significantly higher than that in wintertime in Taiwan. As wet deposition is
the major removal mechanism for most suspended organic compounds, high rainfall
increases wet deposition which results in lower ambient air PCDD/F concentrations
4
during the high rainfall season (Lorber et al., 1998).
In otherwise, the height of
mixing layer changes significantly with seasons. Table 3 indicates that the mixing
height recorded in Taipei area is higher during summertime compared to wintertime.
The lower the mixing height is, the worse the atmospheric dispersion is. Poor
dispersion results in higher localized pollutant concentrations close to the emission
source (Chang et al., 2003). Therefore, the lower mixing height recorded in
wintertime may result in higher PCDD/F concentrations.
3.2 Comparison of gas/particle phase distribution of PCDD/F congener in
ambient air and stack gas
Table 4 shows the gas/particle phase PCDD/F distributions in ambient air and
stack gas. Based on the gas/particle phase distribution of PCDD/F congeners in
ambient air, the particle phase PCDD/Fs account for 80%. In addition, PCDF
accounts for 10% in gas phase and 40% in particle phase, among them the highly
chlorinated (with hexa- to octa- chlorines) PCDD/Fs account for nearly 50%. But the
result of Figure 3 indicates that the particle phase PCDD/Fs of I-TEQ concentrations
were below 70%. It might be caused by 2,3,4,7,8-PeCDF (TEF=0.5) was most
distributed in gas phase, which also results in higher PCDD/F distribution in gas
phase. In stack gas, Table 4 shows that the gas phase PCDD/Fs account for over
85%. In addition, PCDF accounts for 60% in gas phase and 10% in particle phase,
among them the highly chlorinated PCDD/Fs account for over 60%. According to
the result of Figure 4, we find out that 2,3,4,7,8-PeCDF was major contributor of the
I-TEQ concentrations even in gas phase or particle phase. In otherwise, PCDD and
PCDF each accounts for 50% of gas/particle phase PCDD/F measured in ambient air;
while PCDD accounts for about a third of dioxin sampled from MWI’s emission and
PCDF is two-thirds. It might be caused by the particle phase OCDD (25%) in
ambient air is higher than the particle phase OCDF (13%). Besides, the PS1 sampler
is operated with forced suction, which may result in the higher amount of particulate
matter being sucked into the sampler, which also results in higher distribution of
PCDD for ambient sample.
3.3 Variation in gas/particle phase distribution of PCDD/Fs in ambient air and
stack gas
If we compared the gas/particle phase PCDD/F distribution in ambient air with
that emitted from the MWI, we find out that the distribution was complete different.
In ambient air, PCDD/Fs were most distributed in particle phase. In otherwise,
PCDD/Fs were most distributed in particle phase in stack gas. We suggest that
might caused by two factor, they are temperature and particle concentrations,
respectively. According to the equation [1], we can find out that the fraction of
5
semi-volatilize compound (like PCDD/Fs) adsorbed to particles was effected by the
vapor pressures of those compounds. According to previous study (Eitzer and Hites,
1988), we find out that the vapor pressure was affected by the temperature. As
shown as the equation [2], when the temperature increases, the vapor pressure of the
organic compound increases. That also results in lower fraction of PCDD/F
congener adsorbed to particles. In this study, the temperature in stack gas(120℃ to
130℃) is quite higher than that in ambient air (15℃ to 25℃). So that the
distributions of particle phase PCDD/Fs in stack gas is obvious lower than those in
ambient air. The result of Figure 5 also indicates that the variation of temperature
would change the particle phase distribution of PCDD/Fs in ambient air. When the
temperature in ambient air decreases by 10℃, the percentage of PCDD/F in particle
phase increases by about 15% to 25%, especially of some highly chlorinated PCDD/F
congeners (like OCDD).
log p L 
 Qv
 b ………...………..…………………………..……...[2]
2.303RT
P0L: saturation liquid phase vapor pressure of the organic compound（Pa）
T：temperature（K）
Qv: the latent heat of vaporization (J/mol)
R：ideal gas constant (8.314 J/mol-K)
b：constant (related to entropy of vaporization)
In otherwise, the suspended particle concentration would also affect the fraction
of PCDD/F congeners adsorbed to particles. As shown as the equation [3], when the
suspended particle concentrations increase, the fraction of PCDD/F congener
adsorbed to particles decrease (Sheffield and Pankow, 1994). In this study, the
particle concentration in stack gas of MWI is lower than 10 mg/Nm3, which may
result in the lower amount of particle phase PCDD/F congeners adsorbed to particles.
log
Cp
c
 log Kp  log
 log PL ………………………………..……...[3]
Cg
TSP
Cp: the concentration of semi-volatilize compounds associated with particles (ng/μg)
Cg: the gas phase concentration (ng/m3)
P0L: saturation liquid phase vapor pressure of the organic compound（Pa）
Θ：tha particle surface area per unit volume of air (cm2/cm3)
c：a constant which is related to the difference between the heat of desorption from the
particle surface(Pa-cm)
TSP: total suspend particle concentrations (μg/m3)
3.4 Comparison of gas/particle phase distribution and chlorination level of each
PCDD/F congeners
According to the result in this study, different PCDD/F congener patterns were
observed in gas/particle phase. The highly (hexa- to octa- chlorines) chlorinated PCDD/Fs
dominated the particle phase while the lowly (tetra- to penta- chlorines) chlorinated
6
PCDD/Fs dominated the gas phase. Figure 6 and Figure7 show that the chlorination level of
PCDD/Fs congener increases, the percentage of PCDD/Fs existing in gas phase decreases.
The difference is caused by the vapor pressure of PCDD/F congener affects the percentage of
As shown as the equation [2], when the temperature
increases, the vapor pressure of the organic compound increases. In ambient air, he
particle-bound PCDD/F congener.
highly-chlorinated PCDD/Fs congeners are of lower vapor pressure (at 25℃: 1.14×10-4 to
2.17×10-5 Pa) compared to the lower-chlorinated PCDD/Fs congeners (at 25℃: 3.96×10-6 to
2.77×10-7 Pa) and are of higher tendencies to condense on particles in ambient air
(Eitzer and
Hites, 1988). In stack gas, he highly-chlorinated PCDD/Fs congeners are of lower vapor
pressure (at 125℃: 5.75×10-2 to 1.11 ×10-1 Pa) compared to the lower-chlorinated PCDD/Fs
congeners (at 125℃: 5.12×10-4 to 6.51×10-2 Pa) and are of higher tendencies to vaporized to
gas phase in stack gas of MWI (Shiu and Ma, 2000).
4. CONCLUSIONS
The results obtained from the ambient air sampling in Taipei during 1999-2001
indicate that the mean PCDD/F concentration of seventeen 2,3,7,8-substituted
congeners in wintertime (188 to 348 fg-I-TEQ/m3) is significantly higher than that
measured in summertime (56 to 125 fg-I-TEQ/m3). The results obtained on
gas/particle partitioning of ambient PCDD/Fs samples indicate that the particle phase
account for more than 80% of the total concentration. In otherwise, the gas phase
account for more than 85% of the total PCDD/F concentration in stack gas. In
addition, the temperature should also affect the percentage of particle-bound
PCDD/Fs. When the temperature in ambient air decreases 10℃, the percentage of
PCDD/Fs in particle phase increases 15% to 25%(especially the highly chlorinated
PCDD/Fs congeners). On the other hand, the results also show that the chlorination
level of PCDD/Fs congener increases, the percentage of PCDD/Fs existing in gas
phase decreases even in ambient air or stack gas of MWI. The difference is caused
by the vapor pressure of PCDD/F congener affects the percentage of particle-bound
PCDD/F congener.
ACKNOWLEDGEMENTS
The authors gratefully acknowledge the assistance of NIEA for PCDD/Fs
analysis and the financial support provided by the National Science Council
(NSC-89-EPA-Z-008-010 and NSC-90-2211-E-008-036) of Republic of China.
7
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Municipal Waste Incinerator in Taiwan. Chemosphere, 45, 1151-1157.
Chang, M. B., J. J. Lin and S. H. Chang, 2002. Characterization of Dioxin
Emissions from Two Municipal Solid Waste Incinerators in Taiwan. Atmospheric
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Chang, M. B., Weng, M. Y., Lee, T. Y., Chen, Y. W., Chang, S. H., and Chi, K. H.,
2003. Sampling and Analysis of Ambient Dioxins in Northern Taiwan. Chemosphere,
in press.
Eitzer, B. D. and Hites, R. A., 198. 8Vapor Pressures of Chlorinated Dioxins and
Furans”, Environmental Science and Technology, 22, 1362-1364.
Gotoh, Y. and Nakamura, Y., 1999. Japanese Source Inventory, Focusing on the
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Hagenmaier, H., Kraft, M., Jager, W., Mayer, U., Lutzke, K. and Siegel, D., 1986.
Comparison of Various Sampling Method for PCDDs and PCDFs in Stack Gas.
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Hart,K. M. and Pankow, J. F., 1994. High Volume Air Sampler for Particle and Gas
Sampling- 2. Use of Backup Filters to Correct for the Adsorption of Gas/phase
Polycyclic Aromatic Hydrocarbons to the Front Filter. Environmental Science and
Technology, 28, 655-661.
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Related to the Fate of Global Pollutants”, Fate of Pollutants in the Air and Water
Enviroments. Part I, J. Wiley, New York, 7-26.
Janssens, J. J., Daellemans, F. F. and Schepens, P. J. C., 1992. Sampling Incinerator
Effluents for PCDDs and PCDFs: A Critical Evaluation of Existing Sampling
Procedures. Chemosphere, 25(7-10), 1323-1332.
Lohmann, R. and Jones, K. C., 1998. Dioxins and Furans in Air and Deposition: A
Review of Levels, Behavior and Processes. The Science of the Total Environment,
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219, 53-81.
Makiya, K., 1999. National Environmental Monitoring in Japan. Organohalogen
Compounds. 43, 217-220.
Oh, J. E., Choi, J. S. and Chang, Y. S., 2001. Gas/particle Partitioning of
Polychlorinated Dibezo-p-dioxins and Dibenzofurrans in Atmosphere; Evaluation of
Predicting Models. Atmospheric Environment, 35, 4125-4134.
Pankow, J. F., 2001. Review and Comparative Analysis of the theories on Partitioning
between the Gas and Aerosol Particulate Phase in the Atmosphere. Atmospheric
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Sheffield, A. E. and Pankow, J. F., 1994. Specific Surface Area of Urban Atmospheric
Particulate Matter in Portland, Oregon. Environmental Science and Technology, 28,
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Yunje, K. and Jaehoon, Y. 1999. The Study on the Contents of PCDDs/PCDFs in
Ambient Air Edible and Human Serum in Korea. Organohalogen Compounds. 43,
167-172
9
Table 1 Description of ambient air sampling sites in northern Taiwan.
Universal
Sampling
Transverse
site
Mercator
Description
A
N2762772, A primary school about 1.4 km from the MWI
E288637 (upwind of the MWI).
B
N2760934, A junior high school about 1.7 km from the MWI
E287904 (downwind of the MWI).
C
N2761363, A community center about 1.7 km from the MWI
E2860143 (downwind of the MWI).
D
N2763093, A primary school about 3.1 km from the MWI
E284386 (downwind of the MWI).
Table 2 The operating conditions of existing MWI in northern Taiwan
(Chang et al., 2002).
Location (Universal Transverse Mercator)
Capacity (tons/day/incinerator)
Taipei (N2762525, E287275)
450
Operation temperature (℃)
850-1,050
Cyclone
Dry Sorbent Injection
(with Activated Carbon Injection)
Bag Filter
Air pollution control device (APCD)
The stack height (m)
120
Flue gas flow rate (kNm3/h/incinerator)
96.6 ±2.7
1.03 ng/Nm3
Average PCDD/F emission (n=4)
Average PCDD/F I-TEQ emission (n=4)
n = the number of samples.
10
0.083 ng-I-TEQ/Nm3
Table 3 The PCDD/F concentrations in ambient air in four seasons in northern Taiwan.
Sampling
Period
Sampling
Sites
ΣPCDD/F Concentrations
Meteorological Data (n= 96-144)
Wind
direction
Rainfall
(mm)
Mixing height
(m)
0.0
465
(210 to 762)
Temp
(K)
（fg/m3）
（fg-I-TEQ/m3）
4,004
188
8,959
348
2,893
201
2,312
178
3,123
191
D
2,382
139
A
2,052
101
3,273
144
5,465
208
D
3,624
194
A
1,041
56
2,212
125
2,943
124
1,381
59
6,549
323
1,313
74
3,876
233
5,702
338
4,136
242
A
Nov.1999
(11/11-11/15)
B
NNE
294
D
A
Jan. 2000
(1/14-1/17)
Apr.2000
(4/6-4/10)
Jul.2000
(7/14-7/18)
B
B
C
B
C
ENE
ESE
SSE
27.4
8.5
78.9
475
(284 to 799)
489
(124 to 882)
530
(183 to 995)
291
293
299
D
Oct.2000
(10/6-10/11)
B
C
NNE
0.0
480
(196 to 835)
297
A
Jan. 2001
(1/30-2/05)
B
ENE
9.2
455
(205 to 722)
C
n = the number of recorded data.
11
288
Table 4 Percentage of Gas/particle phase PCDD/Fs concentrations in ambient air and
stack gas
Stack Gas
Sampling
sites
MWI (n=2)
Ambient Air
A (n=2)
B (n=4)
C (n=4)
Gas
(%)
Particle
(%)
Gas
(%)
Particle
(%)
Gas
(%)
Particle
(%)
Gas
(%)
Particle
(%)
2,3,7,8-TeCDF
0.33
0.03
1.48
0.36
0.99
0.40
1.60
0.27
1,2,3,7,8-PeCDF
3.16
0.23
1.35
0.84
1.00
0.84
1.75
0.68
2,3,4,7,8-PeCDF
4.14
0.44
2.34
2.59
1.96
2.44
2.99
1.96
1,2,3,4,7,8-HxCDF
9.44
1.03
1.14
3.59
1.02
3.72
2.27
3.02
1,2,3,6,7,8-HxCDF
5.76
0.61
0.99
3.12
0.86
3.32
1.89
2.64
2,3,4,6,7,8-HxCDF
4.71
0.58
0.56
5.18
0.67
5.32
1.56
3.96
1,2,3,7,8,9-HxCDF
0.62
0.05
0.18
1.38
0.20
1.52
0.55
1.21
1,2,3,4,6,7,8-HpCDF
16.3
2.38
0.50
15.8
0.92
16.1
2.99
13.9
1,2,3,4,7,8,9-HpCDF
3.69
0.41
0.02
1.82
0.05
1.83
0.23
1.78
OCDF
13.9
2.01
0.06
13.7
0.12
13.6
0.43
13.8
62.1
7.78
8.63
48.4
7.81
49.0
16.3
43.2
2,3,7,8-TeCDD
0.15
0.01
0.21
0.03
0.15
0.04
0.19
0.01
1,2,3,7,8-PeCDD
0.91
0.09
0.44
0.50
0.30
0.44
0.47
0.32
1,2,3,4,7,8-HxCDD
1.02
0.13
0.16
0.82
0.14
0.84
0.30
0.60
1,2,3,6,7,8-HxCDD
1.17
0.17
0.24
1.61
0.26
1.57
0.55
1.19
1,2,3,7,8,9-HxCDD
1.66
0.22
0.16
1.36
0.14
1.36
0.41
1.01
1,2,3,4,6,7,8-HpCDD
6.25
1.09
0.18
10.5
0.40
11.6
1.27
9.11
OCDD
14.2
2.99
0.63
26.2
0.87
25.1
2.03
23.1
Σ PCDD
25.4
4.72
2.01
41.0
2.25
40.9
5.22
35.3
TOTAL
87.5
12.5
10.6
89.4
10.1
89.9
21.5
78.5
Σ PCDF
12
300
250
200
Elevation (m)
250-300
150
200-250
150-200
100-150
50-100
0-50
100
50
2765400
2763600
2761800
2760000
284000
284600
285200
285800
286400
287000
287600
Univers al Trans vers e Mercator (N.E)
Figure 1 Location and elevation of four sampling sites in northern Taiwan.
13
288200
288800
0
289400
STACK
Stack sampling
point
ECONOMIZER
DSI (ACI)
FABRIC FILTER
COMBUSTOR
BOILER
IDF
CYCLONE
Figure 2 Flow diagram and sampling points of MWI
14
100
100
90
90
OCDD
OCDD
1,2,3,4,6,7,8-HpCDD
80
1,2,3,4,6,7,8-HpCDD
1,2,3,7,8,9-HxCDD
80
1,2,3,7,8,9-HxCDD
1,2,3,6,7,8-HxCDD
1,2,3,6,7,8-HxCDD
1,2,3,4,7,8-HxCDD
70
1,2,3,7,8-PeCDD
2,3,7,8-TeCDD
60
OCDF
1,2,3,4,7,8,9-HpCDF
50
1,2,3,4,6,7,8-HpCDF
1,2,3,7,8,9-HxCDF
40
2,3,4,6,7,8-HxCDF
1,2,3,6,7,8-HxCDF
30
Percentage of I-TEQ conc
Percentage of conccentrations
70
1,2,3,4,7,8-HxCDF
1,2,3,4,7,8-HxCDD
1,2,3,7,8-PeCDD
60
2,3,7,8-TeCDD
OCDF
1,2,3,4,7,8,9-HpCDF
50
1,2,3,4,6,7,8-HpCDF
1,2,3,7,8,9-HxCDF
40
2,3,4,6,7,8-HxCDF
1,2,3,6,7,8-HxCDF
30
1,2,3,4,7,8-HxCDF
2,3,4,7,8-PeCDF
1,2,3,7,8-PeCDF
20
2,3,4,7,8-PeCDF
20
1,2,3,7,8-PeCDF
2,3,7,8-TeCDF
10
2,3,7,8-TeCDF
10
0
0
Gas phase
Particle phase
Gas phase
Particle phase
Figure 3 Partitioning of PCDD/Fs in gas/particle phase of ambient air
100
100
90
90
OCDD
OCDD
1,2,3,4,6,7,8-HpCDD
80
1,2,3,4,6,7,8-HpCDD
80
1,2,3,7,8,9-HxCDD
1,2,3,7,8,9-HxCDD
1,2,3,6,7,8-HxCDD
1,2,3,6,7,8-HxCDD
70
1,2,3,4,7,8-HxCDD
1,2,3,4,7,8-HxCDD
1,2,3,7,8-PeCDD
60
1,2,3,7,8-PeCDD
Percentage of I-TEQconc
Percentage of concentrations
70
2,3,7,8-TeCDD
OCDF
1,2,3,4,7,8,9-HpCDF
50
1,2,3,4,6,7,8-HpCDF
1,2,3,7,8,9-HxCDF
40
2,3,4,6,7,8-HxCDF
1,2,3,6,7,8-HxCDF
30
1,2,3,4,7,8-HxCDF
60
2,3,7,8-TeCDD
OCDF
1,2,3,4,7,8,9-HpCDF
50
1,2,3,4,6,7,8-HpCDF
1,2,3,7,8,9-HxCDF
40
2,3,4,6,7,8-HxCDF
1,2,3,6,7,8-HxCDF
30
1,2,3,4,7,8-HxCDF
2,3,4,7,8-PeCDF
20
2,3,4,7,8-PeCDF
20
1,2,3,7,8-PeCDF
1,2,3,7,8-PeCDF
2,3,7,8-TeCDF
2,3,7,8-TeCDF
10
10
0
0
Gas phase
Gas phase
Particle phase
Particle phase
Figure 4 Partitioning of PCDD/Fs in gas/particle phase in stack gas of MWI
15
ambinet airtemperature (15℃)
16
2,
3,
7,
8Te
1,
2,
C
3,
DD
7,
81,
Pe
2,
3,
C
4,
DD
7,
81,
H
2,
xC
3,
6,
D
7,
D
81,
H
2,
xC
3,
7,
D
8,
1,
D
92,
H
3,
xC
4,
6,
D
7,
D
8H
pC
D
D
O
C
D
D
Percentage of PCDD/Fs concentrations in particle phase of ambient air(%)
2,
3,
7,
8Te
1,
2,
C
3,
DF
7,
8P
2,
eC
3,
4,
DF
7,
81,
Pe
2,
3,
C
4,
DF
7,
8
1,
H
2,
xC
3,
6,
D
7,
F
82,
H
3,
xC
4,
6,
D
7,
F
81,
H
2,
x
3,
C
7,
D
8,
1,
F
92,
H
3,
xC
4,
6,
D
7,
1,
F
82,
H
3,
pC
4,
7,
D
8,
F
9H
pC
D
F
O
C
D
F
50
45
40
35
30
25
20
15
10
5
0
ambinet airtemperature (25℃)
Figure 5 Distribution of PCDD/F in particle phase change via temperature variation
Percentage of concentrations (%)
-1.0
95%
-1.5
90%
-2.0
-2.5
85%
80%
-3.0
-3.0
-3.5
-3.5
log vapor pressure (25℃ )
-6.5
0%
-7.0
Gas phase
Gas phase
Particle phase
log vapor pressure(Pa)
0.0
-0.5
Particle phase
17
8TC
D
8
1,
-P 2 F
2,
e ,3
3,
7, 2, CD,7,8
1,
8- 3,4 F-T
2,
3,
6, P1 eC,7,8 C DF
7, ,2 D -Pe
1,
8- ,3 , F C
2,
3,
4, 1,H2,3xC7,8-P DF
7,
2,
8,1, ,6,7D, F eC D
3,
-2H 8
F
4,
6, ,3x,4C,7 -HxC
7, 2
1,
D
,
D
8
8-,3, ,F-H F
2,
H4,6 x
3,
-7.0
-0.5
-1.0
-1.5
-2.0
-2.5
log vapor pressure(Pa)
Figure 7 Comparison of gas/particle phase distribution and vapor pressure of
PCDD/Fs congener in stack gas of MWI
7,
-6.0
20%
4,
40%
-5.5
log vapor pressure (125℃ )
-5.0
7,
60%
3,
-3.0
-2.0
-3.5
-2.5
-4.0
-4.5
-5.0
-5.5
-6.0
log vapor pressure (25℃ )
-3.0
3,
-4.5
log vapor pressure (25℃ )
-4.0
80%
2,
Percentage of concentrations (%)
-3.5
2,
2,3
2,
3
2,3 ,7,8- ,7,8-T
1
T
,4,
,C
eC
2,
3
7
1,2 ,8-P ,D7,8F-P DF
e2,3, eC
,
4D
1,2 3,7,8 C
D
-P1,2 ,7,8F-P F
,3,
e
3,
eC
1,2 6,7,8 ,C
4
-H1,2 ,D7,8F-H DF
,3,
4
x,
xC
2,3 ,7,8, 3C,6,D
-H2,3 7,8F-H DF
,4,
x,4, xC
6
6D
1,2 ,7,8 C
-H1,2 ,7,8F-H DF
,3,
x
7
,
1,2
3C
,
,7 D x C
D
,8
,3, 8,9-H
1,
,9F F
2,
4,6
-H
3,
x
4C
1,2
,
,6 D x C
,7 F DF
,3, 7,8-H
1,
,8
2,
-H
4,7
3,
p
4C
,8,
,7 D pC
9-H ,8,9 F DF
pC -HpC
D F DF
OC
2,3
O
2
, 7 F CD
1,2 ,7,8- ,3D
,8
T1,2 -Te F
,
1,2 3,7,8 C
,D C
-P1, 3,7,8D- DD
,3,
e
2
P
4
,3
, D eC
1,2 ,7,8 C
-H1, 4,7,8D- DD
,3,
x2 3 Hx
6
,6D C
1,2 ,7,8 ,C
D
-H1, ,7,8D
D
,3,
-H
2
x
7
1,2
,C
xC
,8,
3,
7
D
,3,
9 1, ,8,9D DD
4,6 -H
2
-H
xC
,7, x,3,C
8-H 4,6D
,7 D DD
,8
pC -Hp
D D CD
D
OC
D D O CD
D
log vapor pressure (25℃ )
100%
-3.5
2,
3,
2, 7,8
3,
4, TC
7
D
1, ,8-P F
2,
e
3
C
21,,2, ,7,8- DF
3, 3, Pe
2, 1, 7,86,7, CD
3, 2,3 -T8-H F
4, ,4 C x
7 ,7 D C
1, 2,3 ,8-P,8,- F DF
2, ,4 e H
3 ,6 C x
1, 1,,7, ,7,8 D CD
2, 2,38- -HF F
3, ,7Pe x
16
C
1, ,2,,73, ,8,9C-D DF
2, ,48- HF
,6H x
3
2, 2,3
3 ,
2, ,7,87,8
1, 3,4 -Te-TC
2, ,7 C
3
D
1, ,7,8,8-P DF F
2, 2,3 -Pe eC
1, 3,4, ,7, CD D
1, 2,3 7,8-8-P F F
2, ,6 P e
1, 3,4, ,7, eCDCD
2 7 8
1, ,3, ,8- -H F F
2, 4 H x
3 , x
2, ,6,77,8 CDCD
2, 3,4 ,8- ,-H F F
3, ,6 H x
x
4
1, ,6,7,7,8 CDCD
1, 2,3 ,8-H-H F F
1, 2,3, ,7,8 xCxC
2 7
1, ,3 ,8,9,9- DFDF
2, ,4 - H
1, 3,4,6,6,7 HxCxC
2
1, ,3 ,7,8,8- DFDF
2, ,4 - H
3, ,7 H p
4, ,8 pC C
7, , D D
8, 9- F F
9- H
H p
pC C
D DF
F
O
2
2, ,3, OCC
3, 7
1, 7,8 ,8 DFDF
2
1, ,3, -Te TC
1, 2,3 7,8 CD D
2 ,
1, ,3, 7,8- -P D D
2, 4 P eC
1, 3,4,7,7,8 eCD DD
2
1, ,3 ,8- -H D
2, ,6 H x
1, 3,6, ,7,8 xCDCD
2 7
1 ,3 ,8- -H D D
1, ,2,3, ,7,8 HxCxC
2, 7, ,9 D D
1, 3, 8,9 -H D D
2, 4, 3, 6 Hx xC
4, ,7 C
6 , ,8 D D
7, - D D
8- H
H p
pC C
D DD
D
O
O CD
C
DD D
log vapor pressure (25℃ )
log vapor pressure at 25℃ (Pa)
-2.0
-2.5
-2.0
-2.5
-6.5
100%
0.0
-3.0
-3.5
-4.0
-4.5
-5.0
-5.5
-6.0
-6.5
-7.0
Figure 6 Comparison of gas/particle phase distribution and vapor pressure of
PCDD/Fs congener in ambient air
log vapor pressure at 125℃ (Pa)
0.0
-0.5
-1.0
-1.5
-2.0
-2.5
-3.0