United States
                    Environmental Protection
                    Agency
Air and Energy Engineering
Research Laboratory
Research Triangle Park NC 27711
                    Research and Development
EPA/600/S7-86/011 May 1986
£EPA         Project  Summary
                    Environmental  Assessment  of  a
                    Commercial  Boiler  Fired   with  a
                    Coal/Waste  Plastic  Mixture
                    R. DeRosier, H. I. Lips, and L. R. Waterland
                      This report describes emission results
                    obtained from field testing of a stoker-fired
                    commercial  boiler firing  a  coal/waste
                    plastic mixture. Two tests were perform-
                    ed: in one (test 1), the unit fired its typical
                    coal  fuel; and  in the other (test 2),
                    granulated    waste   polyethylene
                    terephthalate (PET) beverage bottles were
                    added to the coal to about 16 percent by
                    weight  in  the  mixed fuel.  Emission
                    measurements performed  included con-
                    tinuous monitoring of flue gas emissions;
                    source  assessment sampling system
                    (SASS)  sampling of the flue  gas, with
                    subsequent laboratory analysis of samples
                    to obtain total flue gas organics in two
                    boiling point ranges, compound category
                    information within these ranges, specific
                    quantitation  of the  semivolatile organic
                    priority pollutants, and flue gas concenta-
                    tions of 73 trace elements; EPA Method
                    5 sampling for paniculate; EPA Method 8
                    sampling for SO2 and SO3 emissions;
                    volatile  organic  sampling  train (VOST)
                    testing for volatile organic priority pollu-
                    tant emissions (test 2 only);  HCI  train
                    sampling (test 2 only); gas grab sampling
                    for N2O emissions  measurements; and
                    grab  sampling of fuel ash bottom and
                    cyclone  collector hopper  for inorganic
                    composition determination.
                      NOX,  total unburned  hydrocarbon
                    (TUHC), and solid participate emissions
                    were relatively unchanged for the two
                    tests, averaging 286 and 214 ppm, <2 and
                    3ppm, and 54 and 69 mg/dscm, respec-
                    tively, for tests 1 and 2. The emitted par-
                    ticle  size distribution was  apparently
                    unchanged  as  well. SOX  emissions
                    decreased with the coal/PET fuel in keep-
                    ing with its lowered sulfur content. S02
                    and SO3 levels were 930 and  640  ppm.
and 4.4 and 2.5 ppm (all corrected to 3
percent O2), respectively, for tests 1 and
2. Average CO emissions at 81 ppm were
also decreased in test 2, from 184 ppm in
test 1, apparently due to higher excess air
levels in test 2. HCI emissions were mea-
sured at 336 ppm (at 3 percent 02) with
the coal/PET fuel;  however, this level is
almost 3 times that which was accounted
for by the fuel chlorine level.
  Flue  gas  emissions of most trace
elements were comparable for both tests,
as were the trace element compositions
of corresponding ash streams. However,
estimated lead emissions (1,100 ^g/dscm)
were significantly  increased for test 2
when compared to levels for test 1 (30
^g/dscm). This increase apparently reflects
the increased lead content of the mixed
coal/PET fuel, the increased lead coming
inexplicably  from the PET additive. The
cyclone hopper ash for the coal/PET test
had consistently lower leachable trace ele-
ment and anion content than that for the
coal fuel test.
  Total flue gas organic emissions were
comparable  for  both  tests,  in the  1
mg/dscm range. Most (90 percent) of the
flue gas organic  was nonvolatile (boiling
point greater than about 300 °C). Of the
semivolatile  organic priority pollutants,
napthalene was detected in flue gas sam-
ples for both tests, emissions increased
from about 2 (test 1) to 16 ^g/dscm (test
2) with the coal/PET fuel. Phenanthrene,
f luoranthene, and phenol were present in
test 2 at  levels  ranging from 2 to 20
Mg/dscm; they were not detected in test
1. In addition, several phthalates were
measured in the test 2 flue gas at levels
of 0.4 to  6  /jg/dscm, while none were
found in test 1. Phthalates present at such

-------
levels are often ascribed to sample con-
tamination; however, the observed in-
creased emissions of these with the coal
/PET in these tests may be real.
Of the volatile organic priority
pollutants, several chlorinated C, and C2
hydrocarbons, chlorobenzene, toluene.
and ethylbenzene were measured in the
test 2 flue gas at levels of 1 to 25 pig/dscm.
This Project Summary was developed
by EPA's Air and Energy Engineering
Research Laboratory, Research Triangle
Park, NC, to announce key findings of the
research project that is fully documented
in two separate volumes of the same title
(see Project Report ordering information
at back).

Introduction
Some states, Vermont included, are now
requiring deposits on beverage containers
as a means of controlling litter and en-
couraging recycling and reuse. Plastic
beverage containers cannot be reused as
containers; however, one way to reclaim
these is to use them as a fuel supplement
in an energy recovery operation. In one
Table 1, Summary of Boiler Operation and Fuel Analyses
Test 1
(coat fuel)
Boiler operation (over the SASS
sampling period)
Steam load, kg/s (1O3 Ib/hrl
Steam pressure, kPa (psig)
Feedwater inlet temperature, °C (°F)
Stack temperature, °C (°F)
Firebox temperature, °C (°F)
Fuel feedrate, kg/hr (Ib/hr)
Excess air, percent
Boiler efficiency, percent
Fuel ultimate analysis (percent
by weight as fired)

Carbon
Hydrogen
Sulfur
Nitrogen
Oxygen3
Ash
Moisture
Chloride
Higher heating value, kJ/kg (Btu/lb)
PET, weight percent
aBy difference.

0.38 (3.0)
17 (2.5)
12 (54)
146 (295)
768 (1,415)
110 (240)
47
79.3



69.5
5.2
1.0
1.5
11.4
8.5
2.7
0.2
31,212 (13,450)
0

Test 2
(coal/PET fuel)

0.42 (3.3)
21 (3.0)
13 (55)
165 (329)
882 (1,620)
130 (285)
77
79.1



71.4
5.5
0.6
1.4
11.7
6.8
2.4
0.2
31,270 (13,479)
16.4

such project, the use of waste PET bot-
tles is being evaluated as a fuel supple-
ment in a commercial boiler at a quarry
and stonecutting plant in Barre, Vermont.
Past efforts have indicated that PET is a
clean-burning, high-heating-value fuel with
no apparent environmental problems as-
sociated with its use as a solid fuel sup-
plement. The tests described in this report
were performed to confirm that this is the
case by performing a comprehensive eval-
uation of the emissions and ash discharge
compositions from a  boiler burning its
typical coal fuel and a coal/PET mixture.
  The boiler tested is a coal-fired firetube
unit with an underfeed stoker.  The unit is
rated at 0.6 kg/s steam at 100 kPa (4,640
Ib/hr at 15 psig).  Nominal full load coal
feed rate  is 180 kg/hr (400 Ib/hr). The
boiler was equipped with a cyclone collec-
tor for particulate emissions control.

Summary and Conclusions

Boiler  Operation
  The test program called  for flue gas
emission  measurements  and  ash dis-
charge stream sampling with the boiler
operating at constant, near-rated capacity
with both fuels. Two tests were perform-
ed: test 1 with the unit firing its typical
coal fuel, and test 2 with a coal/PET mix-
ture containing  about  16 percent  by
weight granulated PET beverage bottles.
  Table 1 summarizes the boiler operating
conditions and the fuel ultimate analysis
for both tests. As indicated, test 2 was run
at about the same coal feedrate as test 1
(110 kg/hr); however, the test 2 fuel mix-
ture contained about 20 kg/hr  of added
waste PET. Consequently heat input and
boiler load were slightly higher for test 2.
Boiler efficiency, calculated by the ASME
heat loss method, was unchanged  at
about 79 percent. The boiler underwent
some load excursions during test 2. These
excursions  could  have some effect on
emissions over and above the change in
fuel composition.

Emission Measurements and Results
  The sampling and analysis procedures
used in this test program conformed to an
extended EPA Level 1 protocol. All flue gas
was sampled in the unit's  stack, down-
stream of the cyclone collector, except for
the continuous  flue gas analyzers which
were operated both at the stack and at the
boiler  exit.  Emission  measurements
included:
  •  Continuous monitoring for 02, C02,
     NOX, CO, and TUHC.
  •  Source assessment sampling system
    (SASS) for trace elements and semi-
    volatile  and non-volatile organic
    emissions.
  • Volatile  organic  sampling  train
     (VOST) for volatile organic emissions
     (test 2 only).
  •  Combined  EPA Method 5/8 for par-
    ticulate and SOX.
  • HCI train sampling.
  • Grab samples for N2O analysis.
In addition, samples of the fuel, bottom
ash, and a cyclone hopper ash were col-
lected for analysis. The analysis protocol
included:
  • Performing proximate, ultimate, and
    heating value analyses of fuel sam-
    ples, and ultimate analyses of bottom
    and cyclone hopper ash samples.
  • Analyzing the fuel, ash,ash aqueous
    leachates,  and  SASS train samples
    for 73  trace elements using spark
    source  mass spectrometry (SSMS),
    supplemented by atomic absorption
    spectrometry (AAS).
  • Analyzing ash aqueous leachates for
    selected   anions   using   ion
    chromatography.
  • Analyzing VOST traps for the volatile
    organic priority pollutants.
  • Analyzing  ash  sample  organic  ex-
    tracts for  total nonvolatile organic
    content by gravimetry (GRAV).
  • Analyzing the SASS train organic ex-
    tract samples for total organic con-
    tent in two boiling point  ranges: 10C
    to 300 °C by total chromatographic
    organics (TCO) analysis, and >300°C
    by GRAV.
  • Analyzing  the  SASS train  extrad
    samples for the 58 semivolatile or
    ganic species, including  many of the
    polynuclear  aromatic hydrocarbor
    (PAH) compounds.

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   •  Performing infrared (IR) spectrometry
     analysis of organic sample extracts.
   •  Performing  liquid chromatography
     (LC)  separation of selected sample
     extracts with subsequent TCO, GRAV,
     and  IR  analyses  of  eluted  LC
     fractions.
   Bioassay tests were also performed on
SASS train and ash samples to estimate
their potential toxicity  and mutagenicity.
   Table 2 summarizes flue gas emissions
measured in the test program. Emissions
are presented as  nanograms per Joule
heat input and as milligrams per dry stan-
dard cubic meter of flue gas. As a measure
of the potential significance of the emis-
sions levels  for  further  monitoring or
evaluation,  an occupational exposure
guideline for most pollutants is also noted
in the table. The  occupational exposure
guideline noted   is  either  the  time-
weighted-average  Threshold Limit Value
(TLV) established by the  American Con-
ference of Governmental Industrial  Hy-
gienists, or the 8-hr time-weighted-aver-
aged  exposure limit established  by the
Occupational Safety and Health Admin-
istration (OSHA). These are noted only to
aid in ranking the potential significance of
the emission levels. In this respect,  pol-
lutants emitted at levels several orders of
magnitude higher than their occupational
exposure guidelines might warrant further
evaluation, while species emitted at levels
significantly lower than their occupational
exposure guidelines might be considered
of lower priority. Only elements emitted at
levels exceeding 10 percent of their occu-
pational exposure guidelines in these tests
are noted in Table  2.
   Table 2 shows that flue gas concentra-
tions of chromium, sodium, nickel, iron,
lead, and cobalt were significantly higher
for test 2 than for test 1. The test 2  flue
gas levels for all these (except cobalt) were
also greater than their respective occupa-
tional exposure guidelines. The higher  lead
emissions for test 2, are thought to be ac-
tual  increases. The coal/PET  fuel  had
significantly higher lead content (28 ppm)
than did the coal itself (3 ppm). The source
of the added lead is apparently the waste
PET, although no  lead source within the
PET is known. Unfortunately, the trace ele-
ment emission levels noted in Table 2 for
test 2 are based on an estimated 1 to 3
/urn SASS train paniculate emission  rate
and the assumption that the Mo 3 urn par-
ticulate had the same composition as the
less-than-1-/dn paniculate  (the 1 to 3 urn
SASS particulate  sample for test 2 was
destroyed in transit from the field to the
laboratory). Consequently, the significance
Table 2.    Summary of Flue Gas Emissions8
                                         Concentration
                              Test 1 (coal fuel)    Test 2 Icoal/Pet fuel)
Component

(ng/J
heat input)

(mg/dscm)

(ng/J
heat input)

(mg/dscm)
Occupational
exposure
guideline
(mg/m3)b
Major constituents

  NOX (as NO2)
  SO2
  S03
  CO
  HCI
  Solid particulate
  Total semivolatile
    organics (TCO)
  Total nonvolatile
    organics (GRAV)

Trace elements
176
800
4.6
69
_c
35

0.049

0.575
270
1,210
7.0
105
_c
54

O.075

0.875
165
690
3.4
38
206
41

0.071

0.641
280
1,160
5.7
64
347
69

0.12

1.08
6.0
5.0
1.0
55
7.0*
10*
Chromium, Cr
Sodium, Na
Nickel, Ni
Iron, Fe
Lead, Pb
Phosphorous, P
Arsenic, As
Aluminum, Al
Lithium, Li
Calcium, Ca
Beryllium, Be
Silicon, Si
Potassium, K
Cobalt, Co
Cadmium, Cd
Vanadium, V
Copper, Cu
Platinum, Pt
Silver, Ag
Selenium, Se
Barium, Ba
0.0065
0.42
0.017
2.05
0.020
1.39
0.011
1.38
>0.017
1.24
0.00063
>1.52
0.59
0.0019
0.0016
0.011
0.020
_h
0.0017
0.0068
0.036
0.010
0.65
0.027
3.18
0.030
2.15
O.017
2.15
>O.026
1.93
0.00097
>2.36
O.91
0.003
0.0025
0.018
0.032
_h
0.0026
0.010
0.056
3.03
63
2.23
16.2
0.65
0.79
0.029
1.43
>0.081
0.28
0.00093
3.00
0.57
0.024
0.010
0.0073
0.021
0.00031
0.0010
0.024
0.012
5.17
107
3.81
27.6
1.10
1.35
0.049
2.45
>0.014
0.49
0.0016
5.12
0.97
0.041
0.018
0.012
0.035
0.00052
0.0018
0.041
0.021
0.05
2.0?
0.10
1.0
0.0503
0.10
0.010
2.0
0.025
2.0
0.002
10°
2.0*
0.10
0.0 5d
0.050
0.109
0.002
0.010
0.20
0.50
aFlue gas O2 and CO2 averaged 7.0 and 12.0 percent (dry) for test 1 and 5.2 and
  12.9 percent for test 2.
b Time-weighted average TLV unless noted.
CHCI sampled for test 2 only.
dCeiling limit.
eFor nuisance particulate.
fNo occupational exposure guideline applicable.
g8-hour time-weighted-average OSHA exposure limit.
hLess than the method detection limit.
of the increased lead emission levels cited
deserves further study.
  Several possibilities exist to explain the
higher  concentration  of  chromium,
sodium,  nickel, iron,  lead,  and  cobalt.
These are conjectures, however, so addi-
tional  sampling and  analysis may  be
merited.
  Emission levels of the other elements
noted in  Table  2 were quite comparable
between the two tests. In fact, the trace
element content of all SASS train samples
(except the impinger solution and lead in
              the fine particulate noted above), the bot-
              tom ash, and the cyclone hopper ash were
              quite comparable for both tests.
                The data in Table  2 show that boiler
              emissions of  NOX, solid particulate, and
              total semi- and non-volatile organics were
              relatively unchanged with the addition of
              the PET to the boiler fuel.  Emissions of
              S02, and S03 were decreased, in keeping
              with the  lower sulfur content of  the
              coal/PET fuel (the apparently small  dif-
              ference noted in Table 2 is amplified con-
              siderably when corrected in each instance

-------
to a common flue gas 02 level; e.g., 3 per-
cent). On a mass loading basis, total sulfur
emissions were relatively unchanged due
to the constant coal firing rate. CO emis-
sions were decreased with the coal/PET
fuel as well due probably to the higher level
of excess air used with the mixed fuel.
  The HCI emission level noted in Table 2
for test 2 corresponds to almost 3 times
the amount  which would be expected
from the chlorine content of the fuel. The
above discussion regarding the possible in-
troduction  of inorganic chloride  into the
SASS train suggests that perhaps ex-
traneous chloride was introduced into the
HCI train as well. This train measures total
vapor phase (at stack temperature)  in-
organic chloride, not strictly  HCI.
  Further  analysis  of the  SASS  train
organic  sorbent module extract via  LC
fractionation and IR  spectroscopy of both
the total extract and the eluted  LC frac-
tions suggests that the organic emissions
for both tests were roughly 25 to 35 per-
cent aliphatic hydrocarbons,  40 percent
less polar oxygenated hydrocarbons, and
25 to 35 percent more polar oxygenates.
  Table 3 summarizes the organic priority
pollutant emission results. Emission levels
of the semivolatile compounds detected
were  significantly  increased with  the
coal/PET fuel, despite the fact that total
semivolatile  organic  emissions  were
relatively  unchanged.  The  phthalates
noted in the table could be sample con-
taminants.  Phthalates are common con-
taminants in SASS train samples  at levels
comparable to those noted  in Table 3.
However, that levels detected in  the test
2 samples were generally significantly
higher than those in the test 1 samples,
and that phthalates are expected to  be
found in PET, suggest that these com-
pounds may actually have been present in
the test 2 flue gas.
  Table  3 also notes  that several chlor-
inated C1 and C2 aliphatic hydrocarbons,
chlorobenzene, toluene, and ethylbenzene
were  emitted during test 2  at levels of
from <1 to about 24 ^g/dscm. The levels
of  the   aromatic  hydrocarbons  noted
(toluene and  ethylbenzene)  are in the
range typically encountered in VOST tests
of combustion sources. The source of the
chlorinated compounds is not clear,  al-
though these compounds do  arise when-
ever chlorine,  even  inorganic chloride, is
introduced into a combustion process. It
is interesting that these compounds were
detected in the test 2 flue gas, the same
test with apparent  chloride introduction
into the  SASS train, and unaccountably
high (perhaps again due to extraneous flue
 Table 3.    Summary of Organic Priority Pollutant Emissions

                                                  Emission concentration fog/dscm)
        Compound
                    Test 1
                  (coal fuel)
         Test 2
     tcoal/PET fuell
 Volatile organic priority
  pollutants:

    Chloromethane
    Chloroform
    1,2-Dichloroethane
    Trichloroethylene
    Tetrachloroethylene
    Toluene
    Chlorobenzene
    Ethylbenzene

Semivolatile organic priority
  pollutants:
                                         1.0
                                         4.5
                                         2.0
                                         24
                                         2.5
                                         14
                                         7.5
                                         0.7
Naphthalene
Phenanthrene
Fluoranthene
Phenol
Bis(2-ethylhexyl)phthalate
Diethyl phthalate
Di-n-butyl phthalate
2.2
>0.4
>0.4
>0.4
4.4
>0.4
>0.4
16
3.0
2.2
20
4.2
6.0
O.4
aVolatiles sampled for test 2 only.
gas chloride) chloride emissions measured
with the HCI train.
  Table 4 summarizes the results of the
nonvolatile (GRAV) organic analyses of the
bottom ash and cyclone hopper ash ex-
tracts. For test 1, only the cyclone hopper
ash contained measurable levels of non-
volatile organics.  For test 2, the organic
content  of  the  bottom ash increased,
although that of the cyclone hopper ash
was about half that for test 1. The  total
ash loading was less in test 2 than test 1.
In test 1, total ash was 13.5 percent of fuel
fed, whereas ash was only 8.2 percent in
test  2. For both tests, cyclone ash was
about 3 percent of  total ash.
  Infrared spectra of bottom ash extracts
suggest that only aliphatic hydrocarbons
were present. Analyses of cyclone ash ex-
tracts via LC fractionation and IR spec-
troscopy suggest that these contain: 30
to 40 percent aliphatic hydrocarbons,  15
to 20 percent less polar oxygenated hydro-


Table 4.   Ash Stream Total Organic Content
         carbons (e.g., aldehydes and ethers), and
         40 to 55 percent more polar oxygenates
         (e.g.,  carboxylic  acids,  alcohols,  and
         ketones).
           Table 5 summarizes the concentrations
         of the priority pollutant trace metals in
         aqueous leachates of the ash stream sam-
         ples prepared according to Level 1 guide-
         lines. As a measure of the potential signif-
         icance of these concentrations for further
         analyses,  the water quality criterion for
         each element is noted in the table. Again,
         these are noted only to aid in ranking the
         potential significance of the teachable ele-
         ment levels noted. Only elements having
         at least one leachate concentration greater
         than its water quality criterion are noted.
         On a mass flow basis, it is noteworthy that
         the ash mass flow was 40 percent lower
         for test 2.
           The  data in Table 5 show that the cy-
         clone ash leachates for both tests con-
         tained  considerably  higher levels of the
                                        Total nonvolatile organics by gravimetry
                                                   (mg/kg ash)
      Sample
Test 1 (coal fuel)
Test 2 (coal/PET fuelt
Bottom ash

Cyclone hopper ash
 >80

 1,100
       220

       5OO

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Table 5.   Inorganic Priority Pollutants in Ash Leachates at Concentrations Exceeding
           Their Water Quality Criteria

              Bottom ash leachate
              concentration (\ng/l)
                                        Cyclone hopper
                                        ash leachate
                                      concentration lug/1)
Element

Test 1
(coal)

Test 2
(coal/PET)

Test 1
(coal)

Test 2
(coal/PET)
Water
quality
criterion
(mg/l)
Arsenic
                  0.030
                    0.0 JO
                                           4.1
                                                        0.20
2.2 x 10
                                                                           -5a
Beryllium
Nickel
Selenium
Chromium
Cadmium
Thallium
Mercury
Lead
Barium
Antimony
>O.OOJ
0.01
0.10
0.02
>0.001
>0.001
0.002
>0.004
0.06
>0.004
>0.002
0.02
0.10
0.06
0.004
>0.002
>0.001
0.009
0.30
0.20
0.32
4.0
0.80
3.7
0.17
0.21
>0.001
0.27
2.1
0.15
0.070
0.80
0.2O
1.0
0.10
0.09
>0.001
0.10
0.05
0.05
3.7 x 10'
0.0134
0.010
0.050
0.010
0.013
1.44 x 10
0.050
1.0
0.146
5*





-4



a Water quality criterion based on cancer risk; level noted
 corresponds to increased lifetime risk of 10~5.
inorganic priority pollutants than did the
bottom ash leachates. The test 2 bottom
ash  leachate  contained slightly  higher
levels  of most of the elements  noted.
However, the cyclone ash leachate for test
2 contained significantly lower levels of all
the elements  noted (with the possible
exception of mercury). This suggests that
the addition of waste PET to the boiler's
fuel may have had the beneficial effect of
decreasing leachable toxic trace element
discharges in  the cyclone hopper ash
stream. This effect is augmented by the
observed 40 percent reduction in ash out-
put in  test 2 relative to fuel flow.
  Table 6 summarizes the leachable anion
content of the  ash stream aqueous leach-
ates. As for the inorganic priority pol-
lutants, the anion levels in cyclone ash
leachates are  significantly higher than
those of bottom ash leachates. However,
no consistent  trend  in composition  be-
                               tween corresponding ash leachates for the
                               two tests is apparent.  Interestingly, the
                               chloride and sulfate concentrations in the
                               test 2 ash stream leachates are  slightly
                               lower than those from test 1. One might
                               expect that, if a corrosive component were
                               present in the test 2 combustion  gas, as
                               implied by the results of the SASS, HCI,
                               and VOST analyses discussed above, evi-
                               dence of this component would appear in
                               the ash leachates, especially the cyclone
                               ash leachate. An alternative explanation
                               would be that the component was  present
                               in the vapor phase at the cyclone temper-
                               ature, although this seems unlikely.
                                 Bioassay tests  were performed  on the
                               SASS train organic sorbent module  extract
                               and the ash stream samples. The health
                               effects  bioassays  included  the  Ames
                               mutagenicity assay and the CHO cytotox-
                               icity assay. The results of these assays are
                               summarized in Table 7.  The results sug-
Table 6.
Ash Stream Leachable Anion Analysis Results
                            Concentration (mg/l)
                        Test 1 (coal fuel)
                                             Test 2 (coal/PET fuel)
An ions
Chloride
Fluoride
Nitrate
Nitrite
Phosphate
Sulfate
Sulfite
Bottom
ash
leachate
2.6
0.25
>1.0
>1.0
>1.0
300
20
Cyclone
hopper ash
leachate
300
0.46
>10
>10
>10
19,000
5,000
Bottom
ash
leachate
1.3
0.10
>1.0
>1.0
>1.0
220
20
Cyclone
hopper ash
leachate
180
1.8
>10
>10
>10
12,000
5,000
gest that the flue gas was of moderate to
high toxicity and mutagenicity for both
tests. The cyclone hopper ash had nonde-
tectable toxicity for both tests. However,
this sample's  mutagenicity apparently
decreased from borderline moderate/high
in test  1 to borderline low/moderate for
test 2. This observation is consistent with
the decreased leachable arsenic and beryl-
lium contents  noted in Table 5, and con-
firm that the addition of waste PET to the
unit's fuel  may have and the beneficial
effect of decreasing the potential environ-
mental  hazard  posed by  this discharge.
  The  positive Ames responses for the
sorbent module extracts  noted above are
typical for such extracts from SASS tests
of combustion sources.  Current studies
are investigating if such  bioassay re-
sponses are due to  artifact compounds
formed when  combustion product gas
containing  NOX is  passed over XAD-2
resin.
  Quality assurance  (QA) performed for
these tests to establish the percision and
accuracy of the laboratory analyses gen-
erally gave  results within the project QA
objectives for these measures. However,
the precision of the  SSMS analyses, as
determined by analysis of blind duplicate
samples, was of only borderline accepta-
bility and the accuracy of  this analysis, as
determined by analyzing a blind audit sam-
ple, was not generally within a factor of
3 as specified  by Level 1  protocol. How-
ever, this failure to  achieve reasonably
good  precision and  accuracy has  little
effect on test conclusions. The conclusion
that corresponding  samples from both
tests had comparable trace element com-
positions (except for lead) should be unaf-
fected.  The high lead levels  in test 2
samples were quantified  using AAS ana-
lyses, which met appropriate QA objec-
tives for precision and accuracy. The con-
clusions that cyclone ash leachates had
significantly higher trace element concen-
trations than bottom ash leachates, and
that the test 1  cyclone ash leachate had
higher trace element  concentrations than
that from test 2, were based on observed
order of magnitude differences. Further-
more, these differences were often sub-
stantiated by AAS analyses which, again,
met appropriate QA  objectives.

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Table 7.    Bioassay Results
                                                   Bioassay response3
Test Sample
1 (coal) XAD-2 extract
Bottom ash
Cyclone hopper ash
2 fcoal/PET) XAD-2 extract
Bottom ash
Cyclone hopper ash
Ames
mutagenicity
H
ND
M/H
M
ND
L/M
CHO
clonal
toxicity
M
ND
ND
H/M
ND
ND
aND — Nondetectable mutagenicity/toxicity.
L — Low mutagenicity/toxicity.
M — Moderate mutagenicity/toxicity.
H — High mutagenicity/toxicity.
   R. DeRosier, H. Lips, andL. Water/and are withAcurex Corp., Mountain View, CA
     94039.
   Joseph A. McSorley is the EPA Project Officer (see below).
   The complete report consists of two volumes, entitled "Environmental Assess-
     ment of a Commercial Boiler Fired with a Coal/Waste Plastic Mixture:"
     "Volume I.  Technical Results," (Order No. PB 86-183 811/AS; Cost: $16.95)
     "Volume II. Data Supplement," (Order No. PB 86-183 829/AS; Cost: $22.95)
   The above documents will be available only from: (cost subject to change)
          National Technical Information Service
          5285 Port Royal Road
          Springfield,  VA 22161
          Telephone: 703-487-4650
   The EPA Project Officer can be contacted at:
          Air and Energy Engineering Research Laboratory
          U.S.  Environmental Protection Agency
          Research Triangle Park,  NC 27711
                                                          ' -&U. S. GOVERNMENT PRINTING OFFICE:1986/646-116/20847

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