High Ozone Concentrations in Nonurban Atmospheres - American

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15

High

Ozone

Concentrations

in

Nonurban

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Atmospheres

LYMAN A. RIPPERTON, JOSEPH E. SICKLES, W. CARY EATON, CLIFFORD E. DECKER, and WALTER D. BACH Research Triangle Institute, Research Triangle Park, N. C. 27711

The N a t i o n a l Ambient Air Q u a l i t y Standard f o r photochemical oxidant(1) was set in 1971 as

178

REMOVAL

O F TRACE CONTAMINANTS F R O M

T H E AIR

Θ ΚΑΝΕ, ΡΑ. Δ COSHOCTON, OHIO /

^Δ ^Δ-Λ

· LEWISBURG,W. VA.

ε οίο α. ο ο. χ οΖ Q Ο lu

w

Ζ

£

Θ—Ο—©·

g ËJ005I

J 0000 0200 0400 0600 0800

1000

I

I

L

1200

1400

1600

J 1800

L

2000 2200

0000

TIME OF DAY (EDT)

Figure

3.

Mean

diurnal

nitrogen tember

dioxide

concentrations,

June

26-Sep-

30,1973

FLIGHT DATE-9/11/73 I - 900'

ABOVE TERRAIN

Δ- GROUND ELEVATION

PPM

EDT

.045

τ

13©

.047

4

1325

.076

4- 1327

.086 -J- 1329

.093 .091

1335

Δ2301* LEWISBURG, W. VA. STATION DATA PPM HOUR .093 1315 .095

1330

.097

1345

.098 .100

1400 1415

Figure

4.

Vertical ozone measurements, September 11,1973

Deitz; Removal of Trace Contaminants from the Air ACS Symposium Series; American Chemical Society: Washington, DC, 1975.

15.

RiPPERTON E T A L .

High

Ozone

Concentrations

179

I t s h o u l d be noted a l s o t h a t t h e l a r g e p e r c e n t o f time t h a t t h e h i g h c o n c e n t r a t i o n s e x i s t e d and t h e p e r i o d o f t i m e ( n e a r l y f o u r months) t h a t h i g h c o n c e n t r a t i o n s were observed argues a g a i n s t a s t r a t o s p h e r i c o r i g i n o f t h e ozone r e p o r t e d i n t h i s s tudy. A l t h o u g h o n l y n i n e h y d r o c a r b o n samples were t a k e n a t t h e s t a t i o n s i n t h e c o u r s e o f t h e 1973 s t u d y , a c e t y l e n e was f o u n d i n a l l o f them, a t c o n c e n t r a t i o n s r a n g i n g f r o m 2 t o 63 p a r t s p e r b i l l i o n (ppb). I t i s w e l l known t h a t a c e t y l e n e h a s no known sources other than anthropogenic.(6) The CO c o n c e n t r a t i o n s i n t h e s a m p l e s r a n g e d f r o m 0.27 t o 0/46 ppm. A l t h o u g h n a t u r a l b a c k g r o u n d v a r i e s , i t i s g e n e r a l l y c o n s i d e r e d t o r a n g e b e t w e e n .08 t o .12 ppm. T h e s e d a t a i n d i c a t e t h e p r e s e n c e o f a n t h r o p o g e n i c pollution. The m e a s u r e d N O 2 c o n c e n t r a t i o n s were l o w , 0.005 t o 0.030 ppm, b u t a r e s t i l l g r e a t e r t h a n t h o s e c o n s i d e r e d a s b a c k g r o u n d , a b o u t 0.008 ppm. T h i s i s a n o t h e r i n d i c a t i o n o f a n t h r o p o genic sources. T h e s e d a t a r e v e a l t h e c o n s t a n t p r e s e n c e o f some a n t h r o p o g e n i c p o l l u t i o n w h i c h r e f u t e s t h e argument t h a t t h e s y n t h e s i s o f h i g h c o n c e n t r a t i o n s o f O 3 i s accomplished from n a t u r a l precursors only. I t s h o u l d be p o i n t e d o u t t h a t n a t u r a l e m i s s i o n s o f b o t h o r g a n i c v a p o r s and o f o x i d e s o f n i t r o g e n ( 7 ) o c c u r and t h e s e w i l l e n t e r i n t o t h e ozone g e n e r a t i v e p r o c e s s e s and p a r t i c i p a t e i n t h e same k i n d s o f p h o t o c h e m i c a l r e a c t i o n s a s t h e i r a n t h r o p o g e n i c counterparts.(8) The t r a n s p o r t o f O 3 , e s p e c i a l l y a l o f t , w i t h i n a f e w t h o u s a n d f e e t o f , b u t o u t o f touch w i t h , t h e ground, has been demonstrated. (9) However, t h e f a c t t h a t a l o c a t i o n l i k e I n d i o ( p o p u l a t i o n a b o u t 14,000) c a n e x c e e d t h e NAAQS more f r e q u e n t l y t h a n a n y o t h e r sampling s i t e i n C a l i f o r n i a ( 1 0 ) (e.g., Los Angeles, R i v e r s i d e ) i s c l e a r p r o o f t h a t O 3 s y n t h e s i s does n o t s t o p a t t h e c i t y l i m i t s b u t c o n t i n u e s a s t h e p h o t o c h e m i c a l s y s t e m t r a v e l s downwind. I f i t i s a d m i t t e d t h a t t h e O 3 measured i n h i g h c o n c e n t r a tions i n our f i e l d synthesized i n the troposphere, the l a r g e q u e s t i o n t h a t remains i s : i f t h e p r e c u r s o r s a r e n o t a l l n a t u r a l , w h e r e do t h e y come f r o m a n d d o e s a n t h r o p o g e n i c p o l l u t i o n h a v e a s p e c i a l r o l e i n g e n e r a t i n g t h e h i g h nonurban c o n c e n t r a t i o n s o f 0 ? A l t h o u g h F i g u r e 6 shows t h a t t h e t r a j e c t o r i e s o f a i r a r r i v i n g a t K a n e , P e n n s y l v a n i a i n t h e summer o f 1973 w h i c h c o u l d b r i n g h i g h c o n c e n t r a t i o n s o f O 3 , more t r a j e c t o r i e s f r o m t h e same l o c a t i o n s n o t e d o n t h e map h a d l o w c o n c e n t r a t i o n s o f O 3 ( i . e . , NO + 0

0 + 0 +M—>0 +M 2

NO + 0

3

3

-> N0 + 0

2

No Net 0

3

2

NO O x i d a t i o n (Non-0j —) 0

NO + R00 —> N0 + R02

0 0 RCOO* + NO —>• N0 + RCO* 2

H0 * + NO —> N0 + Η0· 2

2

One 0^ Netted f o r Each NO Oxidized P e r o x y - r a d i c a l Formation RH + -OH —>• R* + H 0 2

0 Ο RCH + ·0Η — * RC- + H 0 2

R- + 0

— * ROO*

2

0

Ο

RC* + 0

R C 0 2

°*

Selected Hydroxyl R a d i c a l Formation Schemes HO 1.

NO + N0 -=—> 2HONO 2

HONO + hV —>• N0 + ·ΟΗ 0 2

2.

H C=0 + hV —>• Η· + H O 2

Η· + 0

2

— • Η00·

Ο H

0

+

C

HC* +02"-* ° " ° Η00· + NO —y NO + ·0Η 3.

o

3

+ hv

ο oh)) + o

2

H 0 + 0("h>) —> 2·0Η 2

Table 2.

Selected Reactions Involved i n Ozone Generation

Deitz; Removal of Trace Contaminants from the Air ACS Symposium Series; American Chemical Society: Washington, DC, 1975.

15.

High

RIPPERTON E T A L .

Ozone

Concentrations

185

kinds o f r e a c t i o n s a r e i n v o l v e d i n generating the O 3 i n the nonurban areas t h a t a r e a l s o o p e r a t i v e i n t h e urban atmosphere, t h i s w i l l be more a m a t t e r o f r e l a t i v e r a t e s t h a n o f new r e a c t i o n s . F i e l d and chamber measurements o f s t a b l e i n t e r m e d i a t e s i n t h e HC-N0 -03-hV s y s t e m a r e e m i n e n t l y d e s i r a b l e f o r p r o p e r i n t e r p r e ­ t a t i o n o f such c h e m i c a l r e l a t i o n s h i p s . x

Conclusions A i r i n t h e a r e a o f s t u d y ( O h i o , P e n n s y l v a n i a , M a r y l a n d and West V i r g i n i a ) i n w h i c h h i g h O 3 c o n c e n t r a t i o n s w e r e g e n e r a t e d had e v i d e n c e o f a n t h r o p o g e n i c c o n t a m i n a t i o n ( o t h e r t h a n O 3 ) . T h i s a i r a p p e a r e d n o t t o come a l w a y s f r o m a s p e c i f i c g e o g r a p h i c a l location. The O 3 g e n e r a t i v e c a p a c i t y o f t h e s y s t e m i s j u d g e d by t h e a u t h o r s t o b e a n a i r mass c h a r a c t e r i s t i c . The O 3 i s p o s t u l a t e d a s b e i n g g e n e r a t e d i n a r e l a t i v e l y "spent photochemical system." The s y s t e m i s r e f e r r e d t o a s " r e ­ l a t i v e l y spent" because there i s evidence o f continuous i n j e c t i o n o f a s m a l l amount o f p o l l u t i o n . The a u t h o r s h a v e p r e s e n t e d a rough paradigm i n which t h e c a p a c i t y o f t h e s o - c a l l e d spent pho­ t o c h e m i c a l system t o generate O 3 from l o w c o n c e n t r a t i o n s o f N 0 ( i . e . , 5-20 ppb N 0 ) i s due t o a r e d u c e d c a p a c i t y o f t h e s y s t e m t o d e s t r o y O 3 a n d a n enhancement o f t h e r a t e o f O 3 a c c u m u l a t i o n due t o r e a c t i o n s i n v o l v i n g s t a b l e i n t e r m e d i a t e s w h i c h p r o v i d e a s o u r c e o f ·0Η r a d i c a l s . The r o l e o f c o n t a m i n a t e d c i t y a i r i s t o p r o v i d e a source of t h e s t a b l e i n t e r m e d i a t e s g r e a t e r than would occur i n nature. X

X

Literature Cited 1. 2. 3.

4.

5.

6.

Federal Register (April 3 0 , 1 9 7 1 ) , 36 ( N o . 84), 8187. J u n g e , C . Ε., "Air C h e m i s t r y and Radioactivity," pp. 37-59, A c a d e m i c Press, New Y o r k ( 1 9 6 3 ) . Research Triangle Institute, "Investigation o f Ozone and Ozone Precursor C o n c e n t r a t i o n s a t N o n u r b a n Locations in t h e Eastern United States," R e s e a r c h Triangle P a r k , N.C. ( 1 9 7 4 ) . (Also issued as E n v i r o n m e n t a l Protection Agency Report No. 450/3-74-034.) Richter, H . G., "Special Ozone and O x i d a n t Measurements i n the Vicinity o f Mount S t o r m , West Virginia," RTI Task No. 3, NAPCA C o n t r a c t N o . 7 0 - 1 4 7 , R e s e a r c h Triangle P a r k , N.C. (1970). Research Triangle Institute, "Investigation o f H i g h Ozone Con­ centrations in the Vicinity o f Garrett C o u n t y , M a r y l a n d and Preston County, West Virginia," R e s e a r c h Triangle P a r k , N.C. (1973). ( A l s o issued as E n v i r o n m e n t a l Protection Agency Report No. 450/3-75-036.) Miller, S. Α., "Acetylene: Its Properties, M a n u f a c t u r e and Uses," A c a d e m i c Press, New Y o r k ( 1 9 6 5 ) .

Deitz; Removal of Trace Contaminants from the Air ACS Symposium Series; American Chemical Society: Washington, DC, 1975.

186

7.

8.

9.

10. 11.

12.

13.

R E M O V A L O F T R A C E C O N T A M I N A N T S F R O M T H E AIR

Robinson, E . and R. C. Robbins, "Sources, Abundance and Fate of Gaseous Atmospheric Pollutants," Stanford Research Insti­ tute P r o j e c t PR-6755, prepared f o r American Petroleum Insti­ tute, New York (1968). R i p p e r t o n , L . A . and D. Lillian, "The E f f e c t of Water Vapor on Ozone Synthesis in the P h o t o - o x i d a t i o n of Alpha-Pinene," J . Air Poll. C o n t r o l Assoc. (1971) 21:629-635. L e a , D. Α . , "Vertical Ozone Distribution in the Lower Tropo­ sphere Near an Urban Pollution Center," J . A p p l . Meteor. (1968) 7:252-267. Maga, John, California Air Resources Board, personal commu­ nication. Niki, H., C. E . Daby, B . Weinstock, "Mechanics of Smog For­ mation," p r e p r i n t of Fuel Science Department, Ford Motor C o r p o r a t i o n , presented 101st N a t i o n a l Meeting, American Chemical S o c i e t y , Los Angeles, California (1971). Fox, D. L., R. Kamens, Η. E . Jeffries, "Photochemical Smog Systems: E f f e c t s of Dilution on Ozone Formation," Science (1975) 188:1113-1114. Demerjian, K . L., J . A . K e r r , J . G. C a l v e r t , "Mechanism of Photochemical Smog Formation," in Advances in Environmental Science and Technology, Vol. 4, pp. 1-262, J. N . Pitts, R. M e t c a l f , eds, John W i l e y , New York (1974).

Deitz; Removal of Trace Contaminants from the Air ACS Symposium Series; American Chemical Society: Washington, DC, 1975.