low btu gasifier emissions toxicology status report june

LMF-95 UC 48

95

FEBRUARY 1982

LOW BTU GASIFIER EMISSIONS TOXICOLOGY STATUS REPORT JUNE 1981

R, F.

HENDERSON, Ph.D.

PROGRAM

MANAGER Edited

by

J. M. BENSON, Ph.D.

INHALATION LOVELACE P.O.

Prepared for Department

TOXICOLOGY RESEARCH INSTITUTE BIOMEDICAL & ENVIRONMENTAL RESEARCH INSTITUTE Box 5890 Albuquerque, NM 87185

the Office of Energy

of Health and Environmental under Contract

Research of the U.S.

Number DE-ACO4-76EVOIOI5

NOTICE This report

was prepared as an account of work sponsored by the United

States Government. Neither

the United States

of Energy, nor any of their tractors,

or their

sumes any legal usefulness represents

employees, makes any warranty,

liability,

or responsibility

of any information, that its

tion

apparatus,

use would not infringe

The research described mal care facilities

nor the United States Department

employees, nor any of their

fully

in this

accredited

report

contractors,

expressed or implied,

for the accuracy, product privately

involved

or process

or as-

completeness or disclosed,

or

owned rights.

animals maintained

by the American Association

of Laboratory Animal Care.

Printed in the United States of America Available

subcon-

From

National Technical Information Service U. S. Department of Commerce 5285 Port Royal Road Springfield, VA 22161

in ani-

for Accredita-

LMF-95 Category:

LOWBTUGASIFIER EMISSIONSTOXICOLOGY STATUSREPORT DECEMBER I, 1980 - MAY31, 1981

Prepared by The Staff

of ITRI

R. F. Henderson, Ph.D., Program Manager Edited by J. M. Benson, Ph.D.

Lovelace Inhalation

Toxicology Research Institute

Lovelace Biomedical and Environmental Research Institute P. O. Box 5890, Albuquerque,

NM87185

March 1982

For Questions Please Contact: Rogene F. Henderson, Ph.D. Program Manager Inhalation Toxicology Research Institute P.O. Box 5890 Albuquerque, NM 87185 Telephone:

Commercial: (505) 844-8676 FTS: 844-8676

Prepared for the Office

of Health and Environmental Research of the U.S.

Department of Energy Under Contract Number DE-ACO4-76EVOlOI3

UC-48

ACKNOWLEDGEMENTS In addition thusiastic William

to the contributing

support Wallace,

Carpenter,

John Notestein,

listed

Ultrich

in Appendix II,

Edward Barr,

staff,

we acknowledge the enespecially

Grimm and Augustine Pitrolo.

of our sampling crew, which included

Robert Royer, Charles Mitchell,

Tamura, Douglas Horinek, Finally,

staff

of the Morgantown Energy Technology Center’s

Kal Pater,

tant were the efforts

scientific

John Kovach, Equally

impor-

at various times, George Newton, Robert

Janet Benson, Suzanne Weissman, E. Roger Peele, Richard

Katherine

Sass, John Stephens, Brian Wong and Kirk Yerkes.

we .note the encouragement of the ITRI Directorate,

Jones, Bruce B. Boecker and Charles H. Hobbs.

Drs. Roger O. McClellan,

Robert K.

TABLEOF CONTENTS

ACKNOWLEDGEMENTS ............................................................................

Page i

LIST OF TABLES..............................................................................

iii

LIST OF FIGURES.............................................................................

iii

EXECUTIVESUMMARY ...........................................................................

1

INTRODUCTION .................................................................................

3

General ................................................................................. Goals and Approach ...................................................................... SAMPLING ANDPHYSICALCHARACTERIZATION ..... The METCLow Btu Coal Gasifier Samp]e Collection

3 4

.................................................

......................................

4 . ...................

4

.......................................................................

4

Sampling Systems ........................................................................

6

Physical Characterization

................................................................

I0

RESULTSANDDISCUSSIONOF CHEMICAL CHARACTERIZATION .........................................

12

General ................................................................................. Organic Analyses of Process Gas Samples .................................................

12

Organic Analyses of Cleanup Device (Potentia]

15

Waste Effluent)

Samples ...................

Elemental Analyses of Process Stream and Cleanup Device Samples ......................... RESULTSANDDISCUSSIONOF BIOLOGICALCHARACTERIZATION ....................................... Screening Tests ......................................................................... Results of Mutagenicity

Testing .........................................................

Summaryof Chemical/Biological

Characterization

.........................................

In vivo Testing ......................................................................... APPEN DI CES

14 15 19 19 19 22 23 24

I.

Publications

and Presentations

II.

Contributing

Professional

Staff

..........................................................

24

.........................................................

27

ii

LIST OF TABLES Table 1.

Page

Analytical System Samples Used on Gaseous Effluent Streams from METCLow Btu Coal Gasifier ................................................................................

7

Summaryof Aerosol Characteristics of METCLow Btu Gas Process Stream During September 1980 Tests ....................................................................

II

3.

Process Stream and Potential

13

4.

Relative Amounts of Vapor Phase and Particulate Material in the Cooled and Diluted Process Stream ..................................................................

2.

Waste Effluent

Samples for Chemical Analysis ...............

5.

Percent of Material

Contained in Fractions

6.

Percent of Material

in LH-20 Fractions

7.

Concentration of Selected Metals in Coal, Cyclone Ash and Process Stream Materials, December ]979 ................................................................

17

8.

Concentration of Selected Metals in Coal and Low Btu Gasifier Samples, December 1979 ..................................................................

18

9.

Size Distribution

I0. Mutagenic Activity II.

Mutagenic Activity

of Gasifier

15

Process Stream Material

..........

of Tar-Trap Tar and Venturi Scrubber Water .......

of Selected Metals in Low Btu Gasifier

Potential

Effluent

Raw Gas, December 1979 .........

of Process Stream Samples and Their Sephadex LH-20 Fractions of Process Stream LH-20 Fractions

5 and Their Subfractions

......... ...........

12. Mutagenic Activity of Tar Trap Tar and Venturi Scrubber Water and Their LH-20 Fraction ..........................................................................

16 17

18 2O 21 22

LIST OF FIGURES Page I. Schematic diagram of METCcoal gasifier 2. 3. 4.

.................................................

Schematic diagram of the METClow Btu coal gasifier and cleanup system during September 1980 tests ....................................................................

5

Schematic diagram of extractive aerosol sampling system used on METClow Btu coal gasifier ...........................................................................

6

Schematic diagram of the condenser train sampling system used to obtain gram quantities of condensed hydrocarbons from gaseous process streams of the METC low Btu coal gasifier ...................................................................

8

Schematic diagram of the multi-cyclone train sampling system used to obtain gram quantities of size classified aerosols from gaseous process streams of the METC low Btu coal gasifier ...................................................................

9

6. Schematic of the combustion chamber with sampling systems ............................... 7.

5

Schematic diagram of high-temperature, high-pressure cascade impactor sampling system used on the METClow Btu coal gasifier as position B (1980) ......................

8. Elution

profiles

of compounds from Sephadex LH-20 columns ...............................

iii

9 I0 14

LOWBTU GASIFIER EMISSIONSTOXICOLOGY PROGRAM STATUSREPORT - DECEMBER 1981 EXECUTIVE SUMMARY Natural one-third fication called

gas is one of the United States’

of the total

is scheduled for "producer

fossil

a significant

for

electrical

role in our future power generation.

range from economic viability

of various

Since June 1977, a cooperative Lovelace Inhalation

Uncertainties

Toxicology

The major goal of this

goal,

it

population

determine liquid

Research Institute

that

research effort

(ITRI)

aerosol

streams.

concentrates

results

and the Morgantown Energy Technology associated

with low Btu coal gasificahazards to plant

toxicants

in liquid

low Btu gasifier

and solid

process and

obtained from December I,

of the June 1981 sampling trip.

data to date and draw tentative

conclusions

1980 to June I,

The following which will

duces a dense, respirable

toxicants

in

were in September 1980 and 1981 and

summary is intended

be subjected

to further

ing in future sampling and analysis efforts. ¯ Diluting and/or cooling low Btu producer gas, as would happen in fugitive ¯

workers and

To achieve this

at METC has been sampled to

The most recent sampling efforts on results

en-

between the

components in gaseous process streams and to assess potential effluent

June 1981. This report does not include

effort

with low Btu coal gasification.

the potential

impact.

making potential

research

is to assess inhalation

may be associated

To these ends, the experimental

and solid

organize all

about

coal gasifica-

of environmental

characterized,

comprehensive multidisciplinary

is necessary to characterize

waste streams.

for

Low Btu gas, commonly

surrounding

processes to questions

Center (METC) has been addressing basic human health risks the general

accounting

however, and coal gasi-

energy options.

Process streams in gasification processes are only partially vironmental problems difficult to estimate.

tion.

fuels,

gas," is derived from coal and could supply some of our energy needs, especially

peak load requirements tion

most important

energy produced. Natural gas reserves are limited,

releases,

to

testpro-

aerosol.

Use of a high-temperature, high-pressure cascade impactor at stream conditions (400°C and 8.7 atm) indicated the particles in the actual process stream are larger in size 3 (~ 3.0 um MMADvs. ~ 0.7 um MMAD) and smaller in amount (0.I vs. 10-15 due to more organics representative

in the vapor phase) than in the cooled and diluted

of fugitive

aerosols

which are

emissions.

Some trace elements are in higher concentrations ,

gas streams at METC. Gasifier operating conditions

°

gas aerosols. Gasifier bottom and cyclone ash are similar

have little

effect

in aerosols from clean gas than from raw on the elemental

to coal combustion fly

composition of cleaned ash in elemental com-

position. °

Ba and Ge are enriched coal gas aerosols;

in large

Sn, V, Cr,

(> 5 L~m) aerosol

particles

Mn, Fe and Pb are enriched

of the cooled and diluted in small

aerosol

particles

(~ 5 .m). ¯

Chromium, nickel, 104 over values

manganese and cobalt in coal,

indicating

in raw gas were enriched

possible

corrosion

by factors

of stainless

steel

of 102 and in the gas

producer. ¯

Corrosive centrations

metals are present in raw gas in relatively of lithium

and uranium are noticeably

high concentrations,

enriched over concentrations

but only conin coal.

Lead is removed from the process gas stream by the humidifie~ tar trap and Venturi ber and may contribute to the health hazard associated with handling gasifier tars. Under stream conditions, stainless

steels,

50-90% of alkali

cadmium and lead

metals,

metals

are associated

with

representing particles

scrub-

components of with

diameters

4.2 ~m. Gas combustion products contain low concentrations

of aliphatic

and aromatic hydrocarbons

which may be produced from CH4 during combustion. Mass loading of process stream organics is reduced by the METCcleanup system 1000-fold. The METCgas cleanup system preferentially removes high molecular weight organic compounds. Relative

amounts of polar compounds in the process stream increase as gas is cleaned.

Biologically

active

streams are primarily cyclic

organic

compounds present

in fractions

containing

in the gasifier aromatic,

effluent

substituted

and process

aromatic,

hetero-

and phenolic compounds.

Producer gas aerosol vapor-phase material Producer gas particulate~phase

material

is rarely

mutagenic in the Amestest.

is mutagenic

in the Ames test

with metabolic

activation. Waste tars and water are also mutagenic in the Ames test with metabolic activation. Cleanup devices are effective

in removing mutagenic and cytotoxic

organic

compounds from

the process stream. Mutagenic and cytotoxic

tars

and oils

removed from the stream appear as waste material

which should be disposed of or reused as fuel with appropriate

precautions.

INTRODUCTION With the need to derive more of the nation’s leum, there

has been increased

which produce liquid tial

health

objective

emphasis on further

and gaseous fuels

impacts from inhalation

effluents

(ITRI)

toxicology

is to obtain

to man from this

technology.

stirred-bed,

pressurized,

low Btu gasifier

effluent

various

of cleanup devices.

combinations

mining the effect formation

This report

previous

reports

during a field

logical

Re-

of airborne

effort

with the

The experimental,

at METCis designed to produce clean gas for Since June 1977, we have sampled pro-

The information

of the gasifier

with

gained has also proved useful in deterstreams

at ITRI designed to acquire

assessments for low Btu coal gasification reports,

in-

during the period

one should refer

to the

LF-58; 1977-1978, LF-60; 1978-1979, LF-69; 1979-1980, LMF-84) and

on the low Btu gasifier

During the six-month period covered by this tained

West Virginia.

1980 through May 31, 1981. For more in-depth

status

toxicity

through a cooperative

is a summary of research activities

ITRI Annual Reports (1976-1977,

The primary Toxicology

or cleanup devices on the composition of the effluent

for use in human health risk

from December I,

inhalation

waste and combustion products during operation

of various control

of the gasifier.

on the possible

to generate electricity.

cess stream material,

on the poten-

to allow a more accurate assessment of the health risk

Center (METC) in Morgantown,

turbine

technologies

exists

emissions from these technologies.

The program has been possible

Lurgi-type

use with a combined-cycle

than petro-

development of coal conversion

program at the Lovelace Inhalation

information

associated with coal gasification

Morgantown Energy Technology

from coal rather

from coal. However, scant information of airborne

of the coal gasification

search Institute

energy requirements

sampling effort

research

report,

efforts

(LF-75,

major activities

LMF-77 and LMF-85).

were analyses of samples ob-

at METCin September 1980 for

physical,

chemical and bio-

properties.

General Low Btu coal gasification options.

This is partly

leads to diversion fuel

is scheduled for

due to decreasing

of petroleum and natural

uses. This would leave electrical interest

and turbine

for

use in combined-cycle

exhaust would pass through

could also be used as a raw material

role in this

petroleum

without

generation

sufficient

some of this

electrical

nation’s

and natural

gas from electrical

utilities

Low Btu gas produced from coal could provide ticular

a significant

world-wide

a low temperature

stream generating

technologies

system to have an upper size limit ization fiers

of fine

particle

fractions

since these particles

for assessment of the efficiency

available

are a potential

health

hazard,

is of par-

cycle.

a turbine Low Btu gas

making assessment of characterization of

we have designed our sampling

interests

In addition,

(I)

character-

those designing coal gasi-

when low Btu gas is used to fire

have two major restrictions:

process and

are needed to pinpoint areas Because respirable aerosols

of about I0 ~,m aerodynamic diameter. in process streams greatly

cause blade erosion

gasifiers

It

of the gasification

high Btu gasification plants, fine particles may also cause methanation increase gas distribution system maintenance costs. Currently

fluid

in syngas poroduction.

of cleanup devices. Accurate sampling methods and characterization where process and control technology modification may be desirable. from coal conversion

which

capabilities.

where gas would fire

Process streams in coal gasifiers have been only partially characterized, the environmental impact of this technology difficult to define. Accurate process streams is also required

energy

to other vital

peak period

peak load requirement.

generation

future

gas reserves

catalyst

turbines.

For

poisoning

and

they are restricted

caking coals and hence are unable to use large eastern USA coal reserves;

to non-

and (2) they are limited

to low operating

pressures which result

in limited

throughput.

at METCis under way to overcome these restrictions.

A research and development program

Program goals at METCinclude

gas cleanup systems to enable use of combined-cycle low Btu gas-fired

development of

turbines.

Goals and Approach The major goal of this the general population the project effluent

research effort

that may be associated

is designed

to determine

waste and combustion

determination

of (I)

physical

streams.

toxicants

including

exposure of laboratory battery

of tests

cytotoxicity characterized conjunction

inhalation

to plant

toxicity

Asssessment of potential

materials,

risks

early

animals to representative

inhalation

tests,

For this

and (b)

and the most biologically

by more in-depth

toxicological

with the chemical characterization

studies

deposition

toxicological

in vivo.

active active

inhalation

evaluation,

a

are screened for

samples are further

The biological

so that biologically

of potential

after

is used in which large numbers of samples from the METCgasifier in vitro

end,

hazards requires

inhalation,

responses to inhalation

screening

materials.

To this

of gaseous process,

that influence

and (2) biological

responses in (a)

and mutagenicity

workers and

with producing low Btu gas from coal.

the potential

and chemical characteristics

and subsequent fate of airborne airborne

is to assess human health

testing

is used in

samples undergo further

chemical fractionationto facilititatethe identificationof the active components.As the active component types become known, model compounds represenatitveof the class of substances in the biologicallyactive samples are chosen for studies on the cellular and molecular mechanismsfor damage to target cells and for inhalationstudies. These animal studies allow determinationof the deposition,retentionand fate of the inhaledcompoundsand the tissuesat risk. SAMPLING ANDPHYSICALCHARACTERIZATION The METCLow Btu Coal Gasifier The METCcoal gasifier

is a pressurized

atmospheric pressure stirred-bed ducers in its

smaller

size (I.I

coal gasifier

version

exits

I) and differs

m ID) and various provisions

lower end of the pressure vessel supports the coal. through

of the McDowell-Wellman

(Fig.

which spent ash is removed. The gasifier

for stirring

which requires

heat, air,

pro-

the bed. A grate in the

The vessel bottom is sealed with lock hoppers top is a hemispherical

and also where coal is fed via a lock hopper. The gasifier

coal gasification

(Wellman-Galusha)

from commercial fixed-bed

steam and coal.

dome through

which gas

uses a Lurgi process for low Btu

Inside

the gasifier,

coal undergoes a

complex series of reactions beginning with devolatization which produces tars and oils and ending with combustion of coal char to CO. This mixture of vapors and gases with entrained ash particles exits

the gasifier

operating

conditions,

and passes through but generally

cleanup

consists

systems.

Gas composition

varies

with fuel

of 15 to 20 percent CO, 5 to 15 percent

and

C02, 55 to

60 percent N2, I0 to 15 percent H2, < 5 percent CH4 and < 1 percent each of C2H6 and H2S. Heat content of the gas is 3.7 to 7.4 x 106 J/m3 at STP (100-200 Btu/SCF) and historically, it has been called producer gas. Sample Collection The gas cleanup system at METCis experimental different

conditions

for

and consequently

most of the low Btu gasifier

gas cleanup is to remove fly

ash, oils,

is evolving.

sampling efforts

tars and entrained

metallic

to date.

This results

in

The purpose of

compounds to produce a low Btu

Figure I. Schematic diagram of METCcoal gasifier. gas suitable for methanation or for use in combined cycles with turbines. representation

of the gasifier

cleanup system as it

Figure 2 is a schematic

existed in September 1980. The main portion

of the cleanup system was the same as in a previous sampling effort.

The total

gasifier

output

flow went through the main stream cleanup system which consisted of a cyclone, humidifier,

tar

Trap DUST Ga~

T!R

ASH Flare

TAR & WATER

TAR -

" _1 ..-----.

[

~ ~

JPrecipitator

I (i) (’. (~) ! , n (- i~-)1 ---- I nI u(l il)Stretford n ~-~: ~uoolers ~’1 --Scrubbers

Temp. Reduction

I

II

To Exhaust Figure 2. Schematic diagram of the METClow Btu coal gasifier 1980 tests.

and cleanup system during September

trap,

Venturi

flare.

All

scrubber and several

pressure-reducing

valves,

followed

gas cleanup procedures tend to reduce temperature

densation of vapors to a liquid

state.

Resultant

by a muffler

and a final

and pressure which results

tars and oils

in con-

are removed by disengagement cham-

bers and scrubbers. Major changes from the earlier involved

redesign

and several

of the primary

additional

devices were: (I) furizer,

(4)

versions cyclone,

cleanup devices

an electrostatic

alkali

scrubber,

consisted

humidification (2)

indirect

new cleanup stages served to remove tars,

direct

cooler,

and entrained

(3)

full

scrubber

flow cleanup

Holmes-Stretford

by the muffler particles

system which

trap and Venturi

These additional

cooler followed

oils

flow cleanup

chamber, tar

not used previously.

precipitator,

and (5)

of a new full

flare.

All

of these

from the process streams.

Sampling positions used by ITRI were labeled A, B, C, D, etc. All downstream of the Venturi scrubber could be bypassed and during

stages of the cleanup system the September 1980 sampling

periods,

units were bypassed.

Sam lin

both the electrostatic

and the Holmes-Stretford

S stems

Five different which collected niques,

precipitator

sampling systems were developed and used. The first,

cooled and diluted

is shown schematically

formation

of an aerosol

The resulting

in Figure 3. Extractive

consisting

an analytical

samples of producer gas aerosol using extractive principally

sampling,

of tars and oils

aerosol was sampled from a chamber by filters,

diluting

and cooling

with small inclusions

cascade impactors,

system,

sampling techresults of fly

electrostatic

in ash. pre-

ANALYTICAL SYSTEM

SAMPLE COOLED AND DILUTED AEROSOL SAMPLE

SAMPLERS

[~ CHAMBER EXHAUST

Figure 3. gasifier.

¯

AEROSOL SIZE

¯

AEROSOLCONCENTRATION

-

¯

ELECTRON

-

¯

VAPORSAMPLES

-

IMPACTORS

MICROSCOPY

Schematic diagram of extractive

aerosol

FILTERS ESP

TENAX sampling

system used on METClow Btu coal

cipitators

and a hydrocarbons

vapor adsorbent

trap.

These instruments

and the purpose of each

sample type are listed in Table I. Samplers were chosen to determine aerodynamic and real size distributions in the less than I0 ~m range to obtain samples for chemical and biological characterization.

The size-distribution

from cascade impactor selected

parameters

substrate

samples from an earlier

and filter

and concentrations weights.

sampling effort

of the aerosol

Inorganic

composition

were determined

was determined

by spark source and atomic adsorption

scopy. Organic composition was determined by gas chromatography and mass spectrometry of the organic positions

fraction

of the samples. The analytical

B, D, E and G (Fig.

To obtain

larger

dry-ice

sample amounts, a condenser train

(~ 20°C),

Samples were obtained

The third

consisting

of four

the Venturi

sampling system employed used a five-cyclone

producer gas. Samples were obtained

(MCT) was dimensionally

and dynamically

condenser traps

scrubber series

from Positions

similar

(Position

sampling train

B), after

E). The condenser and also sampled

B, D and E. This multicyclone

System Samplers Used on Gaseous Effluent

Streams

from METCLow Btu Coal Gasifier

Sampling Device Lovelace Multi-Jet

Cascade

Flow Rate

Total Sample

(I/min~

Size

Comments

21

400 mg

Eight aerodynamicsize fractions0.6 to 12 um

25

~ 1 g

On glass fiber filters to help determine mass loading and provide unsized samples for inorganic analysis

0.5

> 1 ng

Samples for transmission electron microscopy for geometric size analysis and samples for scanning electron microscopy for morphological and elemental analysis

12.0

~ lO mg

Samplesfor determination of vapor-phaseand particle-associated polycyclicaromatichydrocarbons above C 6

Impactor (LMJ) Filter

(47, 90 mm)

Point-to-plane Electrostatic Precipitator

Tenax Samplerwith Prefilter

Concentric Electrostatic Precipitator

100-125

train

to one developed by the Southern Research Insti-

TABLE1 Analytical

was

O°C) and Numbers 3 and

from downstream of the cyclone (Position

the tar trap (Position D) and directly after train is shown schematically in Figure 4. undiluted

samples from

baths with condenser Number 1 at ambient

Number 2 in an ice water bath (approximately

acetone (-77°C).

of extracts

2) in September 1980.

used. Condensers were placed in temperature-controlled temperature

system was used to obtain

on

spectro-

Device is used as a sample static chamber exhaust cleanup. Samples are used for major elemental analysis and particulate hydrocarbon analysis

CONDENSER TRAIN

SAMPLING SYSTEM

FROM SA_~M PLIN~ PORT

~

’ ,~

BATHS:

ICE

WATER

(OPTIONAL)

ICE

-I~

WATER

DRY ICE/

DRY ICE/

ACETONE

ACETONE

TO

Figure 4. Schematicdiagram of the condenser train samplingsystem used to obtain gram quantities of condensedhydrocarbonsfrom gaseousprocessstreamsof the METC low 8tu coal gasifier. tute (SRI). The MCT is schematicallyshown in Figure 5. This sampling device was used to obtain size-fractionatedsamples of producer gas aerosol in large enough Quantitiesto enable chemical and biologicalcharacterization of the aerosolas a functionof aerodynamicsize. The fourth sampling system was designed to obtain samples of aerosol after combustionof low Btu producergas. A 6-inch cylindricalcombustionchamber with a samplingsystem was constructed (Fig. 6). Clean gas extracted from position L, close to the after-burnerof the gasifier, was introducedinto the bottom of the combustionchamber.A pressure regulatorwas used to reduce the gas pressureto 35 psig. An optional absolutefilter was placed in the gas line to remove particles. Gas was burned with or without premixed air. Emissions from two different flames were studied: (1) the premixed flame where 35 and 70 standard cubic foot per hour (SCFH) of gas clean air, respectively,were mixed before combustion,and (2) the diffusion flame where only SCFH of gas were introduced. Combustion products were diluted and carried aloft with an additional 800 SCFH of clean air. An 0.5 in. ID samplingprobe was placed 2 feet above the burner to sample at 22 L/min. A Kr-85 deionizer was used to bring the particles into the Boltzmann charge equilibrium.Three systems were used simultaneouslyto collectparticles and organic vapors: (1) a quartz crystal microbalance(QCM) cascade impactor,(CaliforniaMeasurements,Carmel, CA); an electricalaerosolanalyzer(EAA) or a point-to-plane electrostaticprecipitator(ESP); and Tenax-GC~ or XAD-2 columns. Filters were also placed before both Tenax*GC~ and XAD-2 columns to collectbulk samplesof particles. The three aerosol instrumentshave the following detection ranges: (I) 0.0032 to l.O ~m for the EAA, (2) 0.064 to 36 m for the QCM cascade impactor, and (3) 0.01 to 30 ~m for the Aerosolsamplingflow rates were 0.25, 0.3 and 4 L/min for the QCM cascade impactor,ESP and EAA, respectively.To avoid overloading the EAA and ESP, a two-stage dilutor followed by additional diluting air at 1L/min flow rate was used. Each state of the dilutor had a glass fiber filter with a capillary tube protrudingthroughthe center of the filter to reduce the particleconcentration without introducing a large volume of diluting air. Tenax-GC~ and XAD-2 samples of organicvapors under the same combustionconditionswere collectedto comparethe collectioneffi-

MULTI-CYCLONE

TRAIN

SAMPLING SYSTEM TO EXHAUST LINE

CYCLONE

V~

I AEROSOL INLET

I

-

l

:YCLONE IV 0.65 #m

CYCLONE I 5.4/urn

CYCLONE lU 1.4 ~m

CYCLONE’~ l 2.1

#m

Figure5. Schematicdiagramof the multi-cyclonetrain samplingsystem used to obtain gram quantitiesof size classifiedaerosolsfrom gaseousprocessstreamsof the METC low Btu coal gasifier.

Figure6. Schematic of the combustion chamberwithsamplingsystems.

ciency

and composition

of combustion products

in the presence of nitrogen

oxides.

These vapor

phase adsorbent traps were operated at 20 L/min for 2 hours. The fifth

sampling system was designed to obtain

and was used at Position lace Multi-Jet tions.

the cyclone).

particulate

A modified

Cascade Impactor (LMJ) was designed, built,

From this

calibration

and the molecular high-pressure

B (after

tested

and using known gas composition

mean free

(HTHP) (430°C,

path,

the cascade

110-220 psig)

samples under stream conditions

stainless

version

and calibrated

to calculate

impactor

size selective

steel

of the Love-

at ambient condi-

gas viscosity,

density

was used as a high-temperature, sampler.

The HTHP cascade impactor

sampling system is schematically shown in Figure 7. A single sample was attempted at Position (before the cyclone) but was unsuitable for size determination due to high (33 3) mass loa ding and resultant was solved impactor

plugging

of the probe.

by using gold wire (20 mil

assembly together.

heated tube furnace

In practice,

The problem of interstage

dia)

and compressing

it

with the six

the HTHP cascade impactor

and when temperatures

were at stream

seals for

A

HTHP applications bolts

holding

the

was placed in an electrically

conditions,

the high

temperature

(400-700°C), high pressure (110-200 psig) producer gas was passed through the cascade impactor.

Heoting I:-Iement

Automatic Controlled Resistance Heated Tube/Fuv’nace J I /

(400oc 900K Pal

.

C--

Probe

Flow

Condenser

Figure 7. Schematic diagram of high-temperature, used on the METClow Btu coal gasifier as position ~sical

high-pressure B (1980).

cascade impactor

sampling system

Characterization

Table 2 lists

aerosol

characteristics

of samples obtained during the September 1980 gasifier

run. Aerosol size and mass loading were dependent on sampling position ing condition.

and independent of operat-

In September 1980 the gas cleanup was designed for the total

ducer, whereas previously,

final

cleanup after

the Venturi

scrubber

ouput of the pro-

was designed for

I/4

flow.

Cleaned gas from the full flow cleanup contained insufficient mass to determine particle size or 3 mass loading. Further back on the cleanup train, mass loading was about 2 g/m on either side of the Venturi 0.8 (,~

scrubber

~m MMADafter 0.6 vm) with

size distribution

the

where the MMADwas about 0.5 ~m before Venturi

scrubber.

Raw gas exiting

the Venturi

scrubber

and about

ash cyclone was submicron 3. of about 14 g/m These mass loadings and

a relatively

high mass loading

parameters for

the raw gas were essentially

the

identical

with similar

measurements

obtained in December 1979. No detectable particulate mass loading was found at the entrance to the Holmes-Stretford desulfurizer (not on line). Mass loading increased upon combustion of the clean

producer

gas. We assume that

the gaseous H2S (,~

H2SO 4 on combustion.

I0

0.36% of clean

gas) was converted

x o

:,< x N~’~ ¯ ¯

cO

=*

C~ O~

O

c~ ~

~O

_

v

~.~ ~.~ ~.~ , +~

+~

~n

c,~

+1

= 0 v

o

* v

c:~+~

g g

/,

88~

I

;a =: ~~~ g~ .~ ~ & ,qc

-

11

~ ....

= ~~ =

The HTHPsamples collected sample had a mass loading sample was unacceptable noncollecting

surfaces

for

in September 1980 included one sample before the ash cyclone. This of 5.0 m. The impactor size determination

such as internal

due to excess sample, most of which was lost

walls.

In order to obtain

to

a sample at these high mass

loadings we would need either an impactor with a flow rate of about 2 L/min or a hot N2 dilution system. In any case, the problems of probe blockage made obtaining these samples from Position A too difficult for their actual value, After the ash cyclone (Position B), the mass loading 3 stream conditions was about 0.4 g/m with a MMADof 0.4 pm, ~ = 3.6. Assuming the mass g loading value of 33 g/m3 for Position A is valid, a total cyclone efficiency (based on total mass) is 98.8 percent.

Additional

problems encountered with the September 1980 HTHPsamples were

caused by an increase in effective cutoff calculated viscosity of 3.5 x 10-4 poise.

aerodynamic resistance diameter (ECDar) due to the Etching techniques have been used to fabricate an

additional three stages for the HTHP impactor viscosity of 3.5 x 10-4 poise (500°C at 20 atm).

to extend the ECDar range to about 0.3 ~m at a

RESULTSANDDISCUSSIONOF CHEMICAL CHARACTERIZATION General The chemical

characterization

described

in this

report

December 1979 and September 1980 tests

at METC. Most results

were reported

reports

in the last

source mass spectral

two status

and atomic absorption

pletes information obtained this report and a description

and biological

samples taken during

(LMF-77 and LMF-85). This report

contains

spark

on those samples. Table 3 contains the list of samples studied of sample fractionation and chemical analysis.

and (2) identification characterization

using chemical fractionation

with

spectroscopy data of samples taken in 1979, which com-

Two goals of the chemical characterization cleanup devices,

deals

from samples taken in December 1979

efforts

are (I)

evaluation

of mutagenic or toxic

of the collected to concentrate

of the gasifier

for

effluent

components in the samples. Chemical

samples have been meshed with the objective

the biological

activity.

Biologically

active

of

subfrac-

tions are undergoing further fractionation and characterization to identify the types of compounds that are the active components. This section is arranged to present the data in the following order:

(I)

organic

samples (potential

analysis

of process

waste effluents),

gas samples,

and (3)

(2)

elemental

organic

analysis

analysis

of cleanup

of process

device

stream and cleanup

device samples. A fractionation ciated

procedure has been developed at ITRI for use with the complex material

with the gasifier

effluents.

furan which elutes the least

A Sephadex LH-20 column is eluted

asso-

with 240 ml of tetrahydro-

polar and the higher molecular weight compounds first

followed by the

more polar ones. A final, very polar, fraction is eluted with methanol. Several standards were run to characterize the elution of classes of organic compounds from the column as shown in Figure 8, This fractionation characterization

concentrates

the toxic

used to tentatively fractionations most biologically

active

can be performed on the biologically

are then subfractionated acterize

the biologically

by silica

gas chromotgraphable

and characterization active

fractions.

gel chromotography or by acid/base

components. Gas chromatographic/mass identify

active

compounds so that

is followed

spectroscopic

further

These active

extraction analysis

identification

fractions

to further of fractions

compounds in a sample. These extensive by positive

chemical charis

chemical

and quantitation

of

compounds by comparison with standards in various chromatographic systems.

12

TABLE3 ProcessStream and PotentialWaste EffluentSamplesfor ChemicalAnalysis Sample

Fractionation

_ Chemical Analysis Spark source mass spectral analysis for elemental composition

HTHPImpactor samples of raw gas (1979)

None

® filters Tenax-GC from raw gas, after tar trap,after Venturi Scrubber,cleaned gas and cleanedgas combustionproducts.

Extract with CH2CI 2

Mass percent extractable; processstreammass loading; GC-MS for majorcomponents.

® absorbent Tenax-GC samplesfrom raw gas, after tar trap, after VenturiScrubber, cleanedgas and cleaned gas combustionproducts

Extractwith n-pentane

Mass percentextractable; processstream mass loading; GC-MS for major components.

Process stream samples of raw gas, material after tar trap, after Venturi Scrubber, and cleaned gas.

Fractionated on Sephadex LH-20 Fractions 3 and 4 subfractionated on silica gel. Fraction 5 partitioned into acidic basic and neutral components.

Mass percentin each fraction.

Bottom Ash

None

Content of Zn, Ni, Pb, Cu.

Cyclone Ash

None

Content of Zn, Ni, Pb, Cu.

Humidification Chamber Tar

None

Content of Zn, Ni, Pb, Cu.

Tar Trap Tar

None

Content of Zn, Ni, Pb, Cu.

Fractionation on Sephadex LH-20.

Mass percent in each fraction.

None

Atomic absorption spectroscopy for Zn, Ni, Pb, Cu, Cd, Be, As, Cr.

CH2Cl2 Extraction

Percentextractable.

None

Atomic absorption spectroscopy for Zn, Ni, Pb, Cu, Cd, Be, As, Cr.

CH2CI2 Extraction

Percentextractable.

Extractfractionatedon Sephadex LH-20. Fraction 5 partitionedfor acids,bases and neutrals.

Mass percent in each fraction.

Venturi Scrubber inlet Water

Venturi Scrubber Outlet Water

13

LH-20 - THF ELUTION PROFILE F-I

F-2

F-3 F-4

POLYMERS

I;-5

F-6

I ALKANES

NO2-PAH’S ORGANOMETALLICS PAH’S AMINO-PAH’S KETO-.~PAH’S S-PAH’S PHENOLS AZA-ARENE~

I

ACmS SALTS

100 115 130 145 TETRANYDROFURAN(ml)

240~’

. , I~ ~300 METHANOL (ml)

Figure 8. Elution profiles of compounds from Sephadex LH-20 column using tetrahydrofuran (THF) eluant. The lines for each compound indicate the volume of THF in which the compounds eluted. The dot indicates the center of the elution peak. Elution of compounds was monitored with an ISCO model UA-5 absorbance monitor at 280 nm.

Organic Analysis of Process Gas Samples Tenax-GC ~ prefilters and adsorbent samples were extracted with CH2CI2 and n-pentane respectively. The amount of solvent-extractable material obtained from each sample was determined and related to the amount of process gas at each corresponding sampling position. Results, expressed as mg extractable material from filters or adsorbent per m3 of process gas, are given in Table 4. As expected from the nature of cleanup devices in the process stream, a greater tion

of material

readily

in cleaner

gas samples (positions

removed by the humidifier,

G) consisted

propor-

of vapor phase compounds not

tar trap and Venturi scrubber.

Process stream samples collected in a 4 stage condenser train at gasifier positions B, D and E were fractionated on Sephadex LH-20. Fractions 3 and 4 were subfractionated on a column of silica gel,

while

Fraction

mass percent material

eluting

cleaned,

indicating

humidifier

5 was further

of material

tar

fractionated

in each fraction

in the more polar and Venturi

acidic,

basic and neutral (5 and 6) increased

these and other

Sephadex LH-20 fraction

scrubber.

D) and of tar alkanes.

n-octradecane, tion

B material.

present.

trap

Peaks with

alkanes present

1 (believed

tar

This may also be reflected

in the reduction

in gasifier

proces stream and tar

times

by gas chromatography of n-dodecane,

for

n-tridecane,

their

Alkanes containing

Dodecane was identified

15, 17, 20 and greater

in position

sample, indicating

D material.

content

n-tetradecane,

n-nonadecane, n-heneicosane and n-docosane were identified

were present in this

efforts

to contain alkanes) of process stream material

were analyzed

retention

as the gas was

components of process gas tend to escape removal by the

chromatographable compounds present in process gas as it is cleaned (Table 4). Because alkanes such as dodecane and tetradecane are known tumor promotors, to identify

components. The

are given in Table 5. Percentage of

Sephadex LH-20 fractions

that the more polar

trap

into

and subfraction

trap

in gas were made

material.

(position

B

of C-12 to C-22 n-hexadecane,

in process stream posi-

than 21C atoms also appeared to be

Fewer higher

molecular

weight alkanes

that higher moleculer weight alkanes may be removed by the

14

TABLE 4 RelativeAmountsof Vapor Phase and ParticulateMaterialin the Cooled and DilutedProcessStream PrefilterExtract

SamplingLocation B.

BetweenCyclone and Humidifier (raw gas)

ExtractableMass 3) Loading(mg/m n Pre-filter Tenax Adsorbent

Ratio Particulate/ Vapor PhaseMaterial)

(% Gas Chromatographable)

(1)

12,500

478

D. Between Tar Trap and Venturi Scrubber

(2)

840; 3100

153; 649

5.5; 4.8

20-26

E. After Venturi Scrubber

(2)

1340; 2120

447; 959

3.0; 2.2

12-18

G. Between Direct (2) Coolersand Holmes-Stretford aTenax prefilter humidifier

and tar trap. activity

I-4

with sample.

By comparison, tar

but many above C-21. Results indicate the biological

6

. ool .005;.I~8~

~o ~-l’; 2050

1.43;1.82

was saturated

26

of carcinogens

trap tar had few alkanes in the C-12 and C-19 range,

raw gas contains

some weak tumor promotors which may affect

in other LH-20 fractions.

Higher molecular

weight alkanes

appear to be removed from the stream during early stages of cleanup. Products

of gas combustion were collected

using a prefilter

and Tenax adsorbent.

Prefilter

samples contained 0.66 to 0.70% material extractable in CH2C12, but insufficient material was available for analysis by GC/MS. Vapor phase samples contained low concentration of organic material. Finnigan

These vapor phase samples were analyzed by gas chromatography/mass spectrometry 4023 GC/MS/DS. Results

acenaphthylene,

dibenzothiophene,

tentatively

indicated

phenanthrene, alkyl

pounds may have been present in clean precombustion

the presence of nitrobiphenyl,

using a a nitro-

naphthalene and several alkanes,

These com-

gas or may have been produced from methane

during gas combustion. OrganicAnalysisof CleanupDevice Samples Tar trap tar and Venturi of each fraction

is listed

scrubber water were fractionated in Table 6. It

on Sephadex LH-20. The mass percent

should be noted that almost 50% of the mass of tar

trap

tar elutes in Sephadex LH-20 fractions 3 and 4 which contain mainly neutral polycyclic aromatic compounds. In contrast to this, 85% of the Venturi scrubber water dichloromethane extractables elute

in Sephadex LH-20 fraction

wide variety

of chemicals,

5 and 6. Results

but chiefly

neutral

polycyclic

contains more polar compounds. This is consistent Elemental Analysis

that

the tar

aromatics,

with results

trap tar

consists

while the Venturi

reported earlier

of a

scrubber

(LMF-85).

of Process Stream and Cleanup Device Samples

Two raw gas samples (position December 1979 were subjected samples were collected impactor.

indicate

The particles

without

B),

cyclone

ash and feedstock

to elemental analysis cooling

collected

and dilution

had little

coal from tests

by spark source mass spectrometry.

Process gas

using a high temperature high pressure cascade

associated condensed organic

15

conducted

matter and would not be

TABLE5 Percent of Material Gasifier

Contained in Fractions

Gasifier

E After

After

before humidifier

VenturiScrubber 100

Tar Trap 100

100 27.8

Fx 1

Position D

B After Cyclone, Fraction a LH-20

of

Process Stream Materials

35.4

7

2

6.5

8.4

4

3 4

21.8

18.6

23

16.7

15.6

5

21.7

14 29

6

5.5

15.3 6.7

LH-20 Fx 3b + 4 Silica Subfx A

21

69.7

I00 56.7

B

26.1

29.7

C

4.2

13.6

I00

100

LH-20 Fx 5

100

Acids

0.04

Bases

0.21

0.29

Neutrals

0.08

0.36

~ 99

Amphoterics

~ 99

aSamples were chromatographed as indicated

in Figure 15.

bsamples < .25 g were chromatographed on a 300 x 25 mmcolumn of silica eluted with toluene (Subfraction

A), toluene-n-propanol

(I:I;

Subfraction

and Methanol (Subfraction C). CSubfractionation not performed on these samples. expected

to exist

in the same physico-chemical

gained regarding these particles logical

concern.

form during

is more of an engineering

Because of this,

a fugitive

emission.

and chemical interest

emphasis was not placed on EPA priority

Information

than of a toxico-

pollutant

metals in the

process stream samples. Although many elements were found in the process stream, ash and coal samples, only I0 elements will

be discussed here.

sive properties.

Lithium,

sodium and potassium were chosen because Of their

Knowledge of amounts of these metals in raw gas will

of metal cleanup systems required

to make gas useful.

indicate

Chromium, nickel,

extent

corro-

and types

manganese, cobalt

and

iron were analyzed because they are commoncomponents of stainless steel. Content of these metals in raw process gas may indicate extent of corrosion of the gas producer during the coal gasification

process.

Uranium was chosen because it

and lead were chosen because of their The concentration general,

all

toxic

of metals in coal,

is refactory

to changes in physical

Cadmium

properties. cyclone ash and raw process gas are given in Table 7. In

metals were enriched in cyclone ash and raw gas over their

enrichment in raw gas was noticeably

state.

greater.

Iron

16

was present in all

concentration

in coal,

but

samples in concentrations

TABLE6 Percent of Material

in Sephadex LH-20 Fractions

Tar Trap Tar and Venturi

of

Scrubber Water % Mass

a Tar Trap Tar

LH-20 Fraction

Venturi Scrubber b Water

1

16

6

2

18 34

2

14

5

5

14

75

6

3

I0

3 4

3

aTar was dissolved in CH2Cl2 and filtered prior to fractionation. bFiltered

Venturi

to remove undissolved material

scrubber water was extracted

3 times with one half volume of

CH2CI2. Only 0.07% of the water sample was extractable 2. CH2CI2 solubles were chromatographed on LH-20."

into CH2CI

TABLE7 Concentration

of Selected Metals in Coal, Cyclone Ash

and Process Stream Materials,

December, 1979

ppm Concentration Metal

Coal

Lithium

Cyclone Ash

0.21 -

Sodium

780

Potassium

160

1,600

0.8

Nickel

0.7

Manganese Cobalt

6.3 0.21 -

Cadmium

0.12 -

Lead

1.3

Uranium

1.0

- 2,800

Chromium

Enrichnrent

3.0 7.0

II

I00

Ash/coal

Process stream/coal

I00 - 2,700

800 - 14,000

- 3,200

20,500 - 27,740

1~

4

13 -

36

3,400

- I0,000 220 -

28,500 - 33,800

1-

60

I0 -

200

2,750 - 9,860

33 -

120

17,130 - 20,560

270 171

740

3,530 - 12,450

70 5-

84

1,191 - 4,999

37 -

160

3,410 - 3,730 1,033 - 1,335

12 -

66 49

-

52

.36 1.6

813 - 2,935

2,100

49 1.4

Process Stream

570

1.6

91 -

82

< 0.I

1.2 -

14.0

294

900 - 12,000 2,400 - 29,000

80

400 - 1,400

400

850 - 24,000

4 -

13

300 - 2,400

55 -

I00

2,000 - 2,900

140

I0,000 - 13,000

> I% and therefore appears to be a major metal constituent of coal, ash and process gas. Chromium, nickel, manganese and cobalt in raw gas were enriched by factors of 102 to 104 over values in coal, indicating possible other factors may also be involved.

corrosion of stainless steel in the gas producer, although The corrosive metals are present in raw gas in relatively

high concentrations

is noticeably

but only lithium

enriched over concentrations

cadmium and lead are also enriched in raw process gas. The engineering tions

of this

enrichment and tar

hazard associated

with handling gasifier

small,

Uranium, implica-

remain unknown. Lead does appear to be removed from the process stream

by the humidifier are relatively

in coal.

and toxicological

trap

and Venturi

scrubber

tars.

(Table 8) and may contribute

Concentrations

to the health

of cadmium and lead in cyclone ash

and may represent only a minor health hazard when handled.

Table 9 shows the association of metals with particles impactor. Data from the two samples taken on different

17

of various sizes collected days were highly variable.

in the HTHP This vari-

TABLE8 Concentrations of Selected Metals in Coal a and Low Btu Gasifier Potential Effluent Samples, December, 1979 concentration Sample

Zn

Coal

Ni

35.4

Pb__

34.6

24

27.8

Cyclone Ash

34.1

42.8

280

61.1

44.6

1,890

65.3

32.1

685

Tar

Tar Trap Tar

131

(ppm)

Cd

17.4

As

Be

27.3

Bottom Ash Humidifier

Cu

Cr

-

39.1 < 2.18 24.4

-

-

-

-

12.0

-

Venturi Scrubber Inlet

water

Outlet water

.003

.024

.0005

.016

0.4

0.6

.015

.015

.0067

.044

2.0

3.0

Laboratories

Model 951 Atomic Absorption Spectrometer

aSamples were analyzed using the Instrumentation

Results are the mean of at least two determinations.

Blanks indicate

8.0

12.1

645.

4.0

no analyses for these metals we

made. TABLE9 Size Distribution

of Selected Metals in Low Btu Gasifer RawGas, December 1979 Cumulative % Metal in Particles

Metal Lithium Sodium

> 9.1 ~m

> 6.1 um

> 4.2 um

0.2 ~ 20

1.2 ~ 53

61 - 74

8

Potassium

II

(n = 2)

> 2.4 ~m 77 - 86

> 1.83 um 77 - 90

> 1.25 um 89 - 99

- 17

24

- 57

60 - 76

63 - 81

81 - 89

94 - 96

- 30

45

- 46

60 - 81

75 - 88

85 - 90

92 - 96

Chromium

7

- 40

52

- 53

58 - 74

62 - 81

81 - 89

87 - 94

Nickel

4

- 58

53

- 85

67 - 91

75 - 94

85 - 97

92 - 99

Manganese

4

- 31

45

- 84

58 - 89

63 - 92

83 - 96

89 - 98

Cobalt

2

66

67

- 92

78 - 96

81 - 97

83 - 98

93 - 99

Cadmium Lead

5

- 24

69

- 75

86 - 92

88 - 95

93 - 98

95 - 99

6

- 27

42

- 56

51 - 74

58 - 81

77 - 85

Uranium

4

-

15

- 73

93 - 97

95 - 98

98

89 - 95 99

ability

8

may be a reflection

mental composition

of the instability

of the gasification

of coal used, variations

the amount of sample available 50-90% of each metal is

for

associated

analysis), with

process, inhomogeniety of ele-

in spark source mass spectral or a combination

particles

(depending on

of these factors.

with diameters

associate with or tended to form larger size particles. in concentrations > I%. Therefore analysis of particle

analysis,

In general,

~ 4.2 l~m. Metals tended to

Iron was present on all impactor stages size distribution was not possible using

spark source mass spectroscopy data. Metal content of several gasifier determined. nickel,

Feedstock

coal,

ashes,

lead and copper. Venturi

effluent tars

samples obtained during the December 1979 tests

and Venturi

scrubber

and chromium. Metals analyzed were chosen from the EPA priority are shown in Table 8. Notable enrichment tar

trap tars occurred.

water were analyzed

for

scrubber water was also analyzed for cadmium, beryllium, (30 to 80 fold)

Cyclone ash also was enriched

18

metal pollutant

list.

of lead in humidification

in lead but to a lesser

extent

was

zinc, arsenic Results

chamber and (I0 fold).

In addition, there was also an 80-fold enrichment of the concentration scrubber outlet water as compared to the concentration in municipal inlet cate that tar,

cyclone ash and scrubber outlet

mize exposure to at least two toxic

of arsenic in Venturi water. These data indi-

water should be handled carefully

in order to mini-

metals in these effluents.

RESULTSANDDISCUSSIONOF BIOLOGICALCHARACTERIZATION Screenin~Tests Mutagenicity mutagenicity position

after

These materials

subfractioned activity

samples was assessed using the Ames Salmonella

assay. Process stream samples included

B (raw gas just

scrubber).

cell

of low Btu gasifier

into

the cyclone),

were subjected

acidic,

Venturi

collected

the tar

to fractionation

basic and neutral

included tar trap tar,

material

D (after

bacterial

in condensers at gasifier

trap)

and E (after

the Venturi

on Sephadex LH-20. Fraction

components. Waste effluents

scrubber water and their

assayed for

5 was

mutagenic

LH-20 fractions.

Samples that are highly mutagenic in the Ames test are currently being tested in a mammalian test system (Chinese hamster ovary cells in culture). Preliminary results indicate gasifier

samples (tar

trap tar

and raw gas) are mutagenic with metabolic

activation.

Complete results

will

be reported in the next status report. Results of Mutagenicitz All

Testin~

process stream samples were mutagenic in Salmonella strain

TA-98, but only with metabolic

activation. Reduction in specific mutagenic activity with cleanup by the humidifier, tar trap and Venturi scrubber was small (Table I0). However the large reduction in mass loading of the process stream with cleanup led to a significant stream (revertants all

reduction

in the mutagenicity

eluting

in LH-20 fraction

bute to mutagenic activity

majority

neutral

in fractions

samples from previous gasifier

and polar

of the mutagenic activity

and normalized

2, only material

polycylic

of gasifier

mutagenic activity

materials.

are consistent

tests

and heterocyclic It

contri-

with findings

that LH-20 fractions

aromatic

of LH-20 fractions

2, 3, 4 and 5 of small mass

3, 4 and 5 significantly

of the process samples. These results

process stream and tar effluent 5, containing

of the process

/L of process stream).

Significant specific mutagenic activity was associated with LH-20 fractions process samples (Table lO). However, taking into account the relatively

material

fic

overall

on

3, 4 and

compounds, contribute

the

should be noted that both the speci~ decreased as the gas was cleaned.

should also be noted that the sum of the normalized mutagenic activity less than or equal to that of the crude samples, indicating

It

of the LH-20 fractions

no masked mutagenicity

is

in the crude

samples. Mutagenic activity

of acidic,

basic and neutral

subfractions

of LH-20 fraction

5 materials

are

given in Table II. The acidic subfractions contribute little to the mutagenic activity of LH-20 fraction 5 samples; most activity is associated with the neutral and basic subfractions. These results are consistent with those reported earlier (LMF-85) for process stream and tar effluent samples. Mutagenic activity

of tar trap

given in Table 12. Specific greater fractions

tar and Venturi

mutagenic activity

than that of raw process gas or its containing

polycyclic

and 4) and the fractions

scrubber water and their

of tar

trap

LH-20 fraction

tar

(position

aromatic hydrocarbons and their

containing

polar

polynuclear

19

and its

LH-20 fractions

LH-20 fractions

B). As in earlier

alkylated

compounds (Fraction

derivatives

are

is much findings,

(Fractions

5) contributed

most

TABLEI0 Mutagenic Activity

of Process Stream Samples and

Their Sephadex LH-20 Fractions Revertants Fraction

a Mass

Per ~g

Percent

With S-9

Mutagenicity Percent

Revertants Per L Process Stream

POSITIONB -- RAWGAS I00

Crude

6.7 ± 0.6

I00

50,348

0.7 + 0.2

3 3

1,569 1,867

39

16,957

LH-20 Fraction 1

27.8

2

6.5

3

21.8

4

16.7

2.8 ± 0.3 10.4 +- I.I 5.0 ± 0.6

14

6,200

5

21.7

10.4 ± 1.0

6

5.5

2,8 ± 0.2

38 3

16,807

3.7 ± .2

100

9,689

1,120

POSITIOND -- AFTERTAR TRAP Crude

I00

LH-20 Fraction 1

0

0

14

713

18

924

0

35.4

2

8.4

3.2 ± 0.4

3

18.6

1.9 ± 0.6

4

15.6

4.5 ± 0.4

5

15.3

4.1 ~ 0.2

35 31

1,848

0.5 ± 0.3

2

79

6

6.7

1,637

POSITIONE -- AFTERVENTURISCRUBBER 100

4.11 ± .3

I00

2,161

7

0.2 ± 0.2

0

I0

2

5

2.8 +- 0.4

6

74

3 4

23

1.8 + 0.3

24

220

14

2.3 + 0.4

18

168

2.9 -+ 0.2 0.2 -+ 0.2

49

442 26

Crude LH-20 Fraction 1

5

29

6

21

aMass percent of material bTA-98 revertants/ug regression

analysis.

3

fractionated.

determined from slope of dose-response curve by linear No mutagenic activity

was found without

activation. CMutagenicity percent is the percent of the mutagenicity tributes

to the crude material. 20

metabolic

each fraction

con-

TABLE] ] MutagenicActivityof ProcessStream LH-20 Fractions5 and Their Subfractions b Revertants a Mass Fraction

cMutagenicity

per ~g

Percent

With S-9

Percent

POSITIONB -- RAWGAS LH-20 Fraction

5

21.7

9.7 _+ 0.5

I00

Acids

0.9

1.0 + 0.5

]

Bases

4.1 1.6

5.5+- 1.0 46.7 , 2.6

20

Neutrals

15.2

Not tested

15.3

2.1 + 0.2

Amphoterics Water solubles

79

POSITIOND -- AFTERTAR TRAP LH-20 Fraction

5

I00

Acids

0.03

0.4 + 0.I

0

Bases

3.8

4.2 + 0.4

50

Neutrals

4.6

5.2 + 0.3

50

AmphotericsWater solubles

6.6

Not tested

-

POSITIONE -- AFTERVENTURISCRUBBER LH-20 Fraction

5

29.0

Acids

0.7

Bases

1.6

Neutrals Amphoterics Water solubles

2.3 ± 0.3

I00

0

0

12.4 ± 0.7

83

2.1

2.2 * 0.2

17

24.6

Not tested

aMass percent of crude sample. bTA-98 revertants determined from slope of dose-response curve by linear gression analysis.

There was no mutagenic activity

without

CMutagenicity percent is the percent of the mutagenicity contributes

to the total

Fraction

5.

21

addition

re-

of S-9.

each subfraction

TABLE12 Mutagenic Activity

of Tar Trap Tar and Venturi

Scrubber Water

and Their LH-20 Fractions

Sample Tar Trap Tar

mass

TA-98 Revertants

%

per m9 (wit h S-9[ 21.6 ± 1.8

I00

Mutagenicity Percent I00

LH-20 Fraction 1 2

16

2.9

+

0.2

2

18

2.9

+

0.5

2

3 4

34

2.5

± 0.8 ± 49.1

3 60

5

14 3

56.6

+ 8.0

32

10.2

± 0.5

14

6

107

1

Venturi Scrubber Inlet Water Lyophilized (50 ml)

I00

0.0 0

Venturi Scrubber Outlet Water Lyophilized (50 ml)

I00

1.14 ± 0.06

I00

0.72 ± (0.18)

100

Outlet Water DichloromethaneSolubles (0.07%) LH-20 Fraction

Venturi

7 3

75

+- 0.3 1.7 ± 0.3 1.8 ± 0.4 0.6 ± 0.2

64

I0

0.4

± 0.2

6

6

0.8

2

2

I.I

3

3

4

5

5 6 the mutagenic activity activity

.+- 0.2

1

of tar collected

scrubber inlet

upon metabolic

in September 1980.

water has negligible

activation.

7 13

mutagenic activity

In agreeement with earlier

whereas outlet

studies

on Venturi

water has weak Scrubber outlet

water, only a small percent of material was extractable into dichloromethane, and this chiefly of polar aromatic compounds eluting in Sephadex LH-20 fraction 5. The specific activity eluted

of the water was distributed in fraction

5, this

dichlormethane-soluble

fraction

samples of tar

cleanup devices, polycylic

most significantly

Characterization

to the mutagenicity

of the

Studies

taken from the METC gasifier,

the majority

aromatic

contributed

but because most of the mass

fraction.

Summaryof Chemical/Biological In all

throughout the LH-20 fractions,

consisted mutagenic

of the mutagenic activity

hydrocarbons

and their

alkylated

22

either

from the process stream or the

has been found in the fractions derivatives

(Fractions

containing

3 and 4) and in the

polar

fraction

material

containing

polynuclear

is subfractionated

basic and neutral/phenalic

by acid/base fractions.

with somewhat higher cytotoxicity the identification not volatile izations

aromatic

of the active

enough for analysis

hydrocarbons

partitioning,

The greatest

in the phenolic

(Fraction

5).

the mutagenic activity cytotoxicity

by GC/MS. Future work will

is mainly in the

is found in the same fractions

fractions.

components in those portions

When the latter

A major problem to be addressed is of the mutagenic fractions emphasize further

that are

chemical character-

of such material.

In vivo Testin~ Preparations for (3H-2-aminoanthracene) 2-aminoanthracene will 9-[14C]-fluorenone

exposure of Fischer-344 rats to a model primary aromatic amine and a model azarene (14C-phenanthridone) are continuing. Radiolabeled be purchased commercially. 9-[14C]-phenanthridone was synthesized from

in a 78% overall

yield.

The product was purified

by chromatography on silica

gel and the radiochemical purity was checked by thin layer chromatography. The final < 99% radiochemically pure. The specific activity was 8 x 107 dpm/mg. A method for generating The process material nebulizer.

was emulsified

The aerosol

concentration

a respirable

studies

of crude process stream material

in water and the aerosol

had a mass median aerodynamic

of 60 g/l

of air,

size nor chamber concentration co-inhaled

aerosol

suitable

for

animal inhalation

of I-2 studies,

period.

to determine

was developed.

Hm. An exposure chamber was achieved.

This aerosol

will

will

be reported in the next status report.

23

Neither

be used in

the retention , fate and effects of inhaled gasifier materials model compounds added to the crude process material prior to aerosolization.

of animal exposure studies

was

was generated using a LKB ultrasonic

diameter

changed during a 30 min test

material

and of Results

APPENDIX I PUBLICATIONS ANDPRESENTATIONS Publications I.

Benson, J. M. and R. F. Henderson,"Isolationand Characterizationof a Low Molecular Weight Cadmium-BindingProtein From Syrian Hamster Lung," Toxicol. Appl. Pharmacol. 55: 370-377, 1980.

2.

Benson, J. M., R. L. Hanson, C. E. Mitchell, J. O. Hill, G. J. Newton and R. L. Carpenter, "ToxicologicalCharacterizationof the Process Stream of an ExperimentalLow Btu Coal Gasifier," to be publishedin the Proceedingsof the HanfordLife Science Symposium,Coal Conversion and the Environment - Chemical, Biomedical and Ecoloqical Considerations, held in R#chland,WA, October19-23,"1980(in press).

3.

Benson, J. M., J. O. Hill, C. E. Mitchell, G. J. Newton and R. L. Carpenter,"Toxicological Characterization of the Process Stream of an Experimental Low Btu Coal Gasifier," Arch. Environ.Contam.Toxicol.(in press).

4.

Benson, J. M., R. E. Royer and J. O. Hill, "Metabolismof Phenanthridineto Phenanthridoneby Lung and Liver Microsomes,"Toxicol.Appl. Pharmacol.(submitted).

5.

Benson, J. M., C. E. Mitchell, R. E. Royer, C. R. Clark, R. L. Carpenter and G. J. Newton, "Mutagenicity of Potential Effluents from an Experimental Low Btu Coal Gasifier," Arch. Environ.Contam.Toxicol.(in press).

6.

Cheng, Y. S., G. J. Newton,R. L. Carpenter,E. B. Barr and H. C. Yeh, "ImpactorData Analysis for High Temperature-High PressureAerosolSampling,"in Proceedingsof DOE Contractors’Workshop on the ParticulateSampling and Characterization"held in Morgantown,WVA, June 16-17, 1981, pp. 98-II0,1981.

7.

Dahl, A. R. and T. J. Briner, "BiologicalFate of a RepresentativeLipophilicMetal Compound (Ferrocene) Deposited by Inhalation in the Respiratory Tract of Rats," Toxicol. App.].t Pharmacol.56: 232-239,1980.

8.

Dahl, A. R., W. M. Hadley, F. F. Hahn, J. M. Benson and R. O. McClellan, "Association of Cytochrome P-450 Mediated Mixed-Function Oxidase Activity with Olfactory Epithelium in Dogs," Science (in press).

9.

Dahl, A. R. and S. H. Weissman, "Lipid Soluble Stream," Environ. Sci. Technol. (submitted).

lO.

DeNee, P. B. and R. L. Carpenter, "Application of Heavy-Metal Staining (OsO4)/Backscattered Electron Imaging Technique to the Study of Organic Aerosols," in Microbeam Analysis, pp. 8-10, San Francisco Press, Inc., San Francisco CA, 1979.

II.

Green, D. A., P. B. DeNee and R. G. Frederickson, "The Application of Heavy Metal Staining (Os04) and Backscattered Electron Imaging for Detection of Organic Material in Gas and 0ii Shale," in Scanning Electron Microscopy pp. 495-500, AMFO’Hare, IL, 1979.

Metal Compounds in a Coal Gasifier

12. Hadley, W. M. and Dahl, A. R., "Cytochrome P-450 Mediated Mixed Function Rat Nasal Epithelial Membranes," Toxicol. Lett. (in press). 13. Hanson, R. L., C. Ro Clark, R. L. Carpenter and C. H. Hobbs, "Evaluating as Polymer Adsorbents for Sampling Fossil Fuel Combustion Products Oxides," Environ. Sci. Technol. 15: 701-705, 1981.

Process

Oxidase Activity

in

of Tenax-GC and XAD-2 Containing Nitrogen

14. Hanson, R. L., R. E. Royer, R. L. Carpenter and G. J. Newton, "Characterization of Potential Organic Emissions from a Low Btu Gasifier for Coal Conversion," in Polynuclear Aromatic Hydrocarbons, pp. 3-19, Ann Arbor Science Publishers, Inc., Ann Arbor, MI, 1979. Gas Chromatography of Coal," 15. Hanson, R. L., "Pyrolysis Smith, ed.) Marcel Dekker, Inc., (in press).

in Analytical

Chemistry of Coal (W. T.

16. Harpaz, R. and C. E. Mitchell, "DNA Modification in Rat Lungs Following Intratracheal or Subcutaneous Administration of 4-Nitroquinoline l-Oxide, Benzo(a)pyrene or 2-Aminoanthracene," Chemico-Biol. Interact. 36: 129-140, 1981. "In Vitro Cytotoxicity for Alveolar 17. Henderson, T. R., R. E. Royer and C. E. Mitchell, phages of Tar from a Low Btu Coal Gasifier," Environ.~ci. Technol. (submitted).

24

Macro-

18. Hill, J. 0., R. E. Royer and C. E. Mitchell, "In Vitro Cytotoxicityfor Alveolar Macrophages of Tar From a Low Btu Coal Gasifier,"Environ.Sc-T. Techno].(submitted). 19. Hobbs, C. H., R. O. McClellan,C. R. Clark, R. F. Henderson,L. C. Griffis,J. O. Hill and R. E. Royer, "InhalationToxicologyof PrimaryEffluentsfrom Fossil Fuel Conversionand Use," in Potential Health and EnvironmentalEffects of Synthetic Fossil Fuel Technologies , pp. 78-94, CONF-780903, 1979. 20. Mitchell,C. E., R. Harpaz and K. W. Tu, "Distribution,Retentionand Effectsof Some Aromatic CompoundsFollowingInhalationor IntratrachealInstillationin Rats," to be publishedin the Proceedingsof the Hartford Life.SciencesSymposiu9 on Coal Conversionand the EnvironmentChem~c’al,Biomedicaland EcologicalConsiderations, held’ in Richland,WA, October19-23, 1980 (in press}. 21. Mitchell, C. E. and K. W. Tu, "Distribution, Retention and Elimination of Pyrene in Rats FollowingInhalation,"J. Toxicol.Environ.Health 5: llTl-l179,1979. 22. Mitchell,C. E., "A Method for the Determinationof PolycyclicAromaticHydrocarbonsin Animal Tissues,"Bull. Environ.Contam.Toxicol.23: 669-676,1979. 23. Mitchell, C. E., "Induction of Aryl Hydrocarbon Hydroxylase in Chinese Hamsters and Mice Following IntratrachealInstillationof Benzo(a)pyrene,"Res, Comm. Chem. Pathol. Pharmacol. 28: 65-78, 1980. 24. Mitchell, C. E., "Distributionand Retention of Benzo(a)pyrene in Rats After Inhalation," Toxico].Lett. (in press). 25. Newton,G. J., R. L. Carpenter,H. C. Yeh, S. H. Weissman,R. L. Hanson and C. H. Hobbs, "Sampling of Process Streams for Physical and Chemical Characterizationof RespirableAerosols," in Potential Health and Environmental Effects of Synthetic Fossil Fuel Technologies, pp. 78-94,CONF-780903,1979. 26. Newton, G. J., R. L. Carpenter, Y. S. Cheng, E. B. Barr and H. C. Yeh, "Sampling a High Temperature-HighPressure Process Stream with a Cascade Impactor,"in Proceedingsof the DOE ContractorsMeetinq on High Temperature,High PressureParticulateand AIkal{"Controlin Coal Combustion ProcessStre’amsheld in Morg’a’ntown, WVA, February2-5, 1987",pp, 667-682,1981. 27. Newton, G. J., R. L. Carpenter,Y. S. Cheng, E. B. Barr and H. C. Yeh, "High Temperature-High PressureCascadeImpactorDesign, Performanceand Data AnalysisMethods,"J. ColloidInterface Sci. (in press). 28. Royer, R. E., C. E. Mitchelland R. L. Hanson,"Fractionation,ChemicalAnalysisand Mutagenicity Testingof Tar From a Low Btu Coal Gasifier,"Environ.Sci. Technol.(submitted). 29. Tu, K. W., G. M. Kanapillyand C. E. Mitchell, "Generationand Characterizationof Homogenous CondensationAerosolsof Benzo(a)pyrene," J. Toxicol.Environ.Health 7: 353-362,1981. 30. Weissman, S. H., R. L. Hanson, G. J. Newton and R. L. Carpenter, "Chemical and Physical Characterization of ProcessStreamsin an ExperimentalLow Btu Coal Gasifier,"to be published in the Proceedingsof the Hanford Life ScienceSymposium,Coal Conversionand the Environment - Chemical, Biomedical and Ecoloqical Considerations,held in Richland, WA, October 19-23, Presentations I.

Benson,J. M. and C. R. Clark, "Use of Rat Lung Homogenatesin MicrobialMutagenesisTesting," presentedat Joint Meetingof AmericanSociety for Pharmacologyand ExperimentalTherapeutics and Societyof Toxicology,Houston,TX, August 13-17, 1978.

2.

Bice, D. E., C. T. Schnizlein and C. E. Mitchell, "Effects of Acute Lung Exposure to Benzo(a)pyreneon Immunity Induced by Lung Immunization,"American Thoracic Society Meeting, Las Vegas, NV, May 13-16, 1979.

3.

Brooks,A. L., "The Genetic Toxicologyof Inhaled Benzo(a)pyrene," Societyof ToxicologyMeeting, San Diego, CA, March I-5, 1981.

4.

Carpenter,R. L. and G. J. Newton, "Sampling Methods for FluidizsedBed Coal Combustors and Low Btu Coal Gasifiers," DOE Contractors’Workshop, on Review and Developmentof Biotesting Programsfor Energy Utilization,Boca Raton, FL, Novemberll-14, 1978.

25

5o

6.

Cheng, Y. S., C. J. Newton, R. L. Carpenter, E. B. Barr and H. C. Yeh, "Performance of a HTHP Cascade Impactor," ACS/IEC 1981 Winter Symposium Aerosol Systems, Tuscon, AZ, January 25-28, 1981. Cheng, Y° S., G. J. Newton, R. L. Carpenter, E. B. Barr and H. C. Yeh, "Impactor Data Analysis for High Temperature-High Pressure Aerosol Sampling," DOE Contractors’ Workshop on the Particulate Sampling and Characterization, Morgantown, WVA,June 16-17, 1981. Clark, C. R. "Mutagenic Survey of EFfluents Collected from the Low 8tu Gasification and Fluidized Bed Combustion of Coal," DOEContractor Workshop on Review and Development of Biotesting Programs for Energy Utilization, Boca Raton, FL, November 11-14, 1978.

8°

g°

DeNee, P. B. and R. L. Carpenter, "Application of Heavy-Metal Staining (OsO4)/Backscattered Electron Imaging Technique to the Study of Organic Aerosols," Conference of the Microbeam Analysis Society, San Antonio, TX, August 12-17, 1979. Green, D. A., P. B. DeNee and R. G. Frederickson, "The Application of Heavy Metal Staining (Os04) and Backscattered Electron Imaging for Detection of Organic material in Gas and Oil Shale," Scanning Electron Microscope Meeting, Washington, DC, April 16-20, 1979.

I0. Hanson, R. L., R. E. Royer, G. J. Newton and R. L. Carpenter, "Characterization of Organic Emissions from a Low Btu Gasifier for Coal Conversion," Third International Symposumon Polynuclear Aromatic Hydrocarbons, Columbus, OH, October 25-27, 1978. II.

Henderson, T. R., R. E. Royer and C. R. Clark, "lodine Derivatives for Detection of Trace Levels of NiLro-PAH and Primary Aromatic Amines in Environmental Samples," Finnigan Users Forum, Minneapolis, MN, May 24, 1981.

Toxicology of Primary Effluents from Fossil Fuel Conversion and 12. Hobbs, C. H., "Inhalation Use," Symposium on Potential Health and Environmental Effects of Synthetic Fossil Fuel Technologies, Gatlinburg, TN, September 25-28, 1978. 13. Mitchell, C. E., "Induction of Aryl Hydrocarbon Hydroxylase in Rodent Tissue Following Intratracheal Instillation of Intraperitoneal Administration of Benzo(a)pyrene," Society of Toxicology Meeting, San Francisco, CA, March 12-16, 1978. 14. Mitchell, C. E., R. C. Pfleger and C. H. Hobbs, "Induction AcLivity in Lung Cells and Tissues of Syrian Hamsters," Research, NewOrleans, LA, May 16-17, 1979.

of Aryl Hydrocarbon Hydroxylase American Association for Cancer

15. Mitchell, C. E., DNAModification in Rat Lungs Following Intratracheal tic Hydrocarbons," Federation of American Societies for Experimental April 13-17, 1981.

Instillation of AromaBiology, Atlanta, GA,

16. Newton, G. J., R. L. Carpenter and H. C. Yeh, "Sampling Process Stream for Physical and Chemical Properties of Respirable Aerosols," Symposium on Potential Health and Environmental Effects of Synthetic Fossil Fuel Technologies, Gatlinburg, TN, September 25-28, 1978. 17. Newton, G. J., R. L. Carpenter, Y. S. Cheng and H. C. Yeh, "Design and Performance of Cascade Impactor for Both Ambient and High Temperature-High Pressure Applications," Annual Meeting of the ASME,San Francisco, CA, August 10-21, 1980. 18. Newton, G. J., R. L. Carpenter, Y. S. Cheng and H. C. Yeh, "A Cascade Impactor for High Temperature-High Pressure Process Stream Sampling," DOE Contractors Meeting, Morgan°own, WVA, February 2-5, 1981. 19. Newton, G. J., R. L. Carpenter, H. C. Yeh, R. L. Hanson and C. H. Hobbs, "Physical, and Biological Characterization of Low Btu Gasifier Process Streams," Air Pollution Association Meeting, Philadelphia, PA, June 22-26, 1981.

Chemical Control

20. Royer, R. E., C. E. Mitchell and R. L. Hanson, "Fractionation, Chemical Analysis and Mutagenicity Testing of a Low Btu Coal Gasifier Effluent," American Chemical Society Meeting, Washington, DC, September 10-13, 1979. 21. Weissman, S. H., "Chemical Characterization of Effluents Collected from Fluidized Bed Coal Combustion and Low Btu Gasification," DOEContractor Workshop on Review and Development of Biotesting Programs for Energy Utilization, Boca Raton, FL, November 11-14, 1978.

26

APPENDIX II CONTRIBUTING PROFESSIONAL STAFF A major effort duals with diverse

of the type described skills.

The listing

in this

report

below identifies

requires

input

the major contributors

the Inhalation Toxicology Research Institute° It by no means includes the effort. In the unnamed category are many highly skilled technical, shop, administrative

and secretarial

personnel

From a number of indivi-

whose efforts

all who are contributing to animals care, maintenance,

are essential

meaningful research program. Rogene F. Henderson, Ph.D.

Chemist/Toxicologist,

Charles H. Hobbs, DoV.M.

Toxicologist,

Janet M. Benson, Ph.D. Robert L. Carpenter, Ph.D.

Aerosol Scientist

Yung Sung Cheng, Ph.D.

Aerosol Scientist

C. Richard Clark, Ph.D.

Toxicologist

Alan R. Dahl, Ph.D. Ray L. Hanson, Ph.D.

Toxicologist

Assistant

Toxicologist

Chemist

George M. Kanapilly,

Ph.D.

AerosolScientist

Charles E. Mitchell,

Ph.D.

MolecularBiologist

George J. Newton Robert E. Royer, Ph.D.

AerosolScientist Chemist

27

Program Manager Director

to the program at

to a productive

and