analysis of voc to nox ratios in the south coast air basin
DESCRIPTION
California Environmental Protection Agency. Air Resources Board. Analysis of VOC to NOx Ratios in the South Coast Air Basin. Eileen McCauley Research Division . Methodology. TNMOC from PAMS used for VOC concentration 3 hour canister samples C2 - C10 hydrocarbons - PowerPoint PPT PresentationTRANSCRIPT
Analysis of VOC to Analysis of VOC to NOx Ratios in the NOx Ratios in the South Coast Air South Coast Air
BasinBasin
Eileen McCauleyResearch Division
Air Resources Board
California Environmental Protection Agency
MethodologyMethodology
TNMOC from PAMS used for VOC concentration– 3 hour canister samples– C2 - C10 hydrocarbons
NOx concentrations are averages of 3 one hour average
AzusaAzusa
Azusa 1995-1998All VOC/NOx data
0
5
10
15
20
25
0:00 4:00 8:00 12:00 16:00 20:00 0:00
Start Time for 3 hr sample
ppbC
/ppb
Weekday Weekend
BanningBanning
Banning 1997-1998All VOC/NOx data
0
5
10
15
20
25
4:00 8:00 12:00 16:00 20:00 0:00
Start Time for 3 hr sample
ppbC
/ppb
Weekday Weekend
8:00 Weekday value of 33
BurbankBurbank
Burbank 1998 (+ 9 days in 1997)All VOC/NOx data
0
5
10
15
20
25
4:00 8:00 12:00 16:00 20:00 0:00
Start Time for 3 hr sample
ppbC
/ppb
Weekday Weekend
HawthorneHawthorne
Hawthorne 1997-1998All VOC/NOx data
0
5
10
15
20
25
4:00 8:00 12:00 16:00 20:00 0:00
Start Time for 3 hr sample
ppbC
/ppb
Weekday Weekend
17:00 Weekday values of 28 and 36
LA North MainLA North Main
LA N. Main 1995-1998All VOC/NOx data
0
5
10
15
20
25
0:00 4:00 8:00 12:00 16:00
Start Time for 3 hr sample
ppbC
/ppb
Weekday Weekend
UplandUpland
Upland 1995, 1997, 1998All VOC/NOx data
0
5
10
15
20
25
0:00 4:00 8:00 12:00 16:00 20:00 0:00
Start Time for 3 hr sample
ppbC
/ppb
Weekday Weekend
Azusa Average Azusa Average VOC/NOxVOC/NOx
Azusa 1995-1998Average VOC/NOx
0.00
2.00
4.00
6.00
8.00
10.00
12.00
0:00
2:00
3:00
5:00
6:00
8:00
9:00
11:00
12:00
14:00
15:00
17:00
18:00
20:00
21:00
23:00
Start Time for 3 hr sample
ppbC
/ppb
Weekday Weekend
Banning Average Banning Average VOC/NOxVOC/NOx
Banning 1997-1998Average VOC/NOx
0.0
2.0
4.0
6.0
8.0
10.0
12.0
2:00 5:00 8:00 11:00 14:00 17:00 20:00 23:00
Start Time for 3 hr sample
ppbC
/ppb
Weekday Weekend
Burbank Average Burbank Average VOC/NOxVOC/NOx
Burbank 1998 (+ 9 days in 1997)Average VOC/NOx
0.00
2.00
4.00
6.00
8.00
10.00
12.00
2:00 5:00 8:00 11:00 14:00 17:00 20:00 23:00
Start Timefor 3 hr sample
ppbC
/ppb
Weekday Weekend
Hawthorne Average Hawthorne Average VOC/NOxVOC/NOx
Hawthorne 1997-1998Average VOC/NOx
0.00
2.00
4.00
6.00
8.00
10.00
12.00
2:00 5:00 8:00 11:00 14:00 17:00 20:00 23:00
Start Time for 3 hr sample
ppbC
/ppb
Weekday Weekend
LA North Main LA North Main Average VOC/NOxAverage VOC/NOx
LA N. Main 1995-1998Average VOC/NOx
0.00
2.00
4.00
6.00
8.00
10.00
12.00
5:00 12:00
Start Time for 3 hr sample
ppbC
/ppb
Weekday Weekend
Upland Average Upland Average VOC/NOxVOC/NOx
Upland 1995, 1997, 1998Average VOC/NOx
0.00
2.00
4.00
6.00
8.00
10.00
12.00
0:00
2:00
3:00
5:00
6:00
8:00
9:00
11:00
12:00
14:00
15:00
17:00
18:00
20:00
21:00
23:00
Start Time for 3 hr sample
ppbC
/ppb
Weekday Weekend
Percent Weekend Percent Weekend IncreaseIncrease
Percent Increase in Weekend VOC/NOx
-40
-30
-20
-10
0
10
20
30
40
50
60
0:00 3:00 6:00 9:00 12:00 15:00 18:00 21:00
Start Time for 3 hr Samples
% In
crea
se
Azusa Banning Burbank Hawthorne N Main Upland
THC vs PAMSTHC vs PAMS
Time Az Bn Bb Hw NM Up5:00 1.30 1.54 1.08 1.34 1.28 1.486:00 1.51 1.358:00 1.40 1.06 1.33 1.00 1.389:00 1.45 1.06
11:00 1.41 2.02 1.20 1.11 1.3612:00 1.39 1.23 1.29
Weekday TNMOC/Weekend TNMOC
Both the 8202 and Beckman THC instruments observed approx.10 - 20% weekend decrease.
Is there a change in VOC inventoryon the weekend?
Recommendations:Recommendations:
Calculate VOC/NOx ratios with carbonyls data and/or correction to total
18 months of hourly total VOC measurements at several sites in SOCAB
Investigate possible differences in weekday / weekend data of THC and PAMS