Post on 25-Dec-2015
Arifa Lodhi and Badar Ghauri
Pakistan Space And Upper Atmosphere Research Commission (SUPPARCO), P. O. Box 8402, University Road, Karachi-75270,
Pakistan
AEROSOL ANALYSIS AND SOURCE APPORTIONMENT IN URBAN AREA, LAHORE
PAKISTAN
Presentation Overview Air Quality Monitoring Results of four winter studies (1999, 2000,
2001, 2005) Source Apportionment-Application of SO4
2-/Se Tracer technique, Statistics analysis, Factor analysis
Local and distant source identification Future plans
Sampling Location Aerosol Samples were collected at Lahore, which is the capital of Punjab and the second largest city in Pakistan with a population of 7 million.
Sampling Details
• Aerosol Sampling (PM2.5) was carried out during last few winters on following Dates:
1. January 1-5 1999
2. December 25-31, 1999 and January 1-8, 2000
3. January 9-11 2001 sampling interval was 5 min.
4. Nov. 21 2005 to Dec. 9, 2005
• During winter, northeastern Pakistan is under the influence of a high-pressure system resulting in dry weather and low wind speeds. These conditions are ideal for accumulation of pollutants in the atmosphere.
SUPARCO OFFICE
WaghaBhati Gate
Lhr. Cantt
Township
METHODOLOGY
(i) The samples were collected on 47-mm Zelfluor (Teflon) filters using Millipore Swinex holder trains.
(ii) Thermo Electron Corporation RAAS PM2.5 Aerosol Sampler
(iii) Black Carbon/Elemental Carbon and Organic Carbon Magee Scientific Model AE21 Aethalometer
Analysis Carried out for following parameters (Wadsworth Center, NY State Department of Health)
a) Anions & Cations (Ion Chromatograph)
b) Trace and Toxic metal (ICP-MS)
Mean Concentration and Range of Trace Species
STUDY 1 January 1-5 1999
S.No. Species Mean Max Min
1 SO42- 50.29 98.90 17.50
2 NO3- 37.03 65.50 22.80
3 Cr 19.00 28.20 5.70
4 Sc 1.34 2.30 0.10
5 Fe 4944.67 8767 535
6 Zn 1253.56 3892 301
7 Se 7.74 11.70 5.10
8 As 13.13 25.30 6.80
9 Sb 19.07 61.90 4.80
Concentrations of SO4 2-, NO3-, are in µg/m3, other in ng/m3.
S.No. Species Mean Max Min
1 SO42- a 43.2 141.3 3.78
2 NO3- a 31.7 74.5 3.1
3 SO2 a 21.2 68.5 0.83
4 Se 26.1 257.6 0.73
5 As 10.6 25.97 1.94
6 Sb 13.1 84.8 0.69
7 Cu 843.9 5305 29.4
8 Zn 2200 7796 111.5
9 Pb 846 4786 31.1
10 Al 13391 54351 1004
11 Fe 8176 24197 741.8
12 Ca 8696 30811 1312
13 Mg 1078 4409 101
14 Cr 22.1 67.6 1.44
15 Mn 177.1 503.9 16
16 Co 3.33 9.53 0.28
17 Ni 16.5 55.6 1.53
a Concentrations of SO4 2-, NO3-, and SO2 are in µg/m3, other in ng/m3.
STUDY 225 December 1999 to 8th January 2000
Mean Concentration and Range of Trace Species
the two sampling time intervals of 6 hour periods from 0800 to 1400 and the two sampling time intervals of 6 hour periods from 0800 to 1400 and 1400 to 2000 hours followed by a 12 hour over night period from 2000 to 1400 to 2000 hours followed by a 12 hour over night period from 2000 to 0800 hours.0800 hours.
Date (2001)
Time zone Mean SO2-
4 (µg/m3 )
Se conc. (ng/m3 )
January 9
08:00-10:00 19.02 3.55
12:00-13:15 17.32 2.05
January 10
00:00-02:00 18.64 3.46
08:00-10:00 10.63 3.4
12:00-13:00 27.84 4.02
January 11
00:00-01:00 13.9 0.95
08:00-09:45 8.8 1.87
Summary of 5-min aerosol measurements at Lahore, Pakistan, during January 2001
Concentration (µg/m3) of black carbon at Lahore
Date(2005)
Min.BC
Max. BC
Avg. BC
Nov 21 1.6 46.1 14.3Nov 22 6 54.4 18.2Nov 23 3.7 52.8 15.8Nov 24 4.4 38.3 16.5Nov 25 3.2 55.2 12.1Nov 26 4.7 58.8 21.2
Nov 27 11.4 45 21.4
Nov 28 4.8 52.4 14.3
Nov 29 1.5 40.4 10.8
Nov 30 1.7 34.7 12
Dec 01 2.1 57.9 20.9
Dec 02 3.1 68.7 26.3
Dec 03 2.2 56.7 21.4
Dec 04 3.3 51.4 19.5
Dec 05 3.1 57.6 15.9
Dec 06 2.1 76.3 20.7
Concentration (µg/m3) of black carbon at Lahore
STUDY 4Nov. 21 2005 to Dec. 9, 2005
0102030405060708090
100
21-N
ov-0
5
22Nov
.05
23Nov
.05
24Nov
.05
25Nov
.05
26Nov
.05
27Nov
.05
28Nov
.05
29Nov
.05
30Nov
.05
1-Dec
-05
2-Dec
-05
3-Dec
-05
4-Dec
-05
5-Dec
-05
6-Dec
-05
7-Dec
-05
8-Dec
-05
BC
(u
g/m
3)
0
50
100
150
200
250
300
350
400
Mas
s (u
g/m
3)
BC (µg/m3)
MASS (µg/m3)
Time series showing filter mass and BC Concentrations in Lahore, Pakistan
CITY YEAR BLACK CARBON
Kanpur, India
(Tripathi et al)
2005 12.3
Five cities of Bangladesh (Salam et al)
2003 10.1 to 41.3 (EC)
Beijing, China (He at al) 2001 and 2004 8.1 (EC)Measurement of EC in other cities in China by various groups.
2003, 2005, 2006 4.7 to 11.8 (EC)
Mumbai, India (Venkataraman)
2002 12.5 (EC)
Dhaka 2001 22
Lahore 2005 21.7
New York 2002 <2
London 1995 2.3
Concentrations (ug/m3) of Black Carbon/Elemental Carbon in
Metropolitan Areas
STUDY 1January 1-5 1999
SOURCE EVALUATION OF CHEMICAL SPECIES
Application of Tracer technique
STUDY 225 December 1999 to 8th January 2000
0
20
40
60
80
100
120
140
25 27 29 31 2 4 6 8
December 1999-January 2000
Con
c. N
O3,
Se,
As
in u
g/m
3
0
20
40
60
80
100
120
140
Con
c. S
O4
in u
g/m
3
NO-3 (µg/m³)AsX 1000 (µg/m³)SeX1000 ( µg/m³)SO-24 (µg/m³)
0
10
20
30
40
50
60
70
80
90
100
Jan.1 Jan.1 Jan.2 Jan.2 Jan.3 Jan.3 Jan.4 Jan.4 Jan.5
con
c. N
O3
(ug
/m3)
, S
e, S
b,
As
(ng
/m3)
0
20
40
60
80
100
Co
nc.
SO
4 in
ug
/m3
Se *2
NO3 -
Sb
As
SO4-2
Concentrations in ug/m3 of SO42- , NO3
- , Se, As, and Sb in 12 hour samples at Lahore, Pakistan.
Five-min aerosol concentrations of (a) SO4 -2 (nmoles/m3) and (b) Se (pmoles/m3) at Lahore, Pakistan on January 9, 2001. The inverted solid triangles in (b) represents the detection limit
for Se is approx. 20(pmoles/m3). The SO4 -2 /Se ratios are shown in (c).(L. Husain et al 2004)
STUDY 3January 9-11 2001
In January 2001 the sampling interval was 5 min. In January 2001 the sampling interval was 5 min.
Sulfate was good correlated with Se and not with any element indicating their common source, most likely coal combustion
The SO4/Se ratios vary from ~1800 to 10,000 with a mean of 4070 are in the range typically observed at sites in the US and indicative of substantial contributions to sulfate concentration due to the oxidation of SO2.
The sulphate/Se ratio were suggestive of longe-range transport from several hundred kms
Application of Tracer technique
STUDY 1January 1-5 1999
S.No. Species
Factor
1 2 3
1 Fe 0.976
2 Sc 0.973
3 Cr 0.966
4 Sb 0.985
5 As 0.898
6 Zn 0.870
7 SO42- 0.876
8 Se 0.875
9 NO3- -0.603 0.701
Rotated Factor Analysis of Aerosol Data
Factor loadings less than 0.4 have been omitted.
Statistics analysis
S.No. Species 1 2 3 4
1 Al 0.980
2 Mg 0.977
3 Fe 0.967
4 Co 0.963
5 Cr 0.952
6 Mn 0.935
7 Ca 0.923
8 Ni 0.695 0.573
9 As 0.522 0.590 0.414
10 Pb 0.965
11 Sb 0.828 0.477
12 Zn 0.661
13 SO42- 0.958
14 NO3- 0.841
15 Se 0.951
16 Cu 0.469 0.470
Rotated Factor Analysis of Aerosol Data
Factor loadings less than 0.4 have been omitted
STUDY 225 December 1999 to 8th January 2000
Element Crustal concentration (ppm)
Aerosol concentration (ng/m3)
EFa R2
Al 81300 13392 1 1
Fe 50000 8176 0.99 0.940
Ca 36300 8696 1.45 0.819
Mn 950 177.1 1.13 0.895
Cr 100 22.1 1.34 0.90
Ni 75 16.5 1.33 0.91
Co 25 3.33 0.81 0.927
Zn 70 2333 202.3 0.096
Cu 55 843.9 93.2 0.253
Pb 13 846 395 0.020
Se 0.05 20.6 2498 0.011
As 1.8 10.8 36.5 0.388
Sb 0.2 13.3 405 0.015
Crustal Enrichment Factors of Trace Elements
aEnrichment factor =(Xair/Alair)(Xcrust/Alcrust)
STUDY 225 December 1999 to 8th
January 2000
The high levels of pollutants especially aerosol sulfate The high levels of pollutants especially aerosol sulfate concentration were observed may be due to local sources and concentration were observed may be due to local sources and extensive coal utilization of coal in Indian power plants. extensive coal utilization of coal in Indian power plants.
The high level of BC may be due local activities such as The high level of BC may be due local activities such as frequent garbage burning, diesel combustion, sugar mill and bick frequent garbage burning, diesel combustion, sugar mill and bick kilin activities around the city.kilin activities around the city.
A detailed scientific investigation of aerosol chemistry has A detailed scientific investigation of aerosol chemistry has been initiated at multiple sites in Lahore been initiated at multiple sites in Lahore
The control measures are required to be placed because of The control measures are required to be placed because of potential threat to the inhabitants of the region where millions of potential threat to the inhabitants of the region where millions of people live. people live.
Conclusion and Future plansConclusion and Future plans