i m mm mm]
        Air Pollution Aspects of Emission Sources
             NITRIC ACID MANUFACTURING
             A  Bibliography with Abstracts

                                         '•X"""X"
                                       llll;
                                         i • • • •
             U. S. ENVIRONMENTAL PROTECTION AGENCY

-------
       AIR POLLUTION  ASPECTS
         OF EMISSION SOURCES:
   NITRIC ACID MANUFACTURING-
A BIBLIOGRAPHY  WITH  ABSTRACTS
       Office of Technical Information and Publications
        Air Pollution Technical Information Center
        ENVIRONMENTAL PROTECTION AGENCY
              Air Pollution Control Office
         Research Triangle Park, North Carolina
                     May 1971
For sale by the Superintendent or Documents, U.S. Government Printing Office, Washington, D.C., 20402 - Price 45 cents
                Stock Number 6603-0004

-------
The AP series of reports is issued by the Air Pollution Control Office to report the results
of scientific and engineering studies, and information of general interest in the field of air
pollution.   Information reported  in this series  includes  coverage of APCO intramural
activities and of cooperative studies conducted in conjunction with state and local agencies,
research institutes, and industrial organizations.  Copies of AP reports are available  free
of charge to APCO staff members, current contractors and grantees, and  nonprofit organ-
izations  - as supplies permit - from the  Office of Technical  Information and Publications,
Air Pollution Control  Office, Environmental Protection Agency, P.O. Box  12055,  Research
Triangle  Park,  North Carolina  27709.  Others  may  obtain  copies from  the Government
Printing Office.
                      Air Pollution Control Office Publication AP-93

-------
         BIBLIOGRAPHIES IN THIS   SERIES
AP-92,  Air Pollution Aspects of Emission Sources:
        Municipal Incineration —A Bibliography with Abstracts
AP-93,  Air Pollution Aspects of Emission Sources:
        Nitric Acid Manufacturing —A Bibliography with Abstracts
AP-94,  Air Pollution Aspects of Emission Sources:
        Sulfuric Acid Manufacturing —A Bibliography with Abstracts
AP-95,  Air Pollution Aspects of Emission Sources:
        Cement Manufacturing —A Bibliography with Abstracts
AP-96,  Air Pollution Aspects of Emission Sources:
        Electric Power Production —A Bibliography with Abstracts
                               III

-------
                                  CONTENTS
INTRODUCTION	vii
ANNOTATED BIBLIOGRAPHY
      A.  Emission Sources	   1
      B.  Control Methods	   3
      C.  Measurement Methods	....11
      D.  Air Quality Measurements (None)
      E.  Atmospheric Interaction	  ,	14
      F.  Basic Science and Technology	16
      G.  Effects - Human Health	  18
      H.  Effects - Plants and Livestock	20
       I.  Effects - Materials	.21
      J,  Effects - Economic	  22
      K.  Standards and Criteria	...23
      L.  Legal and Administrative  .	24
      M.  Social Aspects (None)
      N.  General (None)
AUTHOR INDEX	25
SUBJECT INDEX	27

-------
                    AIR POLLUTION ASPECTS


                      OF EMISSION SOURCES:


              NITRIC ACID MANUFACTURING -


          A BIBLIOGRAPHY WITH ABSTRACTS



                             INTRODUCTION


   Nitric  acid manufacturing contributes  significantly to the overall air pollution level in
the United States.  To aid efforts to improve air quality, the Air Pollution Technical Infor-
mation Center (APTIC) of the Office of Technical Information and Publications, Air  Pollu-
tion Control Office, has compiled this bibliography relevant to the problem and its solution.

   Approximately 81 abstracts have been selectively screened from the contents of APTIC's
information storage and retrieval system to cover the 14 categories  set forth in the table of
contents.   The compilation is intended to be representative of available literature,  and no
claim is made to all-inclusiveness.

   Subject and author indexes referjtothe abstracts by category letter and APTIC  accession
number. Generally, higher accession numbers, representing the latest acquisitions, cover
the most recent material.

   All documents abstracted herein are  currently  on file at  the Air Pollution Technical
Information Center, Air Pollution Control Office,  Environmental  Protection Agency, P. O.
,Box 12055, Research Triangle Park, North  Carolina 27709. Readers  outside the Environ-
mental Protection Agency may seek duplicates  of documents directly from libraries, pub-
lishers, or authors.
                                      VII

-------
                                 A.  EMISSION  SOURCES
01583
R.W. Gerstle R.F. Peterson
ATMOSPHERIC EMISSIONS FROM NITRIC ACID MANU-
FACTURING PROCESSES - A COMPREHENSIVE SUMMA-
RY. Preprint.  (For Presentation  at  the  American  Inst.  of
Chemical Engineers, Detroit, Mich., Dec. 8, 1966.)
Atmospheric emissions from  nitric acid plants depend on plant
operating conditions, production rates, and the use of control
devices.  Data in this article show  that plants operating within
design capacities and producing 55-60% nitric acid can limit
the nitrogen oxides concentration to 0.3% in the stream leaving
the absorption tower. This is equivalent to about 50 pounds of
nitrogen  oxides per ton  of nitric acid (100% basis) produced.
Installation of  scrubbers or catalytic reduction equipment can
reduce these emissions by 50 to 97%. Emissions during startup
or  shutdown usually do not  create  any special problems.
(Author summary modified)

13698
Mohrnheim, Anton F.
AIR POLLUTION AND THE METAL FINISHING INDUS-
TRY. Plating, March 1969.
The role of nitrogen  oxides in air pollution is discussed in
order to inform those who work with nitric acid and aqua regia
of  their  capacity  for creating  or preventing  air  pollution.
Nitrogen dioxide itself is toxic and, in addition, contributes to
chemical smog production through a photochemical chain reac-
tion. Even though the metal manufacturing and finishing indus-
try uses larger quantities of nitric acid than the precious metal
industry,  the  latter  may  release comparable  amounts  of
nitrogen dioxide. This is  demonstrated by the quantititive reac-
tion of gold and nitric acid. In the precious metal industry,
closed systems  should be  used  with only  stoichiometric
amounts  of  aqua regia.  For  pickling and similar work in the
metal manufacturing and finishing industry, mist collectors or
air scrubbers should be used.

16699
British Oxygen Co. Ltd., Glasgow, Scotland
CURRENT METHODS  OF  COMMERCIAL PRODUCTION
OF NITROUS OXIDE. APPENDIX 1. Brit. J. Anaesthesia, vol.
39:440-442, May 1967.
Nitrous oxide is produced on a commercial scale by passing an
ammonium nitrate solution through a primary scrubbing tower
to a gas-heated reactor. As decomposition takes place, nitrous
oxide leaves the reactor, together with  steam, ammonia, nitric
acid, nitrogen,  and traces of nitric oxide and nitrogen dioxide.
Initial cooling of the merging gases causes  most of the am-
monia and nitric acid to  revert to ammonium nitrate, which is
returned  to the reactor. Residual ammonia and nitric acid are
removed  by a  water scrubber; higher oxides, by caustic/per-
managanate  scrubbers;  and ammonia traces,  by an acid
scrubber. When  free  of  all  impurities  except  moisture and
nitrogen,  the gas is compressed and dried in an alumina drier
battery. The dry, compressed gas  is next liquefied to release
nitrogen  and evaporate  pure nitrous  oxide.  The evaporated
nitrous oxide is  then compressed to cyclinder pressure  and
passed through a second alumina drier battery to a cylcinder
filling line. In purity tests for nitric oxide and nitrogen dioxide
determination, the gas leaving each drier is passed through a
visual  bubbler containing  an acid potassium permanganate
solution and  a Saltzman reagent.  An alarm is automatically
sounded if nitric oxide and nitrogen dioxide  concentrations
reach 1 vpm.

17076
Belaga, M. B. and P. N. Maystruk
SANITARY PROTECTION OF AIR IN VINNITSA. U.S.S.R.
Literature on  Air Pollution and Related Occupational Diseases,
vol.  8:241-246,  1963. (B. S.  Levine,  ed.) (Also: Gigiena i
Sanitariya, 26(l):73-76, 1961. CFSTI: 63-11570
Plans are presented for the purification of discharges from dif-
ferent shops and departments of a superphosphate plant which
currently emits 10.5 tons of sulfur dioxide, 6.5 tons of nitric
acid, 1.2 tons of sulfuric acid, 0.5 tons of fluorides, and  one
ton of superphosphate and tricalcium dust each day. Even at a
distance of 2000 meters from the plant, the maximum fluorine
concentrations are  13 times in excess of the allowable limit.
Similarly, sulfur dioxide concentrations at 1000 meters and sul-
furic acid aerosols  at 500 meters  have  been found to exceed
allowable limits. The maximum concentration of dust at 200 m
from the plant is  15.4 mg/cum, or thirty times in excess of the
allowable limit.  Dust samples collected at  200-1000 meters
from the plant showed a fluorine  content of 0.8 to 1.4%. Soil
samples at 200, 500, and 1000 meters contained 16.9, 9.61,  and
8.7 mg of fluorine per 100 g of soil. Among the measures being
taken to reduce pollution are the elimination of gas leaks by
equipment hermetization, the installation of dust catching and
gas purification equipment, and the construction of high stacks
for greater dispersion of pollutants. It is further recommended
that the sulfuric acid department build a separate housing for
its exhaust fans, use filters to raise tail-gas utilization efficien-
cy, and build a warehouse to store the apatite concentration.

18305
Lindau, L.
Am  POLLUTION  AND THE MANUFACTURE OF INOR-
GANIC CHEMICALS.  (Luftfororening  vid  framstalhiing  av
oorganiska baskemikalier.)  Text in Swedish. Statens Natur-
vardsverk, Stockholm, Publikationer No. 4, 66p., 10 refs.
The investigation deals with air pollution problems in connec-
tion with the manufacture of basic inorganic chemicals such as
sulphuric acid, hydrochloric acid, phosphoric acid, ammonia,
nitric acid, chlorine and sodium  hydroxide. The report con-
tains a survey of present conditions, an analysis of various
technical methods to reduce the emissions, and a discussion of
the economic  consequences of these methods. The purpose of
the survey is  to supply information to the Swedish authorities
dealing with air pollution control. The rates of emission from
the chemical plants are described as kg/ton product. The costs
of air  pollution abatement  vary. In certain cases, e.g.,  the
recovery of sulphur in connection with the production of  am-

-------
                                             NITRIC ACID PLANTS
 monia, the necessary investments can be written off. In other
 cases, e.g., introduction of the double-contact process for the
 manufacture  of sulphuric acid,  the increasing yield can  only
 partially  motivate  the  investments required.  There  are  also
 cases when the costs entirely belong to the air pollution ac-
 count. A comparison between Swedish and foreign plants in-
 dicates that emissions  are of the same magnitude. Essential
 improvements are  possible to  obtain in new plants and the
 latest Swedish production units have applied this to a great ex-
 tent.

 21204
 Hals, Finn A.
 ENVIRONMENTAL  POLLUTION  CONTROL  THROUGH
 MHD POWER GENERATION. Combustion, 41(ll):27-29,  May
 1970.
 In addition to offering advances in power technology of sig-
 nificant benefit  to society, magnetohydrodynamics  (MHD)
 shows promise of solving serious  air  and thermal pollution
 problems  faced by steam-electric power plants.  The use of
 MHD-steam  power plant could significantly  reduce thermal
 pollution of water  since, due to higher efficiencies, less  than
 half the amount of cooling water used by conventional fossil-
 fueled steam power plants would be required. Since the  sup-
 plemental steam  turbine can be replaced with a supplemental
 gas turbine, MHD generators can be designed to reject all heat
 into the atmosphere and none to water.  With no cooling water
 necessary, MHD generators can be located in water-poor but
 fuel-rich  areas, opening them to industrialization. Particulate
 emission would be controlled by careful electrostatic precipita-
 tion, since the economic operation of  the plant requires the
 recovery of an alkali seed impurity added to enhance electrical
 conductivity of the combustion gases. Particulate removal in
 excess of 99% is,  therefore ensured.  The temperatures at
 which MHD generators operate make the recovery of nitrogen
 oxides and sulfur oxides in the form of nitric and sulfuric acid
 technically feasible and economically attractive.

 22877
 Stuttgart Univ. (West Germany), Inst. fuer Verfahrenstechnik
 und Dampfkesselwesen
 KEEPING THE AIR PURE. (Reinhaltung der Luft). 58p., 1968.
 25  refs.  Translated  from German.  Belov and  Associates,
 Denver, Colo., 80p., Feb. 5, 1970.
A review of  technical articles relating  to  air pollution is
presented. Sampling techniques and statistical evaluation of
results are discussed. The effects of gaseous impurities on hu-
mans and plants are briefly mentioned. Maximum emission
values for nitric oxide, nitric acid, chlorine, hydrogen chloride,
hydrogen  sulfide, and sulfur dioxide are tabulated. Measure-
ment methods, including filters,  absorption bottles, and vari-
ous continuous methods are described. SO2 is generally mea-
sured by the silica gel method, the West Gaeke method, the
'Ultragas 3' method, the Pico-flex instrument, or by  infrared
spectrophotometry. Isopropanol is a good absorption  medium
for sulfur trioxide. Dewpoint  measurement and  detectors are
mentioned. NO2 can be measured by the Saltzman  method,
and  by photometric or  colorimetric means.  Measurement of
H2S  and  fluorine emissions  may be  done by the sodium
hydroxide method. Methods for carbon monoxide and dioxide
are mentioned. Organic compounds are measured by gas chro-
matography. Methods for measuring and counting dust con-
taminants, and stack sampling are discussed.  Optical and elec-
trostatic methods of determining smoke shade are described.
The  Konimeter, impinger, and  dust fall  methods are con-
sidered. A  disucssion of  plume  behavior, including  stack
height, turbulence, diffusion, and winds, is presented. Several
laws regarding emissions are mentioned.

26226
Perrine, Richard L. and Limin Hsueh
POWER   AND  INDUSTRY:   CONTROL  OF   NITROGEN
OXIDE EMISSIONS. In:  Project Clean Air. California Univ.,
Berkeley, Task Force 5, Vol. 1, Section 9, lip.,  Sept.  1, 1970.
32 refs.
When fossil fuels are burned with air  some of the nitrogen
reacts with oxygen forming nitrogen oxides; the  major source
of emissions of NOx in California is motor vehicles,  but sta-
tionary power sources and others also contribute large quanti-
ties.  The higher the peak combustion temperature the  more
nitric oxide is formed. Most current efforts  to  deal  with the
problem are  centered  on  developing improved combustion
processes  and  on the design of the burner and type of firing.
Some  improvement may be  obtained  through combustion
process modifications, but these are constrained by  existing
designs, stable operating requirements, and adverse secondary
effects. Some  basic approaches which  have been developed
for removal of NOx  emissions from nitric  acid plant  stack
gases include catalytic decomposition, catalytic reduction, ab-
sorption on solids, and caustic scrubbing. A number of modifi-
cations to operating conditions or burner design include low
excess air combustion, flue gas recirculation, steam and  water
injection, burner configuration, and fluidized bed composition.
The  complex  interaction  of  mixing,   heat  transfer,  fluid
mechanics, and chemical kinetics  within the burner needs  to
be understood.  Simplified models of the combustion  process
are necessary to aid  in  the  understanding  of the  critical
processes  controlling nitric oxide formation and to provide a
means for the systematic analysis of cause-effect  relationships.

-------
                                B.  CONTROL  METHODS
00587
J.A. Brink, Jr., W.F. Burggrabe, L.E. Greenwell
MIST REMOVAL FROM COMPRESSED GASES. Chem. Eng.
Progr., 62(4):60-66, April 1966.
Fiber mist eliminators have been successfully used to purify
gases and solve  difficult air  pollution  problems involving:
methanol  synthesis gas, sulfonation and chlorination process
gases, nitric acid process gases, chlorine, and compressed air.
Extensive  research and  development work resulted in the
development of fiber mist eliminators for the collection of sub-
micron mist particles. The first plant-scale installations  were
made for  the  control  of  air pollution  from  sulfuric  and
phosphoric acid plants. After full-scale units had been proven
highly efficient on stack gases containing submicron particles,
further research was undertaken to develop fiber mist elimina-
tors which would be most economical for the collection of par-
ticles which are predominantly 1 to 20 microns in diameter.
The installation  of  fiber  mist  eliminators within various
processes to purify gases was started after several difficult air
pollution problems had been solved. The widespread applica-
tion of fiber units to chlorine plants was reported in detail, but
the applications to many other processes has not been re-
ported previously. It should be noted that mists are present in
many chemical processes at  pressures ranging up to  5,500
Ib./sq. in.  gauge. The temperatures at whcih mists are present
are usually moderate since many mists vaporize at higher tem-
peratures.

00959
B. B. Sundaresan, C. I. Harding, F. P. May, and E. R.
Hendrickson
A DRY PROCESS FOR THE REMOVAL OF NITROGEN OX-
DDES FROM  WASTE GAS  STREAMS  IN NITRIC  ACD)
MANUFACTURE.  Preprint. (Presented at the  59th Annual
Meeting, Air Pollution Control Association, San Francisco,
Calif., June 20-25, 1966, Paper 66-96.)
Experimental studies  were conducted  using a  commercial
zeolite to remove NOx from waste gas streams in a nitric acid
plant. NOx retained  in  the bed  was recovered  as enriched
NOx and HNO3 gy regenerating the bed at elevated tempera-
tures with hot air and/or steam. Test results indicate that such
a system  could be incorporated  into an  existing nitric acid
plant, thereby  eliminating release of significant quantities of
NOx into atmosphere.  The conclusions are enumerated below:
(1) A process to remove NOx from the waste gas streams of
nitric acid plants has been found; (2) Complete  NOx removal
as proved by this system will eliminate release of NOx into
the atmosphere; (3) Commercial zeolite used in this process
can remove NOx  along with most of the moisture present in
the tail gas; (4) NOx and H2O retained in the  bed has  been
recovered as enriched  NOx and HNO3 for possible feedback
into the process stream; (5) It has  been estimated that in a 300
ton acid plant by feeding back the recovered NOx  into the
process stream, about  4 to 5 tons  per day of 60% HNO3 now
being wasted could be added to production;  and (6) The in-
creased production should offset the additional investment for
such a  system,  making  the process economically feasible.
(Author summary and conclusions)
01125
D. Zanon and D. Sordelli
PRACTICAL SOLUTIONS OF Am POLLUTION PROBLEMS
FROM CHEMICAL PROCESSES .  (Realizzazioni nel Campo
delia Prevenzione dell' inquinamento Atmosferico di Origine
Industriale.)  Translated  from  Italian.   Chim. Ind. (Milan),
48(2):251-261, March 1966.
A strict control of pollutant to be dispersed in the atmosphere
offers technical and economic problems,  both in the  design
and the operation of chemical processing  units. Three exam-
ples  of processes  for  which  pollution  control  has  been
established are described: SO2 derived from  contact sulfuric
acid  and from hydroxylamine sulfate plants, nitrous gas from
low and high-pressure  nitric acid plants, and fluorine-contain-
ing effluents from hydrogen fluoride production. The general
approach,  kind of abatement process adopted, materials and
construction  costs are discussed.

02051
J. Feist.
THE CATALYTIC REDUCTION OF NITROUS GASES DUR-
ING  THE MANUFACTURE OF NITRIC ACID. Die Kata-
lytische Reduktion Von Nitrosen Abgasen  Sei Der Erzeugung
Von  Salpetersaure. Proc. (Part  I) Intern. Clean Air Cong.,
London, 1966. (Paper VI/15). pp. 199-202.
Discusses  a  catalytic  reduction process for  reducing  nitric
oxide present in the waste gases from nitric acid for manufac-
ture to a concentration of 100 ppm. Flow sheets illustrate ther-
mal  integration of  the  catalytic  process with  the overall
process. Discusses the use  of metal and ceramic catalysts.
(Author abstract)

04658
R. W. Bayley
DESORPTION OW WASTE WATER GASES  IN ADI (PART
1). Effluent Water Treat. J. (London) 7, (2)  78-84,  Feb. 1967.
The air stripping of volatile  or gaseous  polluting  constitutents
from industrial waste  waters in desorption units is used for
pretreatment of the waste prior to descharge to a  public sewer
or stream. Where an air-pollution problem exists, the desorbed
gas must be  dispersed by stacks or the desorbed constituent
recovered. The design of such desorbing units based on known
chemical  engineering principles is illustrated by  examples  of
the removal  of the cyanide  from the effluent of a gas plant
and ammonia from the effluent from a nitric  acid plant. The
desorption unit may use either duffused air bubbles passing
through the  liquid  or counter-current  towers  packed  with
Rasching rings.

051511
B. A. Kerns
CHEMICAL   SUPPRESSION  OF  NITROGEN   OXIDES.
Westinghouse Electric Corp., Pittsburgh,  Pa., Headquarters
Mfg.  Lab.  (1964). 6 pp.

-------
                                              NITRIC ACID PLANTS
 An approach to NO and NO2 fume control by eliminating the
 fumes before their release from pickling,  milling  and bright
 dipping solutions was investigated. Since classical chemistry
 shows a reaction between most primary amines and the oxides
 of nitrogen, a study of an available, inexpensive, and readily
 adaptable amide, urea, was undertaken. The investigations in-
 cluded a thorough study of the urea-nitric acid-nitrogen oxides
 reactions for both copper and iron-68 analyses of the urea (for
 purity), and of the  evolved gases; and the effect of the urea
 nitric acid system on the various types of stainless steels and
 other metals which could be employed. A thorough study of
 the possible hazards of  the urea-nitric acid system was un-
 dertaken also . In the case of chemical milling urea sucessfully
 lowered the NO2 fumes to almost undetectable levels, but this
 treatment  did not  suppress  the HNO3  vapors which  coin-
 cidentally  are released from these hot chemical milling solu-
 tions. Thus a small water scrubbing apparatus is still required
 to prevent these  vapors  from being  released to  the at-
 mosphere. The use  of a HN03-urea solution system produces
 a satin finish in less than half  of the time now required to
 bright dip and release no toxic fumes to the atmosphere.

 05309
 E. C. Betz and H. J. Feist
 CATALYTIC AFTERBURNING  OF ORGANIC AIR POLLU-
 TANTS. Technik (Berlin) 20 (6), 395-400 (June 1965). Ger. (Tr.)
 Newly  developed all-metal catalysts are  discussed which are
 designed on the basis of the building block assembly system;
 in practice, they achieve an average running time of  25,000-
 35,000 working hours. A catalyst, which speeds up a reaction
 because of its presence, without itself participating in the reac-
 tion,  reduces the  decomposition temperature  during  com-
 bustion. A reaction temperature of 250-350 C  was achieved
 with all-metal catalysts developed for catalytic exhaust  gas pu-
 rification.  The  cold exhaust  gases  flow through   a  heat
 exchanger and are preheated. Then they are heated by means
 of oil burners, gas burners, or electrical heating  elements until
 they  reach the  catalytic reaction temperature. A fan then
 moves the exhaust gases to the catalyst where the irritants are
 oxidized. The heat released during catalytic combustion is lar-
 gely recovered in the heat exchanger and it is used for  heating
 the cold exhaust gases as combustion here is exothermal. At a
 reaction temperature of about 250-350 C, all combustible com-
 ponents are oxidized in  the exhaust gas.  As a result of the
 temperature increase  in the exhaust gas  in the catalyst, the
 positive heat change of this reaction can measured which gives
 a figure directly  proportional to the irritant concentration. The
 catalytic exhaust gas  purification unit thus serves  as  a  mea-
 surement instrument for the concentration of the exhaust gas.
 A measurement system used for  continual surveillance  is
 presented in diagram. Applications of catalytic afterburning
 are discussed in relation to the following: drying and hardening
 processes, phthalic acid and maleic acid anhydride production,
 nitric acid production, NO/NO2 reduction.

 05401
 ATMOSPHERIC EMISSIONS FROM NITRIC  ACID MANU-
 FACTURING PROCESSES. Public Health Service, Cincinnati,
 Ohio,  Div.  of Air Pollution and  Manufacturing  Chemists As-
 sociation, Washington, B.C. 1966. 96 pp. (999-AP-27.)
 Emissions to the atmosphere  from the manufacture of nitric
 acid were investigated jointly by  the Manufacturing Chemists'
Assoc., Inc. and the  U.S.P.H.S.; the study was the second in  a
 cooperative program for evaluation of emissions  from selected
chemical manufacturing  processes. The report  describes the
growth and potential of the nitric acid industry, the principal
processes for production of  nitric acid, process variables,
emissions from plants under normal operating conditions, and
the methods and devices used to limit and control emissions.
The sampling and analytical techniques  by  which emissions
were assessed are presented in detail. (Author's abstract)

06123
O. Jeitner, and K. Konig
ELIMINATION  OF  NITROUS GAS EMISSION  BY  CATA-
LYTIC REDUCTION.  Beseitigung  der  Nitrosegasemission
durch  katalytische Reduction. Chem.  Tech. (Berlin) 19, (3),
166-9, Mar. 1967. Ger.
At the nitric acid plant in Piesteritz, East  Germany, NO in the
waste gas was to be catalytically reduced by  hydrogen. The
hydrogen  was a by-product and contained 0.1% by volume of
H2S and  0.05% by  volume  of  PH3, both  toxic  to  the Pd
catalyst used.  Therefore, the hydrogen had to be washed by
passing it through two washing towers containing 30% HNO3.
One tower also contained 15%  NaOH and  the other water.
Complete  elimination of the NO was possible using 0.4 to 0.6%
more hydrogen than the stoichio metrically required volume. If
the flow of hydrogen through the catalyst is closely controlled,
the resulting nitrogen is virtually free of oxygen and hydrogen.

06844
H. C. Anderson, P. L. Romeo and W. J. Green
A NEW FAMILY OF CATALYSTS FOR NITRIC ACID TAIL
GASES. Engelhard Ind. Tech. Bull. 7 (3), 100-5 (Dec. 1966).
The palladium unitory  ceramic  catalyst remove  oxides of
nitrogen from tail gases  produced  during the production of
nitric acid was evaluated. The new catalyst, provides excellent
abatement at  100 p.s.i.g., using  space velocities  of 100,000.
Even at 150,000, 94% of the NOx was removed, with ammonia
in only slight excess  over the NOx. Bench-scale and field ex-
perience have shown that the unitary ceramic catalyst  is well
adapted to the treatment of nitric  acid stack gases.

07093
REVIEW   OF  RESTRICTING   GAS   EMISSION   FROM
NITRIC-ACID PLANTS. ((VDI (Verein Deutscher  Ingenieure)
Kommission Reinhaltung der  Luft, Duesseldorf,  Germany,))
(VDI No.  2295.) (July 1963) Ger. (Tr.) 12 pp.
The control of nitrogen oxides during the production of nitric
acid was  discussed. Nitrogen  oxides emissions  are restricted
by absorption, suitable discharge outlets,  and on the basis of
missions.  Because of the particularities of nitrous gases, the
content of the waste gases cannot be completely controlled.

07535
W. Leithe
CLEAN AIR MAINTENANCE  - AN IMPORTANT TASK FOR
CHEMISTRY  AND ECONOMY.  (Reinhaltung der Luft   ein
dringendes Anliegen fur Chemie und Wirtschaft.) Text in Ger-
man. Allgem. Prakt.  Chem. (Vienna), 18(8):239-241, Sept. 10-
17,  1967. 4 refs.
This article is a summary of two  lectures given  at meetings of
chemical societies. The problem of air pollution and some con-
trol methods are outlined. Typical examples of well-known air
pollution  problems  are  mentioned: London's  smog chiefly
caused by domestic heating,  the  smog  of  Los Angeles  due to
automobiles, the sun, and temperature inversions,  and the in-
dustrial air pollution  of the Ruhr Valley.  Some  characteristic
data for all three examples are quoted. The techniques for the
control  of dust emissions are  farthest  advanced. This  is

-------
                                           B.  CONTROL METHODS
verified by the fact that in Germany, emission of cement dusts
decreased to one third while the production of cement tripled
in the last 17 years. Far less satisfactory is the control of SO2
emissions. About twice as  much sulfur is blown  into the  air
than is used for the production of sulfuric acid. Some wet and
dry processes for the elimination of SO2 from smoke are men-
tioned, but no method is known today which is both effective
and  economical. The  chemical industry  tackled its problems
mostly by reducing the emission of air polluting substances by
increasing the efficiencies of the relevant chemical processes.
Examples are the production  of sulfuric acid and nitric acid.
Organic compounds can be recovered by either absorption on
activated charcoal or oxidation by catalytic afterburners.

07552
Billings, Charles E., Charles Kurker, Jr., and Leslie Silverman
SIMULTANEOUS REMOVAL OF ACID GASES, MISTS, AND
FUMES WITH  MINERAL WOOL  FILTERS. J. Air Pollution
Control Assoc., 8(3):195-202, Nov. 1958. 20 refs. (Presented at
the  51st  Annual  Meeting, Air  Pollution  Control Assoc.,
Philadelphia, Pa., May 26-29, 1958.)
Investigations have  indicated that two in. thick filters at four
Ib/cu. ft. packing density  will remove up to 80% of acid mist
and  up  to 99% of acid gases and fumes. Total filter life de-
pends upon concentration of contaminant in the entering air. A
summary of  filter performance is given. Estimated operating
life based upon one use of the filter material can  be obtained
from the data given. With particulates such as iron  oxide and
fly ash, it has been found  possible to wash and reuse filters
about ten times. When iron oxide was collected simultaneously
with SO2, filters were reused about eight times. Acid gas col-
lection is significantly improved by the presence  of moisture
on slag wool filters. Mineral wool filters have several features
such as, low cost (about 1 cents/lg.),  small fiber diameter (4
micron and  ability to withstand high temperatures  (1000 deg
F.). Slag wool will simultaneously remove sub-micron particu-
late  materials with  90  to 99% efficiency. Resistance to flow
through two  in.  slag wool  filters  (with an HF efficiency of
95%) is  on the order of one or two in. of water, or if continu-
ously moistened, at most 6 in. of water.

09773
FAN SCRUBBER HALTS CORROSION ENDING  NEED FOR
ROOF REPAIRS. Chem. Process., 31(4):67, April 1968.
The  manner in which escaping acid  fumes were controlled at a
particular  plant  is  described.  An  existing  system  of  water
scrubbers was supplanted by a separator based on a centrifu-
gal fan. Flow through  the separator is 14,000 cfm  of an ex-
haust containing 750 ppm of nitric acid and nitrogen oxides
and  350  ppm of hydrofluoric acid. Most of  the fumes are
separated by centrifugal force in the fan, into which 6 gpm of
water is  sprayed. The partially cleaned  exhaust then passes
through a 48 x  80 x 6 in thick polypropylene filter  which
removes nearly all of the remaining wetted fumes. Fumes leav-
ing the  separator were reduced to trace amounts. Scrubbing
water requirements  were  reduced by  34 gpm. The complete
system was installed at a cost of $8100, less thatn $.70 cfm.

09981
Tikhonenko, A. D. and M. N. Nabiev
NATURAL-GAS  CATALYTIC  REDUCTION  OF   NITRIC
OXIDE TADL GASES  FROM NITRIC ACID PRODUCTION.
Translated from Russian. Uzbesk. Khim. Zh., ll(4):6-9, 1967.
2 refs. CFSTI: PB 178106T
The catalytic reduction of nitrogen oxides is the most progres-
sive means of purifying tail gas from nitric acid production.
The process of catalytic reduction of nitric oxides by methane
in the form of natural gas at atmospheric pressure with the use
of platinized nickel-chromium foil and a two-layer catalyzer is
described. In operation over 710 hrs, the nickel-chromium foil
showed sufficient thermal  stability under conditions assuring
complete purification of the gas; catalyst activity significantly
decreased and was reduced with H2 at 320 deg. C. The condi-
tions for complete nitric oxide reduction were  found and also
those  for achieving the  sanitary norm of NO+NO2 content
(0.02  percent).  In a  two-layer  catalyst it  was  possible  to
decrease the temperature of  the gas entering the catalyzer to
450 deg. and the resulting CH4:O2 ratio was 0.8.

10017
Bloomfield, Bernard D.
CONTROL OF GASEOUS POLLUTANTS.  Heating, Piping,
Air Condition ing, 40(1): 195-206, Jan. 1968. 26 refs.
Control technology in relation to air pollution involves the ap-
plication, singly or in combination, of tall stacks for dispersio
process changes,  and  control equipment. Most gaseous con-
taminants can be controlled  using the techniques of absorp-
tion, adsorption, direct flame combustion, and catalytic com-
bustion. The theoretical principles of design  and  operation
preclude under most circumstance the use of any of the shelf
items  for air pollution  control purpose Good design,  construc-
tion, and proper operation  are the  requisites  of a satisfactory
system. The special characteristics  of a number systems  are
described. A table of selected air quality standards i  given for
such pollutants as SOx, NOx, CO, H2S, and ozone.

10159
Atroshchenko, V. I., and E. G. Sedasnova
RATE OF NITROGEN  OXIDES  ABSORPTION  BY  AL-
KALINE SOLUTIONS AND NITRIC ACID. Zh. Prikl. Khim.,
25(11):! 143-1150, 1952. 13 refs. Translated from Russian by B.
S. Levine, U. S.  S. R.  Literature on Air Pollution and Related
Occupational Di- seases, Vol. 6, 299p., April 1961. CFSTI: TT
61-21982
The absorption of nitrogen  oxides by alkaline solutions has be-
come  economically advantageous to the nitric acid industry. In
connection with the complex processes which take place in the
for mation of nitric acid and alkaline nitrates from nitric oxide,
an experimental study was  made of the relative velocity of the
total nitric oxide conversion at different ratios between acid
and alka line absorption.  The  results of the  study demon-
strated  that a  functional  relationship  existed between  the
degree of nitrogen oxides  absorption and the increase in  the
specific gravity of al kaline absorbers, accompanied  by a cor-
responding reduction in the degree of nitric acid absorption.
The results also established that at the combined production of
nitric  acid and sodium nitrate by the method  of increasing the
degree of nitrogen oxides absorp tion by alkaline solution, the
reaction volume can be reduced considerably.

11058
W. Teske
IMPROVEMENTS IN  THE PROCESSES AND OPERATION
OF PLANTS IN THE CHEMICAL INDUSTRY LEADING TO
REDUCED EMISSION. Staub (English  translation), 28(3):25-
33, March 1968. CFSTI: TT 68-50448/3
The emissions from chemical plants can be reduced,  in special
cases, by changing the production process or, in general,  by
using a gas cleaning method. Change in the production process

-------
                                             NITRIC ACID PLANTS
 may be achieved by a basic alteration of the process itself, by
 changing the mode of operation, by modifying the equipment
 and by using a different raw material. For this purpose, the
 doublecontact method for sulphuric acid production, the pres-
 sure method for nitric acid recovery and the introduction of a
 covered carbide furnace  are mentioned as examples. The su-
 perphosphate  process,  viscose  process,   production  of
 betanaphthol, production of thermal  phosphoric  acid  and
 production  of  calcium chloride are  given as examples for
 waste gas cleaning. (Author's summary)

 11549
 Bingham, E. C. Jr.
 NITRIC ACID PLANT'S CATALYTIC BURNER PREVENTS
 TAIL  GAS STREAM  AIR POLLUTION. Preprint, Farmers
 Chemical Association, Inc., Tyner, Tenn., 3p., 1968.
 Air contamination  is prevented from a ton per day nitric acid
 manufacturing plant by passing the tail gas through a catalytic
 burner which reduces  residual oxides of nitrogen into a color-
 less stream. After purification  in the combustion chamber,
 which contain a catalyst charge, the exhaust stream can be
 safety directed to  a turbine  expander  for power recovery to
 assist in driving the main compressor of the acid manufactur-
 ing  unit. The catalytic reaction  also increases the life of the
 expander because the afterburner exhaust stream has no nitric
 acid carry over that  could  eventually strip out the  turbine
 blades.  Tests conducted during the first six months of opera-
 tion of the charge showed a cleanup of NO2 pollutants ranging
 between 95 and 98 percent. The  unit maintained the high rate
 of reduction of fumes while operating at space velocities in the
 order of 120,000 cubic feet of gas per cubic foot of catalyst
 system per hour.

 12637
 W. Teske
 EMISSIONS AND ABATEMENT OF OXIDES OF NITROGEN
 IN  NITRIC ACID MANUFACTURE.  Chem. Eng., No. 221,
 CE263-266, Sept. 1968.
 The emission problem in the manufacture of nitric acid results
 from incomplete conversion of  nitrous oxide to nitric  acid.
 Some of the processes for reducing the emissions which are
 discussed  briefly include: Alkaline absorption with milk of
 lime or aqueous ammonia; oxidation with hydrogen peroxide
 or ozone; absorption in an aqueous solution of magnesium ox-
 ide; removal as nitrosylsulfuric acid by treatment with a sul-
 furic acid,  nitric  acid  mixture; and  catalytic  reduction
 processes.

 13202
 Schmitt, Karl, Wilhelm Ester, Hans Heumann, and Harry
 Pauling
 NITROGEN OXIDE CONVERSION. (Hibemia Chemie GmbH,
 Gelsenkirchen-Buer, Germany, and Harry Pauling, Munich,
 Germany) U. S. Pat. 3,453,071. 7p., July 1, 1969. 4 refs. (Appl.
 May 16, 1966, 29 claims).
 In  the  production of  nitric  acid  and other  nitrogenous
products, exhaust gas  is produced which contains significant
quantities  of nitrogen  oxides, particularly NO and NO2. A
process for absorbing these oxides and recovering them as am-
monium nitrite includes adjusting the mole ratio of NO to NO2
to 1 and then introducing the adjusted gas into  an ammoniacal
solution of  ammonium nitrate. The ammonium  nitrate content
of the  absorbent solution is controlled so that the solution
viscosity at any given temperature is higher than the viscosity
of water at the same temperature. When the ammonium nitrate
concentration is maintained at about 40 to 50 weight percent
and the absorption process is operated at 20 to 30 C, at least
half the ammonium nitrite formation takes place at the liquid-
vapor  interface. The  remainder of  the ammonium  nitrite is
produced  in the gas phase by successive absorption of small
amounts of gaseous ammonia in the vapor space, where it is
neutralized with water vapor  and nitrogen oxide  to form am-
monium nitrates as well as the ammonium nitrites. These dis-
solve in the absorbent solution. By  preventing the develop-
ment  of  easily  decomposable  ammonium  nitrite mists,  the
process minimizes efficiency losses and explosion dangers.

13205
Markvart, Miroslav and Vladimir Pour
SELECTIVE REDUCTION OF NITROGEN OXIDES WITH
AMMONIA.    (Selektivni    redukce   kyslicniku    dusiku
amoniakem). Text in Czech. Chem. Prumysl (Prague), 19(1):8-
12, 1969. 12 refs.
In  manufacturing   nitrogen  acids,  catalytic  reduction  of
nitrogen oxides in fall gases is  the most effective method of
neutralization.  Using ammonia as a catalyst, nitrogen oxides
can be selectively eliminated. The consumption of fuel using
ammonia  is approximately ten  times lower  than with other
reducers.  Tests  were conducted to  gain more  information
about the method. All measurements were  taken  under  at-
mospheric pressure, and the reaction took place in the kinetic
range. Nitrogen oxides were detected by the standard titrimet-
ric  method. Catalyzers were prepared  by  depositing active
metal on aluminium. In the absence of oxygen, the reduction
is fastest  on platinum catalyzers; 95% conversion is reached
with temperatures above C. In the presence  of oxygen on the
same catalyzer, the temperature may be as low as 180 C. The
increase in speed of reaction is most evident with small con-
centrations. The activity of the catalyzer is greatest when the
amount of Pt is 1%. In all of the tests, the greater the speed of
the gases,  the higher the temperature must be. The only disad-
vantage of this method is that  ammonia  salts are generated
that may deposit on the cool parts of the reactor.

13689
Atroshchenko, V. I., A. N. Tseytlin, A. P. Zasorin, and V. S.
Zolotarev
UTILIZATION OF NITROGEN OXIDES - BY-PRODUCTS OF
CERTAIN  INDUSTRIES.  (Utilizatsiya  okislov azota   otk-
hodov nekotorykh proizvodstv).  Text in Russian.  Khim. Prom.
(Moscow), 1(1):79- 80,  1960.
Production of nitric acid from exhaust gas with high NO con-
tent as compared with exhaust gas with low NO content plus
NO2 is discussed. A method is described which involves cool-
ing  the gases to 25-30  C, introducing additional air, and carry-
ing  out oxidation in a  cooler-oxidizer. About 8% absorption is
achieved with 35% nitric acid  absorbent. Specifications for an
operating installation which produces 2500 kg of 55% acid are
given. A modified version using oxygen rather than air is men-
tioned.

13893
Anderson, H. C., P. L. Romeo, and W. J. Green
A NEW FAMILY OF CATALYSTS FOR NITRIC ACID TAIL
GASES. Nitrogen, no. 50:33-36, Nov./Dec. 1967. 6 refs.
A unitary  ceramic cartridge was designed to  act as a precious
metal  catalyst  support. The  support  consists of  a  block  of
ceramic, through which a multitude of small parallel channels
pass which are coated with the precious  metal. Bench-scale
and field experience have shown that the unitary catalyst is

-------
                                           B. CONTROL METHODS
 well-adapted to the treatment of nitric acid stack gases. Using
 natural gas as a fuel, decolorization of stack gases is effected
 using palladium as the catalyst on the  ceramic support. The
 ceramic structure is well designed for the two-stage catalytic
 removal of NO and NO2 in gases containing more  than the 3%
 maximum oxygen level required for one stage removal. By ap-
 plying platinum-alumina on  the  ceramic cartridge,  excellent
 abatement (94%) of the nitrogen oxides present in the gases is
 achieved at 100 psi and space velocities up to 150,000.

 13899
 Varlamov, M. L.,  G. A. Manakin, Ya. I.  Starosel'skiy, and L.
 S. Zbrozhek
 INVESTIGATION  OF  THE   AMMONIA  METHOD  OF
 REMOVING NITROGEN  OXIDES  FROM THE EXHAUST
 GASES OF A NITROGEN-OXIDE NITRIC-ACID TOWER
 SYSTEM. I. (Issledovaniye ammiachnogo metoda ochistki ot
 okislov azota otkhodyashchikh  gazov  bashennoy  nitroznoy
 semokislotnoy  sistemy).  Text  in  Russian.  Nauchn.  Zap.
 Odessk. Politekhn. Inst.,  vol.  40:24-33, 1962. 4 refs.
 Data from laboratory study of  the removal of low concentra-
 tions of nitrogen oxides using gaseous ammonia and ammonia
 water are  presented. The use of gaseous ammonia, in conjunc-
 tion with acoustic coagulation with  an aerosol, yielded an
 average degree of removal of 85% when incoming gases were
 highly oxidized. Nitrogen dioxide, and an equimolecular mix-
 ture of NO and NO2, reacted with 82-93%  completeness with
 gaseous ammonia, this value  increasing slightly with  increased
 reaction volume. A gas lift using ammonia water yielded 63.6%
 purification with a 40% content of nitrogen oxides. The degree
 of oxidation of industrial exhaust gases  is an important factor
 determining the degree of purification  by this method. The
 data given correspond to an  equimolecular NO and NO2 mix-
 ture.

 14007
 Hsieh, Yu Hsioh
 AN EXPERIMENT IN THE PRODUCTION OF NITROGEN
 FROM NITRIC ACID PLANT TAIL GAS. (Ts'ung hsiao suan
 wei ch'i chih ch'i fan ch'i ti shih yen). Text in Chinese. K'o
 Hsueh T'ung Pao, vol. 10: 307-308, 1957. 6 refs.
 By passing nitric acid tail gas first an alkali scrubbing tower to
 remove CO2 and then through a catalyst  reactor to reduce
 NO2 and O2 in the presence  of excess hydrogen, it was found
 practical to  recover nitrogen. Three types  of catalysts were
 made  by depositing Cu and Ni  on soil diatoms:  CuO:diatoms,
 NiO:diatoms, and CuO plus  NiO:diatoms,  all in  a  1:9 ratio.
 The highest absorption rate could be attained with  a sodium
 hydroxide  concentration of 1% and a gas linear velocity of 0.2
 m/sec. The concentration of CO2  could be reduced to 30 ppm.
 By using CuO with a firebrick carrier at  a temperature of 600-
650 C, a space velocity of 6000  reciprocal hours, and 4-6% ex-
cess hydrogen, it was possible to produce a gas with 1-5 ppm
NO, 10-20 ppm 02, and 400 ppm NH3.  By using  the copper-
nickel catalyst with diatoms  as carriers at a temperature of
300-500 C, a space velocity of 1500 reciprocal hours, and 5%
excess hydrogen, a gas with  0.4-0.7 ppm NO, 10-20 ppm 02,
and 300-500 ppm NH3 could  be produced with the content of
noxious gas within acceptable limits. The temperature of reac-
tion increases rapidly with  oxygen content of the tail gas and
with space velocity. Since the reactor was of simple construc-
tion, there was no way  to control the  temperature, and no
tests were performed under conditions of low temperature and
high space velocity.
14382
Pozin, M. E., B. A. Kopylev, and G. V. Bel'chenko
ABSORPTION OF  NITROGEN OXIDES  WITH A SODA
SOLUTION IN A FOAM APPARATUS FOR THE PRODUC-
TION OF SODIUM NITRATE. (Pogloshcheniye okislov azota
sodovym rastvorom  v pennom apparate dlya proizvodstva
nitrata  natriya). Text in Russian. Tr.  Leningr. Tekhnol.  Inst.
Imen. Lensoveta, vol. 36:120-32, 1956.12 refs.
A foam apparatus proved effective for the alkaline absorption
of nitrogen oxides for the purpose of producing nitrates and
decreasing the loss  of nitrogen oxides in the production  of
nitric acid. The coefficient of efficiency of a single platform-
cascade apparatus was decreased from 30 to 16% on increas-
ing the linear gas flow rate from 0.5 to 3 m/sec in a cross sec-
tion  of the foam apparatus. The coefficient of absorption in-
creases with increase in the linear flow rate of the gas, attain-
ing a value of 1860 kg/sq m-hr-kg/cu  m,  which was approxi-
mately 6-7 times larger than the value of the absorption coeffi-
cient for a packed column under laboratory conditions, and 20-
25 times greater than for factory-type scrubbers. With increase
in the rate of flow of the liquid, the efficiency of a single plat-
form of the apparatus  and the coefficient of absorption in-
creased insignificantly. Thus, increase in  the  rate of  flow  of
the liquid by  3 times  (from 1 to 3 cu m/hr) at a gas flow rate
of 1  m/sec leads to an increase in efficiency of 22-24%. In-
crease in the  concentration of absorbent in solution from 5 to
20%  Na2CO3 at a linear gas flow rate of 1 m/sec leads to a
decrease in efficiency from 26 to 16%. Correspondingly, the
coefficient of absorption is also decreased.  If the initial  con-
centration of nitrogen oxides in the gas is increased from 0.05
to 1.4% at a linear gas flow rate of 1  m/sec, the value of the
efficiency of a single platform of the apparatus increased from
8 to  25%. Choice of the number of platforms in the apparatus
can be based on  the data for a single  platform in  accordance
with  the required degree of absorption  of nitrogen oxides.

14387
Nabiyev, M. K., A. A. Kulik, P. T. Merenkov, and  A. D.
Tikhonenko
PURIFICATION OF NITROGEN OF EXHAUST GAS IN THE
PRODUCTION  OF  WEAK  NITRIC  ACID  FOR  THE
SYNTHESIS  OF AMMONIA.  (Ochistka  azota vykhlopnogo
gaza pri proizvodstve slaboy azotnoy kisloty dlya  sinteza am-
miaka).  Text  in  Russian.  Dokl.  Akad. Nauk  Uz.  SSR,
20(11): 17-20, 1963. 9 refs.
The  small amount of nitrogen oxides in exhaust gases was
reduced by natural gas using a nickel catalyst. On  a platinum-
nickel catalyst, a  volume rate  of 2800 cu cm was obtained.
Complete purification occurred at 500-600 deg. The resulting
gas containing 93.85% nitrogen, can be used for the synthesis
of ammonia. A method is proposed for a single-step  conver-
sion  to  a nitrogen-hydrogen  mixture  using water vapor and
nitrogen obtained by catalytic purification of exhaust gas.

14481
Van  Der Drift, J.
CATALYTIC REMOVAL  OF  NITROGEN  OXIDES  FROM
WASTE GASES  OF NITRIC ACID  PLANTS. A  METHOD
FOR THE PREVENTION OF Affi POLLUTION. (Katalytische
verwijdering van N-oxyden uit afgewerkte gassen van salpeter-
zuurfabrieken.  Een   methode  voor de   bestrijding  van
luchverontreiniging). Text  in Dutch.  Chem.  Tech. (Amster-
dam), 24(10):301-305, 1969. 11 refs.
Removal of  nitrogen oxides  from nitric  acid plants can  be
achieved by catalytic decomposition or reduction. The cata-

-------
 8
NITRIC ACID PLANTS
 lytic  decomposition follows the reaction 2NO yields N2 plus
 O2. With a copper-silica gel catalyst, the nitrogen oxide con-
 tent of waste gas was reduced from 892 to 277 ppm at 510 C.
 The reduction method uses hydrogen, natural gas, or ammonia
 as  reducing agents. Various installations  for the removal of
 nitrogen oxides  from waste  gases  are  described.  A  heat
 exchanger  is used to lower the temperature of waste gases
 from  around 515  C to 300 C after reduction.  Several commer-
 cial  catalysts  are   described.   In  an   experiment  using
 Honeycombgrid  HCM-S-900  and ammonia, waste  gas  of
 100,000 vol/vol catalyst/hr containing 0.3% nitrogen oxides and
 3% O2 (inlet temp. 286 C) was reduced to 50 ppm NO2 and 86
 ppm  NO plus NO2.  Using 0.3% Pt on  a  Torvex  ceramic
 honeycomb and  natural gas,  waste gas  of  100,000  vol/vol
 catalyst/hr containing  0.3% nitrogen oxides and 2.58% O2 (in-
 let temp. 440 C) was reduced to 58 ppm nitrogen oxides.

 14533
 A METHOD FOR THE RECOVERY OF NITROGEN OXIDES.
 (Werkwijze voor het  winnen van  stikstofoxyden). Text in
 Dutch.  (Universal Oil Products Co.,  Des Plaines, HI.) Dutch
 Pat. 6,607,036.  13p., Nov. 25, 1966.  (Appl. May 23,  1966, 8
 claims).
 The system is particularly suited to handling  tail gases  from a
 nitric acid factory and from the lead chamber process of a sul-
 furic  acid factory. This method also gives a distinct improve-
 ment  in the output of a  nitric acid  plant. The waste gas is
 passed  over a bed of adsorbing coal particles followed by a
 hot fluid desorption medium to remove the adsorbed nitrogen
 oxides from the particles. The desorption medium consists of
 steam at about 10 atm at a temperature greater than 157 C and
 preferably  more  than  177 C.  The nitrogen  oxide-containing
 steam is cooled and the mixture obtained is returned to the ad-
 sorption zone of the nitric acid plant. The desorption medium
 can also be hot air. The depth of the bed should not exceed
 0.3m  to prevent a large pressure drop. The stream waste gas
 through the adsorption bed is diverted upon saturation  with
 nitrogen oxides to another bed of adsorbing coal. The  coal in
 the first bed is then desorbed until the second bed is saturated
 and the cycle is repeated. Waste gas from sulfuric acid plants
 is treated the  same way. The advantages of this method are
 better removal of  nitrogen oxides with cost reduction, since no
 extra  fuel  is required.  Due to  integration of the units  for
 preparation  of  acid and for  recovery, higher output is  ob-
 tained; output of a nitric acid plant can be increased by 5% by
 more  complete use of NO2.

 14568
 Safiullin, N. Sh. and M. I. Olevinskiy
 RENDERING HARMLESS THE WASTE GASES FROM SUL-
 FURIC  ACID TOWER  SYSTEMS.  (Obezvrezhivaniye  otk-
 hodyashchikh gazov bashennykh sernokislotnykh sistem). Text
 in Russian. Khim.  Prom. (Moscow), no. 3:132-136, 1955.
 It is reported that a complex consisting of a precipitation sec-
 tion irrigated with strong acid and a moist electrofilter will as-
 sure reliable purification of waste gases from tower systems.
 Such  a system reduces the  aerosol  and vapor sulfuric  acid
 content to 0.04-0.10 g/cu m, a 20-fold reduction. Complete ab-
 sorption of an equimolar mixture of nitrogen  oxides results in
a reduction in  specific consumption rate of nitric acid by 6-8
kg/ton. Absorption of  nitrogen oxides and reduction of nitric
acid discharge rate may be increased significantly by supplying
the equipment with nitrogen oxides with a degree of oxidation
of 45-50%.  In order to assure normal operation of the equip-
ment,  the amount  of original sulfuric acid circulating in it must
be not less  than  88%. Joint operation of both  the irrigating
                system and the electrofilter is imperative for proper purifica-
                tion of waste gases.

                14664
                Atsukawa, Masumi, Yoshihiko Nishimoto, and Naoyuki
                Takahashi
                STUDY ON THE REMOVAL OF NITROGEN OXIDES FROM
                EFFLUENT  STACK GASES.  Mitsubishi  Heavy  Industries,
                Ltd., Tech. Rev., 5(2):129-135, May 1968. 9 refs.
                Pilot plant  tests  of the  Mitsubishi  process  for removing
                nitrogen oxides from stack gases demonstrate that nitrogen ox-
                ides can be  economically  reduced  to less than 0.02% of gas
                content. By  limiting threshold concentrations of nitric acid to
                200 ppm or below,  the method  should meet the removal
                requirements of the major sources of nitrogen oxide  emis-
                sions: metal  pickling plants, nitric acid plants, chemical plants
                using nitric acid, nitrate, and nitrite plants. Nitric oxide is con-
                verted  to NO2 by either homogeneous or catalytic oxidation,
                while nitrogen compounds are recovered through absorption of
                stack gases  in wetted-wall towers  packed with PVC sheets.
                Homogeneous oxidation is a slow process and requires  large
                equipment. However, this equipment is easy to  operate.  Cata-
                lytic oxidation can be performed on small-scale equipment, but
                the catalyst is affected by water, dust, and mist present in the
                effluent gas  and regeneration is necessary. The PVC equip-
                ment has a large absorption coefficient and a small pressure
                drop.

                15152
                Schwanecke, Rudolf
                WASTE GAS  CLEANING THROUGH  COMBUSTION  OF
                NITROGEN  OXIDES. (Abgasreinigung durch Verbrennen von
                Stickstoffoxyden). Text in German.  Zentr. Arbeitsmed. Ar-
                beitsschutz, 19(9):262-264, 1969. 3 refs.
                Various methods for elimination of NO and NO2 from waste
                gases are reviewed. Absorption of the nitrogen oxides on  silica
                gel has recently interested the nitric acid plants. Water vapor
                is used for desorption,  and the recovered nitrogen oxides are
                returned to the nitric acid plant. If no recovery of the nitrogen
                oxides  is desired, they can be removed from waste air by
                scrubbing with water or bases such as sodium hydroxide or
                ammonia water. The reaction follows the equation 3NO2  +
                H2O yields  2HNO3 + NO. As can be  seen, only NO2 is
                removed. A patented process for dissociation of NO and NO2
                in the reducing part of  the flame is based on the reaction of
                carbon monoxide with NO2 and NO in a flame sustained  in an
                atmosphere of low air. The reaction follows the equation 2NO
                + 2CO yields N2 + 2CO2. It has also been discovered that the
                nitrogen oxides  dissociate  in an atmosphere of 20% or  more
                excess air. The process depends on the thorough mixing of the
                gases with the flame,  as accomplished by atomization.  In a
                chemical plant, NO and NO2 are eliminated by a combination
                of  scrubbing and combustion. Nitric oxide escapes from the
                scrubber at a rate of up  to 30 cu m/hr with a temperature  of 30
                C. It is mixed with air and atomized with the fuel oil in a muf-
                fle furnace;  it serves as combustion air and as an atomizing
                agent for the fuel oil. About 3 to 5 ppm of NO and NO2  were
                measured in the waste gas of the furnace.

                16726
                Kazakova, E. A., R. Z. Khiterer, and V. E. Bomshtein
                PURIFICATION OF EXHAUST GASES FROM NITRIC ACID
                PLANTS. Brit. Chem. Eng., 14(5):667-668, May 1969.
                The presence of unabsorbed nitrous  gases in the tail gases
                from nitric acid plants created a serious pollution problem and

-------
                                           B. CONTROL METHODS
 efforts to deal with it have followed various lines. In this arti-
 cle a pilot plant that applies  the principle of adsorption of the
 nitrogen oxides by a fluidized stream of silica gel particles is
 described. The pilot plant consisted of an adsorption column
 operating at 5.5 atm and a desorber operating at atmospheric
 pressure.  In the adsorption column, fluidized silica gel flows
 counter-current to the gas stream. The NO is partly oxidized
 to NO2 and adsorbed on the silica gel. The adsorbent satu-
 rated with NO2  is withdrawn from the adsorber  base and
 passes to  the desorption column. Here the adsorbent is heated
 with steam to  180 to 190 C while a current of air desorbs the
 silica gel. The  desorption  products,  after  dedusting  in a
 cyclone are returned to the process.

 19847
 Kazakova, E. A., R. Z. Khiterer, and V. E. Bomshtein
 PURIFICATION OF EXHAUST GASES FROM NITRIC ACID
 PLANTS.  Brit.  Chem. Eng.,  14(5):667-668, May  1969. (Also:
 Khim. Prom. (Moscow),  vol. 7:517, 1968.)
 A method for  adsorbing the exhaust gases from a nitric acid
 plant is discussed. Exhaust gases were cooled with water and
 brine to O C, and after  separation of condensate, entered the
 500 mm diameter  adsorption column. This has 22 trays spaced
 at 400 mm,  and fluidized silica gel flows  from  tray  to tray,
 countercurrent to the gas stream. Nitric oxide  is partly  ox-
 idized to  nitrogen dioxide and is adsorbed on  the  silica gel.
 The adsorbent saturated  with NO2, is withdrawn from the ad-
 sorber and passed to the  desorption column. This column is
 heated with steam  to 180 to 190 C,  while an air  current
 desorbs the silica gel. The desorption products, containing 65%
 acid vapor, water, NO2,  nitrogen, and oxygen, after dedusting
 in a cyclone, are returned to the process.  It was found con-
 venient to locate  the adsorption column above the  desorber,
 and to conduct both operations at 5 atm. A gate valve controls
 the flow between  columns; a penumatic conveyer transfers the
 adsorbent from column  base  to column head. By raising the
 temperature in the desorber to 190 C, the nitrogen oxides con-
 centration can be reduced to 0.01%.

 20313
 Newman,  Daniel J. and Jorge M. Malta
 APPARATUS FOR  NITROGEN OXIDES ABSORPTION  TO
 PRODUCE CONCENTRATED NITRIC ACID. (Chemical Con-
 struction Corp., New York,  N. Y.) U.  S. Pat 3,499,734. 7p.,
 March 10, 1970. 4 refs. (Appl. Jan. 5, 1967, 14  claims).
 An apparatus is provided for the absorption of nitrogen oxides
 from a gas stream into an  aqueous absorbent  solution  to form
 nitric acid, in  which  re-oxidation of nitric oxide also takes
 place. The apparatus  is provided with a lower combination
 heat exchanger-absorber  section in which the  simultaneous ab-
 sorption of nitrogen dioxide, re-oxidation of  nitric oxide, and
 cooling  of the liquid  phase  takes place. Two  or more heat
exchanger sections may be  provided in series.  A  gas-liquid
contact section such as a packed section or a plurality of per-
forated trays is provided above the  heat exchanger sections.
The feed  gas  stream  containing nitrogen oxides and excess
free oxygen is passed  into  the apparatus  below  the heat
exchanger sections, while the aqueous absorbent solution is
admitted above the  upper gas-liquid contact  section.  (Author
abstract)

20775
Ermenc, E. D.
CONTROLLING  NITRIC  OXIDE EMISSION. Chem. Eng.,
77(12):193-196, June 1, 1970. 1 ref.
Industries using nitric acid in their processes should now be
planning to meet  the anticipated legal standards, which may
limit emissions of nitrogen oxides to about 500 ppm. Data for
controlling emissions are presented. The reaction kinetics of
nitrogen and oxygen in air are characterized at high tempera-
tures by standard second-order equations,  while the reaction
becomes zero orders at temperatures below 2000 F. Because
the reverse reaction rate is many times greater than the for-
ward rate, cooling must be very rapid to retain nitric  oxide,
and very slow to promote its reversion to oxygen and nitrogen.
The problem of pollution control is that most processes involv-
ing high temperatures  are designed for minimum  residence
time (i.e., rapid cooling) to reduce capital requirements.  Below
3200 F, the rate of formation controls nitric oxide production;
above 3200 F,  the reverse rate is the controlling factor. Nitric
oxide production departs from equlibrium  at  a  maximum
around 2800 F, and  then approaches equilibrium at 3200 F. As
3200 F is passed,  the departure from equilibrium becomes
more pronounced with  rising temperature, showing  the effect
of the  reverse reaction rate. Emissions could be lowered by
some   of the  following means:   better   recovery through
refrigeration, cooler circulating acid, or the compression  of
nitrogen oxides after the condensing phase; a good balance of
oxygen after condensation to oxidize nitric oxide; catalytic in-
cineration of tail gases to reduce nitrogen  oxides to nitrogen
and oxygen; and further absorption tail gases in an alkaline
tower followed by catalytic incineration. Besides being a func-
tion of temperature, the formation of nitric oxide also depends
on the amount of excess air used in a process.

21232
Hunter, J. B.
PLATINUM CATALYSTS FOR THE CONTROL  OF AIR
POLLUTION.  A  TAIL GAS  REDUCTION  SYSTEM FOR
NITRIC ACID PLANTS. Platinum Metals Rev., vol. 9-12:2-6,
1965-1968. 1 ref.
Effective reduction  of nitrogen oxides, hydrocarbons, and or-
ganic vapor is  obtained by the use of platinum catalysts sup-
ported   by a  ceramic  honeycomb.  Use  of the ceramic
honeycomb support  overcomes the two principle objections to
platinum as a catalyst in pelletized form, pressure drops across
pelleted beds, and loss of fines. Other important advantages
for honeycomb catalysts are the elimination of hot spots, more
uniform gas distribution, greater structural strength, and no
channelling. From the standpoint of system design, the rigid
structure also provides greater process flexibility. Horizontal
as well as vertical reactors may be used. In nuclear  power in-
stallations, intense  radiation  causes the  decomposition  of
water into a hydrogen/oxygen mixture. Platinum honeycomb
catalysts are effective as hydrogen/oxygen recombiners.

23372
Teske,  W.
EMISSIONS AND ABATEMENT OF OXIDES OF NITROGEN
IN NITRIC ACID MANUFACTURE. Chem. Engr. (London),
46(7):263-266, Sept. 1968.
The 12 nitric acid factories of West Germany, producing acid
mainly  for use in fertilizers, emit a total of about 100 tons/day
of nitric oxide. Stack gases have a brown color, due to  a visi-
bility limit of 200 ppm  NO. New plant construction is  of the
pressure  type,  in which the NO content of the stack gases is
about half that of older plants. The NO content of these gases
is due to the incomplete conversion, or the absorption yield,
of NO  to nitric acid. Thus, to  eliminate the NO in  the waste
gases,  the absorption  yield  must be  increased or the NO
destroyed. Various absorption processes are briefly reviewed

-------
 10
NITRIC ACID PLANTS
in terms of possibilities for accelerating absorption, but total
absorption in an acid system is not practical. Catalytic reduc-
tion processes reduce nitrogen oxides by means of hydrogen,
hydrocarbon gases, or ammonia, and can be carried out in two
stages: partial reduction  of the NO2 to NO  (decoloring the
waste gases),  and total  reduction of NO and NO2 to N2.
Because the price of the reducing agent is a decisive factor, an
attempt should be made to decompose the nitrogen  oxides
directly, which would permit general adoption of catalytic pu-
rification by the nitric acid industry.

23880
Stankus, L.
NAPCA'S  SEARCH FOR  FLUE  GAS  DESULFURIZING
PROCESSES. Preprint,  22p., 1969 (?). (Presented at the  Gor-
don Research Conference, Aug. 18-22, 1969.)
The  National Air Pollution Control Administration's work on
sulfur oxides and nitrogen oxides control  is summarized by
briefly stating the scope of major investigations, showing prin-
cipal concepts generated, and indicating present achievements
and possible future developments. There are several methods
for desulfurizing flue gases under investigation, such as am-
monia scrubbing and  aqueous  scrubbing. Organic liquids,  such
as olefins, carbohydrates, and amines,  appear promising for
extracting sulfur dioxide from flue gas. Solid organic materials
including newsprint,  sawdust,  and cotton are capable  of ab-
sorbing SO2. The most suitable catalyst for oxidizing SO2 to
SOS is vanadium pentoxide. Several methods for reducing SO2
to elemental sulfur  were also investigated. Coal gasification
was  studied as a method for eliminating the varous forms of
sulfur contained in coal. Methods for reducing nitrogen  oxides
emissions  include catalytic reduction, staged combustion, and
fuel combustion with oxygen. Combustion with low excess air,
steam or water injection  into  the fuel burning zone, and flue
gas  recirculation into  the fuel-air mixture  were  also in-
vestigated.  A study on  the availability and  use of  natural gas
as a  sulfur-free fuel for power  generation was conducted. The
                principal chemical reactions  that  occur with these control
                methods are included.

                25714
                Funk, Andrew B. and James C. Moore
                CHEMICAL SUPPRESSION OF NITROGEN OXIDES. (Grace
                (W. R.) and Co., New York) U. S. Pat. 3,528,797. 5p., Sept.
                15, 1970. 2 refs. (Appl. Nov. 8, 1967, 6 claims).
                A scrubbing apparatus containing urea is provided which sub-
                stantially eliminates all nitrogen oxides that are formed as by-
                products of the phosphate fertilizer manufacturing process.
                Urea when dissolved in water reacts with nitrogen oxide and
                nitrogen dioxide gases to  produce nitrogen, carbon dioxide,
                and water.  The preferable range of urea is 0.1 to 0.3 weight
                percent, based on  the total weight of the batch size, and it
                may be employed in an aqueous scrubbing tower or added to
                the acidulation mass.

                26071
                AIR POLLUTION.  Chem. Process., 16(11):11, 13, Dec. 1970. 7
                refs.
                Nitric acid manufacture,  nitrogen  processes, and  dissolving
                operations  using nitric acid contribute the major portion of ox-
                ides of nitrogen emitted to the atmosphere by non-combustion
                processing.  Several methods  which exist for the control  of
                these oxides from  stack gases include catalysis, adsorption,
                absorption,  and direct  flame incineration. Palladium on a par-
                ticulate  alumina support and  a  ceramic catalyst are recom-
                mended for nitric  acid tail gas  purification. Adsorption on
                molecular sieves appears  economically  attractive where high
                oxygen  concentrations  preclude non-selective  catalysis.  Ab-
                sorption in liquids, while  technically  feasible,  usually  in-
                troduces by-product disposal problems. Direct flame incinera-
                tion is  most effective  for reduction of nitrogen  dioxide  to
                nitric oxide. Modifications for combustion processes  include
                low excess air,  staged combustion, flue  gas recirculation,
                steam and  water  injection,   combustion with oxygen,  and
                fluidized bed combustion.

-------
                                                                                                                11
                         C.  MEASUREMENT  METHODS
02570
M.D. Manila V.P. Melekhina
A SPECTROPHOTOMETWC METHOD FOR THE DETER-
MINATION OF  NITRIC AND HYDROCHLORIC ACIDS IN
THE  ATMOSPHERIC  ADX  IN   THE  PRESENCE  OF
NITRATES   AND  CHLORIDES.   (Spektrofotometricheskii
metod  opredeleniya azotnoi i solyanoi  kislot  v prisutstivii
nitratov v  atmosfernom vozukhe.)  Hyg. Sanit. 29,  (3) 62-6,
Mar. 1964. CFSTI: TT65-50023/3
A  spectrophotometric  method  for  the  determination  of
hydrochloric and nitric acids in the presence of nitrates and
chlorides is described. This method is based on the determina-
tion of the optical density of colored aqueous solutions con-
taining the above acids after the addition of methyl  red in
ethanol. The  sensitivity of the method is 0.18 microgram of
HcL per ml and  0.31 microgram of HNO3 per ml. Other acids
and bases  interfere with the  assay.  CO2 and SO2 always
present in  atmospheric air do not interfere with  the  spec-
trophotometric determination of hydrochloric and nitric acids
when this is carried out under the conditions described.

04257
E. Kh. Gol'dberg
PHOTOMETRIC DETERMINATION OF SMALL AMOUNTS
OF VOLATDLE  MINERAL ACIDS (HYDROCHLORIC AND
NITRIC)   IN   THE   ATMOSPHERE.   (Fotometricheskoe
opredelenie malykh kolichestv letuchikh mineral'nykh kislot
(solyanoi i azotnoi) v atmosfernom vozdukhe.) Hyg. Sanit. 31,
(9) 440-3, Aug. 1966. Russ. (Tr.) CFSTI: TT 66-51160/7-9
A spectrophotometric method was recommended for the anal-
ysis of low concentrations of mineral acids in the atmosphere.
However, it is not always possible  to use this method at the
laboratories  of  the district  sanitary-epidemiological centers
because of the absence of a spectrophotometer. Modification
of the spectrophotometric method for purposes of photometric
determinations with  a  photoelectrocolorimeter  required  a
calibration graph for the relationship between the optical den-
sity and the concentration of hydrogen ions in micrograms per
1 ml for an FEK-56 photoelectrocolorimeter. Standard solu-
tions were prepared from fresh 0.005 N HC1 and HNO3. Solu-
tions were made  containing 0.005 to  0.02 microgram/ml H+. A
zero solution (distilled water) was prepared simultaneously. In
all cases, an addition was made of 0.4 ml 0.01% alcohol solu-
tion of methyl red. The optical density of standard  solutions
and of  a zero solution with the methyl red reagent was deter-
mined  with respect  to  distilled water. This  photometric
technique made possible the establishment of constant optical
densities of aqueous solutions of acids in the standard scale,
independent of the pH  of the distilled water used. The sen-
sitivity  of the photoelectro colorimetric method and  the sam-
pling procedure are the same as for the spectrophotometric
method. Studies were also made of the possibilities of visual
colorimetric determinations. It was found that in the absence
of a photoelectrocolorimeter the solutions can be determined
colorimetrically by visual means by the method of standard se-
ries with an artificial scale.
06889
Antoshechkin, A. G.
INSTRUMENT FOR DETERMINATIONS OF THE CONCEN-
TRATIONS OF  NITROGEN OXIDES  AND NITRIC  ACID
FUMES IN  AHi.  (Pribor dlya opredeleniya  kontsentratsii
okislov azota i parov azotnoi kisloty v vozdukhe.) Hyg. Sanit.
(Gigiena i Sanit), 30(2):234-236, Feb. 1965. Translated from
Russian. CFSTI: TT 66-51033
The  author designed and tested an instrument for the deter-
mination of the concentrations  of nitrogen oxides and nitric
acid  fumes in  air. The action of the instrument is based on
measurements of the electrical conductivity of a solution ob-
tained by drawing the air with nitrogen oxides through distilled
water. The instrument is  portable, its design  is simple and it
can be constructed under laboratory conditions. Its sensitivity
is from 0.0003 to 20 mg nitrogen oxides  per 1 liter of air. One
analysis takes  1 to  2 min. Thirty ml of distilled water is in-
troduced with the syringe into the upper tube and into the ves-
sel. The water cannot leave the vessel  because of the valve,
and it forms a 1 cm layer between the two electrodes, now the
pump is attached and 5 1  of air are drawn in distilled water.
Nitrogen oxide from the  air combines with water to produce
nitrous acid. The higher the concentration of nitrogen oxide in
the air, the higher will be the concentration of the HNO2 solu-
tion  in the vessel. Since HNO2, like HNO3, is a strong elec-
trolyte and completely  dissociated to ions in  dilute solutions,
the electrical conductivity of the solution is proportional to the
concentration. The electrodes are fed with a constant voltage
from a 4.5V source. In using  the  instrument,  one must re-
member that interference is caused by  gases that are  readily
soluble in  water and produce a  strong electrolyte on solution
(the  sulfuric acid fumes). After suitable graduation, the instru-
ment can also  be used for the determination of sulfuric acid
fumes in air.

11130L
Saltzman, Bernard E.
METHODS OF  MEASURING  AND  MONITORING  AT-
MOSPHERIC NITROGEN OXIDES AND THEIR PRODUCTS.
(Part I.) World Health Organization, Geneva, (Switzerland),
WHO/AP/68.31,99p., 1968. (93) refs.
A working text of NOx measurement methods in common use
is presented. Sufficient details  are provided so that no addi-
tional material should be needed to conduct the analysis. How-
ever, abundant references are  provided. The actual texts of
methods whic have been selected by appropriate organizations
are  quoted in exact form. Measuring and monitoring at-
mospheric nitrogen  oxides are complex because  of the fact
that  many interrelated  oxides and products exist.  These un-
dergo chemical reactions and equilibria both in the atmosphere
and in air sampling apparatus. The effects of  the various sub-
stances are different. Their interferences also differ for vari-
ous  analytical  procedures. Therefore  to fully expoun  the
problems in making these measurements, an introductory sec-
tion is presented giving chemical and physical properties, vari-
ous reaction rates, and equilibrium data. In these analyses we

-------
 12
NITRIC ACID PLANTS
 are seeking to measure concentrations that vary both in time
 and space. Rational  design of a sampling program therefore
 requires  a knowledg  of these distribution patterns. Only then
 can we clarify the effects of sampling time, numbers of sam-
 pling locations, numbers of samples collected, and correlate
 these with the objectives which ar sought. These topics  there-
 fore also are included.

 18226
 INVESTIGATION AND APPRAISAL OF FLU-GAS DAMAGE.
 (Untersuchung und Begutachtung von Rauchschaden. Part I.),
 Translated  from German. Hamburg Staatsinstitut fur Ange-
 wandte Botanik Jahresbericht, 5(119-120), 1938. 3 refs.
 Plants exposed  to  flue  gas  showed  definite  damage  from
 fluorine (F) and acids of sulfur and nitrogen. A crystalization
 method utilizing the microscopic identification of silico-sodium
 fluoride proved best for qualitative fluorine analysis of the 102
 samples  examined through 1936. As in previous studies, the
 samples tested showed that F was taken in through the branch
 bark and leaves of cherries and pears. For the first time, how-
 ever, the fruit itself was damaged and F detected there. Black,
 hard disks  had  formed around the flower and in the fruit ad-
 jacent to the flower.  Samples examined long after damage
 took place showed no F present. Twenty-one samples were ex-
 amined for acid damage. Large concentrations of nitrates were
 detected in the  specimens by means of the diphenylamine-sul-
 furic  acid reaction. Different plant  species  showed markedly
 different sensitivities to flue gases.

 23560
 Aleksandrov, Yu. I., V. D. Mikina, and G. A. Novikov
 CORRECTION FOR OXIDATION OF NITROGEN  IN THE
 DETERMINATION OF HEAT OF  COMBUSTION. Tr.  Vses.
 Nauch.-Issled. Inst.  Metrol.,  111(171):95-102,  1969.  11  refs.
 Translated  from Russian by D. P.  Biddiscombe, Ministry of
 Technology (England),  Div. of  Chemical Standardds,  lip.,
 March 1970. CFSTI: N70-28918
 At present, the heat effect due to  oxidation of nitrogen in a
 calorimetric bomb is computed on  the basis of determination
 of the amount of nitric acid after the calorimetric  experiment
 by titration of the bomb liquid with  a 0.1-N solution of alkali;
 methyl orange is used  as indicator. Results obtained during a
 prolonged period of  work, by titration of bomb liquid after
 combustion  of benzoic acid, differed one from another more
 than was to be  expected from the errors of the titration
 method. Analysis of literature data on the  formation of nitric
 acid does not give a  thorough explanation of this discrepancy
 in titration results. To elucidate the  reasons for this discrepan-
 cy, a study was made of the  dependence of the  amount of
 nitric acid  formed upon the ageing time of the combustion
 products in  the  bomb,  upon  the initial  concentration  of
 nitrogen, upon the size of the flame, and upon the pressure of
 oxygen  in the bomb. Study of the process of oxidation of
 nitrogen in  the calorimetric bomb has established that, by the
 end of an experiment, when the bomb is opened, the reaction
 between nitrogen dioxide and water  is not complete, and thus
 the end-product contains not only nitric acid, but also nitrogen
 dioxide. By the end of the main period, the amount of each
 component  depends upon the initial  concentration of nitrogen
 in the oxygen, the size of the flame during combustion of the
 substance, and the time of flushing of the bomb with oxygen.
The amount of  nitric acid formed depends upon the time of
ageing of the combustion products in the bomb. In calorimetric
practice at the present time, only the process of nitric acid for-
mation is taken into account. On the basis of the investigations
carried out, a procedure for determining the correction for ox-
                idation of nitrogen, taking account of the incomplete conver-
                sion of oxides of nitrogen into nitric acid, is advised. In order
                to determine more precisely the make-up of the correction, the
                methods  of its  determination must be changed. To  calculate
                the  correction,  it is  necessary  to determine the  amount  of
                nitric  acid formed  by  the end  of the main  period of a
                calorimetric  experiment and thus establish the  amount  of
                nitrogen dioxide present at that time in the gas phase in the
                bomb.

                23771
                Patton, W. F. and J. A. Brink, Jr.
                NEW  EQUD7MENT  AND  TECHNIQUES FOR SAMPLING
                CHEMICAL PROCESS GASES. J. Air Pollution Control As-
                soc., 13(4): 162-166, April 1963.  7 refs (Presented  at the Air
                Pollution Control Association, 55th Annual Meeting,  Chicago,
                May 20-24, 1962.)
                When  the need  for  improved   sampling  equipment  and
                techniques was recognized at Monsanto  a  number  of years
                ago, a  cascade  impactor suitable for adiabatic measurements
                on process gases was developed. Simpler equipment, suitable
                for routine control of air pollution, can determine accurately
                the weight or chemical composition of the particles  in a gas
                stream, as well as separately determine the loading of particles
                greater than three micron  in diameter from particles smaller
                than this. The dust or mist sampling device is contained in a
                small case with a carrying handle and removable sides similar
                to an Orsat analyzer. Gases first enter the cyclone where the
                larger particles  are collected, while the smaller particles are
                carried over and collected by the filter. Sampling preparations
                are discussed for large particles, fine particles, and isokinetic
                sampling. The procedures for sampling are outlined, as well as
                an example for sulfuric acid mist. Calculations of  loadings
                from sampling data are also indicated. Eight sets of  the sam-
                pling equipment have been utilized for sulfuric, phosphoric,
                and nitric acid  mists, mercury  mist, various phosphate salt
                dust, ammonium chloride fume,  ammonium nitrate fume, and
                several organic mists.

                24725
                Lesoine, L. Grant
                EFFECT OF  PARTICLE SIZE ON THE  DETERMINATION
                OF  INORGANIC  SULFUR IN  COAL.  In:  Report  of Bitu-
                minous Research Activities. Pennsylvan State Univ., Universi-
                ty Park, Dept. of Fuel Technology, Serial No. 57, p. 1-8, 1956.
                8 refs.
                The effect of reducing the  standard 60-mesh coal  samples to
                micron size was investigated to determine if the size of the
                coal materially quantitatively affects the determination of inor-
                ganic sulfur using the Eschka, and Powell and Parr Methods.
                A significantly  higher inorganic sulfur content  was  obtained
                with micron-size coal. The pyritic iron content also increased
                in the same proportion. This leads to the conclusion that finely
                divided pyrite is intimately associated with the coal substance
                and is made more amenable to reaction with nitric acid when
                ground to micron size. Since both the sulfur and iron  contents
                increased proportionally, it appears doubtful that any sulfur-
                bearing inorganic material other  than pyrite  is present in any
                significant quantity in the  occluded matter.  The iron content
                calculated to  percent sulfur was greater in all cases  than the
                actual total inorganic  sulfur. Hence, it is assumed that acid ex-
                traction of the coal did not remove organic sulfur from these
                coals. The difference in values leaves a question as to the de-
                pendability of the  usual inorganic sulfur analysis or to the
                validity  of the  term  'inorganic'  sulfur as  applied to acid-ex-
                tractable sulfur. (Author summary modified)

-------
                                       C.  MEASUREMENT METHODS
                                                      13
24975
Grigorescu, I. and L. Bengeanu
SPECTROCOLORIMETRIC  DETERMINATION  OF  HEX-
ACHLOROCYCLOHEXANE  IN   THE  ATMOSPHERE.
(Dozarea hexaclorciclohexanului in atmosfera  prin metoda spec-
trocotorimetrica). Text in Rumanian. Rev. Chim. (Bucharest),
18(9):565-566,1967. 7 rets.
This broad-spectrum insecticide is  finding an increasing use,
so  that accurate detection  measures  are necessary for  its
proper control. A method has been adapted by the Central
Toxicology Laboratory of the Rumanian Ministry of Chemical
Industries,  which makes use of chloride-free toluene, sodium
hydroxide dissolved in 0.1 N ethyl alcohol,  a 1%  solution of
ferric ammonium sulfate in 15% nitric acid, a 0.1% solution of
mercuric sulfocyanide in 96% ethyl alcohol,  and  a  standard
solution of HCH prepared by dissolving 0.5 g of lindane in 100
cc of toluene, from which a working standard is prepared by
dilution, which contains  500 micrograms per cubic centimeter
of HCH. Air samples are collected with an impinger containing
100 cc of toluene, through which the air is caused to flow at
the rate of  10-15 cu m /minute, the total volume of the sample
being dependent on the suspected amount  of atmospheric
HCH, on the average about  10 cu m. Given the  extent of the
sample-collecting time, the presence of chlorine and inorganic
chlorides in the atmosphere will not create  interference with
the determinations, but special care must be taken to eliminate
all chloride impurities from the reagents used. Testing of the
method indicates that the margin of error can amount to plus
or minus 10%, with  an average error of 3%. The amount of
time required for determination is 20 minutes, on  the average.

25381
(Inventor not given.)
DETECTION OF MISSILE FUELS  IN GAS  ATMOSPHERES.
(Mine Safety  Appliances Co., Inc., Pittsburgh, Pa.) Brit. Pat.
1,151,594. 3p., May 7, 1969. 5 refs. (Appl. May 26,  1966,  16
claims).
A simple, rapid, and  reliable method is described of detecting
the presence in a gas of a volatile nitrogen  compound of the
group consisting  of hydrazine, hydrazine hydrate, red fuming
nitric  acid,   nitrogen  dioxide,   unsymmetrical  dimethyl
hydrazine, and alkyl hydrazines. A variety of volatile nitrogen
compounds are used as components of missile fuels, and vari-
ous hazards are attendant upon the fueling, handling and stor-
ing of missiles propelled by such liquids. In the presence of
the above mentioned nitrogen compounds, and also nitrogen
dioxide, a particularly effective color change is produced when
a  hexavalent  chromium  compound  and  the  pentavalent
phosphoric  acid  are  present in proportions providing from
0.0145 to 2.6 grams of hexavalent chromium and from 0.022 to
24 grams of pentavalent phosphorus, per 100 ml of carrier.

25925
Cauer, H.
SOME PROBLEMS OF ATMOSPHERIC CHEMISTRY. In:
Compendium of Meteorology. T.  F. Malone (ed.), Boston,
American Meterological Society, 1951, p. 1126-1136. 60 refs.
Satisfactory methods for the chemical  analysis  of air  will
evolve only when analytical chemists are  also adequately
trained in physical chemistry and  physical  meteorology. A
second requirement is further development of  methodology.
Not until the development is more or less complete will it be
possible to undertake a third major task, that of making many
parallel investigations in micrometeorological as well as world-
wide networks under the most varied atmospheric conditions
and  at various  heights above  the ground.  Of  the chemical
methods  available today,  two methods  developed  in Europe
are briefly discussed: the absorption-tube method for detecting
the presence of secondary gaseous  substances,  and the con-
densation method for the analysis of water-soluble atmospher-
ic  constituents which form  condensation nuclei. Results ob-
tained  by both methods  are evaluated and  suggestions are
made for further research. To explain condensation (cloud for-
mation),  the chemist must  have recourse to intermolecular
forces and,  in the last analysis, to processes of atomic energy.
Four types  of short-range molecular forces are discussed in
light of existing knowledge. It  is anticipated that the first
chemical techniques  developed for  the field  of dynamic
meteorology may be connected with determinations of the pH
value and the reduction power of aerosols. Such uses  would
provide accurate information about the  motion of air masses
and the degree of turbulence.

-------
 14
                      E.  ATMOSPHERIC  INTERACTION
 14408
 Rhine, P. E., L. D. Tubbs, and Dudley Williams
 NITRIC ACID VAPOR ABOVE 19 KM IN THE EARTH'S AT-
 MOSPHERE. Appl. Opt., 8(7):1500-1501, July 1969. 6 refs.
 Atmospheric data obtained  from balloon flights by other in-
 vestigators suggested that previously  unreported atmospheric
 bands at approximately 30 km and a solar zenith angle of 90
 deg were  caused by the association of nitric acid vapor with
 the ozone layer. To estimate the amount of nitric acid vapor in
 the atmosphere at this altitude, atmospheric nitric acid vapor
 was experimentally measured in an absorption cell in the spec-
 tral regions  of 1240-1380 inverse  cm and 810-940 inverse cm.
 Laboratory and atmospheric data were compared by integrated
 spectral  absorbance.  Approximately  10%  of  the total ab-
 sorbance in both laboratory and atmospheric  spectra is as-
 sociated with Q branches at the overlapping bands 879 and 897
 inverse cm,  and it is concluded that any observable nitric acid
 vapor contributions to solar absorption spectra at low altitudes
 would  be  connected with these band  Q branches. Production
 of nitric acid vapor in the ozone layer may proceed according
 to the  reactions H plus O3 yields O2 plus OH*, or OH plus
 NO2 yields  HNO3. The second  reaction is presumed to be
 enhanced by darkness.

 21534
 Leighton, Philip A.
 REACTIONS AND EQUILIBRIA OF THE OXIDES AND OXY
 ACIDS OF NITROGEN. In: Photochemistry of Air Pollution.
 New York, Academic Press, 1961, Chapt. 7, p. 184-200.
 Certain reactions involving  the  oxides  and  oxy acids  of
 nitrogen  occur  simultaneously with the photochemical reac-
 tions of these products. Both the equilibrium and the rate of
 reaction of  nitric oxide with molecular oxygen  have been
 established over a broad temperature range. Reactions involv-
 ing nitrogen  trioxide which are necessary to explain the major
 behavior of  the oxides of nitrogen are given. The reaction of
 nitric  oxide  and nitrogen dioxide with water to  give nitrous
 acid has  been  quantitatively  studied. Nitrogen  dioxide reacts
 slowly  with  unsaturated hydrocarbons, even in the dark. Pure
 nitric acid can be stored in contact with liquid olefins for days
 without reaction, but if a trace of nitrogen dioxide is present,
 reaction occurs. There is no evidence that the reactions of ox-
 ides and oxy acids with aldehydes, organic acids, and other or-
 ganic compounds  are fast  enough to  be  of any importance.
 Rates and equations for the various reactions are discussed.

 21642
 Leighton, Philip A.
 ABSORPTION  RATES AND PRIMARY PHOTOCHEMICAL
 PROCESSES. In: Photochemistry of Air Pollution. New York,
Academic Press, 1961, Chapt. 3, p. 42-99.
For any photochemical reaction, the primary chemical  process
is the first chemical step following the act of absorption of
radiation. In  the lower atmosphere, the absorbers will be the
species which absorb  in the photochemically active region of
the  solar spectrum. Ordinary oxygen absorbs very faintly in
the red end of the visible spectrum. Gaseous ozone absorbs
strongly in the region 2000-3500 A. Nitrogen dioxide absorbs
over virtually  the entire visible and ultraviolet range of the
solar spectrum in the lower atmosphere. Gaseous sulfur diox-
ide shows absorption consisting of bands with sharp rotational
structure. Nitric acid and the organic nitrates show continuous
absorption  which extends  to some extent  into the  solar ul-
traviolet. Compounds containing a carbonyl group all  show ab-
sorption  in the  solar radiation range.  Acyl  and  peroxyacyl
nitrates and nitrites are discussed at length. Reactions follow-
ing absorption by particulate matter are discussed. Rates and
equations of the various reactions are included.

22407
Vohra, K. G. and P. V. N. Nair
RECENT THINKING ON THE CHEMICAL FORMATION OF
AEROSOLS IN  THE AIR BY GAS PHASE REACTIONS.
Aerosol Sci., vol. 1:127-133, 1970. 11 ref
Possible mechanisms of formation of aerosols in the air by
chemical reactions in the gas phase are described. In  the basic
reactions, formation of hydrochloric acid, sulfuric acid, and
nitric acid molecules from chlorine, sulfur dioxide and oxides
of nitrogen, in the presence of water vapor, are considered
along  with the role of solar radiations, ionizing radiations,
electric discharges and ozone in the formation of these acids.
Formation of nuclei by the hydration of acid molecules and
their reaction with other organic and inorganic trace gases are
also discussed. The  reactions important in the  formation of
Aitken nuclei  and aerosols are mainly oxidation, hydration,
acid-base reactions and addition and recombination reactions.
In these  reactions, the combined role  of solar and ionizing
radiations are  considered.  The formation  of embryos  and
growth of particles in the humid air are discussed on  the basis
of Raoult's law. The important role of chemically formed par-
ticles in the atmospheric processes and the possible impact of
nuclear power production  on  the nuclei content of the at-
mosphere are suggested. (Author abstract modified)

23037
Altshuller, Aubrey P.
THERMODYNAMIC CONSIDERATIONS IN THE INTERAC-
TIONS OF NITROGEN OXIDES  AND  OXY-ACIDS  IN THE
ATMOSPHERE.  J. Air Pollution  Control Assoc. 6(2):97-100,
1956. 15 refs. (Presented at the Air Pollution Control  Associa-
tion, 49th Annual Meeting, Buffalo, N. Y., May 20-24, 1956.)
Equilibrium constants,  calculated from  recent spectroscopic
and structural  measurements, are reported for some nitrogen
dioxide reactions. From these constants, estimated concentra-
tions of gaseous nitrogen oxides  and oxy-acids in urban at-
mospheres were calculated. It is emphasized that the  equilibri-
um conditions  to which the data apply  may be reached very
slowly  or rapidly, or at some intermediate rate. Determination
of this  rate is a problem for experimental kinetics rather than
thermodynamics. The value of thermodynamic information is
that it  can tell whether a  small or large amount of a given
reactant will exist at equilibrium. The present thermodynamic

-------
                                     E. ATMOSPHERIC INTERACTION
                                                     15
study indicates that among the nitrogen oxides and oxy-acids,
nitric oxide, nitrogen dioxide, and nitric acid are probably the
most prevalent  in  polluted urban  air. Nitrous oxide is  also
present in urban air but is of less importance because of its
lower chemical reactivity.

23604
Nicolet, M.
THE ORIGIN OF  NITRIC OXIDE IN THE  TERRESTRIAL
ATMOSPHERE.  Planetary Space  Sci.,  18(7):1111-1118,  July
1970. 32 refs.
Recent observations in the stratosphere, mesosphere, and ther-
mosphere indicate  that nitric oxide  is present in significant
amounts, even though its local production seems to be very
small. Reactions  which might account for an  indirect way of
production are discussed. Nitric oxide in the stratosphere and
mesosphere may  be due to downward transport from the ther-
mosphere. Photochemical reactions,  including photodissocia-
tion, are described. Balances of reactions of formation and
removal of nitric oxide and atomic  nitrogen are considered. In
the  lower  thermosphere,  the downward  current  of  NO
molecules depends  on the value of the eddy diffusion coeffi-
cient. In the  stratosphere, the final  sink of NO and NO2 is the
formation of HNO2 and HNO3 by reactions with HO2 and
H202. A small eddy diffusion coefficient is required.

24015
Altshuller, Aubrey P.
THERMODYNAMIC CONSIDERATIONS IN THE INTERAC-
TIONS OF NITROGEN OXIDES AND OXY-ACIDS IN THE
ATMOSPHERE. Preprint, Robert A. Taft Sanitary Engineering
Center, Cincinnati, Ohio, 16p., 1956 (?). 16 refs.
The thermodynamic equilibrium constants are computed for a
number  of  chemical reactions involving nitrogen oxides and
oxy-acids. The nitrogen oxides likely to be present in any sub-
stantial quantity in the  atmosphere are nitrous oxide, nitric ox-
ide, and nitrogen dioxide. The concentrations of reactants and
products in these reactions at  chemical equilibrium are given,
and  the  rates  at which these reactions  proceed towards
equilibrium are discussed. Most of the  reactions considered
are 'dark'  reactions,  but the importance of photochemical
reactions involving ozone is  pointed out and the photolysis of
nitrogen dioxide is discussed in detail. The varying importance
of the individual reactions of  nitrogen oxides in air pollution
problems is emphasized. (Author abstract modified)

-------
 16
               F.  BASIC   SCIENCE  AND  TECHNOLOGY
01619
NITRIC ACID MANUFACTURE (INFORMATIVE REPT. NO.
5). J. Air Pollution Control Assoc. 14, (3) 91-3, Mar. 1964. (TI-
2 Chemical Industry Committee).
Nitric acid manufacture by the ammonia oxidation process and
the concentration process  are described. The  control aspects
are discussed.

10160
Ganz, S. N.
EFFECT OF HYDRODYNAMIC CONDITIONS ON RATE OF
NITROGEN  OXIDES AB-  SORPTION BY Ca(OH)2  SOLU-
TION, WITH THE AID OF A MECHANICAL AB- SORBER
UNDER  SEMI-INDUSTRIAL CONDITIONS.  (COMMUNICA-
TION I.) Zh. PrikL Khim.,  30(9):1311-1320, 1957. 5 refs. Trans-
lated from Russian by B. S. Levine,  U. S. S. R. Literature  on
Air Pollution and Related Occupational Diseases, VoL 6, 299  p.,
April 1961. CFSTI: TT 61-21982
The effect of hydrodynamic conditions on the rate of nitrogen
oxides absorption by a solution of Ca(OH)2 was studied with
the aid of a rapidly rotating mechanical absorber under semi-
industrial conditions, using industrial gas from a  nitric acid
shop. The in vestigations  were conducted in 2 stages: 1) a
study of the effects  of  the system's hydrodynamic, physical
and chemical factors on the absorption rate; during this study
the installation  was operating periodically for time intervals
determined by the requirements of  each test; the phases  in-
vestigated were: the effect of the peri pheral  speed of discs,
the volume rate of gas flow, the quantity of liquid in the ab-
sorber, the CaO and nitrite-nitrate salt concen- trations  in the
solution,  the degree of gas  oxidation,  etc.; 2) during the
second stage, the installtion operated continually under one set
of conditions, selected on the basis of results obtained during
the first stage of the investigation; results of the second stage
indicated that the process of nitrogen oxides absorption had to
be based on a rationally (empirically) developed and controlled
technological procedure. The first study  stage extended over
more than 1-1/2 months, and the second stage over more than
2-1/2 months. More than 3,000  analyses of the gaseous and
liquid phases were made, which yielded sufficient experimen-
tal data for  the determination of optimal technological condi-
tions.

13415
Haseba, S., T. Shimose, N. Kubo, and T. Kitagawa
NITRIC OXIDE EXPLOSION. Chem. Eng. Progr., 62(4):92-96,
April 1966. 8 refs.
A  method was found to analyze low-concentration hydrocar-
bons assumed to have  contributed  to an explosion  in the
second heat exchanger of a nitrogen wash unit. Acetylene, 1,3-
butadiene, and allene existed in the crude gas in the order of 2
to  3 ppm, 0.2 to 0.5 ppm, and 0.2 to 0.3 ppm, respectively.
Nitric oxide was detected  at  concentrations  in the order  of
0.005 to 1 ppm through oxidation with permanganate and sul-
furic acid, followed by calorimetric detection with the Griess-
Saltzman reagent. Findings  showed that more than 90% of NO
entered the  unit accumulated in the  second heat  exchanger,
most of it oxidized to nitrogen dioxide and nitrous anhydride,
which  is more reactive with hydrocarbons than NO.  Experi-
ments  confirmed the possibility of spontaneous ignition in the
second exchanger and the composition of reaction products
between  nitrogen  and  conjugated  dienes.  An  adsorption
process is now used to remove NO, in which Na2CrO2 or C12
are added to the wash-water circuit.

13481
Kirk, Donald G.
NITRIC  ACID  BLEACHING OF  HARDWOOD  NEUTRAL
SULFTTE SEMICHEMICAL PULP. Tappi, 51(4): 145-151, April
1968.  26 refs. (Presented at the Fourth International Pulp
Bleaching Conference jointly sponsore by the  Technical As-
sociation of the  Pulp  and Paper Industry and  the Technical
Section, CPPA, held in Toronto, Ont., May 1-4,  1967.)
Use of nitric acid in place of  chlorine as a first stage bleaching
agent for a hardwood  NSSC pulp has been studied. The pur-
pose was the  production  of a high nitrogen  effluent from
which  a fertilizer material might be recovered and marketed.
Study  of nitric acid stage variables showed the necessity  of
keeping the temperature low  and Obleaching duration short to
prevent strength loss. This required  the application of high
nitric acid concentrations, which made reuse of the acid  an
economic  necessity. Modifications using  alcoholic  nitric acid
or nitric-sulfuric acid mixtures showed some potential strength
benefits, while nitrous acid appeared to cause severe degrada-
tion. Extraction stage variables within broad limits were found
to have little effect on pulp  quality. Ammonia  was found  to
have little effect on pulp quality. Ammonia was successfully
substituted for caustic  soda to increase the nitrogen content of
the effluent  solids. In general, substitution of nitric  acid for
chlorine in the first stage of a chlorine-extraction- hypochlorite
sequence can be made to produce a pulp at least equivalent to
the control pulp in all respects except for a slight yellowing ef-
fect. Chemical costs are  high enough to  render the process
economically unattractive unless a fertilizer by-product can  be
marketed. (Author abstract)

13680
Atroshchenko, V. I., V. M. Kaut
KINETICS OF NITROGEN OXIDE ABSORPTION BY CON-
CENTRATED  NITRIC  ACID.  (Kinetika  pogloshcheniya
okislov azota kontsentrirovannoy azotnoy kislotoy).  Text  in
Russian. Zh. Prikl. Khim., vol.31:  352-360, 1958.  11 refs.
New experimental data regarding the kinetics of absorption of
nitrogen oxides by concentrated nitric acid are presented. De-
pendencies between the absorption  rate coefficient and basic
physicochemical factors such as NO2 and N2O concentration
in the gas phase, content of nitrogen oxides in the gas, HNO3
concentration in the acid, N2O4  content of the solution, and
temperature are established. A dependence between  absorption
rate coefficients  and basic hydrodynamic factors  is demon-
strated.

-------
                                 F.  BASIC  SCIENCE AND TECHNOLOGY
                                                     17
 13948
 Foerster, F., T. Burchardt, and E. Fricke
 PRODUCTION OF CONCENTRATED NITRIC ACID FROM
 NITROUS GASES. PARTS  A AND B. (Ueber die Gewinnung
 konzentrierter Salpetersaeure aus  nitrosen Gasen). Text  in
 German. Z. Angew. Chem. (Weinheim), vol.  1:113-117, May
 11, 1920. PARTS C, D,  AND E. Ibid., p.  129-132, May 25,
 1920. 10 refs.
 A detailed  description and discussion is presented of two se-
 ries  of experiments on  the  formation of nitric  acid  from
 nitrous gases. In the first series, a mixture of gaseous nitrogen
 dioxide and oxygen was passed through a bell-type wash tower
 filled with a nitric acid solution.  In the second series, oxygen
 was passed through a mixture of nitric acid and liquid nitrogen
 dioxide or  else known amounts  of oxygen and that mixture
 were thoroughly shaken together. Conclusions are as follows:
 1. The  notion  derived from previous  experiments that the
 process of  nitric acid formation  from gaseous NO2, O2, and
 water cannot proceed beyond the nitric acid solution with the
 lowest vapor pressure, is erroneous. 2. The rate of this process
 in the  range of concentrations of nitric acid at the lowest
 vapor pressure is  so  low that an  enrichment of  nitric acid
 beyond this range requires a rather long reaction time. 3. For
 such an  enrichment, the  smallest possible excess  of oxygen
 and a low rate of flow of the mixture are preferable. 4. With
 sufficiently long test durations and with progressively decreas-
 ing utilization of the NO2, even under the most favorable test
 conditions,  nitric acid concentration rarely goes above 80%.  5.
 The reason  for this is that when a steaming gas  mixture  is
 used, the conditions favoring a good utilization of NO2, name-
 ly, a small oxygen excess and low rate of flow, are highly un-
 favorable for the thorough mixing of the reaction solution with
 oxygen which is also required. 6.  However, one can easily at-
 tain even the highest nitric acid  concentrations if  one mixes
 less concentrated solutions of it with an appropriate amount of
 liquid NO2 and shakes this mixture thoroughly with oxygen.  7.
 The process proceeds especially  rapidly when the  excess of
 liquid NO2 is so great that, due to its limited solubility in nitric
 acid, the liquid mixture is heterogeneous and remains so dur-
 ing the reaction. 8. When  nitrous gases act on water, from the
 equilibrium 2NO2 yields N2O4, the latter is dissolved in water
 and yields the primary reaction N2O4 plus H2O yields HN03
 plus HNO2. 9. The dissociation of the nitrous acid into nitric
 acid, nitric  oxide, and water (3HNO2 yields HNO3  plus 2NO
 plus H2O), and the rapid oxidation of the latter, effects the
 transformation of the  nitrous gases into nitric acid up to its
 highest concentrations.

 14303
 Von Semel, Georg and Heinz Lehmann
 METHOD OF PRODUCING  CONCENTRATED MIXTURES
 OF NITRIC AND PHOSPHORIC ACID. (Pintsch Bamag A.-G.,
Berlin) U. S. Pat. 2,901,340. 2p.,  Aug. 25, 1959. 4 refs. (Appl.
Dec. 26, 1956, 7 claims).
A method was devised for obtaining higher concentrations of
mixtures of nitric and phosphoric acids by using a phosphoric
acid solution instead of water. The method consists of passing
a nitrogen oxide gas and an oxygen-containing gas into a dilute
phosphoric acid solution with an inorganic nitrate or sulfate
salt dissolved in it in an amount between 1% by weight and
the solubility limit of the salt. The nitrogen oxide gas absorp-
tion is promoted by the inorganic  salt which converts  it to
nitric acid. Thus, a concentrated solution of phosphoric and
nitric acid is formed.
15087
Mucskai, Laszlo
THE PROCESS OF OXIDATION OF NITROGEN OXIDES IN
THE  PRESENCE OF EQUEMOLECULAR NO  +  NO2  AB-
SORPTION IN THE DILUTE TAIL GASES OF NITRIC-ACID
PLANTS.  (Nitrogenoxid oxidacioja hig nitrozus gazokban ek-
vimolekularis NO + NO2 folyamatos abszorpcioja  mellett).
Text  in Hungarian.  Magy. Kern.  Folyoirat,  67(11):488-490,
1961. 1 ref.
A differential equation is derived that gives  the incremental
change in  the partial pressure of nitrogen dioxide  as a  function
of incremental  change  in nitric oxide concentration, oxygen
concentration, the concentration of an inert gas,  and the  total
pressure. The above conditions refer to the tail gas  of a stack
at a plant  where nitric acid is manufactured from nitric oxide,
sodium carbonate, and water; the tail gas (NO and NO2)  con-
centration is 0.7-1.0 vol%. Subsequently, the equation is  used
to derive  another differential equation  rendering the  time
needed to  accomplish an incremental change in NO concentra-
tion. This  latter differential equation is considerably simplified
so that it can be integrated. The resulting equation is presented
in the form of a nomogram that can be used  to  calculate the
volume of the absorber column or the oxygen concentration or
the time needed to perform the reaction.

23882
Satterfield, Charles N. and Douglas H. Cortez
MASS TRANSFER CHARACTERISTICS OF  WOVEN-WDJE
SCREEN  CATALYSTS.  Preprint,  Massachusetts  Inst. of
Tech., Cambridge, Dept. of Chemical Engineering, 38p.,  1969
(?). 19 refs.
Gauze catalysts woven  from a fine platinum-rhodium  wire
have long been used in the partial oxidation of ammonia for
the industrial manufacture of nitric acid. An  investigation of
the possibility that the catalytic  oxidation of hydrocarbons in
air might  under some circumstances proceed  by initiation of
reaction on a catalyst surface followed by propagation of the
reaction  into  the  surrounding  gas,  or so-called  hetero-
homogeneous catalysis, is described. The  rate of  oxidation of
hexene or toluene in excess air on  platinum screen catalysts
under mass transfer  controlled conditions is used to calculate
'j' factors. Previous  literature data on heat and mass  transfer
are re-examined and re-correlated and the transport  charac-
teristics of screen catalysts are  shown to be very  similar to
that of infinite  cylinders. There is no positive evidence  that
any of the hydrocarbon oxidation in these studies or that of
the oxidation of ammonia on platinum gauze under industrial
conditions occurs as a homogeneous process. (Author  abstract
modified)

-------
 18
                         G.   EFFECTS-HUMAN  HEALTH
01049
R. L. Larkin and R. E. Kupel
QUANTITATIVE    ANALYSIS    OF    POLYVINYLPYR-
ROLIDONE IN ATMOSPHERE SAMPLES  AND BIOLOGI-
CAL TISSUES. Am. Ind.  Hyg. Assoc.  J. Vol. 26(6):558-61,
Dec. 1965.
A quantitative method for the analysis of polyvinylpyrrolidone
(PVP), collected in atmospheric  samples  or extracted from
biological tissues, is described. PVP is a component in many
aerosol hair sprays. A 0.4M citric acid solution is used to col-
lect or extract the PVP. The color is developed  by using a
potassium iodide reagent, and the intensity  of the color is read
on a spectrophotometer at a wavelength of 432 millimicrons.
The  low  limit  of  detection  for this method has been
established  at 0.5 microgram of PVP per nuHiliter of final solu-
tion. (Author abstract)

06552
A. Goetz
AN INTERPRETATION OF THE SYNERGISTIC EFFECT OF
AEROSOLS BASED UPON SPECIFIC  SURFACE-ACTION OF
THE AIRBORNE PARTICLES.Preprint. (1956).
Experiments to determine the survival  time of test animals
(mice) exposed to toxic vapor without and with the addition of
an aerosol of defined particulate constitution were conducted.
As toxic vapor,  three different substances were used, (each
for itself, i.e. not as mixtures): two aldehydes (formaldehyde
and acrolein)  and evaporated nitric acid; the concentration of
these vapors was kept constant in the presence and absence of
the aerosol addition, and  it was selected so that the  vapor
alone caused  commensurable survival  periods of the animals.
None of the aerosols caused, in the absence of the toxic
vapors,  any significant change in the  test  animals. However,
when co-existent  with the toxic vapors the aerosols  caused
very marked  differences in the mean  lifetime of  the test
animals  and proved that certain types of particles produce a
Substantial  identification of the toxicity of the vapor  (shorten-
ing of  the  lifetime), while  others had an attenuating  effect
(lengthening of the lifetime), and also  that the  attenuating, or
the intensifying properties of a particular aerosol, depended to
a  large  extent on the nature  of  the  toxic vapor. These in-
vestigators have attempted to interpret  their results qualitative-
ly (and to some extent even quantitatively) by assuming that
the vapor be absorbed by the aerosol, i.e. by the gradual incor-
poration of  the vapor into the particle.  In view of the fact that
the experimental data as  well as the  manner  in which they
were obtained, appear to  have  an unusually significant bearing
upon the mucous irritation  caused by smog, the  present in-
vestigation  has attempted to interpret this data in  terms of
nuclear condensation of the toxic  vapor, (i.e. of a  surface ac-
cumulation on the airborne particles).

11378
Melekhina, V. P.
THE  PROBLEM OF COMBINED  ACTION  OF  THREE
MINERAL  ACIDS. In: Biological  Effect  and  Hygienic Sig-
nificance  of  Atmospheric  Pollutants,  Book   1/9,  V.   A.
Ryazanov and M. S. Gol'dberg (eds.), Translated from Russian
by B. S. Levine, U. S. S.  R. Literature on Air Pollution and
Related Occupational Diseases, Vol.  16, pp.  76-81, 1968. ((6))
refs. CFSTI: PB 179141
The  following  concentrations of odor perception  thresholds
was  established: 0.80 mg/cu m for sulfuric acid,  and 0.40
mg/cu   m   for  hydrochloric   acid;  corresponding   H-ion
equivalents are as follows: 0.01099, 0.01203, and 0.01053 mg/cu
m. Any combination of 2 or 3 acids was clearly odor percepti-
ble if the sum of their concentration fractions in corresponding
relation to their individual  threshold  concentrations  exceeded
unity. Perceptible concentrations expressed in H-ions  exceed
the 0.01 mg/cu  m level. Threshold reflex effect concentrations,
as studied by eye adaptation to darkness,  were on the level of
threshold odor perception,  or just  above  it. The  reflex effect
of nitric, sulfuric, and hydrochloric acids in atmospheric air of
inhabited areas is  a condition of H-ion concentration. The
sanitary-hygienic condition of  atmospheric air containing
mineral acids can be reliably evaluated on the basis of H-ion
concentration for the sum of the three  acids  under considera-
tion  as well  as for  each acid individually based on the H-ion
index should not exceed 0.010 mg/cu m.

16460
Podgornova, N. S.
HEALTH  PROBLEMS IN  THE  INSTRUCTION  OF STU-
DENTS IN  A CHEMICAL  TECHNICAL  SCHOOL.  (Gi-
gienicheskie  voprosy  obucheniya  studentov khimicheskogo
tekhnikuma). Text in Russian. Gigiena i Sanit., no. 9:112-114,
1966.
Psychological and physical studies were made of 85 students
aged 15-18  years enrolled  in three courses  of study at the
Moscow Chemical-Technological school during one semester.
In Course I,  students had 5 weeks of classroom work, 4 weeks
of shop work, and then returned  to  classrooms  for the
remainder of the semester.  Students in  Course II had 6 hours
of laboratory work  one day a week in addition to daily class-
room work.  Students in Course III had classroom instruction
all semester. At the end of the semester,  all  groups showed a
decrease in work capability and physiological changes which
were more  marked in students in  Courses I  and  II. No
decrease in function was noted at the end of the day in stu-
dents having shop or laboratory work. More control by the in-
structor is recommended in order to  decrease fumes of nitric
acid  in laboratories.

16613
Prys-Roberts, C.
PRINCIPLES OF TREATMENT OF POISONING BY HIGHER
OXIDES OF NITROGEN. Brit. J. Anaesthesia, vol. 39:432-439
May 1967. 39 refs.
The  main methods  of treatment for patients exposed to the
noxious effects of nitric oxide, nitrogen dioxide, or the fumes
of nitric acid are outlined. High concentrations of nitrogen ox-
ides cause reflex inhibition of breathing  with laryngospasm. In-

-------
                                       G.  EFFECTS-HUMAN HEALTH
                                                                                                                  19
tense cyanosis develops rapidly.  Therefore, severe hypoxia
may occur. There is a tendency for the ventilatory frequency
to increase, and pulmonary edema may occur in the acute
phase. Oxygen therapy is recommended which consists of ad-
ministering 100%  oxygen, either by spontaneous or artificial
ventilation in  order to  compensate for the decreased oxygen
capacity  and content of the arterial  blood. Reconversion of
methemoglobin by the use of methylene blue (2mg/kg) initially
is  advocated,  with subsequent  dosage titrated  against the
methemoglobin concentration in the  blood.  Prevention  and
treatment of  chemical pneumonitis combines  endobronchial
and  parenteral administration of corticosteroid preparations,
together  with  bronchial  lavage and  suction.  The metabolic
component of acid-base  derangement  is corrected by  in-
travenously administering sodium bicarbonate.  Artificial ven-
tilation by intermittent positive pressure ventilation may be in-
dicated   in  patients  who demonstrate  ventilatory failure
manifested by  a rising arterial carbon dioxide pressure. Circu-
latory  therapy is accomplished  by the use of  vasopressor
agents to combat  severe systemic hypotension. Associated
drug therapy using dimercaprol is advocated in severe cases in
view of the protective action of this type of agent against the
higher nitrogen oxides.  Bronchodilators  may be  indicated in
order to  alleviate bronchospasm arising from the irritant ef-
fects of the inhaled gases. (Author conclusions modified)

21307
Ellis, Richard  E. and Ronald M. Bishop
OXIDES  OF NITROGEN ARE  HEALTH HAZARDS. J. En-
viron. Health,  32(6):676-677, May/June 1970. 4 refs.
Oxides of nitrogen are extremely toxic. Nitrogen dioxide and
tetroxide are most prevalent. Both the  threshold limit value
and ceiling are 5 ppm and should never be exceeded. Occupa-
tional exposure is encountered  in nitric  acid  manufacture,
nitration  of cellulose and inorganic  materials, etching, pickling
of metals, certain welding operations,  explosives manufacture
and use,  and engine exhausts. The gas combines with water to
form nitrous and nitric  acid which, in turn, react with salts in
the tissues of the respiratory tract to produce irritating nitrites
and nitrates. Exposure to high  concentrations  may  be fatal.
Persons  suspected of having been exposed  should  be kept
under observation at rest for 25 hours. Persons known to have
been Exposed  should be hospitalized  at bed rest. Administra-
tion of oxygen and corticosteroids is  indicated and may be
life-saving.

23738
Gray, Edward Le B., Stanley B. Goldberg, and Francis M.
Fatten                                            	
TOXICITY OF THE OXIDES OF NITROGEN. HI. EFFECT
OF CHRONIC EXPOSURE TO LOW CONCENTRATIONS OF
VAPORS FROM RED FUMING NITRIC ACID. Arch.  Ind.
Hyg., Occupational Med., vol. 10:423-425, 1954. 5 refs.
In contrast to animals exposed for four hours a day, five days
a week for six weeks to 9-14 ppm nitrogen dioxide, rats, mice,
and guinea pigs exposed for four hours daily, five days a week
for six months to 4 ppm vapors of red fuming nitric acid ex-
hibited no toxic effects. In fact, the lower concentration of
NO2  produced a  significant prophylactic effect, since the
degree of pulmonary  congestion was less  in the exposed
animals than in control animals. The results lead to the  conclu-
sion that the maximum allowable concentration of nitrogen ox-
ides should be set at 5 ppm.
24588
Gray, Edward LeB., James K. MacNamee, and Stanley B.
Goldberg
TOXICITY OF NO2 VAPORS AT VERY LOW LEVELS. A
PRELIMINARY  REPORT.  Arch. Ind.  Hyg.  Occupational
Med., vol. 6:20-21, July 1952. 9 refs
Forty rats were divided into groups of  10 and exposed to red
fuming nitric acid  containing 9-14 ppm nitrogen  dioxide for
four hrs at a time. Total exposure  for the different  groups
ranged from 40-96 hrs.  Animals examined shortly after the ter-
mination of exposure had inflammatory respiratory tracts and
exhibited evidence of severe rhinitis and tracheitis in the upper
portion of the tract, along with less severe pneumonitis. Pneu-
monia developed in a few of the animals.  In many  of the
animals sacrificed eight or more weeks after  exposure, the in-
flammation had subsided, but there  were localized areas of
emphysema in all lobes  of the lungs. With  the exception of
moderate congestion, liver, spleen, kidney, and brain showed
no pathological changes.  Length of exposure had no effect on
the changes observed. In view of the fact that nitrogen dioxide
concentrations higher than 8 ppm produce damage in rats, it is
concluded that the  maximum allowable concentration of 25
ppm, the value set by the American Standards Association and
others, is too high.

-------
20
               H.  EFFECTS-PLANTS  AND   LIVESTOCK
22622
Noack, Kurt
INVESTIGATIONS  OF  SMOKE  GAS  DAMAGES   TO
VEGETATION. (Untersuchunge uber die Rauchgasschaden der
Vegetation).  Z. Angew. Chem. (Weinheim), vol.  42:123-126,
Jan. 3, 1929. 6 refs. Translated from German. Belov and As-
sociates, Denver, Colo., 12p., May 27, 1970.
Investigations were conducted to determine if nitrous  gas,
hydrochloric acid, and ammonia cause plant damage similar to
that caused by sulfur dioxide, and to determine the participa-
tion  of  the  iron  contained in chloroplasts in this  disease
process. The assimilation apparatus in the moss fontinalis was
primarily affected by  nitrous  gas  and these effects  cor-
responded to the effect of SO2; HC1 had a lesser  effect, and
ammonia was not considered  to  be  an assimilation poison.
Clover, tobacco,  and  spinach  plants  exposed  to  nitrous gas
became withered and bleached with inhibited assimilation after
exposure to light.  Plant damage by SO2 and nitrous gas con-
sists of a fixation of iron followed by a photooxidative poison-
ing of the protoplasm by chlorophyll. Tests on corn were con-
ducted to determine if the water soluble part of iron increases
after introducing assimilation poisons. Pre treatment with fum-
ing nitric acid resulted  in a water soluble  iron content four
times higher than normal. The effect of smoke gases on plants
consists of a direct cancellation of the catalytic activity of the
iron in the chloroplasts. The photooxidative poisoning of the
protoplasm is considered to be a secondary effect.
25481
Clark, J. F.
ON THE TOXIC EFFECT OF DELETERIOUS AGENTS ON
THE GERMINATION AND DEVELOPMENT OF CERTAIN
FILAMENTOUS  FUNGI.  Botan. Gaz., 28(5): 289-404,  Nov.
1899. 47 refs.
An experiment designed to determine the relative and absolute
toxic properties of several chemical compounds,  as shown by
their influence on the spores, mycelium, and the  fructification
of certain of the mold fungi, is described. The procedures used
to select the medium, the method of culture, and the experi-
mental equipment and conditions are described. Cultures were
examined at intervals of 3-6 hr for the 14 hr following their ex-
posure to  the  various  chemical agents, until the fungus had
matured, or the spores in the cultures which had  failed to ger-
minate were transferred to pure beet infusion  to test their
vitality. The cultures in which the  spores failed  to germinate
were divided into two classes; inhibited and killed. The cul-
tures which did germinate were also divided into two groups;
those which matured a fair crop of conidia in about the normal
time and those which presented a markedly retarded  mycelial
development and  generally failed to fruit. The types of chemi-
cal agents tested,  in various strengths, include sulfuric, hydro-
cyanic, hydrochloric,  nitric, and acetic  acids, several metal
sulfates, chromates,  nitrates, and formaldehyde. The results
indicate that fungi are  generally more resistant than higher
plants,  although different species of fungi and different forms
of the same  species present considerable variation in re-
sistance.

-------
                                                                                                             21
                               I.  EFFECTS-MATERIALS
13877
McLeod, W. and R. R. Rogers
CORROSION OF METALS BY AQUEOUS SOLUTIONS OF
THE  ATMOSPHERIC  POLLUTANT SULFUROUS  ACID.
Electrochem. Technol., 6(7 to 8): 231-235, July to Aug. 1968. 7
refs.
The  corrosion  rate of a metal in an acid with a normality
between N/l and N/10,000, such as  H2SO3, HNO3, H2SO4,
or HCL, was found to be related to the concentration of the
acid in accordance with the equation  Corrosion rate equals a x
(Acid Normality) to the b power, where a and b are constant
for each combination of acid and metal and where temperature
is 25 C.  By determining the values of a and b for a number of
acid-metal combinations, it was possible to compare the corro-
sion rates of the various metals in sulfurous acid with those of
the same metals in nitric, sulfuric, and hydrochloric acids, and
to determine the corrosion rate of the metals in sulfurous acid
of different normalities. Data obtained show that nonstainless
steel, with or without nickel, is highly susceptible to sulfurous
acid  corrosion.  However, when  a substantial proportion of
chromium  is present in an alloy which contains nickel, steel is
free  from  corrosion by either sulfurous acid or  nitric acid.
Copper and chromium are not appreciably susceptible to sul-
furous acid corrosion in solutions lower than N/l.3. Tin cor-
rodes more  rapidly than other  nonferrous metals  between
N/100 and N/1000, but  less than cadmium and  zinc at N/10.
Cadmium,  Lead, and zinc corrode more rapidly in sulfurous
acid than in nitric acid. Lead corrodes less rapidly in sulfurous
acid  than  in nitric acid. Aluminum is  rapidly  corroded  by
hyperchloric acid but less so by nitric or sulfurous acid. The
study concludes  that sulfurous acid solutions  causing  the
greatest damage in urban and industrial areas have abnormali-
ties between N/l and N/10,000.

19325
Konda, Kiyoshi, Hisao Ito, and Atsuhiro  Honda
FIELD EVALUATION OF EXHAUST GAS FROM REFUSE
INCINERATOR RELATED  TO  AIR  POLLUTION  AND
METAL CORROSION. Trans. Soc. Heating, Air-Conditioning,
and Sanitary Engrs. (Japan), vol. 7:95-104, 1969.
A study of municipal incinerator exhaust  gas composition con-
ducted at five sites in Japan is described. The study was un-
dertaken to obtain information on odor  and metal corrosion
problems. The exhaust consisted of sulfur oxides, nitrogen ox-
ides,  ammonia, sulfuric  acid,  nitric acid, organic acids, and
hydrochloric acid. Volatile organic acids and hydrochloric acid
are mainly  responsible for the corrosion, with sulfuric and
nitric acids only partially concerned. Percentages of exhaust
products as a function of raw refuse input are tabulated. Con-
tinuous firing rather than batch firing would limit noxious ef-
fluents. Temperature and excess air control would also help.
After-burning chambers should be installed to further reduce
contaminants.

-------
22
                               J.  EFFECTS-ECONOMIC
17203
Oels, Heinriche
AIR  POLLUTION PROBLEMS IN WEST GERMANY AND
THE ROLE OF INDUSTRY.  (Luftforurensningsproblemer i
Vest-Tyskland industriens innsats). Text in Norwegian. Tek.
Ukeblad (Oslo),  116(45): 1245-1247, Dec. 1969.
West Germany  has  been occupied in the last decade with
reducing emissions of dust and smoke. Effectiveness of dust
filters has increased threefold, and filtration is more economi-
cal. The dust content can now be reduced to 150 mg/cu m for
an emission rate of 100,000 cu m/hr. In 1950, the dust output
from the West  German cement industry was 3.5% of the
clinker  produced; in 1967, it was 0.15%. Dust output from the
manufacture of calcium carbide was reduced to 3 mg/cu m of
exhaust gases. Attention now centers on reducing sulfur diox-
ide emissions. An electric power plant in Essen absorbs it with
a new  type of  activated carbon, recovering the SO2 for the
manufacture of H2SO4, the cost per 1000 kWh being about 1
DM (25 cents), and this can be further reduced. Government
standards now  limit  the  sulfur content  of fuel oils  to  1.8%.
About 20% of the total SO2 emission in West Germany comes
from sulfuric acid plants. A new 'double  contact' process can
reduce SO2 emissions of such a plant from 17 to 3 kg per ton
of H2SO4 produced. Nitrogen oxides  emitted from nitric acid
plants  have been  reduced by  50% with special absorption
equipment. New legislation  sets  a maximum  average  of 2
mg/cu m for fluorine emissions, or 5 mg for short  intervals.
Readings as high as 2.7 mg have been  recorded above the
Ruhr from January 1, 1966, to December 31, 1968. During that
period,   industry   in   North   Rhine-Westphalia   invested
4,000,000,000 DM on air pollution problems related to existent
operations and about 275,000,000 DM  on  those related to new
ones.   Exhaust  purification  for the  2-year  period  cost
3,000,000,000 DM, plus an additional  30,000,000 for research
this  in  comparison  with  a  gross  national  product of
300,000,000,000 DM per year. The total amount spent by in-
dustry  is  small  compared with the  damage caused,  which
amounts to 50 DM per capita per year,  or 3,000,000,000 for
the entire republic, not including losses due to sickness or
sanitation problems.

-------
                                                                                                             23
                       K.  STANDARDS  AND  CRITERIA
06778
(INDUSTRY AND ATMOSPHERIC POLLUTION IN GREAT
BRITAIN.) Industrie et pollution atmospherique en  Grande
Bretagne. Centre Interprofessionnel Technique d'Etudes de la
Pollution Atmospherique, Paris, France. (1967.) 6 pp. Fr. (Rept
No. CI 310.) (C J.T.E.P.A. Document No. 24.)
A  summary  of the  basis of governmental action in Great
Britain in the  struggle against industrial emissions is outlined.
The regulations imposed by the 'Alkali Act' are in most cases
based on 'the most practical means.'  Standards are given for
chimney heights. Statutory limits are given for various materi-
als emitted such as hydrochloric acid, sulfuric acid, nitric acid,
hydrogen sulfide, chlorine, arsenic, antimony, cadmium, and
lead. The construction of tall buildings tends to reduce the
benefits obtained by  tall chimneys. A  better knowledge of the
effects of pollutants should be obtained so as not to burden in-
dustry with unnecessary expense in their control. It is urged
that international standards for emission be adopted.

07197
RECOMMENDATIONS  FOR ALLOWABLE  CONCENTRA-
TION (1966.) Kuki Seijo (Clean Air - J. Japan Air Cleaning As-
soc.,  Tokyo) 4(4):62-66, 1966. Text in Japanese.
A report is given by a committee of the Japanese Association
of Industrial Health on 'Allowable concentration'. The values
of allowable concentration are worked out for a healthy man
working 8 hr per day doing moderate  work. Proper considera-
tion must be given to cases in which more than 8 hr of expo-
sure  take place, more than one pollutant is involved, or the
concentration of pollutants increases suddenly during the work
schedule. Included is a discussion on dust measurement. It is
important to measure dusts having a Stokes radius of less than
5 microns, especially at  a height of 1 to 1.5 m from the
ground. The relation between the source of dust and the point
of measurement is illustrated.

20121
RECOMMENDATIONS OF  PERMISSIBLE  CRITERIA  OF
HAZARDOUS WORKING ENVIRONMENTS BY JAPAN AS-
SOCIATION OF INDUSTRIAL HEALTH. 1969. Sangyo Igaku
(Jap. J. Ind. Health), 12(2):37-44, Feb. 20, 1970. 15 refs.
The Japanese Association  of Industrial Health annually recom-
mends permissible concentrations of toxic gases, vapors, mist,
and fumes in the working environment. The 1969 limit values
for  86 toxic substances are shown  in ppm and/or mg/cu m.
Like the Threshold Limit  Values established by the American
Conference of Governmental Industrial  Hygienists (ACGH),
the  concentrations are time-weighted average concentrations
for an eight-hour working day. The table cannot be applied to
works where exposure to toxic substances is extremely irregu-
lar or short-term. The limit values for butyl acetate,  buty al-
cohol, carbon monoxide,  p-dichlorobenzene, ethylene glycol
dinitrate, nitrobenzene, hexane, selenium  compounds, lead,
nitric acid, styrene monomor, toluene, 1,1,1-trichloroethane,
and trichloroethylene differ from those of the ACGH. Factors
affecting the  Japanese  decision are  discussed in the case of
hexane,  lead, styrene monomor, and toluene. The article also
reviews  permissible criteria for noise exposure, thermal stan-
dards for high-temperature work, and permissible dust concen-
trations.

-------
24
                     L.   LEGAL   AND  ADMINISTRATIVE
05407
T. Toyama
AIR POLLUTION  AND HEALTH  IMPEDIMENT. Japan  J.
Ind. Health (Tokyo) 8, (3) 45-8, Mar. 1966. Jap. (Presented  at
the  39th  Annual   Meeting,  Japan  Society  of  Industrial
Medicine, Ube, Japan, Apr. 7-9, 1966.)
The 39th Annual Meeting of the  Japan  Society of Industrial
Medicine was held on April 7-9, 1966 in Ube, Yamaguchi-ken,
Japan. The  theme of one of the symposia was planning pro-
grams for air pollution  control in  which air pollution  and
health impairment and the engineering and practice of air pol-
lution control were  discussed. The  main health impairments
covered deal with  effects  of pollution on  the  respiratory
system and acute diseases resulting therefrom. Prior to World
War II there  were no legal  problems in  pollution control but
by  1963, it was necessary to establish laws covering soot and
dust control. City planning and building restriction ordinances
have come  into effect. Dust and soot fall have decreased by
one-sixth in the past sixteen years. Millions of dollars have
been paid by  factories and industries for the  establishment of
dust collectors and SO2 counter-measures. Waste gas disposal
in nitric and sulfuric acid plants has been brought under con-
trol since 1964. Re-use of the  waste gases has played an im-
portant role in the economic  feasibility of air cleaning.

07597
Heller, A.
MAXIMUM  PERMISSIBLE CONCENTRATIONS  FOR AIR
POLLUTION  IN THE FEDERAL REPUBLIC  OF GERMANY.
Preprint, Federal Inst. of Hygiene for Water, Soil and Air,
Berlin, Germany, 10p., 1963. (Presented  at the Inter-Regional
Symposium on Criteria for Air Quality and Methods of Mea-
surement, Geneva, Switzerland, Aug. 6-12,  1963, Paper No.
WHO/AP/8.)
An advisory  committee  set up  by the Federal  Government
gives expert advice on the proposals of the Clean Air Commis-
sion of the Association  of German Engineers regarding per-
missible emissions as well as on the maximum concentrations
of 'immissions' the MIK values   for various air pollutants.
The task of the Verein Deutscher Ingenieure Commission is to
set scientific and technical bases for appropriate  air pollution
control measures. The main task of the Commission is to draft
recommendations for new technical regulations as a basis for
the determination and control of air pollution,  as follows:
Minimum requirements   regarding  the  concentration  and
precipitation of dusts and gases in the atmosphere, bases for
calculating the distribution of  dusts and gases and for deter-
mining the required height of chimneys, limits to the emission
of dust and gas from sources of air pollution, and procedures
for measuring  dusts and gases. The provisions recommended
for examining applications for  licences to establish new plants
or to alter existing plants are reviewed. Enforcement of these
regulations will depend on the local situation, especially the
existing pollution load. They will also depend on the extent to
which further  pollution  could occur, without exceeding  the
tolerance limit or the  MIK-value for the most sensitive among
the reaction partners, whether human being, animal or plant,
and on the technical processes  of the industrial  plant  in
question. In principle, all reasonable technical and economic
possibilites for purifying waste gases should  be  exploited  in
equal  fashin  by  similar industrial  plants.  Finally, industry
should be prepared  to bear more far-reaching demands regard-
ing waste-gas  removal, if a licence for a new industrial plant
or for the extension of an existing plant is to be issued in an
area already  polluted. MIK-values have  been set and are
discussed for;  sulfur  dioxide,  hydrogen sulfide, some nitrous
gases and chlorine.

-------
                                       AUTHOR INDEX
                                                                                                            25
ALEKSANDROV YU I  C-23560
ALTSHULLER A P  E-23037, *E-24015
ANDERSEN, H C  B-06844
ANDERSON H C  B-13893
ANTOSHECHKIN, A G  C-06889
ATROSHCHENKO V I  B-13689, *F-13680
ATROSHCHENKO, V I  B-10159
ATSUKAWA M  B-14664

                 B

BAYLEY, R W  B-04658
BEL CHENKO G V  B-14382
BELAGA M B  A-17076
BENGEANU L  C-24975
BETZ, E C B-05309
BILLINGS, C E B-07552
BINGHAM, E C JR  B-11549
BISHOP R M  G-21307
BLOOMFIELD, B D  B-10017
BOMSHTEIN V E  B-16726, B-19847
BRINK: A JR 0-23771
BRINK, J A JR  B-00587
BURCHARDT T  F-13948
BURGGRABE, W F  B-00587
CAUER H  C-25925
CORTEZ D H  F-23882
ELLIS R E  G-21307
ERMENC E D  B-20775
ESTER W B-13202
FEIST, H J  B-05309
FEIST, J  B-02051
FOERSTER F  F-13948
FRICKE  E  F-13948
FUNK A B  B-25714


                 G

GANZ, S N  F-10160
GERSTLE, R W A-01583
GOETZ, A  G-06552
GOLDBERG S B  G-23738, G-24588
GOLDBERG, E K  C-04257
GRAY E  L  G-24588
GRAY E  L B  G-23738
GREEN W J B-13893
GREEN,  W J  B-06844
GREENWELL,  L E  B-00587
GRIGORESCU I C-24975
                H

HALS F A  A-21204
HARDING, C I  B-00959
HASEBA S  F-13415
HELLER, A L-07597
HENDRICKSON, E R  B-00959
HEUMANN H  B-13202
HONDA A  1-19325
HSIEH Y H B-14007
HSUEH L  A-26226
HUNTER J B B-21232
                 I
ITO H  1-19325
JEITNER, O  B-06123


                K

KAUT V M  F-13680
KAZAKOVA E A  B-16726, *B-19847
KERNS, B A  B-05151
KHITERER R Z B-16726, B-19847
KIRK D G F-13481
KITAGAWA T F-13415
KONDO K 1-19325
KONIG, K B-06123
KOPYLEV B A  B-14382
KUBO N  F-13415
KULIKAA  B-14387
KUPEL, R E  G-01049
KURKER, C JR B-07552
LARKIN, R L  G-01049
LEHMANN H  F-14303
LEIGHTON P A E-21534, 'E-21642
LEITHE, W  B-07535
LESOINE L G  C-24725
LINDAU L A-18305


                M

MACNAMEE J K G-24588
MANAKIN G A B-13899
MANITA, M D  C-02570
MARKVART M  B-13205
MATTA J M  B-20313
MAY, F P B-00959
MAYSTRUK P N  A-17076
MCLEOD W  1-13877
MELEKHINA, V P C-02570, *G-11378
MERENKOVPT  B-14387
MIKINA V D  C-23560
MOHRNHEIM A F A-13698
MOORE J C  B-25714
MUCSKAIL  F-15087

                 N

NABIEV, M N B-09981
NABIYEVMK  B-14387
NAffi P V N  E-22407
NEWMAN DJ B-20313
NICOLET M  E-23604
NISHIMOTO Y  B-14664
NOACKK  H-22622
NOVIKOVGA  C-23560

                 O

OELS H J-17203
OLEVINSKIY M I  B-14568
PATTON F M  G-23738
PATTON W F  C-23771
PAULING H  B-13202
PERRINE R L  A-26226
PETERSON, R F  A-01583
PODGORNOVA N S  G-16460
POUR V B-13205
POZIN M E  B-14382
PRYS ROBERTS C G-16613


                R

RADELOFFH  C-18226
RHINE P E  E-14408
ROGERS R R  1-13877
ROMEO P L  B-13893
ROMEO, P L  B-06844
SAFIULLIN N S  B-14568
SALTZMAN, B E C-11130
SATTERFIELD C N  F-23882
SCHMITTK  B-13202
SCHWANECKE R B-15152
SEDASNOVA, E G  B-10159
SHIMOSET F-13415
SILVERMAN, L  B-07552
SORDELLI, D  B-01125
STANKUS L  B-23880
STAROSEL SKIY Y  I  B-13899
SUNDARESAN, B B  B-00959
TAKAHASHIN  B-14664
TESKE W  B-23372
TESKE, W B-11058, *B-12637
TIKHONENKO A D B-14387
TIKHONENKO, A D B-09981
TOYAMA, T  L-05407
TSEYTLIN A  N  B-13689
TUBES L D E-14408

-------
26                                     NITRIC ACID PLANTS

               V                                 W                                 Z

VAN DER DRIFT J  B-14481                                                 ZANON D  B-01125
VARLAMOV M L  B-13899                                                  ZJUNUIN, u  B mu.3
VOHRAKG  E-22407                                                      ZASORIN A P B-13689
VON SEMEL G  F-14303                 WILLIAMS D E-14408                  ZBROZHEK L S  B-13899

-------
                                          SUBJECT  INDEX
                                                                                                                     27
ABSORPTION A-01583, A-18305, A-26226,
      B-00587, B-00959, B-01125, B-07093,
      B-07535, B-07552, B-10017, B-10159,
      B-12637, B-13202, B-13689, B-13899,
      B-14382, B-14568, B-14664, B-15152,
      B-16726, B-20313, B-23372, B-25714,
      B-26071, E-21642, F-10160, F-13680,
      F-15087, G-01049, J-17203
ABSORPTION (GENERAL)  A-22877,
      B-07535, B-23880, J-17203
ACETIC ACID G-01049, H-25481
ACETONE K-07197
ACETYLENES F-13415
ACID SMUTS  A-17076, B-26071
ACIDS  A-01583, A-13698, A-16699,
      A-17076, A-18305, A-21204, A-22877,
      A-26226, B-00587, B-00959, B-01125,
      B-02051, B-04658, B-05151, B-05309,
      B-05401, B-06123, B-06844, B-07093,
      B-07535, B-07552, B-09773, B-09981,
      B-10017, B-10159, B-11058, B-11549,
      B-12637, B-13202, B-13205, B-13689,
      B-13893, B-13899, B-14007, B-14382,
      B-14387, B-14481, B-14533, B-14568,
      B-14664, B-15152, B-16726, B-19847,
      B-20313, B-20775, B-21232, B-23372,
      B-23880, B-25714, B-26071, C-02570,
      C-04257, C-06889, C-11130, C-18226,
      C-23560, C-23771, C-24725, C-24975,
      C-25381, C-25925, E-14408, E-21534,
      E-21642, E-22407, E-23037, E-23604,
      E-24015, F-01619, F-10160, F-13415,
      F-13481, F-13680, F-13948, F-14303,
      F-15087, F-23882, G-01049, G-06552,
      G-11378, G-16460, G-16613, G-21307,
      G-23738, G-24588, H-22622, H-25481,
      1-13877, 1-19325, J-17203, K-06778,
      K-07197, K-20121, L-05407, L-07597
ACROLEIN  G-06552
ADMINISTRATION  B-23880, L-05407,
      L-07597
ADSORPTION B-00959, B-01125, B-05401,
      B-10017, B-13893, B-14533, B-16726,
      B-19847, B-26071, F-13415
ADVISORY SERVICES  L-07597
AEROSOLS  A-17076, B-14568, E-22407,
      G-01049, G-06552
AFTERBURNERS  B-05309, B-07535,
      B-10017, B-11549, B-21232, B-26071,
      1-19325
AIR QUALITY CRITERIA  K-07197
AIR QUALITY MEASUREMENTS
      A-17076, A-22877, C-02570, C-04257,
      F-13415, 1-19325,  K-07197, L-05407
AIR QUALITY STANDARDS  B-10017,
      G-11378, G-21307, G-23738, G-24588,
      K-06778, K-07197, K-20121, L-07597
ALCOHOLS   B-05309,  C-24975, K-07197,
      K-20121
ALDEHYDES  B-05309, G-06552, H-25481,
      K-07197
ALIPHATIC HYDROCARBONS B-02051,
      B-09981, B-10017, B-16726, C-24975,
      E-21534, F-13415, F-23882, G-01049,
      K-07197, K-20121
ALKALINE ADDITIVES  B-23880
ALLENES  F-13415
ALTITUDE  C-25925, E-14408, E-21534,
     E-21642, E-23604
ALUMINUM  1-13877
AMIDES  B-05151
AMINES  B-01125, K-07197
AMMONIA  A-01583, A-16699, A-18305,
     B-00959, B-04658, B-13205, B-13899,
     B-14007, B-14387, F-01619, F-13481,
     F-23882, H-22622, 1-19325, K-07197
AMMONIUM CHLORIDE  C-23771
AMMONIUM COMPOUNDS  A-01583,
     A-16699, A-18305, B-00959, B-04658,
     B-07552, B-12637, B-13202, B-13205,
     B-13899, B-14007, B-14387, C-23771,
     C-24975, F-01619, F-13481, F-23882,
     H-22622, 1-19325, K-07197
ANALYTICAL METHODS A-16699,
     A-22877, B-05401, C-02570, C-04257,
     C-11130, C-18226, C-23560, C-24725,
     C-24975, C-25381, C-25925, F-13415,
     G-01049, G-11378
ANIMALS  G-01049, G-23738, G-24588
ANTIMONY COMPOUNDS  K-06778
AROMATIC HYDROCARBONS   B-11058,
     C-24975, F-23882, K-07197, K-20121
ARSENIC COMPOUNDS  K-06778,
     K-07197
ARSINE  K-07197
ASHES  B-07535
ASIA B-14007, B-14664, E-22407, 1-19325,
     K-07197, K-20121, L-05407
ATMOSPHERIC  MOVEMENTS  A-22877,
     C-25925
AUTOMOBILES  B-07535
AUTOMOTIVE EMISSION CONTROL
     A-26226
AUTOMOTIVE EMISSIONS  A-26226,
     B-00959, B-07535, G-21307
AZO DYE   C-11130
                  B
BAG FILTERS A-17076
BELGIUM  E-23604
BENZENES  K-07197, K-20121
BERYLLIOSIS B-00587, C-02570, G-01049
BERYLLIUM K-07197
BIOMEDICAL TECHNIQUES AND
     MEASUREMENT  G-11378
BODY CONSTITUENTS AND PARTS
     G-01049, G-11378, L-05407
BODY PROCESSES AND FUNCTIONS
     F-01619, G-01049, G-11378
BOILERS  B-00959, B-07535, K-06778
BREATHING G-01049
BROMINE  K-07197
BRONCHODILATORS  G-16613
BUBBLE TOWERS  B-10017
BUILDINGS  G-16460
BUTADIENES  F-13415
BY-PRODUCT RECOVERY  A-18305,
     A-21204, B-11549, B-13202, B-14387
     B-14533, B-15152, B-23880, J-17203
CADMIUM 1-13877
CADMIUM COMPOUNDS  K-06778,
     K-07197
CALCIUM COMPOUNDS  B-11058,
     F-10160
CALIFORNIA  B-07535
CANADA  G-01049
CARBIDES B-11058
CARBON DIOXIDE  A-22877, B-14007
CARBON DISULFIDE  B-05309, B-10017,
     K-07197
CARBON MONOXIDE  A-01583, A-22877,
     B-10017, K-07197, K-20121
CARBON TETRACHLORIDE  K-07197
CARBONYLS  K-07197
CARCINOGENS  A-01583, B-01125,
     C-02570, G-01049
CASCADE SAMPLERS  C-23771
CATALYSIS  A-01583, A-26226, B-00959,
     B-01125, B-02051, B-05309, B-06123,
     B-06844, B-09981, B-12637, B-13205,
     B-13893, B-14007, B-14387, B-14481,
     B-21232, B-23372, B-23880, B-26071,
     F-23882
CATALYSTS  B-02051, B-05309, B-06844,
     B-09981, B-13205, B-13893, B-21232,
     B-23372, F-23882
CATALYTIC ACTIVITY A-01583, A-26226,
     B-09981, B-21232
CATALYTIC AFTERBURNERS  B-05309,
     B-07535, B-10017, B-11549, B-21232
CATALYTIC OXIDATION  B-01125,
     B-02051, B-05401, B-13893, B-14664,
     B-21232, B-23880, F-23882
CEMENTS  B-07535, J-17203
CENTRffUGAL SEPARATORS  B-19847,
     C-23771
CERAMICS  B-02051
CHAMBER PROCESSING  B-14533,
     B-14568
CHARCOAL  B-14533
CHEMICAL COMPOSITION  C-02570,
     F-13415, 1-19325
CHEMICAL METHODS  C-02570, C-04257,
     C-11130, C-18226, C-23560, C-24725,
     C-25925, F-13415, G-01049
CHEMICAL PROCESSING  A-01583,
     A-16699, A-17076, A-18305, A-26226,
     B-00587, B-00959, B-01125, B-02051,
     B-04658, B-05151, B-05309, B-05401
     B-06123, B-06844, B-07093, B-07535
     B-09981, B-11058, B-11549, B-12637
     B-13202, B-13205, B-13689, B-13893
     B-13899, B-14007, B-14382, B-14387,
     B-14481, B-14533, B-14568, B-15152
     B-19847, B-21232, B-23372, B-26071
     C-23771, F-01619, F-10160, F-13415,
     F-14303, F-15087, F-23882, G-21307
     J-17203, K-06778, L-05407
CHEMICAL REACTIONS  A-01583,
     A-13698, A-26226, B-00959, B-01125
     B-02051, B-05309, B-06123, 8-06844*
     B-09981, B-12637, B-13205, B-13689'
     B-14007, B-14387, B-14481, B-14664

-------
 28
      NITRIC ACID PLANTS
      B-15152, B-19847, B-23372, B-23880,
      B-25714, C-11130, C-23560, E-21534,
      E-21642, E-22407, E-23037, E-23604,
      E-24015, F-01619, F-13415, F-15087,
      H-22622
 CHEMISTS  C-25925
 CHLORIDES  C-24975
 CHLORINATED HYDROCARBONS
      C-24975, K-07197, K-20121
 CHLORINE  A-18305, A-22877, B-01125,
      B-10017, K-06778, K-07197
 CHLORINE COMPOUNDS  B-00587,
      B-10017, C-24975, C-25925, E-22407,
      L-07597
 CHLOROFORM  K-07197
 CHLOROPLASTS  H-22622
 CHROMATES  H-25481
 CHROMATOGRAPHY A-22877
 CHROMIUM B-09981, 1-13877
 CHROMIUM COMPOUNDS  C-25381,
      H-25481
 CHRONIC   G-23738
 CLOVER  H-22622
 COAL  B-07535, C-24725
 COAL PREPARATION  B-23880
 CODES  K-06778
 COLLECTORS  B-00587, B-19847, C-23771,
      L-05407
 COLORIMETRY A-16699, A-22877,
      C-02570, C-04257, C-11130, C-24975,
      C-25381, C-25925, F-13415, G-01049,
      G-11378
 COMBUSTION  A-26226, B-11549,  B-15152,
      B-23880, F-13415
 COMBUSTION AIR  A-26226, B-23880,
      B-26071, F-23882, 1-19325
 COMBUSTION GASES  A-21204, A-22877,
      A-26226, B-01125, B-05309, B-06844,
      B-11058, B-12637, B-13689, B-13893,
      B-14007, B-14568, B-14664, B-16726,
      B-19847, B-21232, B-23372, B-23880,
      B-25714, B-26071, C-18226, F-15087,
      1-19325, K-06778, L-07597
 COMBUSTION PRODUCTS  A-21204,
      A-22877, A-26226, B-00959, B-01125,
      B-05309, B-06844, B-07535, B-11058,
      B-12637, B-13689, B-13893, B-14007,
      B-14568, B-14664, B-16726, B-19847,
      B-21232, B-23372, B-23880, B-25714,
      B-26071, C-18226, F-15087, 1-19325,
      K-06778, L-07597
 COMMERCIAL  EQUIPMENT  B-01125
 COMPRESSED GASES  B-00587
 COMPRESSION  A-16699
 CONDENSATION (ATMOSPHERIC)
      C-25925
 CONSTRUCTION MATERIALS   B-07535,
      J-17203
 CONTACT PROCESSING  A-18305,
      B-11058
 CONTINUOUS MONITORING  A-22877,
      C-06889
 CONTROL AGENCIES  B-23880, L-07597
 CONTROL EQUIPMENT A-01583,
      A-16699, A-17076, A-21204, A-26226,
      B-00587, B-01125, B-02051, B-04658,
      B-05151, B-05309, B-06123, B-07535,
      B-07552, B-09773, B-10017, B-11058,
      B-11549, B-14007, B-14382, B-14568,
      B-15152, B-16726, B-19847, B-20313,
      B-21232, B-23880, B-25714, B-26071,
      C-23771, 1-19325, J-17203, K-06778,
      L-05407
CONTROL METHODS A-01583, A-16699,
      A-18305, A-21204, A-22877, A-26226,
      B-00587, B-00959, B-01125, B-02051,
      B-05151, B-05401, B-06123, B-06844,
      B-07093, B-07535, B-07552, B-09981,
      B-10017, B-10159, B-11058, B-11549,
      B-12637, B-13202, B-13689, B-13893,
      B-13899, B-14382, B-14387, B-14481,
      B-14533, B-14568, B-14664, B-15152,
      B-16726, B-19847, B-20313, B-20775,
      B-21232, B-23372, B-23880, B-25714,
      B-26071, E-21642, F-01619, F-10160,
      F-13415, F-13680, F-15087, F-23882,
      G-01049, 1-19325, J-17203, L-05407
CONTROL PROGRAMS  L-05407, L-07597
COPPER  B-05151, 1-13877
COPPER COMPOUNDS  B-14007
CORN  H-22622
CORROSION  1-13877, 1-19325
COSTS  A-18305, B-01125, B-02051,
      B-04658, B-07552, B-09773, B-23880,
      J-17203
COUGH G-16613
CRITERIA B-10017, K-07197, L-07597
CROPS  H-22622
CYANATES  K-07197
CYANIDES B-04658, C-24975
CZECHOSLOVAKIA  B-04658, B-13205
                   D
DECOMPOSITION  A-26226, B-14481
DESIGN CRITERIA  B-05309, B-19847,
      B-20313
DESULFURIZATION OF FUELS  B-23880
DIFFUSION  A-22877, E-23604
DIOLEFINS  F-13415
DISPERSION  A-22877, B-01125, E-23604,
      F-23882
DISSOCIATION  E-23604
DISTILLATE OILS  F-01619
DOMESTIC HEATING  B-07535
DRUGS  G-16613
DUST FALL  A-22877, L-05407
DUSTS  A-17076, A-22877, B-07535,
      B-11058, B-19847, C-23771, J-17203,
      K-06778, K-07197, K-20121, L-05407,
      L-07597
ECONOMIC LOSSES  J-17203
ELECTRIC POWER PRODUCTION
      A-21204, A-26226, B-21232, B-23880,
      E-22407, J-17203, K-06778
ELECTRICAL MEASUREMENT DEVICES
      C-06889
ELECTROCHEMICAL METHODS  C-23560
ELECTROCONDUCTIVITY ANALYZERS
      C-06889
ELECTROSTATIC PRECIPITATORS
      A-17076, A-21204, B-00587, B-07535,
      K-06778
EMISSION STANDARDS  K-06778,
      L-07597
EMPHYSEMA G-24588
ENFORCEMENT PROCEDURES  K-06778,
      L-07597
ENGINE DESIGN MODIFICATION
      A-26226
ENGINE EXHAUSTS  B-07535, G-21307
ESTERS  B-05309, K-07197, K-20121
ETHYL ALCOHOL  C-24975
ETHYLENE  B-10017, K-07197
EUROPE  A-01583, A-16699, A-17076,
      A-18305, A-22877, B-00587, B-00959,
      B-02051, B-04658, B-05309, B-06123,
      B-07093, B-07535, B-09981, B-10159,
      B-11058, B-13202, B-13205, B-13689,
      B-13899, B-14382, B-14387, B-14481,
      B-14568, B-15152, B-19847, B-20313,
      B-23372, C-02570, C-04257, C-06889,
      C-18226, C-23560, C-24975, C-25925,
      E-23604, F-01619, F-10160, F-13680,
      F-13948, F-14303, F-15087, G-11378,
      G-16460, G-16613, G-21307, H-22622,
      J-17203, K-06778, L-07597
EXCESS AIR  A-26226, B-23880, B-26071,
      F-23882,1-19325
EXPERIMENTAL EQUIPMENT  B-10159,
      F-10160
EXPERIMENTAL METHODS  B-04658,
      B-10159, B-16726, F-10160
EXPOSURE CHAMBERS  G-01049
EYE IRRITATION G-11378
FEDERAL GOVERNMENTS  B-23880,
      L-07597
FERTILIZER MANUFACTURING
      B-25714, C-18226
FERTILIZING B-11058, G-11378
FILTERS  A-17076, B-07552, B-09773,
      B-14568, C-23771, J-17203
FIRING METHODS  A-26226, B-23880,
      B-26071, F-23882, 1-19325
FLAME AFTERBURNERS  B-10017,
      B-26071
FLARES B-10017
FLOW RATES B-00587, B-09981, B-10159,
      B-16726, C-24975, F-10160, F-23882
FLUID FLOW B-00587, B-06123,  B-09981,
      B-10159, B-16726, C-24975, F-10160,
      F-23882
FLUORIDES  A-17076, B-01125, B-07552,
      B-11058
FLUORINE  A-18305, A-22877
FLUORINE COMPOUNDS  A-17076,
      B-01125, B-07552, B-11058, C-18226
FLY ASH B-07552
FORMALDEHYDES  G-06552, H-25481,
      K-07197
FRUITS  C-18226
FUEL GASES  B-06844, B-13893, B-14387,
      B-23880
FUEL OILS  F-01619
FUELS B-06844, B-07535, B-13893,
      B-14387, B-23880, C-24725, C-25381,
      F-01619
FUMES  B-01125, B-05151, B-07552,
      B-09773, B-09981, B-10017, K-06778,
      K-20121
FUNGI H-25481
FURNACES   B-07535


                  G

GAS CHROMATOGRAPHY  A-22877
GAS SAMPLING  A-22877, C-04257,
      C-11130, C-24975
GAS TURBINES  A-21204
GASES A-01583, B-00587, B-05401,
      B-09981, B-10017, E-22407, F-10160
GASIFICATION (SYNTHESIS)  B-23880
GERMANY  A-22877, B-05309, B-06123,
      B-07093, B-07535, B-11058, B-13202,
      B-15152, B-23372, C-18226, C-25925,
      F-13948, F-14303, H-22622, J-17203
      L-07597
GOVERNMENTS  B-10017, B-23880,
      K-06778, L-07597

-------
                                                  SUBJECT INDEX
                                                                                                                       29
 GREAT BRITAIN  A-16699, B-04658,
      B-07535, B-19847, B-20313, G-16613,
      K-06778
 GUINEA PIGS  G-23738


                   H

 HALOGEN GASES  A-18305, A-22877,
      B-01125, B-10017, K-06778, K-07197
 HALOGENATED HYDROCARBONS
      C-24975, K-07197, K-20121
 HEALTH IMPAIRMENT  G-16460,
      L-05407, L-07597
 HEAT OF COMBUSTION  C-23560
 HEAT TRANSFER  B-20313, F-23882
 HEMATOLOGY  G-16613
 HEMOGLOBIN INTERACTIONS  G-16613
 HEXANES  C-24975, K-07197, K-20121
 HEXENES  F-23882
 HUMANS  G-11378, G-16460, G-21307,
      L-07597
 HUMIDITY   E-22407
 HYDRAZINES  C-25381
 HYDROCARBONS  A-22877, B-00587,
      B-02051, B-09981, B-10017, B-11058,
      B-16726, B-21232, C-24975, E-21534,
      E-21642, F-13415, F-23882, G-01049,
      K-07197, K-20121
 HYDROCHLORIC ACID   A-18305,
      A-22877, B-07552, B-10017, B-11058,
      C-02570, C-04257, E-22407, G-11378,
      H-22622, H-25481, 1-13877, 1-19325,
      K-06778, K-07197, L-07597
 HYDROCYANIC ACID H-25481, K-07197
 HYDROFLUORIC ACID   B-01125, B-07552,
      B-09773, B-11058, K-06778, K-07197
 HYDROGEN B-06123, B-06844, G-11378
 HYDROGEN SULFIDE A-22877, B-05309,
      B-06123, B-10017, B-11058, C-25925,
      K-06778, K-07197, L-07597
 HYDROXIDES  B-23880, C-24975, C-25925,
      F-10160
 HYPERVENTILATION G-16613
 HYPOXIA  G-16613
                   I
IMPINGERS  A-22877, G-01049
INCINERATION  B-10017, 1-19325
INDUSTRIAL AREAS A-18305
INDUSTRIAL EMISSION SOURCES
      A-01583, A-13698, A-16699, A-17076,
      A-18305, A-21204, A-26226, B-00587,
      B-00959, B-01125, B-02051, B-04658,
      B-05151, B-05309, B-05401, B-06123,
      B-06844, B-07093, B-07535, B-09981,
      B-10017, B-11058, B-11549, B-12637,
      B-13202, B-13205, B-13689, B-13893,
      B-13899, B-14007, B-14382, B-14387,
      B-14481, B-14533, B-14568, B-15152,
      B-16726, B-19847, B-21232, B-23372,
      B-23880, B-25714, B-26071, C-18226,
      C-23771, E-22407, F-01619, F-10160,
      F-13415, F-13481, F-14303, F-15087,
      F-23882, G-11378, G-21307, 1-19325,
      J-17203, K-06778, L-05407, L-07597
INFRARED SPECTROMETRY  A-22877,
      E-14408
INHALATION THERAPY G-16613
INORGANIC ACIDS  A-01583, A-13698,
      A-16699, A-17076, A-18305, A-21204,
      A-22877, A-26226, B-00587, B-00959,
      B-01125, B-02051, B-04658, B-05151,
      B-05309, B-05401, B-06123, B-06844,
      B-07093, B-07535, B-07552, B-09773,
      B-09981, B-10017, B-10159, B-11058,
      B-11549, B-12637, B-13202, B-13205,
      B-13689, B-13893, B-13899, B-14007,
      B-14382, B-14387, B-14481, B-14533,
      B-14568, B-14664, B-15152, B-16726,
      B-19847, B-20313, B-20775, B-21232,
      B-23372, B-23880, B-25714, B-26071,
      C-02570, C-04257, C-06889, C-11130,
      C-18226, C-23560, C-23771, C-24725,
      C-24975, C-25381, C-25925, E-14408,
      E-21534, E-21642, E-22407, E-23037,
      E-23604, E-24015, F-01619, F-10160,
      F-13415, F-13481, F-13680, F-13948,
      F-14303, F-15087, F-23882, G-01049,
      G-06552, G-11378, G-16460, G-16613,
      G-21307, G-23738, G-24588, H-22622,
      H-25481,1-13877, 1-19325, J-17203,
      K-06778, K-07197, K-20121, L-05407,
      L-07597
INSTRUMENTATION  C-06889, F-10160
INTERNAL COMBUSTION ENGINES
      B-07535
INVERSION  B-07535, L-07597
IODIMETRIC METHODS  G-01049
IODINE COMPOUNDS  C-25925, G-01049
IONIZATION E-22407
IONS  C-06889,  G-11378
IRON  B-05151, 1-13877
IRON COMPOUNDS  C-24725, C-24975,
      H-22622
IRON OXIDES  B-07552
JAPAN  B-14664, 1-19325, K-07197,
      K-20121, L-05407

                  K

KETONES  G-01049, K-07197
KILNS  B-07535
KONIMETERS  A-22877
LABORATORY ANIMALS  G-01049,
      G-23738, G-24588
LABORATORY FACILITIES  G-16460
LEAD 1-13877, K-07197
LEAD ALLOYS  1-13877
LEAD COMPOUNDS  K-06778, K-07197,
      K-20121
LEGAL ASPECTS  K-06778, L-05407,
      L-07597
LEGISLATION K-06778, L-05407
LIGHT RADIATION  B-07535, E-21642,
      E-22407, H-22622
LIQUIDS  B-07552, C-23560, E-22407
LONDON B-07535
LOS ANGELES  B-07535
LOWER ATMOSPHERE  E-14408, E-21534
      E-21642
LUNGS  G-01049, G-23738


                  M

MAGNESIUM COMPOUNDS  B-12637
MAGNETOHYDRODYNAMICS (MHD)
      A-21204
MANGANESE  K-07197
MATERIALS DETERIORATION  1-13877
      1-19325
MATHEMATICAL ANALYSES A-26226
      F-15087
MATHEMATICAL MODELING A-26226
MAXIMUM ALLOWABLE
      CONCENTRATION G-11378,
      G-21307, G-23738, G-24588, K-06778,
      K-07197, K-20121, L-07597
MEASUREMENT METHODS  A-22877,
      C-04257, C-06889, C-24725
MEETINGS  L-05407
MEMBRANE FILTERS  A-22877
MERCURY  K-07197
MERCURY COMPOUNDS  C-23771,
      C-24975
METABOLISM  G-11378, H-22622
METAL COMPOUNDS  A-18305, B-06123,
      B-11058, B-12637, B-14007, B-14382,
      B-23880, C-23771, C-24725, C-24975,
      C-25381, F-10160, H-22622, H-25481,
      K-06778, K-07197, K-20121
METAL FABRICATING AND FINISHING
      A-13698, B-05151, G-21307
METALS  B-02051, B-05151, B-05309,
      B-06844, B-09981, B-21232, F-23882,
      1-13877, K-07197
METEOROLOGY  A-22877, B-07535,
      C-25925, E-22407
METHANES  B-02051, B-09981, B-16726
MICE  G-23738
MICROMETEOROLOGY  C-25925
MICROORGANISMS  H-25481
MICROSCOPY C-18226
MIDDLE ATMOSPHERE E-23604
MINERAL PROCESSING  J-17203
MINERAL PRODUCTS  B-07552
MISSILES AND ROCKETS   C-25381
MISSOURI A-01583, B-00587, B-00959
MISTS  B-00587,  B-05401, B-07552,
      B-11058,  C-23771, K-20121
MONITORING A-22877, C-06889


                  N

NAPHTHALENES  B-11058
NATURAL GAS  B-06844, B-13893,
      B-14387, B-23880
NICKEL  B-09981
NICKEL COMPOUNDS B-14007, K-07197
NITRATES B-05401, B-10159, B-14382,
      C-23771, E-21642, G-21307, H-25481,
      K-07197, K-20121
NITRIC ACID  A-01583, A-13698, A-16699,
      A-17076, A-18305, A-21204, A-22877,
      A-26226, B-00587, B-00959, B-01125,
      B-02051, B-04658, B-05151, B-05309,
      B-05401, B-06123, B-06844, B-07093,
      B-07535, B-07552, B-09773, B-09981,
      B-10017, B-10159, B-11058, B-11549
      B-12637, B-13202, B-13205, B-13689,
      B-13893, B-13899, B-14007, B-14382
      B-14387, B-14481, B-14533, B-14568,
      B-14664, B-15152, B-16726, B-19847,
      B-20313, B-20775, B-21232, B-23372
      B-23880, B-25714, B-26071, C-0257o'
      C-04257, C-06889, C-11130, C-18226
      C-23560, C-23771, C-24725, C-24975
      C-25381, C-25925, E-14408, £-21534*
      E-21642, E-22407, E-23037, E-23604?
      E-24015, F-01619, F-10160 F-13415
      F-13481, F-13680, F-13948, F-14303'
      F-15087, F-23882, G-01049, G-06552
      G-11378, G-16460, G-16613, G-21307
      G-23738, G-24588, H-22622, H-25481*
      1-13877, 1-19325, J-17203, K-06778
      K-07197, K-20121, L-05407, L-07597
NITRIC ANHYDRIDE (N2O5)  B-07093
      C-11130

-------
 30
     NITRIC ACID PLANTS
 NITRIC OXIDE (NO)  A-16699, A-22877,
      A-26226, B-01125, B-02051, B-05151,
      B-05309, B-06123, B-06844, B-07093,
      B-07535, B-09981, B-10159, B-11058,
      B-12637, B-13202, B-13689, B-13899,
      B-14481, B-14664, B-15152, B-16726,
      B-19847, B-20313, B-20775, B-21232,
      B-23372, B-23880, C-11130, C-23560,
      E-21534, E-23037, E-23604, E-24015,
      F-01619, F-13415, F-15087, G-16613
 NITRITES  B-10159, B-13202, G-21307
 NITROGEN  B-20775, C-25381, E-23604,
      F-13415
 NITROGEN DIOXIDE (NO2)  A-01583,
      A-16699, B-01125, B-02051, B-05151,
      B-05309, B-05401, B-06844, B-07093,
      B-07552, B-09981, B-10159, B-11058,
      B-13202, B-13689, B-13899, B-14007,
      B-14481, B-14664, B-15152, B-16726,
      B-19847, B-20313, B-21232, B-23880,
      B-26071, C-11130, C-23560, C-25381,
      E-21534, E-21642, E-23037, E-23604,
      E-24015, F-01619, F-13415, F-13948,
      F-15087, G-16613, G-21307, G-24588,
      K-06778, K-07197, L-07597
 NITROGEN OXIDES  A-01583, A-13698,
      A-16699, A-21204, A-22877, A-26226,
      B-00959, B-01125, B-02051, B-05151,
      B-05309, B-05401, B-06123, B-06844,
      B-07093, B-07535, B-07552, B-09773,
      B-09981, B-10017, B-10159, B-11058,
      B-12637, B-13202, B-13205, B-13689,
      B-13893, B-13899, B-14007, B-14382,
      B-14387, B-14481, B-14533, B-14664,
      B-15152, B-16726, B-19847, B-20313,
      B-20775, B-21232, B-23372, B-23880,
      B-25714, B-26071, C-06889, C-11130,
      C-23560, C-25381, E-21534, E-21642,
      E-22407, E-23037, E-23604, E-24015,
      F-01619, F-10160, F-13415, F-13680,
      F-13948, F-15087, G-16613, G-21307,
      G-23738, G-24588, 1-19325, J-17203,
      K-06778, K-07197, L-07597
 NITROGEN TRIOXIDE (NO3)  B-07093,
      C-11130
 NITROUS ACID  B-13205, C-11130,
      C-18226, C-23560, E-21534, E-24015,
      F-13481, G-21307, H-22622
 NITROUS ANHYDRIDE (N2O3) B-07093,
      B-10159, C-11130, F-13415
 NITROUS OXIDE (N20)   A-16699, B-12637,
      C-11130, E-24015
 NON-INDUSTRIAL EMISSION  SOURCES
      A-21204, B-04658, B-07535, B-11058,
      C-25381, G-11378
 NOSTRILS G-11378
 NUCLEAR POWER PLANTS  B-21232,
      E-22407
 NUCLEATION  E-22407
                   o
OCCUPATIONAL HEALTH G-11378,
     G-21307, G-24588, K-20121
ODOR COUNTERACTION  B-07535
ODORS   B-04658, B-10017, G-11378,
     1-19325
OLEFINS B-10017, E-21534, F-13415,
     F-23882, G-01049, K-07197
OPERATING VARIABLES  A-26226,
     B-05401, B-09981, 1-19325
ORGANIC ACIDS  B-05309, G-01049,
     H-25481, 1-19325, K-07197
ORGANIC NITROGEN COMPOUNDS
     B-01125, B-05151, B-25714, G-01049,
     K-07197, K-20121
ORGANIC SULFUR COMPOUNDS
      C-24975
OXIDANTS  A-01583, B-05151, B-10017,
      E-21534, E-21642
OXIDATION  A-01583, B-00959, B-13689,
      B-14664, B-19847, B-25714, C-23560,
      E-22407, F-01619, F-13415, F-15087
OXIDES A-01583, A-13698, A-16699,
      A-17076, A-18305, A-21204, A-22877,
      A-26226, B-00959, B-01125, B-02051,
      B-05151, B-05309, B-05401, B-06123,
      B-06844, B-07093, B-07535, B-07552,
      B-09773, B-09981, B-10017, B-10159,
      B-11058, B-12637, B-13202, B-13205,
      B-13689, B-13893, B-13899, B-14007,
      B-14382, B-14387, B-14481, B-14533,
      B-14664, B-15152, B-16726, B-19847,
      B-20313, B-20775, B-21232, B-23372,
      B-23880, B-25714, B-26071, C-06889,
      C-11130, C-23560, C-25381, E-21534,
      E-21642, E-22407, E-23037, E-23604,
      E-24015, F-01619, F-10160, F-13415,
      F-13680, F-13948, F-15087, G-16613,
      G-21307, G-23738, G-24588, 1-19325,
      J-17203, K-06778, K-07197, K-20121,
      L-05407, L-07597
OXYGEN A-01583, B-09981, B-20775,
      E-21642, F-13948
OXYGEN CONSUMPTION  G-01049
OXYGEN LANCING B-07535
OZONE  B-10017, C-25925, E-14408,
      E-21642, E-22407, E-24015, K-07197
PACKED TOWERS  B-04658, B-10017,
      B-20313
PAPER MANUFACTURING  F-13481
PARTICLE COUNTERS  A-22877
PARTICLE GROWTH  E-22407
PARTICLE SIZE  B-00587, B-07552,
      C-23771, C-24725, K-07197
PARTICULATE CLASSIFIERS  B-00587,
      B-07552, C-23771, C-24725, K-07197
PARTICULATE SAMPLING  A-22877,
      C-23771
PARTICULATES  A-17076, A-21204,
      A-22877, B-00587, B-01125, B-05151,
      B-05401, B-07535, B-07552, B-09773,
      B-09981, B-10017, B-11058, B-14568,
      B-19847, C-23771, E-22407, F-01619,
      G-01049, G-06552, H-22622, J-17203,
      K-06778, K-07197, K-20121, L-05407,
      L-07597
PENELEC (CONTACT PROCESS)  A-18305
PEROXIDES  A-01583
PEROXYACETYL NITRATE  E-21642
PEROXYACYL NITRATES  E-21642
PERSONNEL  C-25925, L-07597
PESTICIDES  C-24975
PH  B-10159
PHENOLS  K-07197
PHENYL COMPOUNDS  K-20121
PHENYLS  K-20121
PHOSPHATES  A-17076, B-25714, C-23771
PHOSPHORIC ACID  A-18305, B-00587,
      B-07552, B-11058, C-23771, C-25381,
      F-14303,  K-07197
PHOSPHORUS COMPOUNDS  A-17076,
      B-06123, B-11058, B-25714, C-23771,
      K-07197
PHOTOCHEMICAL REACTIONS  A-13698,
      E-21534, E-21642, E-23037, E-23604,
      E-24015,  H-22622
PHOTOIONIZATION   E-22407
PHOTOLYSIS  E-24015
PHOTOMETRIC METHODS C-04257
PHOTOOXIDATION  H-22622
PHOTOSYNTHESIS  H-22622
PHTHALICACID  B-05309
PHYSICAL STATES  A-01583, B-00587,
      B-05401, B-07552, B-09981, B-10017,
      B-14533, B-14568, C-23560, E-14408,
      E-22407, F-10160, G-23738, G-24588
PLANNING AND ZONING L-05407
PLANS AND PROGRAMS  L-05407,
      L-07597
PLANT DAMAGE  C-18226, H-22622,
      H-25481, L-07597
PLANT GROWTH  H-22622, H-25481
PLANTS (BOTANY)  C-18226, H-22622,
      L-07597
PLATINUM  B-06844, B-09981, B-21232,
      F-23882
PLUME BEHAVIOR  A-22877
PNEUMONIA G-24588
POLYNUCLEAR COMPOUNDS  B-11058
PORTABLE  C-23771
POWER CYCLES  K-06778
POWER SOURCES  A-21204, B-07535
PRESSURE  B-00587, B-11058
PRIMARY METALLURGICAL
      PROCESSING  K-06778
PROCESS MODIFICATION  A-26226,
      B-05151, B-10017, B-11058, B-12637,
      B-23880, B-26071, F-13415, F-23882,
      1-19325
PROTEINS  G-01049
PULMONARY EDEMA G-16613
PYROLYSIS  B-05309
                                                             R
RATS  G-01049, G-23738, G-24588
REACTION KINETICS  A-26226, B-04658,
     B-10159, B-20775, E-21534, E-21642,
     E-24015, F-10160, F-13680, F-23882
REACTION MECHANISMS  A-26226,
     B-25714, C-23560, E-23604, E-24015,
     F-13948, F-23882, H-22622
RECOMBINATION  E-22407
REDUCTION  A-01583, A-26226, B-01125,
     B-02051, B-06123, B-06844, B-09981,
     B-12637, B-13205, B-14007, B-14387,
     B-14481, B-15152, B-23372, B-23880
REGULATIONS  K-06778, L-07597
RESEARCH  METHODOLOGIES C-25925
RESEARCH  PROGRAMS  B-23880
RESPIRATORY DISEASES G-16613,
     G-24588, L-05407
RESPIRATORY FUNCTIONS   G-01049,
     G-16613
RESPIRATORY SYSTEM  G-01049,
     G-11378, G-21307, G-23738, L-05407
SALTZMAN METHOD  A-16699, A-22877,
      C-11130
SAMPLERS  A-22877, C-11130, C-23771,
      G-01049
SAMPLING METHODS   A-22877, C-04257,
      C-11130, C-23771,  C-24975, G-01049
SCRUBBERS  A-01583,  A-16699, A-17076,
      A-26226, B-00587, B-01125, B-0<«658,
      B-05151, B-06123,  B-07535, B-09773,
      B-10017, B-11058,  B-14007, B-14382,
      B-14568, B-15152,  B-16726, B-20313,
      B-23880, B-25714
SELENIUM COMPOUNDS  K-07197,
      K-20121
SETTLING PARTICLES  A-17076, A-22877,
      B-07535, B-11058,  B-19847, C-23771,

-------
                                                 SUBJECT INDEX
                                                                           31
     J-17203, K-06778, K-07197, K-20121,
     L-05407, L-07597
SILICON COMPOUNDS  B-07552, B-23880
SILICON DIOXIDE  B-19847, K-07197
SINTERING  K-06778
SMOG  B-07535, G-06552
SMOKE SHADE  A-22877
SMOKES  A-22877, B-07535, H-22622,
     J-17203
SODIUM CARBONATE  B-14382
SODIUM COMPOUNDS  A-18305, B-06123,
     B-14382, C-24975
SODIUM HYDROXIDE  A-18305, B-06123,
     C-24975
SOLAR RADIATION  B-07535, E-21642,
     E-22407
SOLVENTS  B-05309, B-21232
SOOT  L-05407
SOOT FALL  L-05407
SOURCE SAMPLING A-22877
SO2 REMOVAL (COMBUSTION
     PRODUCTS)  A-18305, A-21204,
     A-22877, B-07535, B-11058, B-23880,
     J-17203
SPECTROMETfcY  A-22877, E-14408
SPECTROPHOTOMETRY  A-22877,
     C-02570, C-04257, C-11130, C-24975,
     C-25925, G-01049, G-11378
SPINACH H-22622
SPORES  H-25481
SPRAY TOWERS  B-06123, B-10017,
     B-14568
ST LOUIS  A-01583, B-00587, B-00959
STABILITY (ATMOSPHERIC)  B-07535,
     L-07597
STACK GASES  A-21204, A-22877,
     A-26226, B-01125, B-12637, B-13689,
     B-13893, B-14568, B-14664, B-19847,
     B-21232, B-23372, B-23880, B-25714,
     B-26071, C-18226, F-15087, 1-19325,
     K-06778
STACK SAMPLING  A-22877
STACKS  A-22877, B-07093, B-10017,
     C-18226, K-06778, L-07597
STANDARDS  B-10017, G-11378, G-21307,
     G-23738, G-24588, K-06778, K-07197,
     K-20121, L-07597
STEAM   B-14533
STEAM PLANTS  A-26226, K-06778
STEEL  B-05151, 1-13877
STYRENES  K-20121
SULFATES  B-01125, C-24975, C-25925,
     H-25481
SULFIDES  A-22877, B-05309, B-06123,
     B-10017, B-11058, B-23880, C-25925,
     K-06778, K-07197, L-07597
SULFITES  C-25925
SULFUR COMPOUNDS  A-22877, B-01125,
     B-05309, B-06123, B-10017, B-11058,
     B-23880, C-24725, C-24975, C-25925,
     H-25481, K-06778, K-07197, L-07597
SULFUR DIOXIDE  A-17076, A-22877,
     B-01125, B-07535, B-07552, B-10017,
     B-11058, E-21642, E-22407, K-06778,
     K-07197, L-05407, L-07597
SULFUR OXIDES  A-17076, A-18305,
     A-21204, A-22877, B-01125, B-07535,
     B-07552, B-10017, B-11058, B-14533,
     E-21642, E-22407, 1-19325, K-06778,
     K-07197, L-05407, L-07597
SULFUR OXIDES CONTROL  A-18305,
     A-21204, A-22877, B-07535, B-11058,
     B-23880, J-17203
SULFUR TRIOXIDE  A-22877, B-01125,
     B-07535, B-07552, B-11058, K-06778
SULFURIC ACID A-17076, A-18305,
     A-21204, B-00587, B-01125, B-07535,
     B-07552, B-11058, B-14533, B-14568,
     B-23880, C-06889, C-18226, C-23771,
     C-25925, E-22407, F-01619, F-13481,
     G-11378, H-25481, 1-13877, J-17203,
     K-06778, K-07197, L-05407
SURFACE COATING OPERATIONS
     B-05309
SURFACE PROPERTIES G-06552
SUSPENDED PARTICULATES  A-22877,
     B-00587, B-01125, B-05151, B-05401,
     B-07535, B-07552, B-09773, B-09981,
     B-10017, B-11058, C-23771, G-06552,
     H-22622, J-17203, K-06778, K-20121
SWEDEN  A-01583, A-18305,  B-00587,
     B-00959, B-02051, B-04658, F-01619
SYNERGISM  G-06552, G-11378
TECHNICAL SOCIETIES  K-07197,
     L-05407
TEMPERATURE  A-01583, A-26226,
     B-00959, B-05309, B-07552, B-09981,
     B-11058, B-19847, B-20775, 1-19325
TEMPERATURE GRADIENT L-07597
TESTING FACILITIES  G-01049, G-16460
TETRAETHYL LEAD  K-07197
TEXTILE MANUFACTURING  B-11058
TEXTILES  B-07552
THERMODYNAMICS  E-23037, E-24015
THRESHOLDS G-11378, G-21307
TIN  1-13877
TISSUES  G-01049
TOBACCO  H-22622
TOLUENES  C-24975, F-23882, K-07197,
     K-20121
TOXIC TOLERANCES  F-01619, H-25481
TOXICITY  G-16613, G-21307, G-23738
TRANSPORT  E-23604, F-23882
TRANSPORTATION  A-21204, B-07535
TREATMENT AND AIDS  G-16613,
     G-23738
TURBULENCE (ATMOSPHERIC)
     A-22877, C-25925


                  u

UNITED STATES  B-05401
UPPER ATMOSPHERE  E-23604
URBAN AREAS  A-18305, E-23037
USSR  A-17076, B-09981, B-10159, B-13689,
     B-13899, B-14382, B-14387, B-14568,
     B-19847, C-02570, C-04257, C-06889,
     C-23560, F-10160, F-13680, G-11378,
     G-16460
VANADIUM COMPOUNDS  B-23880
VAPOR RECOVERY SYSTEMS  B-10017
VAPORS  B-14533, B-14568, E-14408,
     G-23738, G-24588
VEGETABLES  H-22622
VEHICLES  B-07535
VENTILATION (PULMONARY)  G-16613
VENTURI SCRUBBERS  B-01125, B-10017
VOLATILITY  C-25381


                 w

WATER  B-07552, C-23560, E-22407
WATER POLLUTION  A-21204, B-04658
WEST AND GAEKE METHOD  A-22877
WET CYCLONES  B-09773
WINDS  A-22877
WOOLS  B-07552
                  X
XYLENES  K-07197

-------