PROCEEDINGS
FOURTH US-JAPAN CONFERENCE
ON
PHOTOCHEMICAL AIR POLLUTION
February 28-March 2, 1978
East-West Center
Honolulu, Hawaii
US_ DELEGATION
Dr. A.P. Altshuller, Chairman
Environmental Sciences Research
Laboratory
USEPA
Dr. B. Qimitriades
Environmental Sciences Research
Laboratory
USEPA
JAPANESE DELEGATION
Mr. Shoji Takeno, Chairman
Environment Agency
Mr. Senro Imai
Environment Agency
Dr. Michio Okuda
National Institute for
Environmental Studies
COMPILED BY
ENVIRONMENTAL SCIENCES RESEARCH LABORATORY
U.-S. ENVIRONMENTAL PROTECTION AGENCY
RESEARCH TRIANGLE PARK, N.C. 27711 USA
-------
PROCEEDINGS
FOURTH US-JAPAN CONFERENCE
ON
PHOTOCHEMICAL AIR POLLUTION
February 28-March 2,
East-West Center
Honolulu, Hawaii
1978
US DELEGATION
Dr. A.P. Altshuller, Chairman
Environmental Sciences Research
Laboratory
USEPA
Dr. B. Dimitriades
Environmental Sciences Research
Laboratory
USEPA
JAPANESE DELEGATION
Mr. Shoji Takeno, Chairman
Environment Agency
Mr. Senro Imai
Environment Agency
Dr. Michio Okuda
National Institute for
Environmental Studies
COMPILED BY
ENVIRONMENTAL SCIENCES RESEARCH LABORATORY
U.S. ENVIRONMENTAL PROTECTION AGENCY
RESEARCH TRIANGLE PARK, N.C. 27711 USA
-------
Printed in August 1978
by the
US Environmental Protection Agency
Research Triangle Park, N.C. 27711 USA
PROCEEDINGS—PAGE i
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
PREFACE
This conference is a part of the activities fostered under the
US-Japan Environmental Agreement negotiated between the two countries
in August, 1975. Purpose of the Environmental Agreement and associated
activities is to develop environmental awareness and to promote coopera-
tion between the US and Japan in effort to reduce air pollution. Co-
operative activities pertaining to photochemical air pollution were
commenced in June, 1973, when the First US-Japan Conference on Photo-
chemical Air Pollution was held in Tokyo, Japan. The Second Conference
was held in Tokyo also, in November, 1975; the Third Conference took
place in Research Triangle Park, N.C., in September 1976.
PROCEEDINGS—PAGE ii
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
TABLE OF CONTENTS
Introduction vi
Agenda of Meeting viii
Acknowledgment x
xi i
Joint Communique
Technical Papers
1. Legislative Developments in Photochemical
Pollution Area (Altshuller) 1
2. NO and HC Control Measures in
Ja$an (Takeno) 9
3. Scientific Issues Related to
Oxidant Control (Dimitriades) 77
4. Trend of Photochemical Oxidants
in Japan (Imai) 85
5. Emissions to Oxidant and N0~ Air Quality
Relationships (Dimitriades) 125
6. Photochemical Ozone Formation in Propylene-
Nitrogen Oxide-Dry System (Okuda) 133
7. Photochemical Sulfate and Nitrate
Research in the US (Altshuller) 171
8. Sulfate, Nitrate and Nitric Acid Research
in Kanto Area (Okuda) 181
PROCEEDINGS—PAGE iv
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
INTRODUCTION
Dr. Altshuller, head of the US Delegation, welcomed the delegates and
discussed briefly the exchange in correspondence of mutual interest. Such
interests are on recent legislative and research developments in the areas
of the oxidant, sulfate and nitrate problems and constitute the subjects of
this Fourth Conference.
PROCEEDINGS—PAGE vi
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
AGENDA
FOURTH US-JAPAN CONFERENCE
ON
PHOTOCHEMICAL AIR POLLUTION
East-West Center
Honolulu, Hawaii
February 28 - March 2, 1978
Session Chairman;
Tuesday, February 28, 1978
10:00 -- 10:30 a.m. Welcome
Introduction of Participants
Election of Session Chairmen
Approval of Conference Program
Refreshments
10:30 -- 11:00 a.m.
11:00 — 12:00 N
12:00 — 1:00 p.m.
1:00 -- 3:00 p.m.
3:00 — 4:00 p.m.
Legislative Developments in
Photochemical Pollution Area
Lunch
NO and HC Control Measures
inxJapan
Scientific Issues Related
to Oxidant Control
Dr. Altshuller
A.P. Altshuller
A.P. Altshuller
U.S. EPA
S. Takeno
Japan Environment
Agency
B. Dimitriades
U.S. EPA
PROCEEDINGS—PAGE viii
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
Wednesday, March 1. 1978
Session Chairman: Mr. Takeno
9:00 — 10:00 a.m.
10:00 -- 10:30 a.m.
10:30 — 12:00 N
12:00 -- 1:00 p.m.
1:00 — 2:00 p.m.
2:00 — 2:30 p.m.
2:30 — 4:00 p.m.
Trend of Photochemical
Oxidants in Japan
Refreshments
Emissions to Oxidant and
N02 Air Quality Relationships
Lunch
Photochemical Ozone Formation in
Propylene-Nitrogen Oxide-Dry
System
Refreshments
Photochemical Sulfate and
Nitrate Research in the US
S. Imai
Japan Environment
Agency
B. Dimitriades
U.S. EPA
M. Okuda
Japan National
Institute for
Environmental Studie
A.P. Altshuller
U.S. EPA
Thursday, March 2, 1978
9:00 — 10:00 a.m.
Session Chairman: Dr. Altshuller
10:00 — 10:30 a.m.
10:30 — 12:00 N
12:00 — 1:00 p.m.
1:00 « 2:00 p.m.
2:00 — 3:30 p.m.
Sulfate, Nitrate and Nitric
Acid Research in Kanto Area
M. Okuda
Japan National
Institute for
Environmental Studie
Refreshments
Discussion
Lunch
Session Chairman: Mr. Takeno
Plans for Future Activities
Preparation of Joint Communique
Conclusion of Meeting
PROCEEDINGS—PAGE ix
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
ACKNOWLEDGMENT
We wish to express our greatest appreciation to Dr. R. Carpenter
and Mr. H. Ajiroji for the time and effort they took to assist us in
organizing this Conference and in locating interpreters. The success
of the Conference was largely due to the excellent facilities and ser-
vices made available to the Conferees by the East-West Center of the
University of Hawaii through the efforts of Messrs. Carpenter and
Ajiroji. We are grateful.
A.P. Altshuller
Chairman of the host
US Delegation
PROCEEDINGS—PAGE x
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
JOINT COMMUNIQUE
The Fourth US-Japan Conference on Photochemical Air Pollution was
held in Honolulu, Hawaii, on February 28 - March 2, 1978, at the
premises of the EAST-WEST Center.
The Japanese delegation included: Mr. Shoji Takeno, General Chair-
man, Environment Agency; Dr. Michio Okuda, National Institute for
Environment Studies, and Mr. Senro Imai, Environment Agency.
The United States delegates were: Dr. A. P. Altshuller, General
Chairman, Environmental Protection Agency; and Dr. B. Dimitriades,
Environmental Protection Agency.
Discussions were centered around subjects agreed upon by the two
delegations during the Third Conference held in September 8-10,
1976 and in subsequent communications exchanged by. the two dele-
gations. Such subjects included:
— NO and HC Control Measures in Japan
— Trends of Photochemical Oxidants, in Japan
— Photochemical Ozone Formation in Propylene-Nitrogen Oxide
Dry Air System (Smog Chamber Studies)
— Sulfate, Nitrate and Nitric Acid Research in Kanto Area
— Legislative Developments in Photochemical Pollution Area
in the U.S.
Scientific Issues Related to Oxidant Problem in the U.S.
— Emissions to Oxidant/Ozone Air Quality Relationships in
the U.S.
— Recent U.S. Studies on Ambient NO- Problem
Photochemical Sulfate and Nitrate Research in the U.S.
Highlights of the presentations and discussions held in the Con-
ference and conclusions reached are summarized as follows:
1. The two delegations expressed general agreement with the
strategies adopted by the two countries for photochemical
pollution control with respect to both NO and HC.
2. Being aware of the importance to prevent Ihe adverse health
effects by NO2, both Japan and U.S. are now enforcing
nationwide NO emission controls on both mobile and sta-
tionary sources to reduce ambient N02 concentrations.
3. To reduce ambient oxidant concentrations, Japan is pres-
ently enforcing organic emission controls on mobile sources
only; controls on stationary sources are contemplated.
PROCEEDINGS—PAGE xii
Fourth US-Japan Conference on
1 Photochemical Air Pollution
-------
4. Data available suggest that on-rgoing controls in Japan
on particulate and SO- emissions resulted in reduction
of ambient sulfates. The impact, however, of the more
recently initiated NOx controls on ambient N02 and ni-
trates has not been detected yet. Therefore, it is
recognized that Japan as well as the U.S. have to make
an effort to verify such interpretations of the emissions
and air quality trends through more systematic and in-
depth analyses. In this sense, the need of further
research especially on photochemical nitrates in both
countries is recognized.
5. The delegates agreed to exchange additional information
on subjects discussed, including smog chamber data for
modeling use, U.S. criteria documents (drafts) for ozone,
oxidants and for N02, and other requested EPA reports.
6. The delegates agreea on a continuing cooperative program
with immediate and specific interest in exchange of sci-
entific evidence on
(a) emission and air quality trends and their inter-
pretation in terms of impact of emission control
on ambient air quality;
(b) the chemistry and transport processes associated
with the ambient sulfate and nitrate problems;
(c) question of monitoring station siting;
(d) smog chamber methodology.
Overall, it was agreed to continue the effort to generate and ex-
change scientific data including possible exchange of scientific
personnel.
It was tentatively agreed to call the next meeting in 1979 in Tokyo,
Dr. A. P. Altslu
General Chairman
U.S. Delegation
Mr. Shoji Takeno
General Chairman
Japanese Delegation
Date: March, 1978
PROCEEDINGS—PAGE xiii
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
LEGISLATIVE DEVELOPMENT IN PHOTOCHEMICAL POLLUTION AREA
presented by A.P. Altshuller
Environmental Protection Agency
United States
PROCEEDINGS--PAGE 1
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
LEGISLATIVE DEVELOPMENT IN PHOTOCHEMICAL POLLUTION AREA
The Clean Air Act Amendment, Public law 95-95 was enacted in August
1977. A number of provisions of this Act directly relate to photochemical
pollution. Section 106 concerns air quality standards. It requires
review of all existing standards before December 31, 1989 with subsequent
review at 5 year intervals. The National Ambient Air Quality Standard
for Oxidants is currently under review. The air quality criteria document
has been rewritten and reviewed by technical experts, revised, and has been
submitted and discussed with EPA's science advisory board. At the same time,
a working group on Photochemical Oxidants was set up, concerned with the
standard for oxidants. The preparation of the criteria document lies with
the Research and Development Office of our agency, but the actual development
of the standard itself is the responsibility of the Office of Air Quality
Planning and Standards. This office sets up a working group which contains
representatives from all interested portions of the agency. The working
group uses the criteria document draft as the scientific input to its work,
but it is then concerned with the form of the standard itself.
After the working group has established recommendations, there are
public hearings held concerning these, and the first of these was held
a few weeks ago in Washington. These hearings allow representatives from
our state and local governments and representatives of industry to comment
on the proposals.
PROCEEDINGS—PAGE 3
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
To get to the technical recommendations themselves, the first of these
is that the standard be redesignated from oxidants to ozone. The reasons
for this are several. The most important is that the health information
that we have obtained in recent years from toxicological experiments, both
animal and human is for ozone, not oxidants. The measurement technique for
the original standard (chenri luminescence) was for ozone rather than for
oxidants. So, in view of the fact that the only additional scientific
data concerning oxidants concerned ozone and NO^, it is appropriate to
have an ozone standard. In the internal discussions of the working
group, as well as scientific materials discussed with experts, the question
came up as to whether it would be appropriate to set a separate standard
for PANs. The proposal is not to set a separate standard at this time
for PAN. The reasons for thinking it best not to set a separate standard
are several. First, we lack health information on the effects of PAN;
there has been little additional work in recent years. The only effect
which received some attention in past years was the effect of PANs on
eye irritation. But in our working group discussions, it was decided,
subject to reviewing this with health experts, not to consider eye
irritation as a health effect but as a nuisance, more of a welfare effect.
Although we do have measurement techniques for PAN, they have not, at least
in our experience, been acceptable for monitoring by local agencies because
of the scientific complexities of the methods.
PROCEEDINGS—PAGE 4
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
A third recommendation was to redefine the standard in a statistical
form, and fourthly, to retain the 1 hour averaging time for the standard.
Review of the health evidence suggests that the range of the standard
definitely lies between 8 and 15 pphm [ozone, 1 hour average]. There are
several problems in making a decision within this range of concentration
from the scientific standpoint. This is because we have no direct toxi-
cological results which demonstrate an effect within the range of 8-15 pphm.
On the other hand, the law in the U.S. is stated so as to protect not only
the average person but also individuals who are particularly sensitive
to the effects of ozone. As you know, one such group is asthmatics. One
cannot take individuals with serious asthma problems and expose them in
clinical chamber studies. The threshold effect from those subjects that
can be studied is between 15-25 pphm, but how do we estimate the threshold
for those who we cannot study, with severe asthma? We will probably main-
tain that the number of exceedances of the standard shall not exceed 1 per
year. This term "exceedance" now refers to a statistical-type approach.
There has been discussion and some investigation into the possibility that
unusual meteorological events, such as stratospheric intrusions of ozone
at ground level, could result in ozone levels above the standard. Estimating
the statistical probability of these occurrences is very difficult. Some
consideration has been given to the possibility of permitting a day of hourly
values above the standard to allow for rare meteorolgoical conditions.
[one day rather than one hour would be excluded] Based on those estimates
we can make, this would seem to provide an allowance for this sort of event
occurring at any given geographical location.
PROCEEDIN6S--PAGE 5
Fourth US-Japan Conference on
Photoqhemical Air Pollution
-------
Section 106 also contains the provision that not later than 1 year
after enactment a National Primary Ambient Air Quality Standard for N02
shall be promulgated. The wording suggests that a period of not more than
3 hours should be considered unless there is no significant evidence to
support the need for such a standard to protect public health. It was
believed that enough scientific evidence was available to proceed to pre-
pare a revised health criteria document for N02 and a draft criteria document
has been prepared for review. This document emphasizes health aspects
concerning the short term effects of NCL. This document and associated
standards must go through the same process described for oxidant and ozone.
It's believed that a standard will be proposed in the 1-3 hour range,
but one matter to be resolved is whether the adverse short term exposures
should be considered on a one-time or repeated basis. Here again, this
would strongly affect the statistical form of the standard as it is finally
promulgated. It is an intention to revise the entire N02 Criteria document
in all its aspects, and some discussion of other aspects on health are in
the present revision; but it is anticipated that these will be enlarged
upon later. The problem is partly associated with the deadline in the
Clean Ai'r Act of 1 year, so we're concerned with concentrating the efforts
on the health effects to meet what was considered the primary legal mandate
in the Act. It is clear, it follows, that understanding the role of mobile
and stationary sources in contributing through their emissions to producing
such short term NCL concentrations is a major concern. Unless we can
properly define the relationships between emissions and short term air
PROCEEDINGS—PAGE 6
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
quality for NCL, we will not be able to promulgate the standard after it
is written properly; and again, our colleagues at the Office of Planning
and Air Quality Standards are trying to assemble the technical information
related to this problem. Within the Act itself, there is a provision under
a section 202a which is closely related to the present discussion. This
requires that "the EPA administrator shall conduct a study of public health
implications of obtaining an emission standard of the oxides of nitrogen
of light-duty vehicles of 0.4 gm per vehicle mile, the cost and technical
capabilities of such a standard, and the need for such a standard to protect
the public health and welfare. The administrator shall submit a report to
the Congress together with recommendations not later than July !, 1980."
So, this provision reflects the continuing concern and controversy
whether the vehicles sold in the U.S. can meet the standard of 0.4 gm/mile,
taking into consideration deterioration, and fuel economy aspects which
we have to face in other laws in the U.S.
Turning to another major portion of this act which is concerned with
significant deterioration of air quality. This provision of the Act is
directed at preserving and protecting air quality in national parks,
wilderness areas, and similar type areas. Numerical provisions with
respect to concentration levels for S02 and TSP are already provided for
in the Act. However, it is important to note that within 2 years,
provisions must be promulgated to prevent deterioration by the other
criteria pollutants including photochemical oxidants and nitrogen oxides.
PROCEEDINGS—PAGE 7
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
Emphasizing the concern of our Congress about the effects of oxidants on
significant deterioration there is an added provision in section 169 in
that portion of the Act concerning significant deterioration. This
section requires a guidance document to include recommended strategies for
controlling photochemical oxidants on a regional or multistate basis. This
section represents the appreciation by our Congress of the transport of
oxidants, particularly ozone. The report must also include recommendations
for legislative change necessary to implement strategies for controlling
photochemical oxidants on a regional or multistate basis.
Another very interesting section of the Act provides for the establishment
of a National Commission on Air Quality. The composition of this commission
includes a number of important members of Senate and House committees
concerned with air pollution problems, as well as members of the public
appointed by the President by and with the consent of the Senate. This
would make this commission a very high level organization [not more than
1/3 of the public members may have any interest in any business or
activities regulated by this Act]. The law gives a long list of assignments
to the Commission concerned with oxidants and NO . For example, they are
A
asked to report on the technical capabilities of achieving or not achieving
the control levels for mobile and stationary sources for oxides and NO .
X
In doing this, they are supposed to consider the economy, energy, environ-
mental, and health aspects.
PROCEEDINGS—PAGE 8
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
N0¥ AND HC CONTROL MEASURES
/\
IN JAPAN
presented by S. Takeno
Environment Agency
Japan
PROCEEDINGS—PAGE 9
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
CONTENT_S_
Page
I. BASIC CONCEPT 1
II. BASIC CONCEPT OF NOx ABATEMENT SCHEME 1
(A) CONTROLS ON EMISSIONS FROM STATIONARY SOURCES .. 1
-------
I. BASIC CONCEPT
The basic concept of atmospheric Ox control measures in
Japan is to reduce the Ox concentration in the atmospheric
air to a level harmless to human health through the bilateral
reduction of NOx and HC.
As regards the NOx control measures, in particular, an
ambient air quality standard for NO_ has already been established
for the purpose of preventing the adverse effect of N02 on
human health, and all NOx control measures described in II (A)
are being conceived and implemented to achieve this standard.
Therefore, in Japan, there is an existing NO: target level
(daily average value: 0.02 ppm) and the basic Ox control
concept is based on this NOx control scheme and the HC control
scheme to be described in III.
II. BASIC CONCEPT OF NOx ABATEMENT SCHEME
(A) Controls on Emissions from Stationary Sources
1. General
With respect to stationary NOx sources, the Environ-
mental Quality Standard for NO- was established in May
1973, and, within the framework of this standard, the
1st stage regulation was enforced on large establishments
in August 1973, the 2nd stage regulation was enforced to
enlarge the scope of application in December 1975, and
- 1 -
PROCEEDINGS—PAGE 11
Fourth-US-Japan Conference on
Photochemical Air Pollution
-------
the 3rd stage regulation was enforced to apply the
emission standard to smaller establishments in June 1977.
Fig. 1 shows the NOx emission standards for the 3rd
regulation.
These emission standards are national minimum emission
standards based on the Air Pollution Control Law and are
applicable- to all areas in Japan, comprising the permissibl
emission concentrations determined for various types and
sizes of smoke-and soot-emitting facilities/ and the types
of fuel used.
Where the intended environmental quality level cannot
be achieved even though all the applicable facilities
adhere to these emission standards, additional stringent
emission standards are scheduled to be enforced by local
governments; and where the air pollution conditions are
not improved even by these stringent emission standards,
the total mass emission regulation in the area is
scheduled to be enforced, with the total permissible
emission in the area to achieve the ambient air quality
target calculated by means of pollution simulation models,
and this total permissible emission will be allocated to
all the plants within the area possessing smoke-and soot-
emitting facilities.
Such total mass emission regulation systems as this
are in force in Japan for SOx with the following basic
- 2 -
PROCEEDINGS—PAGE 12
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
concepts:
1) In contrast to the emission standard scheme and
the stringent emission standard scheme which are
applicable to individual smoke and soot-emitting
facilities, the total mass emission regulation standards
are applied to individual factories within the limit
determined from the total permissible amount within
the area. Therefore, the owners of smoke-and soot-
emitting facilities are at liberty to arrange the
facilities of the factories as long as the total
emission for the plant is kept within the permissible
amount. This means that despite very strict control
levels, the owners of the factories are able to satisfy
them by installing smoke-and spot-treatment equipment
without modifying all the plant facilities.
2) The total mass emission regulation standards to
be allocated to individual factories are sure to achieve
the ambient air quality goal using pollution simulation
models.
- 3 -
PROCEEDINGS—PAGE 13
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
Table 1. Tha 3rd Regulations Eataaion Standards for HOT
Dollera
Existing Facilities
Types of.
Gas combuaeieu
Solid natarlai
conbuadon
Others
' (Liquid coa-
buation)
Sincurlag
Furnace
Kacal E*»tisg
?uraac«
Patroleua Hue-
ing Furnace
<»»»».•«» rnlrtna
dea Turaaca
Cok* Furnace
Waata- Incinerator
7irtl1rl«i
(Unit: -
1.000 JS» h)
Over 200
100 -500
40-100
10 - 40
5-10
Ov*r 100
40 - 100
10 - 40
5-10
Over 1.000
200 - 1.000
100 - 500
40.- 100
10 - 40
5 - 10
Over 100
Up to 100
Over 100
40-100
10-40
5 - 10
Ores 100
40-100
10-40
3-10
Hew SCd Old Std
130 ppm 130 ppm
130 130
130 130
150 150
ISO
480* 600(750)
600(750) 600(750)
600(750) 600(750)
480
ISO 230(280)*
180(210) 230(280)*
190(210) 230(280)**
1.90(210) 190*(2SO)»
130(250) - (230)*«
220(280) -
160.
S70
160(200) 220
170(200) 220
!00 200
170(200)
170 210*
L70** 210*
180*** 180*
180(190)
480
350
Newly Built Fadlitiaa
(Bait: .
1.000 £>h)
OVBT 500
100 - 500
40 - 100
10-40
5-10
Up to 5
Ovar 100
40-100
10-40
5-10
Up to -2
Ovar 500
100 - 500
40 - 100
* 10-40
5-10
Up to 5
Ovar 100
Over 100
(Mrmlnfc, fair
Ovar 100
40 -100
10-40
5-10
Up to 5
Over 100
40 - 100
10-40
5-10
Up to 5
Over 100
Up to 100
Over 100
Up to 100
Ovar 40
Hew Std Old Std
60 ppm 100 ppm
100 100
100 130
130 130
150
150
400 480
400 480
400 480
400
400
130 150
150 150
150 150
150 150
180*
180*
220 -
200 ~ -
"flti"" T^iirBaea)"
100. 100
130(150) (ISO) 150
130(150) (ISO) 150
150*
180*
100,10" 100
39* 100
130 15O
ISO-
180-
250 250
350
170 200
.170
250
PROCEEDINGS—PAGE 14
Fourth US-Japan Conference on
Photochemical Air Pollution
— 4 —
-------
Remarks
(1) Reference to Boiler-Solid Material Combustion category,
marked * in the "existing" column shows 650 ppm for
ceiling'burner and 550 ppm for divided wall type.
( ) are applied for low-grade coal combustion burners.
(2) Reference to Boiler-Others (Liquid Combustion), ( )
in the "existing" column are applied for the ones
equipped with stack gas desulfurization facilities.
Marked * indicates excluding the ones equipped with
desulfurizer.
Mark ( )** are for crude oil combustion burners,
and the standards marked * in the "newly built
facilities" are applied from September 10, 1977.
(3) Reference to Sintering Furnace, "existing" does not
cover Pellet sintering furnaces.
(4) Reference to Metal Heating Furnaces, "existing" does
not cover the heating furnaces for welded steel pipe.
( ) are applied for heating furnaces of the radiant
tube type. Marked * in the "newly built" column
shows not including heating furnaces for welded steel
pipe. ( ) in the "newly built" column are applied
for radiant tube type heating furnaces. ( ) are
applied for heating furnaces for welded steel pipe.
(5) Marked * in. the "existing" column of Petroleum
Heating Furnace are not applied for Ethylene Resolving
- 5 -
PROCEEDINGS—PAGE 15
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
Furnaces, independent super-heating furnaces,
methanol refining furnaces and ammonium refining
furnaces. Marked ** are not applied for independent
super heating furnaces and methanol refining furnaces
Marked *** are not applied for ethylene resolving
furnaces. ( ) are applied for those equipped with
a stack gas desulfurization facility.
(6) Reference to Cement Calcination Furnace/ standards
in the "existing" column are not applied for wet
type furnaces, and application from April 1, 1981.
(7) Reference to Coke Furnaces, standards in the "existing
column are not applied for Otto type furnaces.
- 6 -
PROCEEDINGS—PAGE 16
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
The flow chart for the enforcement process of the SOx
total emission regulation scheme is shown in Fig. 2.
Smoke
source data
Modelling
Calculation
scope
determination
Diffusion
. model
Meteorology
data
Modelling
Diffusion
calculation
Diffusion
parameter
Measured
nbient.
lity
Expected
future
smoke source
Future
pollution
estimation
Treatment of
singular
values
Modification
of smoke
source
conditions
Pollution
forcasting
Examination of
regulation
values
Future mete-
orological
data setting
Ambient
Air quality
target
Post-
regulation
back-ground
estimation
Calculation of
post-regulation
concentration
Ambient air
quality
standard
Reduction
rate of
total
emission
NO
Area total
permitted
emission
END
Figure 2 Flow chart for SOx
total emission regulation scheme
- 7 -
PROCEEDINGS—PAGE 17
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
2. Problems in NOx Total Mass Emission Regulation
For a NOx total mass emission regulation scheme to
be effective, the following problems seem to require
solutions:
1) Pollution estimation technique
Unlike the case of SO / the establishment of NOx
y\
pollution estimation involves the following problems:
As NOx is formed in all combustion processes by the
oxidation of not only nitrogen in the fuel but also
of N2 in the air, its source including ordinary house-
holds is varied and complicated. In addition to smoke-
and soot-emitting facilities, automobiles also contribute
much to atmospheric pollution, and the dispersion in
the air layer near the ground surface must also be taken
into consideration. Finally, immediately after discharge,
all NOx in the discharged gas is in the form of NO, and
therefore, its conversion into NO2 must be taken into
consideration.
Therefore, at present, efforts are being made in
many related fields to establish good techniques of
estimating NOx pollution that can contribute to the
rational control of NO^ pollution.
For this purpose, continuous efforts must be made
in the following directions:
- 8 -
PROCEEDINGS—PAGE 18
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
(1) Obtaining reliable information about the actual
NOx emission conditions from small and medium
stationary sources and mobile sources.
(2) Establishment of methods for estimating the
diffusion of NOx emitted from these sources
(establishment of low altitude or local diffusion
models).
(3) Obtaining precise information about the conversion
process from NO to NO--
(4) Obtaining precise information about the background
concentration.
(5) Obtaining reliable information about the ambient
air quality concentration.
2) Precise information about emission data
Needless to say, precise information about the volume
of emitted NOx is required, and at present, various
emission sources are under investigation by various
authorities as listed below. A comprehensive nation-wide
NOx emission survey is scheduled to be made by the
Environment Agency in 1978.
- 9 - PROCEEDINGS—PAGE 19
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
Stationary
sources
Mobile
sources
Large smoke — -
sources
Small and
medium smoke
sources
In principle, actual measure-
ments
Estimation based on emission
factor (many data of Environment
Agency, etc. available)
Automobiles
Ships
\
Aircraft
Estimation based on emission
factor (many data of Environment
Agency, etc. available)
Estimation based on emission
factor (data of Environment
Agency, Transport Ministry,
and Kanagawa Pref. are available.)
Estimation based on emission
factor (data of Environment
Agency and Osaka Pref. are
available.)
Many small
sources
Background
Estimation based on emission
factor (Environment Agency
data are available.)
Actual measurement by urban
types (Environment Agency
data are available.)
3) Development of diffusion models
Mobile sources, especially automobiles, are said to
be drastically different in the mode of diffusion from
the emitted NOx from stationary sources, so that new
types of diffusion models are under study for automobile
exhaust gas entirely different from the model used for
the total mass emission regulation scheme for SOx.
At present, several modified total mass emission
PROCEEDINGS—PAGE 20
Fourth US-Japan Conference on
Photochemical Air Pollution
- 10 -
-------
regulation models based on the data obtained from an
actual on-road tracer experiment (assigned to Osaka
Pref. 51' - 53') modified by initial diffusion range,
etc., and non-normal models are under comprehensive
study.
As to the study in diffusion models incorporating
NO - NO~ conversion, although several models have been
proposed based on NO decay functions derived from
reaction velocity theory viewpoints and derived from
statistical treatment of the measured concentrations
of NO, NO~ and NOx, none has provided reliable proof,
and further experience in other areas and further
studies are required to obtain reliable models.
3. The Present State and Problems of Exhaust Gas
Denitrification Technology
As for the exhaust gas denitrification technology, the
last year's report said that there were no technical
problems about the "clean exhaust gases" (containing none
or extremely small quantities of SOx and dust) which are
emitted from the soot and smoke emitting facilities using
LPG and LNG for fuels. Such being the case, in the last
hearings, emphasis was placed on the survey to find what
advances had so far been made in the development of the
denitrification technology for what is called the dirty
11 ~ PROCEEDINGS—PAGE 21
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
exhaust gases containing higher concentrations of SOx
and dust.
As the point of time when the report was completed
in October 1ST75, there were eleven pieces of denitrification
equipment in actual operation and moreover they were for
the most part designed for handling the clean exhaust gases.
The last survey has revealed that the number of denitri-
fication equipment in operation increased to 35 or more,
including an increasing number of those for dirty exhaust
gases.
(1) Speaking about the dry type (ammonia catalytic reduction
type) of exhaust gas denitrification equipment, there
are 26 units now in operation (with a combined capacity
amounting to 4,300,000 Nm /h) , including those which
are used for C heavy oil-burning boilers and various
kinds of heating furnaces.
The operating records of such equipment show that
there are no problems about the exhaust gases as
dirty as those which are emitted by the combustion
of C heavy oil in the respect of catalytic activity
for such reasons that SOx-resistant catalysts have
been put to practical use. The problem of catalystic
being clogged by dust has also been solved, making
so much progress in the practical usefulness of this
- 12 -
PROCEEDINGS—PAGE 22
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
type of exhaust gas denitrification technology.
What is needed in the future is a further improve-
ment in the economy of this type of denitrification
system and an increased reliability by solving the
problem of the safety of the combustion facility
itself which arises from the deposition of acid
ammonium sulfate onto the heat exchangers.
On the other hand, no such advances have yet been
made in the development of denitrification technology
for the dirtier exhaust gases emitted by sintering
furnaces, glass melting furnaces and the like. Though
there are some denitrification equipment of this type
now in operation but they are equipped with various
attachments disregarding the operating economy to
some extent. Such being the case, it is still
premature to evaluate it to have reached the stage
of practical usefulness.
~ 13 ~ PROCEEDINGS—PAGE 23
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
•u o
3- C
O -5
r+ r+ -O
o rr ?o
o o
3- c: o
n> co m
3 i m
-«. c_i a
n fl> i-t
o< TD 2
—i 0) C7>
3 C/)
> I
-J- O I
-J O T3
=3 >
~a -ti en
o ro m
—' n) ro
c 3 *»
r+ O
-J. n)
o
3 O
3
Denitrifi-
cation
technology
Dry-type
denitrifi-
cation
Wet-type
denitrifi-
cation
Contact decomposition
method
Non-catalyst reduction
method
Catalyst reduction
method
Adsorption method
— Absorption method
Electron-beam
radiation method
i— Alkaline neutralization
absorption method
- Acid absorption
method
— Complex salt formation
absorption method
— Oxidation absorption
method
— Liquid-phase reduction
method
Non-selective catalyst
reduction method
Selective catalyst
reduction method
- Gas-phase oxidation
absorption method
- Liquid-phase oxidation
absorption method
- Oxidation liquid-phase
reduction method
'— Direct liquid-phase
reduction method
Figure 1 Classification of exhaust gas denitrification technologies
-------
Table 1
(NH3 Catalyst reduction method)
Development state of smoke denltrlfIcation devices
(Dry-type practical size devices)
Developing
firm
Sumitomo
Chenicals
Mitsubishi
Kakoki
Hitachi
Ltd.
Japan
Gasoline
Source
Ammonia
improvement
furnace
Me tha.no 1
improvement
furnace
Ammonia
improvement
furnace
Boiler
Boiler
Metal heat-
ing furnace
Boiler
Boiler
ii
Metal heat-
ing furnace
Boiler
Boiler
Coke furnace
Boiler
Petroleum
heating
furnace
Boiler
Fuel type
LPG
ii
n
it
n
ii
C-fuel oil
n
n
LNG
C-fuel oil
C-fuel oil
MG
C-fuel oil
C-fuel oil
+ gas
FCC dis-
charge gas
(CO)
Capacity
Nm3/h
200,000
200,000
250,000
100,000
200,000
10,000
30,000
240,000
300,000
5,000
14,000
15,000
500,000
125,000
50,000
70,000
Gas pre-
treatment
none
n
n
n
It
II
Dust
collector.
(Cottrell)
E.P
E.P
none
none (temp.
rise only)
none
none (temp.
rise only)
none
none
none
Type of
catalyst bed
Fixed-bed box type
Fixed-bed
cylindrical type
Fixed-bed
cylindrical type
Fixed-bed
cylindrical type
n
n
n
Fixed-bed box type
Moving bed
Vertical cylinder
n
Intermittent
moving bed
n
Fixed-bed cylind-
rical type (2-
tower type)
Parallel passage
n
SV
SV = 10,000
SV - 7,000
SV - 6,000
SV = 7,000
SV = 7,000
SV = 7,000
-Vl 0,000
SV = 4,000
SV = 5,000
SV - 5,000
SV = 3,100
SV - 3,000
SV - 6,000
SV = 6,200
-
SV = 4,000
SV - 5,000
Reaction
temperature
300 * 350°C
n
n
n
n
n
n
350°C
n
400 * 450°C
350 * 400°C
335°C
335°C
400°C
390 ^ 400°C
390 ^ 400°C
Operation
date
April 1975 *
May 1974 ^
Jan. 1975 *
Jul. 1975 -v
April 1975 *>
Sept. 1975 °»
Jul. 1973 ~
Mar. 1976 *•
Nov. 1976 ^
Feb. 1976 ^
Jul. 1976 ^
Oct. 1976 A,
Nov. 1976 ^
Aug. 1975 ^
Nov. 1975^
Jul. J.976 *
-------
Developing
firm
Mitsui
Ship-
building
Kurashilci
Spinning
Hitachi
Ship-
building
Asahi
Glass
Source
Boiler
Boiler
Catalyst bak-
king furnace
Petroleum
heating
furnace
Power gene-
rator boiler
Plante
annealing
furnace
Metal heating
furnace
Sintering
furnace
Metal heating
furnace
Glass melting
furnace
Fuel type
FCC dis-
charge gas
(CO)
C-fuel oil
LPG
FCC discharge
gas LBG
(Butane)
C-fuel oil
LPG
Kerosine
-
Light oil
Heavy oil
Capacity
Nm3/h
240,000
30,000
10,000
350,000
440,000
6,000
70,900
762,000
10,000
75,000
Gas pre-
treattnent
E.P
none
none
E.P
E.P desul-
furizatlon
none
(cooling)
it
E.p desul-
furization
none
Dust
removal,
desulfuri-
zation
Type of
catalyst bed
Fixed bed
Moving bed
Vertical wall type
Radial flow type
M
Vertical wall type
Radial flow type
Screen type
SV
SV = 3,000
SV = 10,000
SV = 4,000
^5, 000
Under
experiment
Reaction
temperature
350 ^ 400°C
350°C
350 ^ 420°C
under
experiment
Operation
date
Oct. 1975 ~
Aug. 1975 *
Oct. 1975 *
Nov. 1975 ^
Oct. 1975 «\,
May 1976 a,
Nov. 1976 -\>
Dec. 1976 ^
Feb. 1976 ^
(Non-catalyst reduction method)
Tonen
Technology
Boiler
Petroleum
heating
furnace
Heavy oil
ii
450,000
200,000
none
M
Non-catalyst
denitrif ication
-
-
700vL, 100°C
it
Oct. 1975 %
Jul. 1975 *
-------
(2) As for the wet type of exhaust gas denitrification
equipment, they are for the most part still in the
testing stage but there are seven units (with a total
capacity of 350,000 Nm /h) in operation, which can
be evaluated as practically useful. The wet system
is capable of a denitrifying rate of more than 90%
and the remaining problem is the treatment of waste
fluid and the improvement of economy. With regard to
the treatment of waste fluid, the development of a
system is under way. In this respect, the develop-
ment of a system which does not allow nitric acid
radical to remain in the, waste fluid is desired.
Now under way is the development of such wet type
denitrification equipment that they are be readily
attached to the existing desulfurization equipment
and are capable of easily and economically performing
simultaneously such functions as desulfurization,
denitrification and dust removal. Attention should
be paid to further technological advances to be made
in this particular field.
Compared with the time of the hearing of 1975, both
dry e.nd wet systems have reduce the cost of exhaust
gas denitrification considerably.
PROCEEDINGS—PAGE 27
Folirth US-Oapan Conference on
Photochemical Air Pollution
- 17 -
-------
-o o
3" C
O ~i
O 3- xO
O O
3- C= O
g> co m
3 i rn
-i. c_, a
o w •-<
pi T3 ^ST
—-CU CD
3 CO
-"• O I
-J O T3
3 g
T3 "TI tn
o a) rn
—>n> ro
c 3 oo
r+ O
O
3 O
Table 2 Development state of smoke denitrification devices.
(Wet-type practical size devices) (as of August 1976)
Developing
firm
Fuji Kasui
Oxidation
absorption
method
"
n
"
n
n
-
Chlorine.
dioxide
"
n
n
n
Ozone
n
NaOH-N.2S03
n
n
n
n
"
«
Boiler
Metal heat-
ing furnace
n
Boiler
Metal heat-
ing furnace
"
Boiler
C-fuel
oil
B. C-fuel
oil
n
"
n
n
n
62,000
85,000
100,000
39,000
39,000
12,000
16,000
90 ^ 95%
90 ^ 93%
n
n
n
85 ^ 90%
85 -v 90%
99.5%
-
-
-
-
-
21,000 hrs.
8,400
10,500
14,000
12,600
5,900
7,600
-------
4. The Present State and Problems of Low NOx Combustion
Technology
The nitrogen oxides (NOx) are not only the fuel NOx
produced by the reaction of the nitrogen compounds contained
in the fuel itself (hereafter referred to as "N content")
and oxygen in the air during the process of combustion but
also the thermal NOx produced by the reaction of nitrogen
and oxygen present in the air at high temperatures.
Such being the case, the measures to be taken for
reducing the NOx emissions may be classified into the
following three types.
(1) To reduce the N content in the fuel or switch
over to a fuel having less N content. (2) To make the
combustion conditions difficult for the production of NOx.
(3) To remove NOx from combustion exhaust gases.
As for (1), the techniques for removing the N content
selectively from a fuel as the desulfurization of a heavy
oil, still remain to be developed in the future. At the
present time, it is only known that the N content is
partially removed as a secondary effect of the desulfuri-
zation of a heavy oil. As for (2), several techniques
have been developed for low NOx combustion. With regard
to (3), various techniques for exhaust gas denitrification
have been developed as mentioned earlier.
- 19 - PROCEEDINGS—PAGE 29
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
5. Principle and Problems of Low NOx Combustion Techniques
(1) Switching to low-NOx fuels
Generally speaking, the various fuels can be arranged
as follows according to the amounts of NOx they
causes when burnt.
Coal > Asphalt > C heavy oil > B heavy oil> A heavy oil >
Gas oil > Kerosene > LPG > LNG > City gas > Co Methanol >
H~. The above order is also applicable to the ratios
of NOx contents in the fuels, and therefore the best
way to reduce NOx emissions is to use fuels having
lower N content.
The switching to the use of better-quality fuels
involves such economical problem as the increase in
cost of fuel and also such technical problems as the
alterations to be made to the combustion equipment
as required by the use of such new fuels.
The utilization of the byproduct gases, as is done
in the iron manufacturing and chemical industries,
is an effective way to reduce NOx emissions.
(2) Principle and problems of low NOx combustion techniques
As was mentioned earlier, if NOx emissions are to be
reduced, it is necessary to reduce the production of
fuel NOx and thermal NOx.
PROCEEDINGS—PAGE 30 - 20 -
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
First, the N content in the fuels, which causes the
production of fuel NOx, is not completely converted
into NOx through the process of combustion but its
rate of conversion is generally governed by the
combustion conditions. It is known particularly that
the conversion rate is decreased when combustion takes
place in the air with low oxygen concentrations.
The production of thermal NOx can be reduced by (1)
lowering the air ratio, (2) lowering the flame temperature,
and (3) shortening the time the combustion gases and
exposed to high temperatures. These methods can be
used independently or in combination for decreasing
the amounts of NOx to be produced in the process of
combustion.
i) Combustion at a low air ratio (Combustion at low
oxygen concentration)
Generally, combustion is caused to take place in
an oxidizing atmosphere with an excess air but a
lower air ratio will results in the reduction of
fuel NOx and thermal NOx. However, if the air
ratio* is lowered excessively, it will cause
incomplete combustion, thus increasing the emissions
of soot and smoke, carbon monoxide, and hydrocarbons
remaining unburnt and so forth.
- 21 - PROCEEDINGS—PAGE 31
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
-a o
3- c
o -j
rt rt -O
O 3- 70
O O
3" C O
£0 co m
3 i m
-j. c_i a
a o> >-•
CD -a z
—' o» tn
-•• O I
-$ o -a
3 f*
T3 -h CD
o fo m
—' n> co
c 3 ro
rt O
_i. ft)
o
3 o
3
Generation factor
Abating principle
Fuel N
content
°2
concentration
to
to
Flame
temperature
Gas remanent
time
§
x
00
§
(0
rt
H-
§
- Fuel NOx
Thermal NOx
Use of
low-N fuel
concentration)
drop
Flame temperature|
drop
Shortening of
remanent time
Concrete plan
Replacement of
heavy oil by
light oil, fuel
gas, or low
calory fuel gas.
Fuel change
C
a>
COG denitrifi-
cation (COG wet-
type denitrifi-
cation)
Coke denitrifi-
cation and qua-
lity improvement
of heavy oil
8
Fuel
denitrification
Low air ratio
combustion, de-
crease of' pre-
heating tempera-
tue, change of
combus tion-cham-
ber heat load,
etc.
Operation
condition
change
Multi-stage com-
bus tion,exhaust-
gas recircu-
lation, off-
stoichiometric
combustion,
addition of
steam or water,
low-NOx burner
(including
burner tiles)
O H
Mi 9
T3
O >1
O O
& <
cr (o
C B
W (6
rt 3
H- rt
Modification of
combustion
facility
-------
* (Note) The ratio of the amount of theoretical
air to the amount of air which is actually
used for combustion.
Therefore, the NOx reducing measures in the form
of combustion at a low air ratio include (1) a
method in which the excess air is reduced to the
lowest level possible to reduce the production of
soot and (2) a method in which the air ratio is
first lowered to gasify the fuel and then additional
air is injected to cause the complete combustion
of the fuel.
This concept is used in the following applications.
(1) Changing the air ratio Combustion is
caused to take place at the lowest air ratio
possible.
(2) Changing the mixture characteristic
The mixture of air and fuel is changed by
the change of air resistor, etc. to obtain
the lowest air ratio possible.
(3) Use of low NOx burner
Mixture acceleration type The mixture
of fuel and air is accelerated to cause
combustion at a low air ratio.
- 23 - PROCEEDINGS—PAGE 33
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
Split flame type A flame is split
into smaller independent flames, thereby
to increase the radiation of heat from
the flame and to accelerate the combustion
at a low air ratio.
Self-circulation type ..... High-temperature
combustion gas is circulated within the
burner to gasify the fuel at low oxygen
concentrations.
Staged combustion assembly type Low
and high air ratio combustion burners
and two-stage combustion burners are
assembled.
(4) Staged combustion
Off-stoichiometric combustion Low air
ratio burner and high air ratio burner
are used in combination.
Two-stage Combustion Low air ratio
combustion in the first stage and complete
combustion in the second stage.
ii) Lowering of combustion temperature
Generally speaking, the previous furnaces have been
designed mainly to make them compact in size and
to produce a high thermal efficiency by complete
PROCEEDINGS—PAGE 34 - 24 -
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
combustion of the fuel, and therefore the
temperature tends to rise so much higher within
them and produce high concentrations of NOx.
This being so, the production of NOx, particularly
thermal NOx, can be reduced generally by lowering
the combustion gas temperature, except for some
special furnaces which require high temperatures.
This concept is used in the following methods.
(1) Low air ratio combustion In the case of
low air ratio combustion as mentioned in (1),
combustion progresses gradually, therefore,
combustion gas temperature lowers accordingly.
(2) Low thermal load combustion The temperature
within the furnace can be lowered by burning
at a low thermal load.
(3) Exhaust gas recirculation If part of
exhaust gas is recirculated, the amount of
generated heat per unit volume of gas is
so much reduced and combustion temperature
is lowered accordingly.
(4) Use of low-temperature preheated air
Usually preheated air is used to facilitate
combustion or for surplus heat utilization.
Low-temperature air is used for this purpose
- 25 -
PROCEEDINGS—PAGE 35
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
to lower the combustion temperature.
(5) Water or water vapor mixing Water or
water vapor with a large thermal capacity
and heat-removing effects are mixed to
lower the combustion temperature.
iii) Shortening of the stay in the high-temperature zone
The production of thermal NOx can be reduced by
shortening the time the combustion gas stay in
the high-temperature zone.
It may be considered that most of the NOx reducing
measures so far described incorporate the principle
of NOx reduction by the shortening of the stay of
combustion gases in the high-temperature zones.
As we have just discussed, there are various low
NOx combustion techniques in which various principles
are used in combination to eliminate the shortcomings
of the individual methods. Fig. III-l shows such
techniques classified by the NOx reducing methods
employed.
Below, the guarantee values, target values, and
the NOx decrease effect in actual application on
existing smoke emitting facilities, of the makers
developing low-NOx combustion technologies by types
of facilities.
- 26 -
PROCEEDINGS—PAGE 36
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
Table 3 Guarantee values of makers developing low-NOx combustion technologies for boilers
(in ppm)
ra co
3=- '
-•• o i
-s o ~o
3 Ja
ID -h CD
O fD m
—J -J
—i fD 00
C 3 ~-J
rt- n
-j. fD
O
3 O
Type of measure
Self-recirculating type
low-NOx burner
(1)
(2)
(3)
Low-NOx burnerf exhaust gas
recirculation
or 2-stage combustion
Low-NOx burner-f exhaust gas
recirculation
2-stage combustion
2-stage combust ion-fexhaust gas
recirculation
2-stage combustion
In-furnace exhaust-gas recircu-
latlon+steam injection
In-furnace exhaust gas recir-
culation+emersion fuel
2-stabe combustion-i-steam
injection (user)
Low-NOx burner with built-in
2-stage combustion
C fuel oil
(N 0.2 0.25%)
150 * 160
120 ^ 165
Minasu fuel oil
50 '*•' 70
.Crude oil.
140 ( 13Q )
150
150
130 ^ 159
100 * 140
120 ^ 160
N 0.17%
6
B fuel oil
(N, 0.05%)
100 * 135
83 ^ 94
100 * 140
120 * 160
N 0.17%
63
A fuel oil
65
50 ^ 65
40
60 * 72
38 * 57
60 ^ 80
Light oil
kerosine
55
30
80
43 * 51
35 * 55
28 * 34
' Gas
50
LPG
20 ^40
70
50
12 ^ 32
Note
Target value
Target value
for medium
boiler
Large boiler
ii
Medium boiler
Small boiler
Empirical
value
ii
Empirical
value
-------
N = 0.3 ^ 0.5%
50
a
30
Fuel oil 01^0 ^7
or fuel less chan 0
_ oil4-crude
oil or gas
4
0 50 100
Crude oil or
crude oil 4-
.naphtha
, EZZ
13
It
28
'////
50
21
* »
45
7
2-stage 4- 52
recirculation
2-stage 20
Low NOx burner 12
•jc
///£ T,nw Mfhr burner -*~ ?- 8
stage 4- recirculation
vrrr. • Bias eom,bMStlon 6
Low NOx burner 4- 5
T*pr» i T*/MI 1 a f"f rt-n
Others 1 Q
200 250 NOx Concent-
.1 0.3%
. 1 -1- r-> 1 01 PPtfl
less than 0. 1%
-stage 4-
recirculation
Recirculation
Low NOx burner 4- 2-stage
4- recirculation
2-stage
Low NOx 4- recirculation
'///
y//^
*"•*.'•.'.
* • ./•'
jy
15
4
3
1
New
Existing
Modified
Measures
50
100
150
200
10
250 NOx Concentration
ppm
Gas
2-stage 4- recirculation
c
o c
0
0) •!—
^
) 50 100 150
O -M
00 C 3
CO Ol i —
i.r—
LU
-------
Table 4 Guarantee value of makers developing low-NOx combustion technology for metal heating furnace
(in ppm)
Type of measure
Self-recirculating type
low-NOx burner (1)
(2)
(3)
Low-NOx burner with built-in
2-stage combustion
C fuel oil
85 * 90
Minasu crude
oil
50 * 80
105
A fuel oil
45 ^ 50
50
Light oil,
kerosine
50
60
Gas
20 * 50
35 * 55
74 1. 77
50 V85
Note
Target value
Empirical value
Empirical value
Table 5 Examples of metal heating furnaces adopting low-NOx burner
Name of facility
Soaking furnace
Hot-rolling heating
furnace
Heating furnace
(W.B. continuous)
Heating furnace
(W.B. continuous)
Medium pipe heating
furnace
Medium pipe heat-
treatment furnace
Quenching furnace
(W.B. continuous)
Annealing furnace
(W.B. continuous)
Size of exhaust
gas volume ,
(Nm /hr)
33,000
63,400
196,000
131,000
65,700
48,400
r
14,800
13,300
Fuel
BFG + CPG
Heavy oil + COG
Heavy oil
BFG + COG + H"Vy
— oil
LPG
LPG
Kerosine 4- LPG
Kerosine + LPG
NOx concentration
(converted for 0~ 11%)
Before measure
New
200
140
New
150
New
New
New
New
After measure
110
110
75
70
100
70
70
20
20
Reduction rate
(%)
-
45
46
-
33
-
_
-
-
o«
o
m
en
to
OJ
Note) Facilities with * marks are low in furnace temperature and use light fuel. Its exhaust gas has an
intringically low NOx concentration as compared with conventional furnaces, so that after the process,
NOx concentration is made especially low.
-------
-a o
or c
O -i
<-«• H-
O 3-
O
\jr
§ Table 6 Guarantee value of makers developing low-NOx combustion technologies for petroleum heating furnace
o
o
m
m
o
-a
(u
3
-s o
-a 3,
O m
— ' f»
C 3
<-*• O
-i. a>
O
3 O
3
en
to
i
m
-«=»
o
Type of measure
Self-recircu-
lating-type
low-NOx burner
C fuel oil
ppm
123 'v 150
A fuel oil
ppra
70 ^ 90
Light oil
keroaine
ppm
50 ^ 60
Gas
ppro
50 'v 60
Table 7 After-measure NOx concentration for petroleum heating furnace by fuel type and measure jzype
(Note) Numbers indicate No. of
facilities, pew (existing)
Fuel
C fuel oil
(N - 0.08
^ 0.2%)
C fuel oil
+ gas
Light oil
Gas
Measure
LNB
EGR
LNB 4- EGR
Low 0
Sub-total
LNB
EGR
LNB + EGR
Low 0
Sub-total
LNB
LNB
EGR
LNB t EGR
Low 0
Sub-total
Total
Max -50
2 (1)
1
(1)
3 (2)
3 (2)
50 \, 70
1
1 (0)
(1)
0 (1)
1 (2)
5
1
1
7 (0)
9 (3)|
70 ^ 90
1
3
A (0)
2
1
3 (0)
A (1)
4 (1)
90 % 110
(6)
1
1
(1)
2 (7)
3 (1)
1
1
(1)
5 (2)
2
(2)
2 (2)
110 * 130
A (3)
(2)
A (5)
2 (1)
(3)
2 (4)
1
(1)
1 (1)
11 (i) 9 (:.;) 7 do)
130 o, 150
1
(1)
1 (X)
2 (2)
2 (2)
3 (3)
150 ^ 170
(1)
0 (1)
0 (1)
170 -v 190
Total
5 (10)
5 ( 0)
2 ( 0)
0 ( 4)
12 (14)
9 (5)
2 (Q)
I (0)
0 (4)
12 (9)
1 (2)
14 (2)
1 (P)
2 (0)
o (4)
17 (6)
42 (31)
-------
(B) Controls on Emissions from Motor Vehicle.
On December 26, 1977, the Central Council for Control
of Environmental Pollution submitted to the State Minister
and Director-General of the Environment Agency a recommen-
dation pertaining to the Long-Term Policy for Establishment
of Maximum Permissible Limits of Motor Vehicle Emissions.
The recommendation set forth the targets to be attained in
two stages as regards the maximum permissible limits of
nitrogen oxides (NOx) emissions by motor vehicles, other
than gasoline-fueled passenger cars, for which the Fiscal
1978 Emission Controls are scheduled to be enforced as
from April this year.
In line with the recommendation, the. Environment Agency-
issued, a public notice.on January 30 this year regarding
the maximum permissible limits of NOx emissions for the
first stage (dubbed 1979 Emission Controls) (Notification
of the Environment Agency No. 5, Jan. 30, 1978).
At the same time, the Agency issued another notice
as regards the strengthened controls on motor vehicle
noise (dubbed 1979 Noise Controls) (Notification of the
Environment Agency No. 4,. Jan. 30, 1978}. This was based
on a recommendation submitted by the said Council on June
15, 1976 with respect to the long-term targets for the
maximum permissible limits of automobile noise.
- 31 -
PROCEEDINGS—PAGE 41
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
Following is a gist of the recommendation pertaining
to the Long-Term Policy for Establishment of Maximum
Permissible Limits of Motor Vehicle Emissions, the notifi-
cation of the Environment Agency concerning the maximum
permissible limits of NOx emissions (1979 Emission Controls)
and the notification of the Environment Agency concerning
the maximum, permissible limits of automobile noise (1979
Noise Controls):
1. Recommendation:
With reference to the request for a recommendation
pertaining to the Lonq-Term Policy for Establishment of
Maximum permissible Limits of Motor Vehicle Emissions
(dated September 18, 1971), this Council submitted recommen-
dations to the State Minister and Director-General of
Environmental Agency concerning gasoline- and liquefied
petroleum gas (LPG)-fueled passenger cars on October 3,
1972 and again on December 21, 1974. However, in view
of the necessity of stiffening emission controls on other
types of motor vehicles as well, the Council's Expert
Committee on Motor Vehicle Pollution studied the matter
for about two years and a half, and recently came up with
a report as per attached hereto.
The Air Quality Subcommittee of this Council received
and deliberated on the report, and consequently, decided
PROCEEDINGS—PAGE 42 32 ~
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
to accept the report as the Long-Term Policy for Establish-
ment of Maximum Permissible. Limits of Motor Vehicle Emissions
At the same time, the Subcommittee concluded it is desirable
to further promote comprehensive- measures for the prevention
of air pollution due to automobile exhaust gas.
Accordingly, this Council hereby recommends the Govern-
ment to protect the living environment in areas adjacent
to roads as soon as possible by attaining the targets
for maximum permissible levels of motor vehicle emissions
as specified in the following Seciton 1, and at the same
time, taking measures for the prevention of air pollution
due to automobile exhaust emissions as referred to in
Seciton 2.
Section 1. Establishment of Long-Term Targets for Maximum
Permissible Limits and Dates of Attainment
It is considered, appropriate to attain the target
values for maximum permissible limits of nitrogen oxides
(NOx) emissions (average values) in. two stages as indicated.
in the following table:
- 33 -
PROCEEDINGS--PAGE 43
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
Category of Motor Vehicle
Diesel-oil-fueled ordinary
or small-size motor vehicles-
Gasoline— or LPG— fueled
ordinary motor vehicles
& small-size motor vehicles
(excluding those exclusively
used for carrying passengers
with a riding capacity of
10 persons or less)
Direct injec-
tion type
Indirect
Injection
type
With gross
vehicle
weight (GVW)
exceeding
2,500 kg
With GVW of
exceeding
1,700 kg and
up to
2,500 kg
With GVW of
1,700 kg or
less
Light motor vehicles
(excluding those exclusively
used for carrying passengers
or equipped with two-stroke
engine
Target Values of
Maximum Permissible
Limits
(average values)
1st Stage
540 ppm
340 ppm
1,100 ppm
12g/km
l.Og/km
1.2gkm
2nd Stage
470 ppm
290 ppm
750 ppm
0.9g/km
0.6g/km.
0.9g/km
Measurement
Method
Diesel
6-mode
6-mode
10-mode
PROCEEDINGS—PAGE 44
Fourth US-Japan Conference on
Photochemical Air Pollution
- 34 -
-------
The target values for the first stage should be
attained in 1979.. The reason is that this Council, considers
it proper that they be achieved simultaneously with the
first-stage targets under the. long-term policy for
establishment of maximum permissible limits^ of motor-
vehicle noise, recommended earlier by this Council.
To attain the second-stage target values for
gasoline—fueled motor vehicles, it is essential to develop
related technologies, centering on the large-scale adoption
of emission-reducing techniques, as developed for passenger
cars. As regards diesel-powered vehicles, various measures
are now under study, including a further injection retard,
installation of supercharger and exhaust gas recirculation
(EGR) .
Some of these techniques still defy prediction as to
how soon they will become practically applicable. There-
fore, in the enforcement of the emission controls, full
consideration needs to be given to the diversity of the
types of vehicles subject to the controls, and this
makes it difficult to forecast: precisely when the target
values for the second stage could be attained.
Nevertheless, the current state of air pollution due
to nitrogen dioxide is such that even when the emission
controls for the second-stage targets are enforced with
full, effectiveness,it would presumably be very difficult
- 35 -
PROCEEDINGS—PAGE 45
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
to achieve even the intermediate targets of the environ-
mental quality standards in those areas where the degree
of. pollution is- especially high- This being the case,
this Council considers it necessary to put the second-
stage emission controls into practice within several
years after the enforcement of the first-stage controls
or by the first half of the 1980s at the latest.
Section 2. Measures for Lessening Air Pollution Due to
Automobile Exhaust Emissions Other than
Controlling- Exhast Gases of Individual Motor-
Vehicles
In those cities whose air is exceedingly polluted
due to heavy motor traffic, it. is desirable to further
promote the following measures throughout the country
with the object of restricting the total volume of
vehicular traffic and ensuring- a smooth traffic flow
while resolving various related problems, in addition
to controlling exhaust gases of individual motor vehicles.
(1) It is essential to step up measures mainly geared
to improvement of roads, such as the elimination of
traffic bottlenecks through construction of bypasses,
adoption of grade separation, expansion of road width,
etc., and establishment of green buffer zones to
mitigate the effects of automobile exhaust emissions
PROCEEDINGS—PAGE 46 - 36 -
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
upon local inhabitants. In a long-range perspective ,
moreover, it is desirable to take such measures as
the restriction of the establishment or expansion, of
workshops, and. the relocation of those facilities
which contribute- to sharply increasing- motor traffic..
(2) Mass transit systems like railroads and bus services
should be expanded, and measures taken to encourage
the public to use such means of transport with a view
to facilitating a. diversion of transport needs from
i
passenger cars, etc..
(3) As for the transport of goods, the traffic volume of
trucks, etc. should be reduced by such means as the
streamlining of freight collection and distribution,
and the introduction of a freight transit information
system.
(4) Traffic control measures should be further intensified
through the comprehensive regulation of urban traffic,.
the traffic control systems, etc. so as to curb the
total volume of motor traffic and to ensure a smooth
flow of vehicular traffic.
Section. 3. Conclusion
This Council has worked out the present recommendation
regarding nitrogen oxides emitted by automobiles in the
37 PROCEEDINGS—PAGE 47
Fourth US-Oapan Conference on
Photochemical Air Pollution
-------
belief that the allowable limits should be made as strict
as possible in consideration of the current state of
development in. regard to techniques for- reducing exhaust
emissions, of—trucks, etc. and the outlook, for the practical
application of such, techniques. But the current state of
air pollution is such that even in the event all the vehicles
subject to the emission controls achieve the second-stage
targets, the situation would not be fully improved, to the
extent of reaching the present intermediate targets of the
environmental quality standards in those districts where
air pollution has assumed especially serious proportions-
In these circumstances, it is believed imperative to
further strengthen the controls on the emission of nitrogen.
oxides and to carry out various measures for the prevention
of air- pollution, and studies to these ends should be
conducted without interruption. However, although the
Council's deliberations this time have been primarily
devoted to reducing the emissions of nitrogen oxides, it
is also essential to study the necessity of imposing or
strengthening controls on other substances emitted by
motor vehicles. At present, this Council is deliberating
on che conditions for assessment of the effects of nitrogen
dioxide upon human health. Therefore, it must be pointed
out that the results of deliberations on the matter should
also be given full consideration in the implementation
PROCEEDINGS—PAGE 48 - 38 -
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
of the control, as specified in the present recommendation
and the promotion of various related measures.
Revision of Maximum Permissible Limits of Motor
Vehicle Emissions (summary)
The Environment Agency decided to stiffen the controls
on the emissions of nitrogen oxides from vehicles other-
than gasoline— or LPG-fueled passenger-cars as from 1979
in conformity with a recommendation submitted by the Central
Council for Control of Environmental Pollution in December
1977. Consequently, on January 30, 1978, it issued a.
public notice (Notification of the Environment Agency
No. 5) for partial amendment of the Maximum Permissible
Limits of Motor Vehicle Emissions (Notification of the
Environment Agency No. 1, January 21, 1974) . The revised
limits are as follows:
- 39 -
PROCEEDINGS—PAGE 49
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
3" C
O ~S
ft" C"T ~"O
O 3" 73
O O
3- cr o
3 i m
o o> H-*
&> -a z:
~_i P) CD
-$ O -O
3 J>
-o -h cn
o CD m
—' fl> on
C 3 O
<•+ o
o
3 O
3
o
I
Classification
n f
automobi le
Gasoline- or LPG-fueled light-duty
vehicles (ordinary or small-size
motor vehicles with a gross vehicle
weight (GVW) of 1.7 tons or less,
excluding those exclusively used
for the carrying passengers with
a riding capacity of 10 persons
or less)
Gasoline- or LPG-fueled medium-
duty vehicles (ordinary or samll-
size motor vehicles with GVW of
over 1.7 tons and up to 2.5 tons,
excluding those exclusively
used for carrying passengers
with a riding capacity of 10
persons or less) and light motor
vehicles (excluding those exclusive-
ly used for carrying passengers and
those equipped with two-stroke
engines)
Gasoline- or LPG-fueled heavy-duty
vehicles (ordinary or samll-size
motor vehicles with GVW of more
than 2.5 tones, excluding those
exclusively used for carrying
passengers with a riding capacity
Diesel-oil- Direct injection type
tueied
vehicles Indirect injection
type
Measurement
Method
(Unit)
I0,mode(8/k(n)
Il-moi§/fe8t)
.. . (g/km)
10-mode
(g/test)
11-mode
(ppm)
6-mode
(ppm)
Diesel
6-mode
1979 Controls
Maximum
Permissible
Limits
1.4
10.0
1.6
11.0
1,390
700
450
Average
Value
(A)
1.0
8.0
1.2
9.0
1.100
540
340
1975 Controls
Maximum
Permissible
Limits
2,3
20.0
2.3
20.0
1,850
850
500
Average
Value
(B)
1,8
15.Q
1.8
15.0
1,550
650
380
-------
Annex: Changes? o£ Effect: of Automobile- Exhaust: Control
( Average of NOX Emission; Volume )
1 Gasoline or: LPG -fueled ordinary motor vehicles
& small.-si2e- 'motor- vehicles.
(1) With gross, vehicle weight ( GVKT ) of 1,700 kg or less
1,700 kg or less
19%
100%
71%
59%
Before April, 1973:
April, 1973
Aoril, 1975
32%
First Stage
Second Stage-
(2) With- GVW exceeding- 1,700 kg and up to. 2,500 kg-
100%
71%
59%
Before April, 1973
April, 1973
April, 1975
39%
First Stage
29%
Second Stage
Annex-1
PROCEEDINGS—PAGE 51
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
(3). With GVW exceeding 2,500 kg-
100%
70%
59%
Before. April, 1973
April, 1973
August, 197T
42%
29%
First Stage
Sacond Stage-
2 Diesel-oil-fuelded. ordinary or small-size motor vehicles,
(1) Direct injection type
100%
80%
68%
56%
49%
Before September, 1974
September, 1974
August, 1977
First Stage
Second Stage
(2) Indirect injection type
100%
80%
68%
60%
52%
Before September, 1974
September, 1974
August, 1977
First Stage
PROCEEDINGS—PAGE 52
Fourth US-Japan Conference on
Photochemical Air Pollution
Second Stage
Annex-2
-------
III. CONTROL MEASURES AGAINST. EMISSION OF HYDROCARBONS FROM
STATIONARY SOURCES
I.
Hydrocarbons along with nitrogen oxides are precursors
for creating photochemical oxidants. Regarding nitrogen
oxides, emission controls have already been enforced because
of their inherent toxicity. But as for hydrocarbons, only
automobile exhaust gas is subject to control, and no national—
level controls are in force concerning the emission of
hydrocarbons from stationary sources, such as factories and
so on.
The Environment Agency has set up the investigation group
on measures to reduce the emission of hydrocarbons from
stationary sources. Recently, it has announced the result
of the group' s study conducted for about a year from October
1976. Major points of the report are as follows:
(1) Current level and evaluation of techniques for reducing
the emission of hydrocarbons
(2) Information available as of now in regard to the
photochemical reactivity of. hydrocarbons
(3) Recommendations about future measures to reduce the
emission of hydrocarbons from stationary sources
(4) Others
- 41 -
PROCEEDINGS—PAGE 53
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
(i) Present state of application of emission control
techniques for hydrocarbons and problems involved,
as based on inquiries to the industries, concerned
(ii) An outline- of: controls, enforced, by local governments.
As for the contents of emission control, techniques
mentioned in (1), the present techniques applied to different
sources, such, as storage facilities, distribution processes/
painting and printing processes- are evaluated conceptually.
As for (2) information on photochemical reactivity of
hydrocarbons is collected; the degree of reactivity is divided
into five classes for each type of hydrocarbon on the basis of
various experimental data thus far obtained and announced.
Regarding recommendations on emission control measures mentioned,
in (3), it is noted that hydrocarbons are emitted not only from
such stationary sources as oil tanks, but also from various
sources, including paints, printing ink, adhesives and cleaning
solvent. Therefore, measures for emission control will neces-
sarily vary in the degree of difficulty, and full consideration
should be given in working out appropriate control measures.
The report points out such measures will also conceivably have
to take account of the season and time when photochemical oxidant
emerges and areas where it occurs. For the present, it says,
measures should preferably by taken according to the following
guidelines:
PROCEEDINGS—PAGE 54 " 42
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
(1) To prevent the emission of hydrocarbons from tanks
storing them, such as petroleum, and the emission of
hydrocarbons in transferring them from tanks.
(2) To prevent the evaporation of hydrocarbons from factories
and other workshops where hydrocarbons are used, such
as painting and printing factories.
(3) To promote research and development of low-emission
paints and printing ink and enlarge the scope of their
use.
(4) To step up a PR drive for encouraging painters and
printers to use low-emisison materials.
In addition, the report points up the need for effective
measures to prevent the emission of hydrocarbons from
petrochemical and other plants, since such emission cannot
be neglected in some areas.
At is noted in the report, hydrocarbons are emitted from
a large variety of sources, such as organic solvents contained
in paints, printing ink and adhesives, as well as the storage
facilities and distribution process of petroleum products,
and moreover, there are a large number of such sources.
Accordingly, the Environment Agency will have to take this
fact into full account in working out and enforcing administrative
measures to reduce hydrocarbon emission.
- 43 -
PROCEEDINGS-PAGE 55
u s-Japan Conference on
Photochemical Air Pollution
-------
In preparation for establishment of controlling the
emission, of hydrocarbons from stationary sources, the Agency
intends to investigate the actual state of emission from
each type of source, improve the monitoring system of non-
methane hydrocarbons and examine concrete strategies for
control.
For the immediate future, the Agency will take the following
steps:
(1) Reduction of organic solvents contained in paints, etc.
is essentially an effective means for preventing the
emission of hydrocarbons. Moreover, it is also desirable
from a viewpoint of saving resources. Therefore, the
Agency requires the private quarters concerned and public
research institutes to step up their research and develop—
ment efforts for the practical and extensive use of low-
emission paints and printing ink, centering on those with
a low content of organic solvents.
(2) The Agency requires private quarters concerned to widen
the use of low-emission paints, printing ink, etc.
Besides, public agencies will be required to use such
low-emission materials.
(3) The Agency requires private quarters handling hydro-
carbons to cooperate in the prevention of hydrocarbon
emission through their trade associations so that they
may respond smoothly once legislative controls are
introduced.
- 44 -
PROCEEDINGS—PAGE 56
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
(4) The Agency requires local governments to take steps in
conformity with this report, when they intend to set up
the regulations of hydrocarbon emission under local laws.
In addition, the Agency will further- promote- researches
and investigations so far; made, in regard to the behavior of
hydrocarbons in the air.
(1) Emission survey by materials, by types of facilities,
and by sizes of facilities.
(2) Survey on EC measurements
(3) Fact-finding surveys in HC treatment installations.
2. Basic Concept of Emission Control
1) Necessity for regulating the emission of hydrocarbons
Hydrocarbons are substances that produce photochemical
oxidants- together- with NOx-.. The Specialist Committee
for Environmental Hydrocarbon Quality Standard of the
Central Council for Environmental Problems reported that
to maintain the concentration of photochemical oxidants
within the relevant environmental quality standard, the
concentration of hydrocarbons excluding mathane (referred
to as "non-methane hydrocarbon" hereafter) must be kept
below 0.20 - 0.31 ppmC in the three-hour average between
6 and 9 AM, and this report was accepted by the Central
Council (report submitted on August 13, 1976).
According to the available monitoring data, generally,
- 45 - PROCEEDINGS—PAGE 57
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
the 3-hour average values of non-methane hydrocarbons
are 0.5 - 0.6 ppmC, with concentrations as high as
1 ppmC monitored from time to time, indicating the need
to drastically reduce the hydrocarbon emission. Legal
control of automobile hydrocarbon emission was first
enforced in 1970 with the regulations progressively
tightened, and from April 1975, the present regulation
requiring passenger cars not to emit 0.23 g/km of
hydrocarbons, an emission level corresponding to a
reduction of 93 % compared to the un-controlled level.
However, stationary sources for hydrocarbons are at
present only regulated by local government regulations.
With photochemical oxidant alarms issued several times
every year, and victims reported, it is very important
to regulate the emission of hydrocarbons, an important
precursor of photochemical oxidants, from sources other
than automobiles as early as possible.
2) Preferable hydrocarbon regulation measures
Some odorous hydrocarbons have already been legally
regulated, but other hydrocarbons in themselves are
considered to be harmless to human health in the
concentrations in which they are contained in the
atmospheric air. This means that they need only be
regulated because of their causative effect on
- 46 -
PROCEEDINGS—PAGE 58
Fourth US-Oapan Conference on
Photochemical Air Pollution
-------
photochemical, oxidants. However, hydrocarbons are
evaporated, into the air from a great variety of
facilities such as- paints, printing inks, adhesives,
and laundry solvents, in addition to such stationary
sources as petroleum tanks, and their control measures
also differ greatly in their difficulty of control
measures; so when selecting measures, the. degree of
difficulty of application and the seasons and areas
most related to the generation of photochemical
oxidants must be taken into consideration.
For the time being, measures should desirably be taken
along the following guidelines:
(i) To prevent the emission, or hydrocarbons from tanks
storing them, such as petroleum, and the emission
of hydrocarbons in transferring them from tanks.
(ii) To prevent the evaporation of hydrocarbons from
factories and other workshops where hydrocarbons
are used, such as painting and printing factories.
(iii) To promote research and development of low-emission
paints and. printing ink and enlarge the scope of
their use.
(iv) To step up a PR drive for encouraging painters and
printers to use low-emission materials.
47 . PROCEEDINGS—PAGE 59
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
In addition to these measures, in areas where industrial
plants such as petrochemical works account for the major portion
of emission, effective measures must be taken at these works..
3. Emission Control Technology
1) Outline of emission control technology
Hydrocarbon emission control technologies are classified
into two major groups: vaporization-prevention technology
to prevent emission by modifying the structure of the hydro-
carbon-containing facilities, and processing technology to
eliminate emitted hydrocarbons by some means.
2) Evaporation-prevention devices
Evaporation-prevention devices are applied to the storage
installations in refineries, oil tanks, and oil supply
facilities. Principal device are floating roofs, internal
floating roofs for fixed roof tanks, and vapor return
devices.
Floating roofs and internal floating roofs are covers
floating on the surface of oil/ and are capable or rising
and lowering as the oil surface rises and lowers.
Floating roofs are already in use in large tanks and
have proved that loss of hydrocarbons during oil supply is
negligible with tanks with floating roofs, and the larger'
the tanks, the smaller the breathing loss becomes compared
- 48 -
PROCEEDINGS—PAGE 60
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
with fixed roof tanks. For this reason, tanks over 1000
liters in capacity should preferably be floating roof tanks.
Internal floating roofs are simply installed in the existing
fixed roof tanks without special reinforcement, but have
an evaporation-prevention effect comparable with floating
roofs, except for simple ones.
Vapor return devices are mostly used in the gasoline
transportation stage. They are used at the gasoline storage
facilities and gasoline stations to collect the escaping
hydrocarbon vapor from the receiving side, during gasoline
transfer from tank: lorries to the storage tanks, and to
return the collected vapor to the supplying side, thus
preventing its escape into the atmosphere.
This device is expected to prove effective when it
is used at the storage stations when loading tank lorries
with gasoline, to be more beneficial, it should preferably
also be used by the gasoline stations in supplying auto-
mobiles with gasoline, because emission is great in this
final stage of gasoline supply.
In vapor return devices, mostly absorpting techniques
with solution are used to recover vaporized hydrocarbons.
3) Processing devices
Vapor processing devices are based on one of the
following techniques: adsorption technique, solution
- 49 -
PROCEEDINGS—PAGE 61
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
technique^-condensation technique, direct combustion
technique, and catalyzer oxidation technique.
The adsorption technique utilizes the adsorption
of hydrocarbons, on the surface of a porous substance..
Mostly activated carbon is. used as- the porous substance.
When a predetermined amount of hydrocarbon has been
adsorbed onto the porous substance, it is heated by steam
to drive off the hydrocarbons and to renew the adsorbent.
Activated, carbon, adsorbent is used either in the
fixed, bed system or" in the fluid bed system- Although
differing in. the absorption efficiency according' to the
type of hydrocarbons, almost all hydrocarbons are adsorbed
by activated carbon with a high degree of efficiency,
so that it is widely used in painting facilities, printing-
facilities, etc-
The solution technique is based on the dissolving of
hydrocarbon vapor in absorbent liquid. As the absorbent
liquid, mostly hydrocarbons having a high affinity with
ths vapor to be adsorbed are used; but for processing
hydrophilic hydrocarbons, water containing additives is
used.
In some vapor return devices used in oil storage
stations, the returning hydrocarbon vapor is recovered by
the solution technique.
- 50 -
PROCEEDINGS—PAGE 62
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
The. condensation technique is based on the removal, of
hydrocarbon vapor through condensation by means' of a coolant.
As this, technique is advantageous, in recovering- high—
concentration 'hydrocarbon vapor, it is more often used in.
the pre—treatment devices- attached in adsorption devices
or solution devices than as: indipendent units'.
The direct combustion technique is based on the com-
bustion of discharge^ gas containing hydrocarbons, with the
aid of combustion additives. This technique is suited
to treat exhaust gas which contains many types of hydrocarbons"
and. therefore is not suitable for recovery, and/or which
contains resin powder or oil mist. Its efficiency is
generally high.
The catalyzer oxidation technique is based on the
oxidation of hydrocarbon vapor of very low concentration
in preheated gas which is sent through the layer of
catalyzer. If metal powder or resin powder is contained
in the gas to be processed in catalyzer oxidation devices,
the metal, or resin powder adheres to the catalyzer and
deteriorates its oxidation power. For this reason, the
gas to be treated in catelyzer oxidation devices must be
free from these harmful powder materials. Although this
technique requires the gas to be preheated, if hydrocarbons,^
are contained in the gas in high concentration,
preheating fuel can be saved. If the hydrocarbon concent-
ration of the gas is too high, it must be diluted before
treatment.
- 51 -
PROCEEDINGS—PAGE 63
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
This technique is capable, of treating gas with a
wide range of hydrocarbon concentration at. high treat-
ment efficiency, and is used in the petrochemical
industry and printing industry, etc,
4. Low Emission Paint
The FY 1975 national total consumption of paint
is approx. 1.2 million tons, and the breakdown of FY 1976
national consumption by major application classifications
is as shown in Table 4.1.
Table 4-1 Breakdown of 1976 total paint consumption
by application classifications
Classification
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
Roads and vehicles
Buildings
Marine
Metal products
Wood products
Structures
Electrical machinery
Machinery
Household use
Road signs
Export
Rolling stock
Government and public
Others
Total
Percentage
20,3
19.4
11.3
9.1
7.4
6.3
5.3
4.2
3.9
2.2
1.6
1.3
1.0
6.1
100
PROCEEDINGS—PAGE 64
Fourth US-Japan Conference on
Photochemical Air Pollution
- 52 -
-------
Most paints used today are resin-type paints containing
solvents. As these paints consist of body resins dissolved
in approximately equal amount of hydrocarbon solvents, when.
they form a coating film, most solvents are freed into the
atmosphere. AS low-emission paints, containing little or
no organic solvent, the following types are in use or under
development:
i) Powder paint
ii) Water-borne paint
iii) High-solid paint
iv) Other paints (Multi-liquid paint/ inorganic paint,
dry-oil type paint, ultraviolet radiation curing
paint, electron-beam radiation curing paint, and
solvent replacement type paint)
Although some of these paints have been in use for
years because of their other features, the majority of
them were developed as resources-saving type paints. Their
total consumption in FY 1975 is shown in Table'4.2.
In ?Y 1975, approx. 20.8% of the total national paint
consumption is accounted for by low-emission paints, but
they are mostly conventional dry-oil type paints and
water-borne emulsion type paints, and newly developed ones
are used in only very small amounts.
Table :4.3 shows the present state of development of
low-emission paints..
53 PROCEEDINGS—PAGE 65
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
Although many lew-emission paints have been developed
already, .they are used only to a limited extent, and the
cause for this seems to be as follows:
(1) The coating films of these: new paints, are not quite
equal to those of conventional paints in some performance
features.
(2) Most of them require modification of the existing
painting facilities.
(3) Their cost, is higher than that of conventional paints.
(4) Many new paints are being developed, and it is
difficult to predict which one will become the main
paint type.
(5) The future direction of legal regulations is unpredic-
table .-
(6) Their application range is limited as compared with
conventional paints.
• PROCEEDINGS—PAGE 66 - 54 -
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
Table 4-2 1975 low-emission- paint demand.
Paint type
Low-
emission
paints
Powder pain
Water-borne paint
High-solid paint
Multi-liquid solid
Inorganic paint
Dry -oil type- paint
Sub-total
Conventional paint
Thinner
Grand total.
Amount
(tons)
3,000
153,000
-
45,000
3,000
41,000
245,000
714,000
220,000
1,179,000
%
0.25
13.0
—
3.8
0.25
3.5
20.8
60.6
18.6
100
- 55 -
PROCEEDINGS—PAGE 67
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
oo
3- C
D -5
rt r*
a rr
n
3- c:
ro co
3 i
-". c.,
-a
50
o
o
m
O f^
w -o
— ' 0)
3
3>
-••O
-j o
3
TJ -4>
o ro
—•-5
— TO
c 3
rt- r>
CD
I
-a
m
en
CO
Table 4-3 Development and application of low-emission paint
0)
fr
rtJ.
Ul
D
Steel bridges
(steel
structure)
Buildings
(building
material)^
Auto-
mobiles
Top
coat
Under-
coat
Light electri-
cal appliances
Industrial
machinery
Ships
Low-emission paints
Powder
paint
o
o
0
A
Water-
borne
paint
A
o
A
O
o
A
A
High-
solid
paint
A
A
A
A
A
A
A
Multi-
liquid
paint
o
o
A
A
Inorganic
paint
A
Dry -oil
paint
A
Ultravio-
let ray
radiation
curing &
electron-
beam
radiation
curing
paints
Solvent
replace-
ment type
paint
A
A
A
A
A
A
A
Note: o Used in limited areas
A Applicable or application possibility is under study
No mark: Difficult to apply or not be developed
-------
4. Low-Emission Ink
As hydrocarbons are freed into the atmosphere in. the
printing- process, the use of low-emission inks in place of
conventional solvent type inks is a positive measure towards
controlling photochemical oxident generation. At the same
time, the use. of low-emission inks is positively recommendable
from the viewpoint of reducing the use of imported petroleum
products- and of improving working environments.
Today, printing inks are used not only in books and
posters, but also in many items used, in daily life such as
food packages, and building materials, and the trend is
towards more elaborated printing processes, such as gravure
printing in parallel, with the rise of living standard of the
people.
Table 4 shows major printing inks and coating varnishes
used today that are expected to constitute significant hydro-
carbon emission sources, because of their amount of use and
printing process.
As can be seen, in this table, the printing process
involves not only paper but also many other sheet materials
such as cellophane, plastic, building material, and metal.
But among them, gravure inks used such as in book printing,
package printing, building material printing, and metal
coating varnish are used in much larger amounts than other
PROCEEDINGS—PAGE 69
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
materials and are considered to free larger amounts of
hydrocarbons into the atmosphere than other materials.
For youf reason, the replacement of these materials with
suitable low-emission materials is desirable.
For the purpose of preventing emission of solvent
hydrocarbons from these printing inks and coating varnishes,
the following measures are under consideration and partly
in use.
1. Replace the currently used solvents by low photochemical-
reaction solvents.
2. Use the mixture of water and a small amount of low
photochemical-reaction solvent as solvents.
3. Develop new type of resin or resin despersant to
obtain high solid inks containing 80% or more solid
constituents.
4. Eliminate the use of solvent.
The industry-wide states of technical development on
the problem of printing ink typesc.and coating varnish
type in the measures 1 through 4 mentioned above are
roughly shown in Table 4.
As can be seen is Table 4, the progress in control
technology for these inks is in the order of the replacement
of conventional solvent by low photochemical-reaction solvents,
- 58 -
PROCEED INGS—PAGE 70
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
use of water-borne solvents, elimination of solvent, and
use of high-solid paints.
However, because of a large number of applications,
properties of printed sheets and printing methods, these.
technologies have not been fully developed for use with all
types of printing inks and. coating varnishes that require
measures.
- 59 -
PROCEEDINGS—PAGE 71
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
Table 4 Printing inks and coating varnishes applications liable to emit
hydrocarbons and state of conversion into low-emission substitutes
Printing ink &
coating varnish
Web offset ink
(heat set type)
Flexiso ink
Gravure ink
(publication)
Gravura ink
(package)
Gravure ink
(building material)
Metal decoration ink
Metal coating varnish
Screen ink
Paper coating varnish
Applications of printed or coated sheets
School text book, magazine, publication,
leaflet, catalogue, business forms
Bags, craft paper bags for cement, fertilizer,
etc., corrugated cardboard and paper containers
Weekly magazine, monthly magazine, books,
newspaper, postage stamp, poster, calendar
General wrapping paper, packages for food-medicine,
and other industrial products
Decorative board for household electric appliance,.
building material and furniture, wall paper
Can for food and beverage, decorative can, metal.
tube , toy
Same as above
Poster, display, sign board, decorative bottle,
clothes, toy, 1C circuit board, measuring
instrument, road sign
Telephone directory, picture book, record jacketr
glossing of book and magazine cover, glossing
of poster, etc.
Note: (1) This table shows an overall survey of the states of developments
of the industry as a whole.
(2) 9 : In actual use to a considerable extent
o : Potentially usable or partly in actual use with products
already in existance
A : In research, and experimental stage
x : Technically very difficult to use practically
x x : Expected Co be totally out of the question from the
present stage of technical development
(3) * : Depending on the property, type, and application of the
. printed sheets, sometimes impossible to adopt in
practice.
(4) Water-borne solvent means water containing a small amount
of low photochemical-reaction solvents such as alcohol-type
solvents.
PROCEEDINGS—PAGE 72
Fourth US-Oapan Conference on
Photoehemiral Air PnTliit.inn
- 60 -
-------
Conversion into low
photochemical re—
action solvents
o
Q
A
o *
o *
A
A
A
o
Water-borne solvent
X X
For paper ® *
.for plastic *
0 *
For paper o *
for plastic x
For paper o *
for plastic * x
X X
A
X
For offset printing
© *
Elimination of solvent
(ultraviolet-ray radi-
ation curing ink)
0 *
A
x x
A
x x
0 *
A
0 *
A
Usa of
high-solid
ink
A
x x
X X
X X
X X
©
A
A
X X
- 61 -
PROCEEDINGS—PAGE 73
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
Annex I.
Total Amounts of Hydrocarbons, which are discharged
from Stationary Generation Sources, by Generation Source
(Summary Table) in FY 1973. ,. ^
Generation Sources
Petroleum
Industry
Petro-
chemical
Industry
Paint
Industry
Printing
Ink
Industry
Others
Plants-
Oil-Manufacturing
Plants : Tanks
Oil-Storing Facilities;
Tanks
Oil-Fuelling
Facilities
Plants
Tanks
Manufacturing Processes
Paint Solvents
Paint for Car Body
Solvents paiat Solvents
for Ship-
Building
Others
Manufacturing Processes
Ink Solvents
Solvents for Adhesive
Materials
Solvents for Removal
of Fat on Metal
Solvents for
Cleaning
^Solvents for
Rubber
Combustion Processes
T o t a 1
Discharged
amounts
12,100
67,000
68,100
62,800
69,800
4,900
1,600
37,500
19,900
564,500
200
109,600
42,500
85,000
116,500
51,200
13 , 900
1,315,100
(Percents)
%
-
(5.1)
(5.2)
(4.8)
(5.3)
(0.4)
(0.1)
(2.9)
(1.5)
(42.9)
—
(8.3)
(3.2)
(6.5)
(8.9)
(3.9)
(1.1)
(100)
Sub-
total
198,000
• 74,700
623,500
109,800
309,100
-
(Percents)
%
(15.1)
(5.7)
(47.4)
(8.3)
(23.5)
-
o
o
3J -T—
O 4J
e 3
LU a) o
O >— a.
«* c:
o_ o s-
i
i
c/i s
CJ3 rt3 •—
z a-
-------
Annex I HC CONTROL TECHNOLOGIES
HC control
technology
degree of development
reduction rate
storaging and
circulation
of HC
painting
printing
tanks
loading a'nd
receiving
facility
paint
producing
factories
painting
factories
ink
producing
factories
printing
factories
general chemical
factories
cleaning laundry, rubber
processing ind.,metal
degreasing ind.,etc.
a. combustion
technique
direct
combustion
technique
developed
A
A
O
©
O
©
©
A
oxidation
technique
with catalyzer
developed
more than
90 %
O
©
O
©
©
A
b. absorption technique,
etc.
charcoal
technique
developed
more than
95 %
QL_
©
©
©
©
©
©
©
solution
technique
developed
80~95 %
in summer
O
©
O
O
O
O
O
O
condensation
technique
developed
80 %
in summer
A
A
A
A
A
A
A
A
c.use of
close'd
system
vapor
return
system
etc.
developed
©
©
O
O
O
d . improvement
in tank
filling
floating
roof /internal
floating
roof
Developed
©
©
e.improvenent
of products
paint
under
A
ink
others
development
A
A
A
(5):easy for adopting and very effective, Qtpossible for adopting, ^tpossible for adopting among a few facilities
PROCEEDINGS--PAGE 75
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
-oo
o -i
rt rt -o
o rr 73
o o
3- cz o
fo co m
3 i m
-J. C.O
o o< t-«
—' O» CD
3 CO
-J O T3
~O —h O
o n> m
—• -J
—• fD "-J
c: 3 cri
rt O
o
3 O
3
Annex IU COSTS REQUIRED FOR HC CONTROL
HC control technology
a. combustion
techniques
b. adsorption
technique,
etc.
c.use of
closed
system
d . improvement
in tank filling
system.
direct combustion
technique
oxidation technique
with catalyzer
charcoal technique
solution technique
vapor return system
floating roof,
internal floating
roof
initial cost
about 50 million yen for 2Q thousand Mm /h exhaust gas
about 20 million yen for 6 thousand Nm /h exhaust gas
• 3
exhaust gas (Nm /h)
1,000
5,000
10,000
50,000
100,000
construction cpst (million yen)
1^-3
10— J 2
20~45
100-110
180~200
60-70 million yen for 200~300 Nm /h exhaust gas
vapor return system at a gas station, 150-460 thousand yen per tube
costs required
or an internal
capacity
to a floating
roof tank
to an internal
floating roof
tank
for reconstructing a fixed tank to a floating roof tank
floating roof tank (million yen)
1,000 KL 10,0
12 3
8 2.
DO KL 50,000 KL
5 95
3 60
-------
SCIENTIFIC ISSUES RELATED TO OXIDANT CONTROL
presented by B. Dimitriades
Environmental Protection Agency
United States
PROCEEDINGS—PAGE 77
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
SCIENTIFIC ISSUES RELATED TO OXIDANT CONTROL
The emission control for oxidant reduction in the US started in the
early 60's in Los Angeles. Nationwide control strategy was formally
introduced by the federal government in 1971 when the states were asked
to submit emission control standards for the control of oxidants. Shortly
after, it was realized that these oxidant controls were extremely expensive
and even threatened to disrupt the lifestyle. At the same time, we got
reports of high oxidant readings in the rural areas, and we then discovered
that the oxidant problem was not just an urban problem. In fact, violations
of the oxidant standard were more frequent in the rural areas than in many
urban areas. These two factors, to reiterate, the cost of control and the
extent of the rural oxidant problem, are perhaps the two most important factors
that led the technological community both within and outside the federal
government to take another look at the oxidant problem. Thus, in the last
4-5 years, we have been reexamining the oxidant problem by conducting extensive
field and laboratory studies, and by reassessing and analyzing new and old
evidence. The first phase of the reexamination of the oxidant problem was
an in-depth analysis of the problem, in which analysis we identified those
aspects of the problem which were either little understood or they were
subjects of controversial issues. The first phase.is described in a published
report ^ that presents and discusses the key issues as perceived by USEPA.
In the second phase, which is a continuing one, we are doing research which
is addressed to these issues and aims to resolving them. These issues and
related studies and findings are as follows:
JAPCA, vol. 27, NO. 4, pp. 299-307, April 1977 PROCEH)IH6S~P«E 79
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
ISSUES
1. Measurement of oxidants
2. Importance of natural sources of oxidants
3. Role of oxidant transport
4. Optimum control strategy
5. Organic emission reactivity
6. Emission to air quality relationships
It's important to remember that these reports reflect not EPA's viewpoint;
they reflect the viewpoints of experts that were contracted from universities
and state agencies. We agree with some of these viewpoints, but we disagree
with others. The EPA viewpoint can be found in the oxidant criteria document,
a draft of which is now available, but it will be finalized by mid-1978.
On the ozone/oxidant measurement issue, one question of interest is
whether it is ozone or oxidants that should be measured in the atmosphere.
The EPA reference method is specific for ozone. The reasons why EPA preferred
the specific method for ozone were that
a) Ozone was suspected to be the specific oxidant responsible for health
effects.
b) Ozone forms hand-in-hand with other oxidants and therefore it can be
viewed as a surrogate for those other oxidants.
c) Ozone can be measured much more reliably relative to the oxidant
mixture.
More recent studies by EPA and non-EPA researchers convinced EPA that
ozone is responsible for adverse health effects, and EPA is now ready to
PROCEEDINGS—PAGE 80
rourth US-Japan Conference on
Photochemical Air Pollution
-------
abandon the oxidant concept altogether and promulgate a National Air
Quality Standard for ozone, not oxidant. Thus, in the future, it is
expected that both the measurement and air quality standard will refer
to the same species, ozone.
On the issue of natural sources of oxidant, the question is how much
of the oxidant and ozone at ground level comes from natural sources?
The significance of this question is that the natural contribution to
ground level ozone must be known if the benefits from anthropogenic
emission control are to be estimated reliably. The EPA recognizes two
natural sources: intrusions from the stratosphere and photochemical
reactions of natural organic emissions.
In regards to stratospheric intrusion, recent studies have shown that
on occasions, usually in the Spring months of the year, stratospheric ozone
accumulation at ground level could reach as much as 0.2 ppm ozone or slightly
above. During the smog season (summer and early fall), the frequency and in-
tensity of intrusions are not known. From indirect evidence, we estimate the
average stratospheric ozone during the smog season to be 30 ppb (at ground
level). Recently, a new method has been developed by which stratospheric
ozone concentrations can be measured directly during the smog season. This
method is based on measuring radioactive beryllium ( Be) and radioactive
32
phosphorus ( P). Some measurements have been made in a mountain site in
New York, and we are about to start a measurement program in Houston, Texas.
On the other natural ozone source, photochemical reaction of natural
organic emissions, EPA believes that some ozone may come from the reaction
PROCEEDINGS—PAGE 81
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
of natural methane and some from vegetation-related emissions. We are
not sure about the magnitude of the methane contribution, perhaps 10 ppb
is the most we can expect. The vegetation emissions (terpenes) do not
seem to cause appreciable terpene concentrations in the ambient air, only
a few ppb at most. Considering this, and the oxidant reactivity of these
emissions, we have estimated that 10-20 ppb of 0~, at the most, can arise
from this source. Not everyone agrees with EPA. Some investigators claim
that they have measured natural organics at 1 ppm or more.
On the oxidant transport issue, the important question is how much of
the oxidant observed in an urban area originates from local sources, and
how much comes from outside the city. We must know this if we are to
estimate the impact of local emissions on urban air quality, and if we are
to decide whether controls need to be applied upon the upwind sources.
From recent studies, we have found that oxidant transport definitely
occurs at distances from a few km up to perhaps a thousand km. Short
range transport is usually seen in the form of urban ozone plumes which
have been observed very clearly through aircraft measurements to extend as
far as 100-150 miles. Long range (i.e. several hundred miles) transport
has been associated with high pressure, stagnating anticyclone systems.
These high pressure systems cause stagnation conditions over large areas
within which emissions persist with little dilution and react for a number
of days. The result is formation of an "ozone blanket" that covers the entire
high pressure cell area. While we understand the qualitative aspects of
PROCEEDINGS—PAGE 82
Fourth US-Oapan Conference on
Photochemical Air Pollution
-------
this pollutant transport phenomenon, it is the quantitative aspects that
need further study. To explain, when oxidant in a city results from local
emissions (there is no extraneous ozone transported in), then the system
is simple and we have been able to quantify it, that is, we have derived
quantitative relationships between emissions and ambient ozone. Thus, for
this simple situation, the chemistry is well known, dispersion is relatively
limited, and the natural sources are unimportant. However, when considerable
part of the ozone observed is extraneous ozone transported in, then
quantitative relationships are not easy to derive. This is because (a) the
chemistry of such a system, which is reacting for several days, is not very
well known, (b) dispersion is a much more important factor now; and (c) it
is also conceivable that natural emissions or their reaction products may have
a role now. We are just now begining to explore this field in a quantitative
way by developing mathematical models that will treat long-range transport.
The two issues left to be discussed, pertain to the reactivity of organic
emissions, and to the emission to oxidant relationship. In regards to
the reactivity issue, the question is: in view of the pollutant (long range)
transport phenomenon, which organics should be exempted from control as
being truly unreactive. Alternatively, where do we draw the border line
separating the non-reactive organics from the reactive ones?
Two approaches have been offered to answer this question. One is the smog
chamber approach; the other is the modeling approach. By the smog chamber method,
organics are tested in the laboratory and are placed in an order of reactivity
based on the amount of ozone they produce in the smog chamber test. To obtain
PROCEEDINGS—PAGE 83
Fourth US-Oapan Conference on
Photochemical Air Pollution
-------
such reactivity data, smog chamber experiments have to be conducted under
a large variety of conditions (initial concentrations and ratio of organic
and NO reactants). The problem with the smog chamber method is that the
A
reactivities of the very unreactive reactants cannot be measured with
confidence because the chamber artifacts interfere seriously with the
measurement. Also, the chamber method yields data on the organic's
reactivity in the smog chamber but not necessarily in the real atmos-
phere. By the modeling method, the reactivity of an organic could
conceivably be estimated; however, the method is not ready yet to be
used since the model method can be applied only on those organics for
which the reaction mechanism is known. For the time being, we feel
that the best way of answering the question at issue is through combined
use of the smog chamber and modeling techniques. The smog chamber technique
could be used to place the organics in an order of reactivity and the
modeling method could be used to define one organic which is at the border-
line separating the unreactive from reactive ones. Studies are continuing
in the U.S. on these two approachs. We should mention that we have received
from Japan a large number of reactivity data which we thought were excellent
and of great help.
F PROCEEDINGS—PAGE 84
'ourth US-Japan Conference on
Photochemical Air Pollution
-------
TREND OF PHOTOCHEMICAL OXIDANTS
IN JAPAN
presented by S. Imai
Environment Agency
Japan
PROCEEDINGS—PAGE 85
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
Con-bents
Page
1. Introduction ., 1
2. Frequency of warnings issued by four major areas 5
3. Frequency of warnings issued simultaneously for
wider areas 13
4. Concentration of photochemical oxidants on days
when -a warning is issued 15
5. Frequency of warnings issued on the meteorologically
potential days -»~............>..., 18
6. Reports of affected people _ 22
Reference data: 26
1. Temperature, flux of solar radiation, and frequency of
warnings in the Tokyo Bay area in 1973 - 1977
2. Relation between the meteorologically potential days
and days when a warning is issued.
PROCEEDINGS—PAGE 86
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
1. Introduction
To examine the occurrence of photochemical oxidants
and injuries resulting from it in 1977, the Bureau compiled
related data from the last five years.
In view of the fact that the formation of photochemical
oxidants is affected by geographical and meteorological
conditions, we tried, to ascertain not only national con-
ditions as a whole but also trends in major areas. For
this purpose, four areas were selected: the Tokyo Bay area,
the Ise Bay area, the Osaka Bay area and the Seto Inland
Sea area.
This study was conducted on the following points:
(1) Frequency of warnings issued by four major areas7
(2) Frequency of warnings issued simultaneously for
wider areas;
(3) Maximum concentration of photochemical oxidants
on days when a warning is issued;
(4) Frequency of warnings issued on the meteorologi-
cally potential days;
(5) Reports of affected people.
As a result of this study, we found that though the
meteorological conditions in 1977 were conducive to the o.ccur-
rence of photochemical oxidants, the frequency of warnings
issued was lower than previous years both nationally and
PROCEEDINGS—PAGE 87
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
regionally. Also/ the generation of the oxidants in a
wider area was found-to decline, and maximum concentration
went down.
The number of days when sufferers reported was con-
siderably reduced, and the number of people reporting
suffering per day remained on a similar level to 1976.
PROCEEDINGS—PAGE 88 - 2 -
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
Table
Frequency of oxidants warnings issued i
1970 ^1977 (In number- of days)
^\^^ Year
Pre^^^
f ecture ^'^"^^
1 Miyagi
2 Fukushima
3 Ibaragi
4 Tochigi
5 Gunma
6. Saitama
. 7 Chiba
8 Tokyo
9 Kanagawa
10 Shizuoka
11 Aichi
12 Mie
13 Shiga
14 Kyoto
15 Osaka
16 Hyogo
] 7 Nara
18 Wakayama
19 Okayama
20 Hiroshima
21 Yamaguchi
22 Tokushima
23 Kagawa
24 Ehime
Total
'70,
7
7
'71
23
19
33
11
1
4
7
98
'72
16
15
21
33
31
5
4
7
18
19
1
1
3
2
176
'73
3
21
10
1
45
28
45
30
8
8
6
4
17
26
23
6
11
14
9
1
22
328
'74
14
10
4
29
26
26
26
15
2
7
4
17
27
19
3
1
16
18
5
2
4
13
288
'75
3
17
6
11
44
33
41
27
6
6
4
11
23
11
9
5
4
1
2
1
1
266
'76
1
9
7
1
15
21
17
17
3
3
3
5
6
25
3
3
1
1
2
3
4
150
'77
18
11
26
7
21
12
1
2
1
1
9
25
4
3
5
6
5
3
7
167
- 3 -
PROCEEDINGS—PAGE 89
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
Table 2. Frequency of oxidants warnings issued by
month in 1977 (In number of days)
^"•x. Month
Pre— ^^^^
fecture^^\
1 Miyagi
2 Fukushima
3 Ibaragi
4 Tochigi
5 Gunma
6 Saitama
7 Chiba
8 Tokyo
9 Kanagawa
10 Shizuoka
11 Aichi
12 Mie
13 Shiga
14 Kyoto
15 Osaka
16 Hyogo
17 Nara
18 Wakayama.
19 Okayama
20 Hiroshima
21 Yamaguchi
22 Tokiishima
23 Kagawa
24 Ehime
Total
3
1
1
1
4
1
1
1
1
i
1
5
5
2
3
4
1
1
1
1
3
16
6
1
2
2
1
7
2
1
2
1
1
4
2.4
7
10
7
11
3
11
4
1
1
3
7
1
1
1
3
1
65
8
4
2
6
2
4
2
1
1
1
3
5
1
1
3
36
9
2
1
1
1
3
1
1
2
12
10
1
2
1
2
2
8
Total
18
11
26
7
21
12
1
2
1
1
9
25
4
3
5
6
5
3
7
167
PROCEEDINGS—PAGE 90
Fourth US-Japan Conference on
-------
Table 3. Frequency of oxidants warnings issued by month:
1972 - 1977
^\Month
Year \.
1972
1973
1974
1975
1976
1977
3
0
0
0
0
0
1
4
5
17
11
2
6
5
5
14
26
52
19
21
16
6
34
31
81
47
22
24
7
31
126
28
72
29
65
8
54
108
90
68
47
36
9
25
16
17
52
12
12
10
13
4
9
6
13
8
Total
176
328
288
266
150
167
2. Frequency of warnings issued by four major areas
(1972 - 1977)
It is considered that the formation of photochemical
oxidant is considerably affected by different meteorological
conditions, conditions of stationary sources, air advection
patterns, and other regional conditions.
Considering this, we selected the following four
regions as major areas:
Tokyo Bay area: Tokyo, Kanagawa, Chiba and Saitama;
Ise Bay area: Aichi and Mie;
PROCEEDINGS—PAGE 91
Fourth US-Japan Conference on
Photochemical Air Pollution
- 5 -
-------
Osaka Bay area: Osaka, Kyoto, Hyogo and Nara;
Seto Inland Sea area: Okayama, Hiroshima, Yamaguchi,
Kagawa and Ehime.
The combined total number of days in these four areas
when a warning is issued accounted for about 80 % of the
nation's total in 1977. In years 1973 to 1977, the number
of days when a warning is issued was greatest in the Tokyo
Bay area (about 40 % of the total), followed by the Osaka
Bay, the Seto Inland Sea, and the Ise Bay areas.
The fewest number of warning days in the past five
years was recorded in 1976 both for the nation and in each
of the four areas. The figure for 1977 was lower or on a
similar level compared with 1976, except in the Seto Inland
Sea area (Fig. 1).
In the Tokyo Bay, the Osaka Bay and the Seto Inland
Sea areas where the number of warning days has been
relatively high, when comparing the average monthly number
of warning days in the past five years with that in 1977,
the latter was less in each of the four areas (Figs. 2-1 -
2-4)
In general, the number of warning days has tended to
decline gradually. Offset against meteorological con-
ditions, as we discuss in 5. below, the declining trend is
evident.
PROCEEDINGS—PAGE 92
Fourth US-Japan Conference on
Photochemical Air Pollution
- 6 -
-------
Table 4. Number of warning days by year and month
r-l
CO
C
o
u
CO
z
OS
a)
3
a
01
x u-
C3 Q.
«
Q
x -o
Jri C
O 31
o
o
S-r
01
c 3
UJ O> O
CJ3 4- CU
< c
Q. O 5-
I <_3 T-
I <
t/0 C
C3 fO r—
Z Q. «
i— i ro CJ
Q O •!-
LU I £
LU CO O>
CJ ^ .C
O O
C£. J= O
Q. 4-> -M
S- O
3 -C
O 0.
-------
(day:
•200 -
National
Tokyo Bay
19/3 1974 1975 1975 1977 (year):
Fig. 1 Number of Warning Days from April to October:
(1973 - 1977)
Note: The number of warning days is the total of such
days from April to October which is obtained by
adding figures of prefectures comprising the
whole nation and each area.
PROCEEDINGS—PAGE 94
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
fo-
Maximum monthly number of
~* warning days in 1973— 1977
_O Average monthly number of
warning, days in 1973 - 1977
-*• Monthly number of warning
days in 1977
T~
a
(month)
2-1 Monthly Trend_of__the Number nf
(National)
navs
*
- 9 -
PROCEEDINGS—PAGE 95
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
-o?
a -s
rtr+ -o
o 3- ;o
n o
o
co m
3 i m
-J.C_ O
n o* H-J
en
3 tn
So!
-j o -o
3 3>
-o-h cn
o ro m
—•-i
— «n> vo
C 3 W
ri-0
-J.fD
o
3 O
3
(day)
,525
I
M
O
(month)
Fig. 2-2 Monthly Trend of the Number of Warning Days (Tokyo Bay Area)
-------
(day)
30-
-a o
^r c
o T
<-t- rt- "O
o 3-33
n o
3- cro
ec/> rn
i m
SP-
n o»
ft> T3
en
-•• O I
-j o -o
3 3>
-a -h£T)
o m m
— ' -j
— • rt> LO
C 3 ^
rt O
a
(month)
Fig. 2-3 Monthly Trend- of the Number of VJariung Days (Osaka Bay area)
o
3
-------
-n
-o o
3- c
o -j
rt- <-•• ~a
o 3- 73
o o
Scorn
i m
-J. C-4C3
O C" «—i
fV "O ^££
-•• O I
-S O TJ
o CD m
—' -$
—' fO «3
C 3 CO
r+ O
o
3
(day)
I
M
NJ
3,0 -
(month)
Fig>. 2-4 Monthly Trend of the Number of Warning Days (Seto Inland Sea area)
-------
3. Frequency of warnings issued simultaneously for wider areas
(June - August, 1974 - 1977)
In the Tokyo Bay area where the number of warning days
is comparatively great and air advection phenomena are more
conspicuous, we studied the number of days when warnings
were issued simultaneously for wider areas.
In this area, the number of days when a warning was
issued for the total four prefectures was seven in 1974,
nine in 1975, four in 1976 and one in 1977, showing a
drastical decrease.
A similar declining tendency is observed in the case
of the number of days when a warning was issued for three
or two prefectures, and the percentage of warning days for
only one prefecture is increasing..
The maximum value of the average concentration of
oxidant ( ' on the days when a warning was issued for the
total four prefectures was 21 pphm in 1974, 22 pphm in 1975,
22.8 pphm in 1976, and 18.3 pphm in 1977, again indicating
a substantial decrease.
Note: The maximum concentration of each prefecture on the
day when a warning was issued for the total four
prefectures, is added and the total is divided by
four. This figure is the maximum average concent-
ration on the day in the area. The maximum value is
the highest of such average maximum cencentrations.
- 13 -
PROCEEDINGS—PAGE 99
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
Table 7. Number of days when a warning was issued simultaneously
for wider areas (June - August, 1974 - 1977)
Tokyo Bay Area
Pre- -^^^^
features ~~~" -~^_^^
warned •— >— «^
No. of days when the total 4
prefectures were warned.
(FPI*~)
Maximum value or average maxi-
mum concentration of oxidant..
No. of days when three or more
prefectures were warned.
NO. of days when two or more
prefectures were warned.
No. of days when a warning was
issued for only one prefecture.
1974
7
21
13
17
12
1975
9
22
19
30
10
1976
4
22.8
7
14
5
1977
1
18.3
6
12
14
Table 8. Percentage of warning days in Saitama
in the Tokyo Bay area (%)
^\Month-
Xear -^_
1973
1974
1975
1976
1977
4
53
0
0
0
,. 5°
5
43
29
18
10
38
6
11
29
33
17
20
7
29
46
45
33
38
8
28
26
30
26
43
9
0
29
25
33
50
10
100
0
0
0
40
4-10
30
27
30
21
39
PROCEEDINGS—PAGE 100
Fourth US-Oapan Conference on
Photochemical Air Pollution
- 14 -
-------
4. Concentration of photochemical oxidants on days when a
warning is issued (June - August, 1974 - 1977)
As described above, it is observed that the number
of warning days has been declining. So, how about the
oxidants concentration on warning days? We studied this
in the Tokyo Bay and the Osaka Bay areas where warnings
were more frequent than other areas.
First, we found that in both areas the maximum
concentration was lowest in 1977 in the previous years
(1974 — 1977). In particular, in the Tokyo Bay area, the
figure substantially declined in 1977, except in 1976 when
both temperature and flux of salar radiation were abnor-
mally low.
Next, we studied the relation between frequency of
warnings and concentration on warning days. In the Tokyo
Bay area, warnings were most frequently issued around 14
pphm and 18 pphm. But in 1977, there was no peak around
18 pphm, and as the concentration became higher, the
number of warning days gradually declined. Also, the
number of warning days showed a substantial decline in
general in each grade "of concentration (Fig. 3-1?.
Similarly, in the Osaka Bay area (Fig. 3-2), two
peaks were observed. But in 1977 there was only one peak
at 16 pphm. This was higher than the peak at 14 pphm in
1974 - 1976, but in higher concentration grades, the
figures in 1977 were lower than the previous three years.
- 15 •- PROCEEDINGS-PAGE 101
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
T30
3- C
O -S
ct- <-t ~o
o rr TO
n O
3- ci o
§i/> rn
i m
-j. c_, o
o c" •— «
p* -a z
— ' cu d)
3 I/)
~S O "O
3 J>
"O -h CD
o n> m
— • -5
— • (0 — '
C 3 CD
rt O ro
-•• fD
o
3 O
en
I
X >< 1975
Concentration Grades (pphm)
Fig. 3-1 Number'of Warning Days by Concentration Grades
in the Tokyo Bay Area (June - August)
-------
-4
1
-o o
zr c
o -i
o
o
o
n> to m
3 i m
—i. c_.o
O CU t—»
(0 TD Z
—• fu CD
-•• O I
-J O ~O
"O -ti CD
o rt> m
—• -j
c: n o
r+ o co
-J.
o
3 O
3
(day)
M
n?
U>
C
-H
B
g
m
O
0)
t '15
in 1975, 1977
in 1974
23
Concentration Grades (pphm)
Fig. 3-2 Number of Warning Days by Concentration Grades
in the Osaka Bay Area (June - August)
-------
5. Frequency of warnings issued on the meteorologically
potential days
The occurrence of high-concentration oxidant has a
close relation to weather conditions, especially, wind
velocity, wind direction, temperature, flux of solar
radiation and weather. In view of this fact, the
Environment Agency compared and analyzed observation and
weather data from the Tokyo District Meteorological
Observatories and conditions of warnings issued in Tokyo
and Saitama prefecture, and determined as meteorologically
potential days those days which meet the following
conditions:
Factor
Description
Flux of global
solar radiation(R)
Wind velocity
(V)
Wind direction
(D)
Temperature (T)
Weather (W)
2 hrs. or more of radiation of 30 cal/cm /h
between 9:00 - 15:00.
An average velocity of 5 m/s or less at
9:00, 12:00, and 15:00.
Wind with southerly component between
9:00 and 18:00.
A maximum temperature of 24 °C or higher
Fine (including slightly cloudy) or
cloudy at 9:00, 12:00 and 15:00.
The number of meteorologically potential days in 1977
was generally on a similar level in 1973 between June and
August (Table 9).
PROCEEDINGS—PAGE 104
Fourth US-Oapan Conference on
Photochemical Air Pollution
- 18 -
-------
However, the percentage of the number of warning dayson
potential days has declined. The figure in 1977 showed
a substantial decrease when compared with averages of the
past five years (Fig. 4).
Note (1): Report of Meteorological Observation Survey for
Emergency Measures against Photochemical Air
Pollution, Air Quality Bureau, Environment
Agency, February, 1977.
PROCEEDINGS—PAGE 105
_ 19 _ Fourth US-Japan Conference on
Photochemical Air Pollution
-------
o
1=
rfr
c= o
to m
i m
fu t—i
-o -z.
3 01
O »
O T3
3 3>
-h(T>
n> m
Table 9. Relation between potential days and warning Days
3 0
o
n>
o
3
'^^----^^^ Month
Item ^^-^^
No. of potential
days A
No. of warning days
B
No. of waring days
on a potential
day C
No. of xvarning days
on a non-potential
day D ^^,.1^
June
48
9
4
4
0
44
49
12
9
7
2
58
50
14
9
9
0
64
51
8
1
1
0
13
52
9
3
3
0
33
July
48
18
19
16
3
89
49
6
6
6
0
100
50
18
14
14
0
78
51
14
6
6
0
43
52
19
13
11
2
58
August
48
17
15
14
1
82
49
19
12
11
1
58
50
18
14
14
0
78
51
14
8
6
2
43
52
13
6
6
0
46
-,
Total
48
44
38
34
4
77
49
37
27
24
3
65
50
50
37
37
0
74
51
36
15
13
2
36
52
41
22
20
2
49
(Note) 1. The number of potential days is calculated using data from the Tokyo District
Meteorological Observatories.
2. The number of warning days is the total of warning days tn Tokyo and Saitama
prefecture minus overlapping days.
-------
>t
(0
T3
rtj
•H
-P
c
-------
6. Reports of affected people
The number of people who were thought to be affected by
oxidants decreased drastically in 1977. But as the number fluctu-
ated up and down so sharply that it may not help observation
of the actual trendt we used the number of -Says when any
report of oxidant effects was made as the fundamental data
for analysis.
The peak of the number of days when such a report was
received came in 1975 when the number of people reporting
oxidant effects was largest. After that, the figure tended
to decline. This trend was observed both nationally and
in the Tokyo Bay and the Ise Bay areas. Also, in each
area, the number of days reported substantially decreased
in 1977 compared with in 1974 (Fig~ 1) .
In the Tokyo Bay area, the number of days reported
accounted for about 50 % of the nation's total, and its
trend corresponded with the national tendency.
The Ise Bay area, where the number of warning days was
the least of all four areas/ was ranked second in terms of
the number of days reported after the Tokyo Bay area.
The trend in the Osaka Bay and the Seto Inland Sea
areas differed slightly from.the other two: there was no
peak in 1975.
The number of people reporting per day was the
PROCEEDINGS—PAGE 108
Fourth US-Oapan Conference on - 22 -
Photochemical Air Pollution
-------
highest in 1975, too, excluding the Osaka Bay and the
Seto Inland Sea areas. Nationally speaking, 1975 was the
year when oxidant effects had the greatest possibility of
occurring". (Fig. 2)
The condition in 1977 was at a similar level to 1976.
But, taking the weather conditions in 1977 into account,
we can say that some improvement is seen in 1977.
While in the Tokyo Bay and the Ise Bay areas the
condition was at a similar level in 1976 and 1977 after
a peak in 1975, in Osaka Bay and the Seto Inland Sea areas,
the figure in 1975 was far lower than that in 1974 and
thereafter gradually increased (in the Seto Inland Sea
area) or remained on a similar level (the Osaka Bay area).
PROCEEDINGS—PAGE 109
- 23 - Fourth US-Japan Conference on
Photochemical Air Pollution
-------
National
1S74
1975
1976
. Tokyo Bay
-. Seto Inland Sea
197*7 (year).
Table 1. Number of Days Reported (April - October)
PROCEEDINGS-PAGE 110
Fourth US-Japan Conference on
Photochemical Air Pollution
- 24 -
-------
(day)
300
200
/ao
Tokyo Bay
area
National
Seto Inland
area
1974
1975
1976
19r7-7 (year)
Table 2. Nuziber of People Reporting/Number of Days Reported
(April - October)
- 25 -
PROCEEDINGS—PAGE 111
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
Reference ctatai
1. Temperature/ flux of solar radiation, and frequency
of warnings in the Tokyo Bay area (April - October)
380
April
Monthly average temperature
1973
1974
1975
1976
Flux of global solar radiation
(cal/cm2/day)
Frequency of warning days
(days/prefecture)
Part of data not available
^day/pre-
fecture)
\a
1977 (year)
20 -
¥23
380 \
\
/7
300
May
\ (day/pre-
feature)
1973
PROCEEDINGS—PAGE 112
Fourth US-Japan Conference on
Photochemical Air Pollution
1974 1975 1976 1977 (year)
- 26 -
-------
June
280
j( day /pre-
fecture)
so
1973 1974 1975 1976 1977 (year)
°c
324
280
J-glv
1973
(day/pre-
fecture)
1974
1975 1976
1977 (year)
PROCEEDINGS—PAGE 113
Fourth US-Oapan Conference on
Photochemical Air Pollution
-------
2.3 -380 -
Aucms-fc
[(day/pre-
fecture)
1973 1974 1975 1976 1977 :(year)
Saptember
t
300
230-
(day/pre-
fecture)
10
8
6
4
2
1973 1974 19-75 1976 1977 (year)
PROCEEDINGS-PAGE 114
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
October
/
S&G
(day/pre-
fectiare)
19-73 1974 1975 1976 1977 (year)
- 2.9 -
PROCEEDINGS--PAGE 115
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
2. Relation between the meteorologically potential days
and days when a warning is issued
(1) Introduction
In this section/ we studied weather factors on days
when an oxidant warning was issued in Tokyo and Saitama
(in part of the analysis, including Kanagawa) in the past
four years, and found the minimum or maxim-am conditions
for each factor using the upper limit curve method.
Then, with reference to the minimum and maximum con-
ditions, a standard was established by changing combinations
of grades of factors.
As weather factors for this study, we used data on
temperature, flux of solar radiation, wind direction, wind
velocity and weather from the observation data of the Tokyo
District Meteorological Observatories.
(2) Minimum values or conditions of weather factors
Figs. 1-a - 1-d show the minimum values of flux
of solar radiation and wind velocity. Some differences
are seen by years, but on average, the minimum value of
2
maximum flux, of solar radiation is about 30 cal/cm /h, and
that of wind velocity about 5 m/s.
As indicated in Fig. 2, the minimum value of maximum
temperature is 24.1 °C (Only figures in June are shown).
PROCEEDINGS—PAGE 116
Fourth US-Japan Conference on - 30 -
Photochemical Air Pollution
-------
0 concentration is apt to increase when there is a
Jx
breeze off the land in the morning and then the wind
changes to one from the sea. However, when a warning is
issued in Saitama, there are a lot of cases when a wind
with a southerly component blows from midnight and no land
breeee is observed. Similar cases are seen in Tokyo too.
On the contrary, in Kanagawa, a northeasterly wind
frequently blows when a. warning is issued.
Thus, the minimum conditions of wind direction are
hard to determine when we analyze a wider area. In this
study, in which our subject is Tokyo and Saitama, we
determined as the minimum condition "the existence of a
wind with a southerly component in the daytime."
It seemed that there was no need to consider weather
as one of the factors because it is directly or indirectly
represented in flux of solar radiation and temperature.
But as it is one of the representative weather factors, we
added it as one factor to be analyzed.
An 0 warning is sometimes issued on a cloudy day,
J^
but it is rare on a rainy day (a day when it rains at 9:00,
12:00' and 15:00) .
Therefore, the minimum condition of weather
was determined as "a cloudy, rainless day".
PROCEEDINGS—PAGE 117
Fourth US-Oapan Conference on
Photochemical Air Pollution
-------
(3) Meteorologically potential days and their number
The above-mentioned minimum values or conditions of
weather factors are the. minimum weather conditions observed
on those days in the past four years when an 0 warning
X
was issued. The number of days when the minimum conditions
are met is very great, and it does not seem to be suitable
for an analysis of photochemical smog. Therefore/ we made
each condition severer and considering the number of warn-
ing days to be included when the conditions become severer,
determined standards of weather conditions which were con-
sidered the most suitable.
(Note 2.) (Table 4-1-3)
Note 2: We tried to find the best combination of the grade of
each weather factor in determining the standards of
weather conditions so that the percentage of the
number of warning days on such days that meet the
standards to the number of such days that meet the
standards may be as high as possible, and so that the
percentage of the number of warning days on such days
that do not meet the standards to the number of such
days that do not meet the-standards may be as low as
possible.
PROCEEDINGS—PAGE 118
Fourth US-Japan Conference on - 32 -
Photochemical Air Pollution
-------
o
o
IT)
o
o
^ 70
60
a
o
•H
-M
-------
o
o
in
8CV
o
o
7C
JG
CJ
160
nj
o
C
o
•H
-P
tU(
3(
O
(0
o
32Cf
H
«M
1C
0
X X
• • x
x x • x
' x
xx
, 4
(x)
X
X
c
o c
o
Ol-r-
o o-u
co c: 3
i— (Ui—
UJ O) O
CD M-OL
<£ C
Q. O J-
1 O-r-
z: Q-»O
»-« fO O
Q Tr-
uu t E
UJ «/) O)
_
o o
Oi -C O
O. +J4->
J- O
OCL
1974 June - August
«• Days when an O warning was issued.
X Days when no such warning was issued.
i_
10
_i—
11
i
12
Fig. 1-b. Maximum flux of_solar radiation
and wind velocity
Wind velocity (average
of values at 9:00, 12:00
and 15:00) (m/s)
-------
o
o
to
i 80
o
o
4->
$- o
OQ_
I
id
S
10
0
X
Fig. 1-c. Maximum flux of solar radiation
and wind velocity
1975 June - August
• Days when an O warning was issued.
X Days when no such waning was issued.
10
11
12
Wind velocity (average of
values at 9:00, 12:00
and 15:00) (m/s)
-------
in
o
0
**
^^
\
^ 70
»%
v^
id
u
~ 60
C
O
•H
-P
«tf
3 50
rt
M
nJ 40
0
w
»R
O
X
x K x
y
X
x •
x y
x . x • x X x *
x x *
0
.V x x
** >? „ x
• X x >
x x • x*^ )
xx xx x * !
A X 1
X
xx x
X
30 -
c
o c
o
0) -r-
CM O -P
C 3
(Ur—
CvJ
X
UJ Olo
tD H- CU
«t C
0. O J-
I O -r-
I <
CO C
13 <0 t—
Z Q. «J
HH ro O
Q >-p -r-
LU | £
UJ to OJ
o ^3 x:
O O
a: JT o
o. +j +j
J- o
3 x:
o CL
X
a-
20 .
10 .
0
xx
X X
x _
8
Fig. 1-d Maximum flux of solar radiation
and wind velocity
1976 June - August
• Days when an 0 warning was issuGcl.
x
X Days when no such warning was issued,
_i 1
i i _»
9 10 11 12
Wind velocity (average of
values at 9:00, 12:00 and
15:00) (m/s)
-------
°c
24
Temp.
min.
22
x x
X
20
X " X x
x ••
18
16
XX
x X X
xx x x | x x
V I ' *
x I*
14
12
18
20
22
24
26
28 30
Temp . max .
Fig. 2 Maximum temperature and minimum teperature
(June, 1973-1976) • Days when an 0 warning was issued.
* Days when no such warning was
issued.
- 37 -
PROCEEDINGS—PAGE 123
Fourth US-Oapan Conference on
Photochemical Air Pollution
-------
Table 1.
Minimum values of maxim-urn flux of solar radiation and average
wind velocity on warning days in Tokyo and Saitama prefecture
>v Factor
Year\
1973
1974
1975
1976
1977
Maximum flux of
solar .radiation
2
cal/cm /h
Minimum
value
26
36
37
27
32
Second lowest
value .
37
38
42
41
40
Average wind
velocity
m/s
Minimum
value
4.9
4.8
3.7
4.7
4.5
Second lowest
value
4.1
4.6
3.4
4.4
4.1
Maximum flux of solar radiation: One-hour maximum value
between 9:00 and 15:00
Average wind velocity: Average value of velocity at
9:00, 12:00, and 15:00.
Table 2. Standards of meteorological conditions for Tokyo
and Saitama
Factor
Description
Flux of global
solar radiation(R)
Wind velocity
(V)
Wind direction
(D)
Temperature (T)
Weather (W)
2 hrs. or more of radiation of 30 cal/cm /h
between 9rOO - 15:00.
An average velocity of 5 m/s or less at
9:00, 12:00, and 15:00.
Wind with southerly component between
9:00 and 18:00.
A maximum temperature of 24 °C or higher
Fine (including slightly cloudy) or
cloudy at 9:00, 12:00 and 15:00.
PROCEEDINGS—PAGE 124
Fourth USrJapan Conference on
Photochemical Air Pollution
- 38 -
-------
EMISSIONS TO OXIDANT AND N02 AIR QUALITY RELATIONSHIPS
presented by B. Dimitriades
Environmental Protection Agency
United States
PROCEEDINGS—PAGE 125
Fourth US-Oapan Conference on
Photochemical Air Pollution
-------
EMISSIONS TO OXIDANT AND N02 AIR QUALITY RELATIONSHIPS
On the subject of methods for relating emissions to ambient ozone
and NO^, we wish to report here two significant developments: (a) EPA has
developed a new method, the isopleth method, for relating emissions to ozone,
and (b) in 1977, EPA removed the requirement that the Appendix J method be
the only method to be used in the preparation of State Implementation Plans.
EPA now feels that other methods can be used, for example, the rollback
method, the isopleth method, and air quality simulation models. Of the
methods pertaining to ozone, the rollback method and the Appendix J method
are the least acceptable for 3 main reasons.
1. They are not based on cause-effect relationships
2. They do not consider the role of NO
/\
3. They cannot be used in a variety of applications.
Furthermore, the modeling method has not been developed yet to the point
where it can be used. Thus, for the time being the isopleth method is the
most acceptable one.
The isopleth method, often called the EKMA (Empirical Kinetic Mechanism
Approach) method, is based on the use of a mathematical method that predicts
fairly accurately the photochemical behavior of the atmospheric HC-NO
A
reaction system. This mathematical model was validated using smog chamber
data on HC-NO mixtures similar to those found in the atmosphere. Thus, by
A
specifying the sunlight intensity in a given specific city and prevailing
dilution conditions (inversion data), the model will provide the quantitative
relationships between ambient concentration of ozone and concentrations
of NOY and HC.
/\
PROCEEDINGS—PAGE 127
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
To use the isopleth method we need:
1. A measure of ambient ozone air quality (second highest value
observed in reference year).
2. The ratio of non-methane-HC to NO during 6-9 am.
A
3. A measure of N0« air quality, which in the U.S. is the annual
mean ML concentration.
The method has only relative validity and handles only atmospheric
chemistry not dispersion. It does not relate precursor emission rates to
oxidant, but ambient concentrations (of precursors) to oxidant. It can not
treat the effect of ozone transported in from outside the city nor can it
treat sink (removal) processes. However, it has the important advantages
over the earlier methods that it is based on a cause-effect relationship
between ozone and precursors and that it considers the role of NO .
/\
Finally, the air quality simulation model (AQSM) method is based on a
mathematical model of the dispersion, reaction, and removal processes, in the
form of a mathematical equation that is known as the atmospheric diffusion
equation. In order to solve this equation we need:
1. rates of HC and NO emissions with adequate spatial and temporal detail
A
2. meteorological data on atmospheric stability, wind, sunlight, and
temperature
3. the atmospheric reaction mechanism
4. data on removal processes in the form of depostiion velocities
5. initial (early morning) and boundary conditions (concentrations
of pollutants in air masses flowing into the model area)
PROCEEDINGS—PAGE 128
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
The input is very large and complex, making the method difficult and
expensive. However, it has two advantages:
1) It predicts absolute air quality — an important advantage because
it's possible, in principle at least, to validate the method using
real atmospheric data.
2) It can be used in a wide variety or applications.
EPA has been engaged in developing AQSMs for the past several years. We
have just completed a 5 yr study in St. Louis which was designed specifically
to develop and validate this modeling approach. We are now using this infor-
mation to validate several such models. At the end of 1978 or early in 1979
we will finish the first phase of the effort and will have a first assessment
of the accuracy of these models. Following that, we will be testing the
model(s) in cities outside of St. Louis. We are now in the process of
gathering data in other cities for this purpose.
Recent studies concerned with the emissions-to-NCL relationships are
briefly as follows:
EPA has been conducting studies on the occurrence and health effects of
short term (s.t.) concentrations of NCL and has been exploring the need for
a s.t. NCL standard. In one relevant study we examined the 1 hr. and annual
mean N02 data available and specifically the ratio of maximum NCL to annual
NCL concentration, and found that the max. N02 values can be as high as 0.4 ppm
and that the ratio of max. to annual values ranged considerably from location
to location and with time. This latter variation suggests that neither
one of the two indices can represent the other, and that, therefore, we
PROCEEDINGS—PAGE 129
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
may need two standards. Another question of interest is whether the NCL
concentrations are distributed uniformly within the urban area so that
measurements from one or two stations within a city could provide a
reliable measure of NO^-related air quality. The results seem to indicate
that the N02 is uniformly distributed within the city. However, there are
some indications that there may be some hot spots in the heavily trafficked
arteries, suggesting that the concentrations of N02 within roadways, streets,
etc., should be explored further. Existing data, note, are not indicative
of roadway concentrations because the measurement stations are off the
roadways. We also observed that the concentration of N02 degrades rapidly
as we move away from the city into the rural areas where the NCL is barely
detectable.
Another study was addressed to the relative contributions of mobile to
stationary sources to ambient NCL. In that study it was assumed that
(1) CO represents auto exaust (mobile), and
(2) SCL represents stationary source emissions
Using statistical regression analysis to calculate the relative contributions
of the mobile sources and the stationary sources, it was concluded tentatively
that by far most of the NO comes from the mobile sources in the urban areas.
/\
For this reason, EPA is tentatively thinking of placing the NO control
/\
emphasis on the mobile sources.
In another study, we performed an analysis of smog chamber and atmospheric
data in an effort to derive relationships between ambient N02> and HC and
NO , and to determine the effects of HC and NO controls on ambient N0~.
A /\ Cm
PROCEEDINGS—PAGE 130
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
The results were:
1. NO control will probably result in an equal percent reduction in
/\
the maximum or annual NCL.
2. HC control will result in a small effect on the maximum N02 and in
no effect on the annual NCL. The- HC effect was found to be stronger
during the winter time; however, the statistical analysis is such
that the HC effect cannot be distinquished from the meteorological
factors. This means that it's possible that there is no HC effect
at all but the effect observed could be an effect from meteorological
factors.
PROCEEDINGS—PAGE 131
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
PHOTOCHEMICAL OZONE FORMATION IN PROPYLENE-NITROGEN
OXIDE-ORY AIR SYSTEM
presented by M. Okuda
National Institute for Environmental Studies
Japan
PROCEEDINGS—PAGE 133
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
Photochemical experiments were performed investigating
the formation of ozone in propy Lane-nitrogen oxide-drv
air (H70 less than I ppm) system using an evacuabls and
bakable smog chamber.. The maximum concentration of ozone
reached uitimatly, [0,] , were studied varing initial
J ulclX
concentrations of C,H,. (0.1 - 0.5 cram) and NO (0.0093 -
-j o * * x
0.290 ppm) , and also light intensity, k, (0,13 - 0.37 min~~)
When the. initial concentration ratio of C-.H,, and NO is
36 x
larger than about two, the relationship, [0,] - (12.4 •*•
j •
1.5) [0,] was obtained, where [0..] is the photostationarv
O35 J p S ** *"
state concentration of ozone in the absence of C-.H,- for the
J O
same initial concentration of NO- , as that of NO in the
^ ^C
presence of C,Hg. In this initial concentration region,
was found to be proportional to /£7, and the linear
"
relationship between [0.] and. /[NO ]n was obtained.
" 3C U
Introduction
CJsing a so called "smog chamber? or "environmental
chamber," a number of investigations (1-9) has been
conducted on the photooxidation of hydrocarbon (KG)-
nitrogen oxides (NO )-air system in order to evaluate the
^v
effact of initial mixture composition on oxidant err ozone
PROCEEDINGS—PAGE'135
pourth US-Oapan Conference on
Photochemical Air Pollution
-------
formation under simulated atmospheric conditions. Earlier
studies have been reviewed by Altshuller and Bufalini
(10,11)- Although these studies have revealed some
characteristic dependence of oxidant or ozone generation
on the initial concentrations of HC and NO under the
*t
specific experimental conditions, they were not
successful enough to obtain any general relationship
between them due to the complex nature of the dependence.
Recently, an effort to establish a general relationship
between the amounts of ozone generated and the mixture
composition for a cyclohexene—NO -air system has been
X
attempted using a photochemical flow reactor (9).
The establishment of such general relationship in
the smog chamber study is thought to•be of critical
importance for the understanding of ozone formation mechanism
in the atmosphere, and also for proving the usefulness of
smog chamber studies for the planning of ozone control
strategies. From this viewpoint, the photooxidation of
propylene (C,Hg)-NO -air system, which is important as a
basic photochemical smog reaction model, was reinvestigated
in the present work. Although this reaction system has
been studied (1, 2, 6) in some detail in view of obtaining
the dependence of maximum oxident yield on the initial
concentrations of C-H^ and NO , the influece of any
j o x
reaction parameter on the amount of ozone generated has
PROCEEDINGS—PAGE 136
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
not been well established. In this work, the photooxidation
was studied using an evacuable and bakable smog chamber at
the National Institute for Environmental Studies (NIES),
in the lower initial concentration region (C-H-;0.1 - 0.5
36'
ppm; NO ;0,01 - 0.5 ppm) than that for the earlier studies
*£
(1, 2, 6). The .object of this invistigation is to study
the effects of the initial concentration of C3Hg and N0x ,
and also of light intensity on the maximum yield of ozone,
and try to present their effects as functions of
generalized parameters.
Experimental
Experiments were carried out using an evacuable and
bakable smog chamber system (12,13). The reaction chamber
is a Teflon-lined stainless steel cylinder, 1450 mm inner
diameter, 3500 mm long, and 6065 I in volume. One end of
the chamber is sealed with nineteen quartz windows of 280
mmo (effective diameter for light transmission, 250 mmq>)
each and 20 ram thick. The other end is sealed with
eighteen Pyrex and one quartz windows with the same size.
Irradiation is made through the nineteen quartz windows
on axis to the reaction chamber.
The oumping system consists of three oil rotary pumps
PROCEEDINGS—PAGE 137
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
(950i/min each) with a liq. N- foreline trap, a turbo-
molecular pump (65(H/sec) , two titanium getter pumps (10,000V
sec each) and two sputter ion pumps (8002./sec each). The
chamber wall is bakable at the maximum temperature of 200°C
and is also temperature controled at 0^ 40°C within + 1°C
with the circulation of heat transfer agent around the
reaction chamber. Both ends of the chamber where the
windows are flanged, are not temperature controlled but
cooled with water to protect the Viton 0-rings during
baking.
After baking at 200°C under evacuation, the chamber
wall was found to be "activated" for the decay of 0., and
NO-- In order to "deactivate" the wall, the chamber was
treated with a few ppm of 0, for about 24 hours. After
this procedure the decay rates of about 0.03 ppm of O-,
N02 and NO were 0.07 4- 0.01, 0.025 + 0.005, and< 0.01 hr^1,
respectively. The decay rates for 2 ppm of 0- was 0.04
hr after the same procedure These decay rates did
not change appreciably after the overnight evacuation
so for as the chamber wall was not baked. The baking of
the chamber wall was found to be of critical importance
in order to sustain good reproducibility of a low
concentration run, after the reaction chamber was exposed
to the reactants, say, at ten times higher concentrations
than -those for the run. Therefore, the baking and the ozone
PROCEEDINGS—PAGE 138
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
treatment were made occasionally during this study to
maintain system integrity, and consecutive experimental
runs of close initial concentrations were carried out
evacuating the chamber down to 2 x 10 torr with a
turbo-molecular pump without baking between runs. For
data analysis, the corrections- for the wall decay of 0,
and NO were not made in this work.
X
The irradiation source is external to the reaction
chamber and is called a solar simulator. It consists of
nineteen high pressure xenon arc lamps (IKw nominal rating
each, Wacom Co. KXL-1000). The light flux from each lamp
is collimated and directed toward the chamber on axis
using an elliptical mirror, a quartz integration lens
and a quartz collimation lens. The center of each
collimated beam is matched to the center of each quartz
window of the reaction chamber. The beam size is 250 mm
in diameter each at the front window and about 450 mm in
diameter at the back window. A Pyrex 7740 filter (4 mm
in thickness, 50 tramp) is installed just after the each
integration lens in order to match the spectral
distribution of the light source to the actinic irradiance
of the real sun (14) in the near U.V. region. The spectral
distribution of the solar simulator was measured with a
spectroradiometer (Optronic Lab., Model 740A) which was
calibrated bv the manufacturer to the radiometric standards
PROCEEDINGS—PAGE 139
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
supplied by the National Bureau of Standards. Figure 1
shows the relative spectral distribution (spectral bandwidth
5 nm) of the solar simulator as compared with the estimated
actinic irradiance for Z= 20° given by Leighton (16).
Both distributions are normalized at 350 nm.
The effective U.V. light intensity inside the chamber
was measured by photolyzing about 0.1 ppm NO- in "purified
air". After the lamps were turned on and allowed to
stabilize for 30 min, the irradiation was started by
opening a shutter of the solar simulator. Since NO-/ NO
and 0^ reach the photostationary state within a couple of
minute (12) , the k, value, the first order rate constant
for the reaction,
N02 + hv *• NO + 0 , (1)
was calculated by the following equation given by Wu
and NiKi (15).
(NOT [0 ]
ps 3 Ps + *[o] (i)
Here, [NO,] , [NO] , and [0-J are ohotostationarv state
2 ps ps j ps
concentration and k- and k^ are the rate constants (15) of
the following reactions,
NO -i- 0, - NO- +0- k. =ir27.5 pern" min~ (2)
o 2 Z L
PROCEEDINGS-PAGE 140
ourth US-JaPan Conference on
Photochemical Air Pollution
-------
N02 + 0- * NO, •** °2 k3 = 6'8 x 10 PP111 roin (3)
The light intensity was varied in this study by varing
the discharge current of the lamps.
In our smog chamber system, "purified air" is obtained
by passing cruder cylinder air through a air purifier.
The air purifier is composed of heated platinum catalyzer
for the oxidation of hydrocarbons and NO, and molecular
sieve adsorbent for the removal of CO., N0_, S0_, H_0 and
etc. Impurities in the "purified air" were typically
NO (^2. ppb) , hydrocarbons (<10 ppfaC) , CO, (<1 ppm) and
X A
H-0 (<1 ppm).
Measurements of NO and NO (Monitor Labs, chemiluminescence
iC
analyzer, Model 8440L) , and 0. (Monitor Labs, chemiluminescence
analyzer, Model 8410) were made continuously. The reaction
mixture was sampled by means of a glass lined stainless
steel tube (1/8" o.d.) or a Teflon tube (1/8" o.d.) probes
extending 60 cm beyond the interior walls of the chamber.
The NO analyzer was calibrated with a capillary flow
X
calibrator (Standard Technology Inc., Model SGGU-14) using
NO standard gas (Takachiho Co., 490 ppm). For the calibration
of the ozone analyzer, the chamber was filled with zero air
containing 0.5-5 ppm 0, and concentrations of 0^ were
simultaneously monitored with the chemiluminescent analyzer,
an UV analvzer (DASIB5- Co. Model 1003H) and a long path
PROCEEDINGS—PAGE 141
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
(221.5 m) Fourier transform infrared spectometer (Block
Engineering Co.) equipped to the chamber (12,13). The
absolute concentrations of 0^ were determined by the IR
— 4
photometry using the absorption coefficient, £ = 4.06x10
ppm m~ at 105.3 cirT (resolution 2 cm" ) obtained by
McAfee et al. (16). The chemiluminescent analyzer and the
UV analyzer were standardized against the IR photometry.
During the course of this work, the chemiluminescent analyzer
was calibrated against the standardized UV analyzer occasionally
For several experimental runs, the concentration of C-,H- was
JO
monitored by using an automatic sampling gas chromatograph
(Shimazu Co.).
Prior to each experiment, the "purified air" was
introduced into the chamber at about 770 torr. The premeasured
amounts of C,Hg and NO were then injected into the chamber
using the "purified air" as carrier gas. The reaction
mixture was stirred by a fan during the experiment. For each
run, irradiation was continued until the maximum of ozone
concentration was reached, so that real ozone formation
potential of each mixture is obtained rather than the maximum
concentration within a fixed irradiation time. Since the
pressure of the reaction mixture decreased during a run due
to sampling by the NO and 0, analyzer, the pressure was
~ X -J
monitored continuously by a capacitance manometer (M.K.S.
Baratron, 1000 torr full scale), and the outputs of the
PROCEEDINGS—PAGE 142
Fourth .US-Japan Conference on
Photochemical Air Pollution
-------
chemiluminescence analyzers and gas chromatograph were
corrected to the value at 760 torr. All experiments were
carried out at 30' +• 1°C.
Results
In the first series of experiments, the dependences
of the maximum concentration of ozone formed on the initial
concentrations of C,H,. and NO were studied. Throughout
JO X
these runs the light intensity was kept constant at the
level, k, =0.16 + 0.02 min~ . Typical variations of the
concentrations of 0,, C,H.., NO and NO -NO are shown in
o j o x
Figures 2(a)-(c). In these runs, the initial concentration
of C.,H,. and NO were kept constant at 0.1 ppm and about
j b x
0.04 ppm respectively, but the ratio of NO and NO2 in the
initial NO was changed. Thus, the initial contents of NO
x x
were essentially NO, NO/NO2 (1:1) and essentially N02 for
the runs shown in Figure 2{a)-(c), respectively. As shown
ir. these figures, the difference in the NO contents only
^C
affected the time for 0, to reach to the maximum but did
not affect appreciably the maximum concentration of 03
reached. Therefore, although some of the runs in this series
were started with C^Hfi-MO-air mixtures in order to check
the validity of this result, most of the runs were started
PROCEEDINGS—PAGE H3
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
with C,H^-MO_-air mixture from the reasons; (1) the
JO £
irradiation time could be shortened and (2) the constancy
of the initial phase of the photooxidation could be
attained easier for the latter system. When the irradiation
is started with C,H.,-NO-air mixture, the initial rate of
J O
the photooxidation reaction was influenced by the small
content of N0_ in NO, which is somewhat difficult to
control, and the reproducibility of time variation was
poorer. Table I gives the experimental results of ozone
formation along with data on initial concentrations of
reactants. As shown in Table I, the initial concentrations
of C,H- and NO were varied in a systematic manner. First,
.JO X
the initial NO concentration was varied from 0.009 to 0.086
it
ppm, and from 0.045 to 0.29 ppra, while the initial C,H-
concentration was kept constant at 0.1 and 0.5 ppm,
resoectivelv. Second, the initial C-H,. concentration was
~ Jo
varied from 0.05 to 0.4 ppm, and from 0.1 to 0.5 ppm, while
the initial NO concentration was kept constant at about
X
0.04 and 0.09 ppm, reapectively. The variation of the
maximum concentration of ozone generated ([0.,] ) with the
j fflcl^C
initial concentration of NO ([NO ]n) for the constant
X X U
initial C-,H^ concentration are shown in Figure 3. Similarly,
j o
the variation of [0-.] with the initial concentration of
3 max
C,H. ([C,H I.) for the constant initial NO concentration
j b j o 0 X
are shown in Figure 4. The reproducibulity of the CO,
.J
for each run can be estimated to be + 10%. Using the curves
PROCEEDINGS—PAGE 144
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
given in Figure 3 and 4, equiconcentration contours of
[O,I . against the concentration coordinate of [C^H ]
~j UlcL^C j O U
and [NO,,], for a fixed k, value can be drawn as Figure 5.
A (J J.
It should be noted that the [0,] illustrated in Figure
j IllaJC
3 ^ 5 is the ultimate ozone concentration generated for the
initial mixtures instead of maximum ozone concentration
within a fixed irradiation time, as is sometimes presented
(17,18) .
In the second series of experiments, the dependence
of [0,] „ on light intensity was studied for a fixed
j UlcLiC
initial composition of C.H.. and NO . The selected initial
J o x
composition was [C..H-] =0.5 ppm and [NO ] _ ^ 0.076 ppm.
j Q U " X U ~™•
The experimental results with the detailed data on initial
conditions are given in Table' 31 . The time variations of
the concentration of 0, for these runs are shown in Figure 6.
Discussion
It has been well known (9,15,19,20,21) that irradiation
of near U.V. 'light on a NG2-dry-air mixture produces 0^
even in the absence of HC. When the initial concentration
of N02 is low enough (< 1 ppm), the chemistry at the
initial.stage of the irradiation can be described simply by
reactions,
PROCEEDINGS—PAGE 145
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
kl
NO 2 + hv *• NO + 0 (1)
kd
0 + 0- + M —*• 03 + M (4)
03 +• NO *> N02 +• 02 (2)
The reaction between 0- and N02 (reaction (3)) is substantially
negligible under these conditions. When the photoequilibrium
between NO-, NO and 0. is reached, the photostationary
state concentrations of these species may be written as
(K)
{CN02]0-[o3]ps} cm)
-k, + Ik.2 +- 4k1k.(N00)
(V)
When [0^] is much smaller than [NO.].., as in the most
practical situations, the equation (3H) and (37) may be
ao-oroximated as
The deviation from equation (T2t) should be observable when
_i
(N0^)_ is very low (,£0,01 pom for k1 =0.20 min ~) .
PROCEEDINGS—PAGE 146
Fourth US-Oapan Conference on
Photochemical Air Pollution
-------
When HC is added to the N02-dry air system, the NO-NO_
photoequilibrium defined above is shifted to the NO- side
due to the reaction,
R02 + NO * NO2 + RO (5)
resulting in the increase of 03. In our experimental system
of the C,H -NO_-air mixture, for a given initial concentration
JO /
of NO-, [O_] first increased with increasing [C,HC] and
f, j UiclJC j D U
then leveled off as shown in Figure 4 and 5. The effect
of initial increase in CC3Hg]Q is thought to build up RO-
radicals which convert NO to NO2 competing with reaction
(2) , resulting in the increase of [0-,] . However,
j luclX
naturally, [0,] cannot be increased infinitly with the
-j IllclX
increase of [HC]n. The restricting factor to limit [0,]
U «J ITIcLX
in the presence of enough hydrocarbon is thought to be
the loss of NO_ due to reactions,
03 + N02 »• N03 + 02 (3)
(5)
where R02NO2 should be taken as a stable N02 containig
products such as peroxyacyl nitrates. Since N02 is removed
from the reaction system, the recycling of NO and N02 to
form 0, cannot be continued, infinitly and C°3^max ^s limited
to a certain level for a given [NO ]Q. This would result
in the leveling off of the curves in Figure 4 at the higher
PROCEEDINGS—PAGE 147
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
[C3Hg]0. The concentration of [C3Hg]Q above which this
leveling is observed apparently depends on [N0x]Q, but seems
to be fairly independent on the ratio of CC3Hg]0/fNOx^0"
Thus, it can be seen in Figure. 5, that the saturation occurs
at the ratio higher than about [C3Hg] Q/[NOx] Q = 3. Therefore
this region where [NO ]n is the restricting factor for [0-]
X U -5
may be defined as a C,H- excess region.
J O
In most of previous studies (1-3, 9-11) using higher
initial concentrations of olefins and NO , it has been shown
jt
that [O.J for a given [NO ]n has a rather sharp maximum
•3 Iucl2£ X U
at a certain initial concentration of HC, and an further
increase in [HC]Q beyond the value resulted in a decrease
in [0,] . The decrease of [0,] with increasing [HC]n
j lucuC 3 IucL2C U
was interpreted by the reaction of 0, with olefins (9) .
In the present work, however, it is demonstrated that there
is a substantial plateau region where [0,] for a given
O IB9.X
[.NO 1 n is not varied with [C-H.]... In the case of hydrocarbon
X U j D U
which is reactive to 0-, this behavior would be characteristic
to the photooxidation reaction at the low initial concentrations
of C H and NO employed in this work. Similar behavior
for the less reactive hydrocarbon or hydrocarbon mixtures
has already been noted (4,18).
In the C,H- excess region, [0,1 ^ for a given [C-,H.]n
j o J max j b u
increased with [NO ]Q as shown in Figures 3 and 5. In order
to obtain generalized information on ozone formation in the
PROCEEDINGS—PAGE 148
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
C-,H..-NO_-air system, an attempt is made to find out an
Jo z
analytical relationship between [0_] and [NO ] n in this
3 ITlclX X U
initial concentration region. Here we assume that [03
reached in- the presence of enough C-jH- is proportional to
[0.,] , the photostaionary state concentration of 0., for
the same initial concentration of NO_ in the absence of
CH. Thus, using equation (\I) ,
k,
k.
Figure 7 shows the plot of [0,1 „ vs. /[NO ln for the
j TuclX X U
data given in Figure 3. The linear relationship between
them can be seen for the two different set of data with
[C-.H,..]- = 0.5 and 0.1 ppm. Although the plots do not pass
J O U
through the coordinate origin, this may be due to the
approximation used to derive equation (VE) . When we use
equation (V) instead of equation (VI) to calculate f°3^DS'
better proportionality between [0.,] and [O,] can be
j IucL2C -3 p S
confirmed as shown later. In Figure 7, the plots for
[C^Hg] =0.5 .and 0.1 ppm did not overlap perfectly but
shifted each other in near parallel. This is apparently
due to the reason that the data points for [C3Hg]0 = 0.1 ppm
does not belong to the true C^H- excess region as can be
seen in Figure 5.
PROCEEDINGS—PAGE 149
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
Next, the validity of equation (VI) is evaluated by
taking light intensity, k.^ as a variable. In Figure 8,
[0-] given in Table H and shown in Figure 6 was plotted
j Iucl2C
against /kT. As show in Figure 8, the plot gives a linear
line passing through the origin. The proportionality of
[0^] vs. ^/k7 has been predicted by Shen et. al. (9) .
j IucL2C X
Our result offers most clear experimental support for the
prediction.
Since the linear dependence of [O_] on /[NO ]n and
X U
7 was obtained approximately, it is now worthwhile to
evaluate the proportionality between [O_] and [0.,]
j ItlcL2C j
For this purpose, [O.,] obtained in two independent sets
-3 ITlcLX
of data, one for variable [NO ]Q at constant values of
[C3Hg]0=0.5 ppm, and k1=0.16 min" , and another for
variable k, at constant values of tC3Hgl0= °-5 PP1*1 and
[NO ]n=0.09 ppm, were plotted against [0,] calculated
x u j pS
using equation CN) . Figure 9 shows the plot. As shown
in Figure 9, the plots for two independent sets of data
gives nearly a single linear line which passed through the
origin. Although a slight difference in slope for each set
of data, the slope being 11.5 and 13.3, is noted, the
consistency is thought to be good enough to define a single
proportionality factor. Thus, taking the average of the
two slopes, the following relationship is obtained.
[03]max= (12.4 ±1.5) [03]ps
PROCEEDINGS—PAGE 150
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
The error limit given above is a rough estimate taking the
reproducibility and scattering of the data into considaration.
Although the equation (VE) was derived mostly from
the data for C3Hg-NO2-air mixtures in this work, the relationship
should be 'applicable more generally to C3Hg-NO -air mixture
since [O.,] was found to be insensitive to the initial
j max
composition of NO as shown in Figures 3 and 4. Further,
Jv
it is expected that such relationship can be applied to
other types of hydrocarbons. When the corresponding
proportionality constant is determined for each hydrocarbons
and also for hydrocarbon mixtures, it can offer a new reliable
scale of hydrocarbon reactivity in the sense of ozone
formation potential.
In FigureS, [O.J is seen to be more strongly
•J IHcL3C
dependent on [C-H,.],. and less sensitive to [NO ] n in the
j o U X U
low ratio region of [C-Hg] Q/[NO_J Q <, 2. It has been often
reported (1-11) that [0,] for a given initial concentration
•j luclX
of HC first increased with increasing (NO ]_ but then
decreased when [NO ]n was further increased beyond a certain
X* \J
value. This would have been observed if [NO ]Q was further
increased for the experiments shown in Figure 3. However,
as the ratio of tC.w] /[NO ] decresed, the time for 0.,
J b u x u . j
to reach the maximum becomes longer, and it was not practical
to study these behavior in the present study.
In the study of photochemical ozone formation in
cyclohexene-N02-air mixtures using a flow reactor, Shen et
PROCEEDINGS—PAGE 151
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
al.(9) has proposed a general relationship between
/k,[NO_]Q/k2 and [HC]./[NO-]Q. According to the proposition,
the plot of [03]njax//k1[N02]0/k2 vs. [HC]0/[N02]Q is
expected to be fallen on a single curve for each hydrocarbon.
The plot was attempted for the C3Hg-NO2-air system using
the date shown in Table I and IT. However, particularly,
the data for [C,E,.] n = 0.1 and 0.5 ppm (shown in Figure 3)
O O U "
were not fallen on a single curve but formed two different
curves. Although this might be characteristic to the low
initial concentration region, further data for different
types of hydrocarbons are necessary to evaluate the
generealization.
Conclusions
In the photooxidation of the C3Hg-NO -dry air system,
for the initial concentration region of excess C^H-, maximum
level of ozone produced, [0,] , was found to be approximately
* j lucLX
proportional to [O.J . Here [CUl is the photostationary
concentration of ozone in the absence of C,H- for the same
j b
initial concentration of NO, as that of NO in the presence
^ X
of C.,Hg. From the data reduction in the present study, the
following relationship was obtained
PROCEEDINGS—PAGE' 152
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
[03]max=
-------
References
(1) Altshuller, A. P., Kopczynski. S. L., Lonneman, W. A.,
Becker, J. L., Slater, R., Environ. Sci. Technol. ,
1, 899 (1967).
(2) Romanovsky, J. C.r Ingels, R- M. , Gordon, R. J.,
J. Air Pollut. Control Assoc., 1_, 454 (1967).
(3) Stephens, E. R., Price, M. A., Atmos. Environ., _3_,
573 (1969).
(4) Altshuller, A. P., Kopczynski, S. L., Wilson, D.,
Lonneman, W. A., Sutterfield, F.'D., J. Air Pollut.
Control Assoc., 19_, 787 (1969).
(5) Altshuller, A. P., Kopczynski, S. L., Lonneman, W. A.,
Sutterfield, F. D., Wilson, D. L,, Environ. Sci.
Technol., £, 44 (1970).
(6) Glasson, W. A., Tuesday, C. S., Environ. Sci. Technol.,
4_, 37 (1970) .-
(7) Dimitriades, B., Environ. Sci. Technol., 6_, 253 (1972).
(8) Kopczynski, S. L., Altshuller, A. P., Sutterfield,
F. D., Environ. Sci. Technol., 8_, 909 (1974).
(9) Shen, C-H.,.Springer, G. S., Stedman, D. H., Environ.
Sci. Technol., 1^, 151 (1977).
(10) Altshuller, A. P., Bufalini, J. J., Photochem. Photobiol.
£, 97 (1965).
(11) Altshuller, A. P., Bufalini, J. J., Environ. Sci.
Technol. 5_, 39 (1971) .
(12) Akimoto, H., Hoshino, M., Inoue, G., Sakamaki, F.,
Washida, N., Okuda, M., 'Construction and Characterization
of the Evacuable and Saleable Photochemical Smog
Chamber", Paper presented at the Annual Meeting,
Japan Society of Air Pollution,
PROCEEDINGS—PAGE 154
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
Fukuoka (November 1977) (manuscript for Publication
in preparation).
(13) Akimoto, H., Inoue, G., Okuda, M., Fukutome, R. ,
"Long-path Fourier Transform Infrared Spectrometer
System for the Evacuable and Bakable Smog Chamber"/
(manuscript for publication in prepararion).
(14) Leighton, P. A., "Photochemistry of Air Pollution",
Academic Press, New York, N. Y., p.29, 1961.
(15) Wu, C. H., Niki, H. , Environ. Sci. Technol., 9_, 46
(1975) .
(16) McAffee, J. M., Stephens, E. R., Fitz, D. R., Pitts
Jr., J.. N., J. Quant.. Spec. Rad. Trans., 16, 828 (1976)..
(17) Dimitriades, B., Environ. Sci. Technol., 11, 81 (1977).
(18) Holmes, J., Bonamassa F., in "Smog Chamber Conference
Proceedings", Rept. No. EPA-600/3-76-029, U, S.
Environmental Protection Agency, Research Triengle
Park, N. C., April 1976.
(19) Stephens, E. R., Hanst, P. L., Doerr, R. C., Scott,
W. F., Ind. Eng. Chem. 48, 1498 (1956).
(20) Ref. (14) p.155.
(21) Stedman. D. H., Niki, H., Environ. Sci. Technol., T_,
735 (1973).
PROCEEDINGS—PAGE 155
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
Table I Experimental data*3' b) of the dependence of [O-J on lC^H..]n and [NO ]n.
J ITlclX j D U X U
Run [C3H6l0(ppm]
1 0.10
2 0.10
3 0.10
4 0.10
5 0.10
6 0.10
7 0.10
8 0.10
9 0.10
10 0.50
11 0.50
12 0.50
13 0.50
14 0.50
15 0.50
16 0.05
6 0.10
17 0.15
' "*>x
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
Vpp-n.
0093
0196
0260
0342
0359
0430
0516
0630
0864
0452
0896
0890
0901
187
290
0382
0430
0393
[N0]0(ppm)
0.0035
0.0154
0.0046
0.0329
0.0040
0.0217
0.0488
0.0478
0,0064
0.0040
0.0082
0.0811
0.0818
0.0110
0.255
0.0035
0.0217
0.0035
[N02
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
]0(PPm)
0058
0042
0214
0013
0319
0213
0028
0152
0800
0412
0814
0079
0083
176
036
0347
0213
0359
j D 0 x o J nicix ~ nicix
10
5
3
2
2
2
1
1
1
11
5
5
5
2
1
1
2
3
.8
.10
.85
.92
.79
.33
.94
.59
.16
.1
.58
.62
.55
.67
.72
.31
.33
.82
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0264
0681
0776
116
106
115
126
164
148
151
236
232
217
363
443
0850
115
139
480
510
450
720
540
660
720
1160
1020
150
160
315
315
220
660
1020
660
420
(c)
(c)
(c)
-------
continued
18
19
20
9
21
22
11
13
12
~n
-a o
rr c
o -s
r*- rt- ~O
o rr po
n * o
3 i m
o a> t— i
cu "a z
— ' co cr>
3 CO
> i
-"• O 1
-S O t>
0.20
0.30
0.40
0.10
0.20
0.33
0.50
0.50
0.50
(a) Some
(b) k1 =
(c) Ozone
0.0396
0.0391
0.0393
0.0864
0.0863
0.0912
0.0896
0.0901
0.0890
of the runs
0.16 + 0.02
maximum has
However. [0_]
3 max
more than 98% of
0.0042
0.0049
0.0046
0.0064
0.0092
0.0077
0.0082
0.0818
0.0811
are cited twice.
_ i
min throughout
0.0353
0.0341
0.0347
0.0800
0.0771
0.0835
0.0814
0.0083
0.0079
5.05 0.136 280
7.67 0.136 200
10.2 0.139 170
1.16 0.148 1020(c)
2.32 0.216 630
3.62 0.232 270
5.58 0.236 160
5.55 0.217 315
5.62 0.232 315
for convinience of reference.
runs ,
not been reached within
observed at the
the true maximum
given t
value .
the irradiation time.
is thought to be
"O ~h CD
o n> m
3 en
n ~>i
-------
PROCEEDINC
burth US-Jape
Photochemical
f~ u *
3 t/>
3 ft
o n> m
— • -I
— ' n> — <
C 3 Ul
rt- O 00
o
3 0
Table H Experimental
Run [C3H6]0(ppm) [NOx]Q(ppn
23 0.50 0.0850
24 0.50 0.0900
25 0.50 0.0889
26 0.50 0.0830
27 0.50 0.0881
data of the
i) [NOJ0(ppn
0.0115
0.0120
0.0068
0.0094
0.0087
dependence of
[») lNO?]_(ppm)
0.0735
0.0780
0.0821
0.0736
0.0794
[O3Jmax on light
k., (min"1) (O_]
-L J
0.367
0.308
0.247
0.189
0.130
intensity
WPP-°>
0.390
0.366
0.307
0.271
0.233
tmax(n'in)
120
130
135
145
170
-------
Figure 1,
Figure 2,
Figure 3
Figure 4
Figure 5
Figure 6.
Figure Captions
Spectral distribution of the solar simulator for
the smog chamber at NIES ( - ) , and the actinic
irradiance of the sun at Z = 20 ° after Leighton
(14) ( --- ) .
Time variations of the concentrations of 0,, C,Hg,
NO and NO -NO after irradiation. [C-H-]rt=0.1
x j o u
ppm, k.=0.16 min" , in common. (a) [NO ] = 0.0342,
[NO]Q= 0.0329, '[N02]0= 0.0013 ppm; (b) [NOX] Q =
0.0430, [NO]Q= 0.0217, [NOj] Q = 0 . 0213 ppm;
(c) [N0xl0= 0.0359, [NO]Q = 0.0040, [N021 Q = 0 . 0319
ppm.
Variations of [0,] vs. [NO ]n for the constant
•j UiAJC X \j
H. Initial composition
initial concentrations of
of NO is almost entirely NO- (O,A)/ nearly
X £
half and half ( A ) and almost entirely NO ( O; A ) -
Variations of [O.,] vs. [(C^H-)]- for the constant
j max j o o
initial concentrations of NO . Initial composition
J\,
of NO is almost entirely NO, { O A. ) , nearly
X ^
half and half ( 3 } and almost entirely NO ( « , A. ) .
Eguiconcentration contours of [0,1 sv composed
j ITla.X
using the curves in Figure 3 and 4..
Time variations of the concentration of 03 after
irradiation for different light intensities .
PROCEEDINGS—PAGE 159
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
Figure 7. Plot of [0,] vs. / [NO J n . The abscissa is
j nicix x u
in a square root scale, k =0.16 min
Figure 8. Plot of [0-] vs. / k, . The abscissa is in
j max i
a square root scale. [C-H-]A= 0.50,
J D U
]n = 0.09 ppm.
Figure 9. Plot of [033max vs. [Oj] . (a) [NOx] Q = variable,
[C-Hg] Q = 0.50 ppm, k. = 0.16 min ( O ) ;
(b) k,= variable, [C3Hg]Q = 0.50 ppm,
ppra ( •• ) .
PROCEEDINGS—PAGE 160
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
280 SCO
320
Wavelength ( nm )
FIGURE 1
PROCEEDINGS—PAGE 161
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
0
Irradiation Time
FIGURE 2
PROCEEDINGS--PAGE 162
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
L NOX IQ ( ppm )
FIGURE 3
PROCEEDINGS—PAGE 153
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
[ NOX]Q = O.OSppm
[NOX]0 = O.OAppm
0
0.1
0.2
0.3
0.4
0.5
C3H6 IQ ( ppm )
FIGURE 4
PROCEEDINGS—PAGE 164
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
0.10
CL
Q.
0.05
x
O
0
0. 20 ppm
0.15 ppm
O.IOppm
0.05 ppm
0.25
0.50
FIGURE 5
[C3H6]0 (ppm)
PROCEEDINGS-PAGE 165
Fourth USrJapan Conference on
Photochemical Air Pollution
-------
Irradiation time
PROCEEDINGS—PAGE 166
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
0.5
0.4
£
Q.
CL
0.3
X
a
—• 0.2
CO
O
0.1
0
= 0 .10ppm
0.01
0.05 0.1
[NOX]0
0.2
(ppm)
0.3
0.4
FIGURE 7
PROCEEDINGS—PAGE 167
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
0.4
£
a
a.
x
a
0.3
,- 0.2
oo
o
0.1
0
0.01
0.05 0.1
0.2
( mm1)
0.3 0.4 0.5
FIGURE 8
PROCEEDINGS—PAGE 168
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
0.4
e
CL
CL
X
O
£
i—i
00
O
0.3
0.2
0.1
0
0.01
0.02
0.03
0.04
031 ps ( ppm )
FIGURE 9
PROCEEDINGS—PAGE 169
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
PHOTOCHEMICAL SULFATE AND NITRATE RESEARCH IN THE US
presented by A.P. Altshuller
Environmental Protection Agency
United States
PROCEEDINGS—PAGE 171
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
PHOTOCHEMICAL SULFATE AND NITRATE RESEARCH IN THE US
Much of the earlier work done in the U.S. (1974-76) has either been
published or will be out shortly. The work that has been published already
appears in journals available in Japan (Atm. Environment & ES &. T) or
Science (journal of the AAS). There were a series of papers at the
Dubrovnik conference on sulfates presented on U.S. work and my under-
standing is that these papers have been published as No. 1-3 in Volume 12
of Atmospheric Environment. Much of the work which has or will be published
shortly resulted from experimental work conducted in and around St. Louis.
These studies were connected within the Regional Air Pollution Study
(RAPS) or from a closely associated program named MISTT. The results are
in papers published by Charlson, Whitby, Dzubay, and Stevens. Dr. Wilson
of our laboratory was the scientist who coordinated the MISTT programs.
He also will be directing a followup EPA plume program - STATE. There
now are some studies in power plant plumes funded by EPRI (Electric Power
Research Institute). This is an organization in the San Francisco area
which receives a large amount of funds from the U.S. utility industry
and they have a number of different research projects associated with
sulfates. One major aspect of their program has been to set up a number
of monitoring stations in rural sites in the Eastern U.S. where SO^, NO ,
ozone, and aerosols are measured. We supplied them with a number of continuous
monitoring equipment from the RAPS program. We also are participating with
them in making part of the aerosol compositions measurements at these monitor-
ing sites. This EPRI program has the acronym of SURE. Additionally there
PROCEEDINGS—PAGE 173
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
is carryover work from the AEC to the Energy Administration to our new
Department of Energy on sulfate measurements. This is sometimes called
MAP3S. Therefore, several governmental and non-governmental organizations
in the U.S. have programs involving the measurement, monitoring, and transport
properties of sulfates. These programs are informally coordinated by the
program managers for the various programs and there is interchange of
equipment and concurrent measurements. There may be a new program (under-
way next year) concerned with nitrates. There have been a small number
of programs in the U.S. on nitrates but not nearly as much as has been
done on sulfates. There is substantial agreement in the U.S. based on
ground level and aircraft measurements that sulfates can be transported.
These sorts of results are consistent with work done in Western Europe and
this is consistent with the physical and chemical properties of particles
of diameters near 0.2, urn, in the highest oxidation state and therefore stable
to further oxidation, and their deposition velocities are much smaller than
those of gases such as S02 or NCL. The field experiments following plumes
making measurements over long trajectories verify that sulfates can be
transported over long distances. However, we need to know the portion of
the material transported. Also, the chemical composition of the sulfate.
We are interested in the extent to which sulfates removed by dry deposition
processes compared with wet deposition processes. Another proposed new
U.S. program is concerned with deposition of acid sulfates and nitrates.
PROCEEDINGS—PAGE 174
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
One of the types of observations that has been made is that the sulfate
concentrations are relatively uniform at urban and rural sites in the
same geographical locations. For example, the sulfate concentrations at
rural sites, outside of St. Louis were almost the same as the sulfate
concentrations within the city itself. On the other hand, as weather
fronts moved through any particular area, one sees large sulfate variations
over periods of several weeks. In St. Louis, one could see concentrations
as high as 20 or more ug/m and as low as 2 ug/m as various weather fronts
went through. An important general conclusion is that both sulfate and
ozone are distributed relatively evenly over large geographic U.S. areas.
This, of course, would be readily understandable if they are formed by the
same chemical mechanisms or by similar chemical mechanisms; and it does
appear, at least during the summer months, that the formation of both ozone
and sulfates is associated with photochemical reactions. This is also
consistent with the fact that both species, sulfate and ozone are found
together and found rather uniformly in large geographical regions. We
need to do considerable additional work to better identify quantitatively
the urban sources of sulfates as well as the contribution to sulfate from
our large non-urban power plants in the U.S. In another program conducted
in our laboratory, we have been measuring the primary emissions of sulfates
from coal-and oil-fired boilers. What we found is that although we can
confirm the amount of sulfur in the form of sulfate emitted from coal-fired
power plants, we believe that the old data on oil-fired sources cannot be
'used. There is considerably more of the sulfur in the form of sulfate
PROCEEDINGS—PAGE 175
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
from oil-fired sources than have been recorded in older literature. In oil
fired-boilers, we find that 5% and as much as 10% sulfur as sulfate. This
is very dependent on the operating conditions of the oil-fired boiler, and
the fuel used in that facility. The higher values, also are associated with
a high vanadium content of the fuels used in the U.S. Conversely, a
combination of low vanadium content and appropriate operating conditions
can result in as little as 2% sulfur as ful.fate from oil-fired sources.
We have extended these measurements to measurements around oil fired facili-
ties at ground level and we believe we have experimental evidence to show
that immediately downwind of the oil-fired facilities, a significant fraction
of the sulfate measured is directly emitted from the facility. This effect
of direct emissions is possibly more important in the immediate vicinity of
a given oil-fired facility than over large geographical areas. We have
also measured a considerable amount of acidity in these emissions (sulfuric
acid from SCL + FLO or from acid on fly-ash particles).
We have also been working on the problem of reliably measuring the
acidity in -the atmosphere. We have been using the method used and developed
by Professor Brosset in Sweden for the last several years. We have evidence
that, at times, a significant fraction of the sulfate is not ammonium sulfate,
but sulfuric acid or ammonium bisulfate. There is a very difficult analytical
problem here-. Unless one protects the sample as collected both in the field
and the laboratory against reaction with ammonia, ammonia sulfate will form;
and in some of our earlier work, we were finding almost all of the sulfate
as ammonium sulfate. We now have-doubts about these earlier results.
PROCEEDINGS—PAGE 176
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
In work which we did very close to our laboratory at the Research Triangle
Park, N.C., where we used special devices to protect the samples from reaction
with ammonia and also took very careful precautions in the laboratory with
the samples, we found a considerable fraction of the sulfate over a several-
day period to be in the acid form sulfates. Some of these results were
presented at the Dubrovnik meeting (by Stevens, Dzubay). Dr. Charlson earlier
suggested, based on a completely different method of measurement using his
nephelometer, that in the St. Louis area a considerable amount of the sulfate
was acid in form. So results on acidity carried out in very different
geographical areas seem to be consistent.
In our new programs, we will follow power plant plumes over longer
distances and obtain much more meteorological data than we did in earlier
programs so that we will have data in the form that can be used to validate
sulfate air quality simulation models.
NITRATES
Let me now turn to nitrates. We have a few groups of investigators in
the U.S. who have been involved in nitrates. The original monitoring work
supposedly gave us a measure of nitrates in particulate form [samples
collected on glass fiber filters]. As you know, there are now considerable
doubts about the use of glass fiber filters for the collection of both sulfates
and nitrates. Besides the reaction of SCL with the filters to form "artifact
sulfate", the reactions of NO- and nitric acid with these filters to
PROCEEDINGS—PAGE 177
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
form "artifac nitrate" is now rather well established as even a worse
problem than that of artifact sulfate. It appears that the measurement
on glass fiber filters of sulfates are probably usable within limits. In
rural areas where there is very little S02 present, the sulfate measurements
should be reasonably acceptable. Similarly, suflate measurements on a
relative basis in urban areas may be used for certain purposes. We are
even more concerned that it may be that the nitrate results which have
been obtained are not acceptable. A research group at Battelle Memorial
Institute in Columbus, Ohio, headed by Mr. Spicer, which both EPA and one of
the U.S. industrial associations, the Coordinating Research Council funded,
has been making a series of measurements for short periods of time in a
number of urban areas in the U.S., as well as lab studies. They have
compared field results on quartz filters with results on glass fiber filters
and have found much higher nitrate concentrations on the glass fiber than on
quartz filters. In a series of measurements which they reported several
months ago in a Note in Atmo. Envir. from LA, I believe that the average
ratio of nitrate on the quartz to glass fiber was something like 10:1.
There has been some work by Los Angeles Air Pollution Control District
investigators presented in a paper at the Spring 1978 ACS Meeting showing
substantial nitrate artifac on glass fiber filters, although they claim
that it is not nearly as large as that reported by Battelle. However, it
appears that their method may underestimate the artifact. We have obtained
data using dichotomous samplers equipped with teflon-type filters (virtual
impactors) on nitrates also showing much lower values than on glass fiber
PROCEEDINGS—PAGE 178
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
filters. These impactors will be used extensively in a large network of these
samplers in the U.S. These samplers which have been reported on both the Oubrovnik
Conference and in papers in ES&T have several advantages over the high volume sam-
plers. We used filters which do not have problems with respect to sulfate and ni-
trate artifacts. The sampler separates the particles into coarse and fine particles
Measurements can be made by X-ray fluorescence without manipulation of the
material on the filter, as well as permitting more traditional chemical
measurements for sulfates and nitrates. It also is possible to make the
acidity measurements I was referring to earlier in the discussion. Finally
they can be used to measure the mass of particles by beta-gauging or
gravimetric techniques. So, they are very useful samplers for conducting
wide range of measurements. All this seems to.suggest that there is much
less of the nitrate in the form of particles. Since we must account for
the nitrogen oxides which are emitted from sources, either the gaseous and
vapor forms of nitrate are much more important or the nitrogen oxides are
being removed from the atmosphere by dry deposition very effectively. We
have a substantial amount of measurements of peroxyacetyl nitrates (PAN's)
in several locations in the U.S. but these have usually been made without
measuring other forms of nitrate; and many of the measurements of particulate
nitrate has been made without measuring the gaseous and vapor forms of nitrate.
About the only work where all these forms were measured concurrently was
again done by the Battelle group. They have concluded particularly from
measurements in Los Angeles that the vapor forms of nitrate are far more
important than the particulate forms. We do have independent confirmation
PROCEEDINGS—PAGE 179
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
at Riverside, CA, of nitric acid by use of a Fourier Transform Spectrometer
(FTS system) working over an open air path. This is one of the spectrometers
in our laboratory that Dr. Hanst was using which we loaned to Or. Pitts
and his group to set up in an open air path. This is a very useful tool
since we can measure a number of species including not only nitric acid
but ammonia, ozone, PANs, and some of the other reaction products of
photochemical reactions in the ambient atmosphere. What we need to do
next in the U.S. is to make concurrent measurements by the chemical
techniques of nitric acid and by this Fourier Transform Spectrometer technique
to see how similar the concentrations of nitric acid are by the various
measurement methods. One final remark on nitric is that nitric acid seems
to be a quite important contributor to acid precipitation as it affects
lakes and fish and other aquatic species and possibly forest and soil
productivity. Discussions with U.S. investigators in this field as well
as with European investigators indicate that perhaps one-third to one-half
of the total acidity in precipitation may be associated with nitric acid.
We can only speculate at the present time on the importance of nitric
acid in dry deposition but since nitric acid is a vapor and a polar vapor
which is easily absorbed on surfaces, it is possible that nitric acid is
very important compared with acid sulfates in dry deposition. This is
another aspect of the problem of sulfate and nitrates that we hope to
quantitate.
PROCEEDINGS—PAGE 180
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
SULFATE, NITRATE AND NITRIC ACID RESEARCH
IN KANTO AREA
presented by M. Okuda
Environment Agency
Japan
PROCEEDINGS—PAGE 181
Fourth US-Oapan Conference on
Photochemical Air Pollution
-------
Sulfate, Nitrate and ISTltric Acid
Research in Kanto Area
In June and July of 1973 to 1975 many people suffered, from
eye-, throat- and skin-irritations by contaminated drizzle |
droplets.
In order to study the case of the irritation the Japanese
Environment Agency organized a study group. Several examples
of the concentrations of sulfate. nitric acid and nitrate and
other constituents measured by the group are as shown in Figs.
1 to 3.
Fig. 1 shows the ratios Rg = CgQ ~ *s/cso *s/
°HO" 'N/CN02"N dnd ^03 = CHN03'N ^tained in 1977 at five
stations together with oxidant concentration and relative
humidity where C is the each material1 s concentration. The
methods of measurements are as follows.
SO2r automatic electro-conductivity recorder
NO2 i automatic Saltzman ' s colorime-cric recorder
SO^"~ and NO^: sampled on quartz fiber filter and analyzed
by glycerine-alcohol method and sodiunr
salicylate method respectively.
Oxidant: automatic neutral buffered KI colorimetric
recorder
- 1 -
PROCEEDINGS—PAGE 183
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
(2)
o: Okita's impregnated filter method
Aerosol and HNO-, samplings were done between 10 A.M. and
4 P.M. everyday.
The figure indicates that usually the concentrations of
RS and Rm had peaks on June 28 and July 5 when oxidant
concentration was high, suggesting that production of aerosol
sulfate and nitric acid were highly associated with photo-
chemical air pollutions.
Similar trends on the summit of Mt. Tsukuba are shown in
Fig. 2 which exhibits the peaks of SO^-, NH^ and HNO3 con-
centrations also on June 28 and July 5, 1977 together with on
July 7-9, 1976 when oxidant concentration was also high.
As shown in Fig. 3 most of the sulfate would be
at Mt. Tsukuba.
RITQ- in Fig. 1 and NOT concentration in Fig, 2, on the
other hand, usually had no such peaks on the days of high
oxidants concentration besides on July 7-9, 1976. It seems
that in inland area the rate of production of nitrate aerosol
was rather low.
In June and July of 1976 and 1977 airbone samplings of
sulfate, nitric acid, nitrate and other constituents were
conducted on helicopters.
Fig. 4 shows the concentrations of trace constituents
- 2 -
PROCEEDINGS—PAGE 184
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
sampled on two helicopters at 270 and 670 m in the early
afternoon of July 5, 1977- It was found that on the flight
2_
routes B^ and. &2 • S04 an<^ HN03 concentrations were consider-
ably high. Simultaneous measurements of 03 by ultraviolet
absorption on the helicopters indicate the O., concentration
of 0.05 — 0.07 ppm and 0.1 ppm on the route A and B respect-
ively. The presence of relatively high, concentration of
sulf ate and nitric acid in the air coming from the north-east
or east where no big pollution sources were located is also
interesting ..
Fig. 5 shows the vertical distributions of _ SO., and
measured at Ohira using tethered balloons and helicopters
indicating that whereas SO- and NO- concentrations gradually
decreased with height the concentrations of SO^ , HNO., and
NOT had uniform distribution or peak concentration at several
hundred meters above the ground. Such patterns presume that
SO2 and NO. come from nearly, ground level sources whereas
SO^ , HNO, and NO I would be formed during long distance
transport of the pollutants.
The data of. Fig. 6 obtained in 1976 at Ohira indicates
that nitric acid concentration is highly correlated with 0^
and NO- concentrations, which also suggests that nitric acid
was produced by photochemical reactions.
- 3 -
PROCEEDINGS—PAGE 185
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
In conclusion/ it seems that over the Kanto area near
Tokyo high concentration of sulfate and nitric acid occur in
photochemical air pollution and most of the sulfate would be
ammonium sulfate. High concentration of nitric acid was
frequently observed at several hundred meters above the ground.
Aerosol nitrate had no association with oxidants concentration.
Reference
(1) Air Quality Control Division, Environment Agency:
Acid Rain Research. March, 1978 (in Japanese )
(2) Toshiich Okita et al.: Measurement of Inorganic
Gaseous and Particulate Nitrates in the Atmospher.
Bull. Inst. Publ. Health, 24(2): 1975
- 4 -
PROCEEDINGS—PAGE 186
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
1;CL
Q 0.5
Ul
Chiyoda
MOO
-50
a,
•d
•H
27 22i 29 30 "1 4
June
July
Fig.l(a)
ro
a
a;
0.5
Urawa
-100
June
Relative Humidity, Oxidants
in Kanto
( 1977 )
Rs/
Area
-100
a
(d
•d
50
(A°
I
w
rf
27 28 23 30" 1" 4 5 "^~?~8"
June July
• Relative Humidity
O Oxidants
ARS
a RHNO3
X
-------
1.0 H
100
June
1.01
Utsunomiya
I
o
s
O
0.5-
rlOO
-50
JQ
CV
P-.
•H
O
<#>
Fig.l(b) Relative Humidity, Oxidants,
R.., R,,««. and R«^ in Kanto
g f
Area
t— tUr-
f ____
UJ O) O
O <4- 0.
=t C
o. o 1-
I <_>-r-
I r—
21 0- («
i— • rtf (J
Q -D-^
LU I E
UJ OO O)
o :i> ^:
o o
oc jz q
tx •*-> -P
5- o
O Q_
-------
Mt. TSUKUBA
0
.*S6l7S
• o.S.O,'S
II t t • 1
29 30^1 2 .3-4 5 6 7 8 9 - -V ^7 28 29 30 H '2 34 5678
.' • • • •••'. .' , . - • •. • ..
•'.'• 1 976 .. /' , • ••••• •* -1 977 ,
Fig. 2 (a) Fluctuation of SO2 and SO^ concentrations at the top of Mt.Tsukuba
o c
o
O>T-
cn
co c; a
,— tt)r-
i..—
LU a> o
C£) 4-CL
et C
Q- O S-
I 0-r-
i <:
<^o c
CJ3 rtji—
z o-rej
•-•
i. o
U.C
00-
-------
PROCEEDINGS—PAGE 190
Fourth US-Japan Conference on
Photochemical Air Pollution
Mt. TSUKUBA
^
cf>
.:'.:.. o.NOo'N '
_ . . • , £
2829307/(; 2 3 4 5 6 7 8.9
.'':.: . 1976
• '' 6/272829307/i 2- 3 4 5 6*7.8
Fig. 2 (b) Fluctuation of NO2, HNO-, and NO concentrations at the top of Mt.Tsukuba
-------
Mt. TSUKUBA
8
7
• o • •
¥
*x • AJ
, L®. 1® >Q- I _|
6/ • 7/
'28293C/1 2 '3 4 5 6 7'8 9 •
1976
647-2829307/1 2. 3 4' 51 6 -7 8
1977
Fig.2(c) Fluctuation of Nil , NllJ concentrations at the top of Mt.Tsukuba
PROCEEDINGS--PAGE 191
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
Mt.TSUKUBA
0.10
0.05
P;
Q,
X
O
t »
'
,'V' 1 ' \ ''.{'•' ;"•'••''•'/•' ':.; '••.''•• 'V. •..,'•.-••' v -f ,*•,,' :.''.,'
.. * . t.* * • • • • • • ••• ,•• . • . • . •
' '.. '• • ': •,:•',,-,-•••• '' ' • ' • •• • -.
0.00
J—V ,t f 1 i • '•»• i f .1 > i . i
't t ' i i ' i;» i i i ' t i t
/282930a.2' 3J4''5 6 78 9 .- ';6/272829307/(- '2345 6. 78
.,_.._ __ _,_.; ..... :'. . .1 1977.. • '.
Fig.2(d) Fluctuation of oxidant concentration as measured by Mt.TSUKUBA
National Measuring Station
c
O C
O
O» -r-
CM O ^->
C 3
i— tt) i—
5- r—
LU O) O
U3M- CL
ct C
d. o S-
I tJ -r-
I •=£
oo c
07 (O r—
z: a. nj
I-U i E
uj to 33
CJ =) £
o u
O Ou
u_
-------
150
100
i
a\
I
o
I
CM *
O
50
0
PROCEEDINGS--PAGE 193
Fourth US-Japan Conference on
Photochemical Air Pollution
50
100
150
200
NH
Fig. 3 NHand
x 10~9mol/m3
relationship
-------
TOCHIGI PREF.
\
0 UTSUNOMIYA
TOCHIGI
KUMAGAWylA 2
Mt.TSUKUBA
A
5AITAMA PREF.
AGEO
\^T Ki^(
\ \ TATE1
TOKYO
TEND
OMIYA \ X
I ° ^v- .-"
', NAGAREYAMA
CHIBA
LAKE KASUMIGAURA
KASHIMA
IBARAGI PREF.
Flight
route
Route
M
, A2
BJ.
B2
Time
1214-1302
1311-1404
1206-1305
1310-1408
Height
270 m
400 in
270 m
400 m
Mean Concentration
S02
NO ^
HNOj
NH3
HCl
SO2~
4
N03
NH»-
4
Cl~
Al
0. 95
9. 0
5. 9
1. 8
6.2
1.8
0.17
0.03
6.3
A2
0. 95
8. 5
16. 5
1. 6
6. 1
3. 0
<0. 05
2.8
0.90
Bi
2.2
9.3
12.1
1.9
_
10.5
<0,05
4.5
B?
2. 7
7. 5
19. 5
5.. 7
_
18. 7
0. 81
4.9
(pg/m3)
Fig.4 (a) Survey by helicopter
(June 5, 1977)
o c:
o
0) -r-
«* O 4J
cr, c 3
•— (V T—
S- t—
UJ O) O
ex. o s-
I «_> -r-
ei TO •!—
Z Q. «}
•— i rt) O
Q "-3 -r-
1.1 I E
UJ LT) 0)
O ZD -C
O U
oi x: o
O- 4-> -M
s- o
=» x:
o o.
u_
-------
UTSUNOMIYA
O
V. SANO OTOCIIICi...
'
IJYO
o
KUMAGAY
SHIMODATE
A
Mt .TSUKUBA(
KONOSU
TATENO
URAWA !
,\ NAGAREYAMA
SHIN1UKU o-§>
o ,''
TOKV
LAKE KASUNIGAURA
KASHIMA
INDUSTRIAL
AREA
Flight
route
Route
Al
A2
Bl
B2
Time
1525-1615
1623-1710
1528-1624
1628-1728
Height
270 m
670 m
270 m
670 m
Mean Concentration
SO2
NO 2
HN03
NH3
HC1
S02~
4
NO3
NI1+
4
Cl"
Al
-------
/WM,
P.M.
SOi «S
X
O
so«vs
+
&
-p
.c
•S1
(I)
tc
O HNOi • N
N0> ~ «N
500
tn
H
0)
Concentration
Fig.5-a. Vertical Distribution of SOx
(June 28, 1977 )
o i 2
Concentration
Fig.5-b. Vertical Distribution of NOx
(In the Morning of June 29, 1977 )
-------
c
o
id
a
a)
o
G
O
O
(N
O
-oo
rrc
o i
r+H- -a
O 'ZT 73
o o
rrcr o
fl> t/) m
3 i m
-J.C-. CJ
o cu t—i
3=- i
~j O "O
o a> m
C 13 tO
12
10
8
1 PPb
10
0
20
0
2 PPb
_L
-i.
30 40 50 60 70
Oxidant Concentration (PPb)
80
Fig. 6 Relationship between HNC>3 generation concentration and NC>2
and Oxidant concentrations
Note) Superior numerals of X marks
HNO_ concentrations in ppb
-------
REFERENCE
Particulate Matter, NHj, NO^ and 304
in Kanto Area ( 1977 )
2-
PROCEEDINGS—PAGE 198
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
' Part.
NH j QSO|"
~
UNIT:jig/m3
!,-'
124
2.59O17.2
4.4
91
1.17O6.9
2.4
/
144
0.65 O 7.9
2.5 78
'57 0.3O2.4
"----,0.30 5.3. / 1'°
• _!*• J. ,» /
81 " i--.
0.64O8.5
1.3 » .
84
0.10 O 2
5.2CT9.1
1.9
N. „ — -
81
0.17Q5.4
•--....g.4
AMt.Tsukuba
1* — /o.x \
}
2I2,X xn «<
June 27, 1977
PROCEEDINGS—PAGE 199
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
Part.
NO-
144
5.71O38.8
2.0
150
3.83O33.5
1.0
94
-,- 1.14O19.0
-
(
i
^8
0.339-6,
2.9
119
3.18O25.4
1.1
June 28, 1977
PROCEEDINGS—PAGE 200
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
Part..
NO
104
2.71°i5.6
0.5
-0.2685-.3.
96
110
1.S6O 29.5
-00 .~--\
Jxily 4, 1977
PROCEEDINGS—PAGE 201
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
Part.
NO-
( UNIT:
;
no
3.00 O 23.1
0.3
152
5.42O35.8
0.7
147
4.80 O 35.7,
0.6
73,
8.4.
5.40O38.4
0.5
107'
3.43Q22.4
/ 0.5
126
3.79O 30.7 .
0.4
July 5, 1977
PROCEEDINGS—PAGE 202
Fourth US-Oapan Conference on
Photochemical Air Pollution
-------
NH J OSO|
~
_ s
127
3-21O24.S
1.0
•» -C
July 6, 1977
PROCEEDIN6S--PAGE 203
Fourth US-Japan Conference on
Photochemical Air Pollution
-------
Part.
*4 OSO|~
NO^
\
(68
JO15.-V
1-0
/ O.S7OS.7
0.1
f
X
73
-1.40O11-0
Q-S 50
July 7, 1977
PROCEEDIiNGS—PAGE 204
Fourth US-Japan Conference on
.Photochemical Air Pollution
-------
'Part.
NH J QSO|~
NO-
( UNIT:jig/in3 )
34
0,22 O3.S
1.4
July 8, 1977
PROCEEDINGS—PAGE 205
Fourth US-Japan Conference on
Photochemical Air Pollution
------- |