United States
                    Environmental Protection
                    Agency
Hazardous Waste Engineering
Research Laboratory
Cincinnati OH 45268
                    Research and Development
EPA/600/S2-86/059 Sept. 1986
v>EPA          Project Summary
                    Field  Evaluation  of Resource
                    Recovery  of  Hazardous
                    Wastes

                    A. W. Wyss, C. Castaldini, and M. M. Murray
                     The overall objective of this study
                    was to  evaluate the effectiveness of
                    two process kilns in destroying haz-
                    ardous wastes and quantify stack gas
                    emissions. During two 1-week field
                    testing programs, samples of the haz-
                    ardous wastes fired in the kilns were
                    collected and analyzed for principal or-
                    ganic hazardous constituents (POHCs),
                    selected trace metals, and chlorides. Air
                    emissions were sampled and analyzed
                    for paniculate matter (including trace
                    metals); volatile and semivolatile
                    POHCs found in  the wastes and other
                    products of incomplete combustion
                    (PICs); and criteria pollutants including
                    sulfur oxides, nitrogen oxides, carbon
                    monoxide, and hydrochloric acid. Test
                    results indicated that destruction and
                    removal efficiencies (DREs) of POHCs at
                    one site failed to meet the 99.99 percent
                    level. POHC DREs at the  second site
                    were generally above this level. This
                    disparity of results was attributed to a
                    difference in kiln operating tempera-
                    ture. Benzene, chlorobenzene, and car-
                    bon tetrachloride showed lowest DREs
                    at both sites. Total PIC mass emissions
                    accounted for 25 to 80 percent of the
                    total  measured  POHC breakthrough.
                    Trace element emissions,  which were
                    generally below 10 percent of the meas-
                    ured input rate, were dependent on the
                    collection efficiency of the particulate
                    control devices and waste firing rates.
                     This Project Summary  was devel-
                    oped by EPA's Hazardous  Waste Engi-
                    neering Research Laboratory, Cincin-
                    nati, OH, to announce key findings of
                    the research project that is fully docu-
mented in a separate report of the same
title (see Project Report ordering infor-
mation at back).
Introduction
  The full report describes emission re-
sults obtained from field testing of two
rotary process kilns burning liquid  haz-
ardous chemical wastes. The primary
objective of the tests was to evaluate
the destruction and removal efficiency
(ORE) of principal organic hazardous
constituents (POHCs) in these waste
fuels and identify  products of incom-
plete combustion (PICs) emitted from
the two kilns. This work was supervised
by the Hazardous  Waste  Engineering
Research Laboratory of the Environ-
mental  Protection Agency (EPA-
Cincinnati) under  contract no. 68-02-
3176, task 4B.


Kiln Descriptions
  Figure 1 is a schematic of the site I kiln
facility tested in this program and sum-
marizes the key design and  operating
features. Site I  is  a rotary kiln dryer
tested at a capacity of about 10 kg/s (40
tons/hr) when fired with a heat input ca-
pacity of approximately 11 MW (37.5
million Btu/hr). The kiln dries earth-type
clays, reducing  the moisture content
typically from 50 percent to 8 percent.
The 8 percent clay  product is marketed
as cat litter and as an impermeable liner
for ponds. This product can be further
processed to reduce the moisture to 0.5
percent, resulting in a product that is

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                    Surge Tank f~150 gal)
                                                                              Raw Clay
                      Cl    .      Fuel
                      Electnc     strainers
                      Preheaters
                                                                                                                Exhaust
                                                                                                                Gas
             Waste
              Oil
            Storage
           20,000 gal
                              I
 Blended
   Fuel
 Storage
20,000 gal
Atomization
Air
                                                   I®
                                                   *Dryed Clay
                                                   Product
                                                                                                           Collected
                                                                                                           Dust
         Fuel Pump
                                            Compartmented Truck
                   Kiln length, m (ft)
                   Kiln diameter, m (ft)
                   Kiln rotation, rpm
                   Feed material
                   Process capacity, kg/s (tons/hr)

                   Feed material moisture, percent
                   Product moisture, percent
                   Process temperature, °C (°F)

                   Estimated gas residence time, sec
                   Typical heat input at capacity.
                    MW (million Btu/hr)
                   Fuel fired

                   Paniculate control device
                                                                       Waste Solvent Storage
                                   21.3(70)
                                   2.1 (7)
                                   6.25
                                   Earth-type clays
                                   10 (40)

                                   50
                                   8'
                                   590 to 650
                                     (1, WO to 1,200)
                                   2.5
                                   11.0(37.5)

                                   Waste oils and waste
                                     solvents
                                   Fabric filter baghouse
                                                                                                  Sample Collection
                                                                                                  Location
                                         "Product can be reprocessed for 0.5 percent moisture
Figure 1,    Process flow schematic and sample collection locations—site I.
 marketed as an oil  and grease ab-
 sorbant. However, the principal product
 at site I is the 8 percent clay.
  The plant receives  and stores burn-
 able liquid wastes. These wastes are
 blended with reclaimed or virgin oil be-
 fore being fired  in the kiln.  The single
 burner is fired with a typical 20/80 mix-
 ture of waste fuel and reclaimed oil, re-
 sulting in an early combustible fuel. The
 kiln process temperature ranges be-
 tween 590° and 650°C (1,100  and
 1,200°F)  with an estimated gas resi-
 dence time of 2.5 sec. This is a relatively
 low-temperature environment for  effi-
 cient hazardous waste destruction.  Flue
 gas paniculate emissions are controlled
 with a fabric filter baghouse.
  Figure  2 is a schematic of the site II
 kiln facility tested in this program and
 summarizes the key design and operat-
                   ing features. Site II is a rotary aggregate
                   kiln  that processes shales into  a
                   lightweight aggregate material by pro-
                   moting various heat activated chemical
                   reactions and liberating carbon dioxide
                   from the raw material. This causes the
                   aggregate to  expand,  resulting  in  a
                   lightweight product. A process temper-
                   ature greater than 1,040°C  (1,900°F)  is
                   generally required to achieve this reac-
                   tion. The kiln capacity of site II is about
                   2.5 kg/s (12 tons/hr). Its typical produc-
                   tion rate is between 2.3 and 2.5 kg/s (9 to
                   12 tons/hr), requiring a heat input on the
                   order of 7.9 to 8.8 MW (26 to 30 million
                   Btu/hr). The gas residence time is about
                   equal to that of the site  I kiln at 2.3 sec.
                   The fuel burned is generally a combina-
                   tion  of pulverized coal  and hazardous
                   waste solvents injected through two
                   concentric burners.
                                               Liquid waste solvents, transferred
                                             from an isolated tank farm, are air atom-
                                             ized and injected into the kiln along with
                                             pulverized coal. Additional air is pulled
                                             into the kiln through openings near the
                                             flame end of the kiln by an induced draft
                                             (ID) fan. Fuel flow is adjusted by a con-
                                             troller that measures the temperature of
                                             the kiln wall, compares this value with a
                                             present level, and adjusts the fuel flow
                                             accordingly. The maximum permitted
                                             liquid fuel  firing  rate is 370 ml/s (350
                                             gph). Dust-laden  gases from  each kiln
                                             are treated in separate air cleaning sys-
                                             tems consisting of a  multiclone fol-
                                             lowed by a crossflow gravity spray wet
                                             scrubber. Spent scrubber water is sent
                                             to a settling pond for clarification before
                                             being discharged to a local stream. Dust
                                             collected by the multiclone  is landfilled
                                             or sometimes reprocessed in the kiln.

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        Atomization I Expanded
        Blower for  j Product
        Solvent    \^_Pulverized_ Coal
Shale From Conveyor
Mechanical
Collector
	 ^ 	 v Exhaust
r-i -. x Gas
V \
\ Water
Hopper \ From ~~]
led 	 „ \ Lake i
fl'e/- V/ \ |
> \ LJ
Dust Emergency'^
	 1 \ Bypass
"*==^ Coal From^.. 	 ,


Lciassff^r Blower 1 ^ CM/fl//j /D Fa/,
-J-H-^fCp-n ! kj
SfacA
S'°raffe *(9)
Tank I&1
Pump '
CP~i® !
,.L,-.,..T.., |
Scrubber i®
To D/fc/7, Settling
Ponds, and Streams
     fla//
                 ,,,>
                                Kiln length, m (ft)
                                Kiln diameter, m (ft)
                                Kiln rotation, rpm
                                Feed material
                                Process capacity, kg/s (tons/hr)

                                Feed material moisture, percent
                                Product moisture, percent
                                Process temperature, °C (°F)

                                Estimated gas residence time, sec
                                Typical heat input at capacity,
                                  MW (million Btu/hr)
                                Fuel fired

                                Paniculate control device
                                NA—not available.
                       38.1 (125)
                       2.7(9)
                       1.1
                       Shale
                       2.3 to 2.5 (9 to 10)

                       NA
                       NA
                       1,120 to 1,180
                         (2,050 to 2,150)
                       2.3
                       7.9 to 8.8
                         (27 to 30)
                       Pulverized coal and
                         liquid waste
                       Mechanical collector
                         and wet scrubber
         	Coal
         	Exhaust gas
         	 Scrubber water
         = Aggregate
         	Waste solvent
          ®  Sample collection locations
figure 2.    Process flow schematic and sample collection locations—site II.
Test Program
  The test program at site I consisted of
three tests with the kiln firing a blend of
liquid waste and waste oil. Four tests
were performed at site  II.  During  the
first two tests the kiln fired a combina-
tion of pulverized coal and liquid waste.
This mode of operation is typical for this
site. During the remaining two tests, the
kiln  was fired with liquid  waste only.
Table 1  summarizes  the  operation of
both kilns during these tests. Significant
burner combustion stability problems
were experienced during the first test at
site I. These  problems, which caused in-
terruptions  in the test program, were
believed to  result from excessive pre-
heating of the waste fuel mixture. This
excessive preheating was corrected
during the second and third tests. Kiln
operation at site II was uninterrupted by
any recorded upsets due to combustion
conditions.

Sampling and Analytical
Protocols
  The primary objective of the test pro-
gram was to evaluate the DRE of haz-
ardous organic compounds in the liquid
waste fuel and to determine  the  type
and quantities of PIC emissions. There-
fore, the sampling and analytical proto-
cols focused  on measuring  the  hazr
ardous organic  constituents  in the
liquid waste fuels and flue gas streams
and quantifying the mass flow rate of
each stream. Tables 2 and 3 summarize
the protocols used at each test site. Fig-
ures 1  and 2 indicate sample collection
locations.
  Composite samples of the waste fuels
were collected and analyzed for POHC
concentrations of volatile  and non-
volatile organics. Trace metals, total
chlorides and proximate/ultimate analy-
ses were  also performed on each fuel
burned during the tests. All flue gas
emissions were measured at the stack
downstream of particulate  collection
devices. Measurement equipment used
at both sites included continuous gas
monitors, volatile organic  sampling
train (VOST) and a modified version of
the EPA Method 6 sampling train for HCI

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 Table 1.    Summary of Kilns Operation
                  Kiln
        Test   production
 Site   number kg/s (tons/hr)
                                Waste fuel flowrate,
                                    ml/s (gph)
                           Waste fuel heat input
                Test         MW       Percent
   Range       average   (million Btu/hr)a   of total
1


II



1
2
3
1C
2c
3
4
-6.8
-7.6
-7.6
2.17
2.25
2.19

(27)b
(30)b
(30)"
(8.62)
(8.94)
(8.69)
NA
205-216
226-263
220-252
220-284
142-255
270-348
270-354
(195-205)
(215-250)
(209-240)
(209-270)
(135-243)
(257-331)
(257-337)
210
238
237
242
197
315
318
(200)
(226)
(225)
(230)
(187)
(300)
(302)
7.45
8.41
8.39
6.07
5.01
8.50
8.71
(25.4)
(28.7)
(28.6)
(20.7)
(17.1)
(29.0)
(29.7)
100
100
100
59
47
100
100
 Calculated from the fuel higher heating values.
 bNot a measured value.
 cTests 1 and 2 correspond to the kiln firing a combination of waste fuel and pulverized coal.
 During Tests 3 and 4, the waste fuel accounted for 100 percent of the fuel fired in the kiln.
 NA—Not available.
measurements. Paniculate emissions
were also  sampled  using the  EPA
Method 5 equipment and protocol. This
sampling train was modified for site I to
allow sampling of semivolatile and non-
          volatile organics using an organic sor-
          bent cartridge.  Solid and liquid waste
          discharge streams from particle collec-
          tion devices were also sampled. Analy-
          ses of these streams were limited to wet
                    scrubber effluents for volatile organics,
                    trace metals and chlorides. No volatile
                    organics were detected  in  the wet
                    scrubber effluent collected during these
                    tests. Kiln products were not part of the
                    sampling and analysis protocol.
                     Waste fuels at both sites were artifi-
                    cially spiked with a known quantity of
                    1,1,2-trichloro-2,2,1-trifluoroethane
                    (Freon 113) to permit a direct compari-
                    son of ORE results between these two
                    kilns and to investigate the feasibility of
                    using this compound as a surrogate for
                    DRE measurements of other major
                    POHCs present in the waste fuels.
                   Criteria Emissions
                     Table  4 summarizes  the results of
                   criteria gaseous and paniculate emis-
                   sions at  both test sites. The site I kiln
                   was operated at high excess air levels
                   averaging about 280 percent. This high
                   excess air level cooled the combustion
                   products, resulting in relatively low NOX
                   formation. S02 emissions  corre-
                   sponded to  about 30 to  100 percent of
                   the sulfur input from the waste fuel.
                   Low sulfur recovery may be attributed
                   to partial SO2 retention  in  the clay
                   product collected by the baghouse. Hy-
Table 2.   Sampling and Analysis Protocol for Site I Rotary Kiln Clay Dryer
Sample/collection location
Atmospheric flue gas emissions/
stack downstream of
fabric filter
Type of sample/
monitoring equipment8
• Continuous monitors
• Modified EPA Method 5
Number of
samples13
Continuous (8 to
10 hr/test)
3 (1 run/test)
Analysis'
• O2, CO2, CO, NO/NOX, SO2
• Semivolatile and nonvolatile
Fuel (waste oil and liquid
  burnable waste blend)/
  fuel strainers
•  VOST

•  Modified EPA Method 6

•  Composite sample
Fabric filter collected dust/
  fabric filter hopper
   Composite sample
                      organics by GC/MS

                  •  Paniculate matter by gravimetry

                  •  Trace metals by atomic absorption

9 (3 runs/test)       •  Volatile organics by GC/MS

6 (2 runs/test)       •  HCI by titration with silver nitrate

3(1 per test)       •  C, H, N, O, S, and HHV by ASTM
                      methods

                  •  Total chloride, ASTM P808

                  •  Volatile organics by GC/MS

                  •  Semivolatile and nonvolatile organics
                      by GC/MS

                  •  Trace metals by atomic absorption

3 (1 per test)       No analysis performed
aAppendix A (Volume I) presents a detailed description of sampling equipment and protocols used.
bDoes not include blanks, spikes, or other quality control samples.
cAppendix B (Volume I) presents a detailed description of analytical equipment and protocols used.

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Table 3. Sampling and Analysis Protocol for Site II Rotary Aggregate Kiln
Type of sample/
Sample/collection location monitoring equipment3
Atmospheric flue gas emissions/ • Continuous monitors
stack downstream of
wet scrubber
• EPA Method 5

• VOST
• Modified EPA Method 6
Liquid waste • Composite sample
fuel/burner or
fuel storage tank


Coal/pulverized • Composite sample
coal hopper
Mechanical • Composite sample
collector dust/
multicyclone
hopper
Wet scrubber • Composite sample
influent and
effluent/inlet
and outlet of wet
scrubber

Number of
samples'1
Continuous (8 to
10 hr/test)
12 (3 runs/test)

12 (3 runs/test)
8 (2 runs/test)
4 (1 per test)


2 (1 per test)
4 (1 per test)
8 (1 per test for
each stream)

Analysis0
• 02, CO2, CO, NO/NOX, SO2
• Particulate matter by gravimetry
• Trace metals by atomic absorption
• Volatile organics by GC/MS
• HCI by titration with silver nitrate
• C, H, N, O, S, and HHV by ASTM
methods
• Total chloride, ASTM P808
• Volatile organics by GC/MS
• Trace metals by atomic absorption
• Trace metals by atomic absorption
• C, H, N, 0, S and HHV by ASTM methods
No analysis performed
• Volatile organics by GC/MS
• Trace metals by atomic absorption
• Total chlorides, ASTM PS08
"Appendix A presents a detailed description of sampling equipment and protocols used.
bDoes not include blanks, spikes, or other quality control samples.
c Appendix B presents a detailed description of analytical equipment and protocols used.
Table 4. Summary of Criteria Emission Results
Test O2 CO2
Site condition (percent) (percent)
Rotary kiln Waste fuel 14.9-16.4 3.6-4.0
dryer— firing (15.9)b (3.1)
site 1
Aggregate Cofiring 5.0-11.0 6.0-13.1
kiln— (coal and (8.9) (8.8)
site II waste fuel)
Waste fuel 5.0-10.0 6.7-11.9
firing (7.6) (9.4)

CO SO2
(ppm)3 (ppm)
15-1 10 3-63

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drochloric acid emissions represent 25
to 30 percent of the total chlorine fired
with the waste fuel.
  The kiln at site II was operated at sig-
nificantly lower excess air levels, aver-
aging about 80 percent  for the cofired
tests and 50 percent for the waste-fuel-
only tests. Lower combustion air vol-
umes resulted in higher kiln process
temperatures and lead to higher NOX
emissions compared with site I. Sulfur
dioxide emissions were significant for
both cofiring and waste-fuel-only tests.
Total  sulfur input (coal and waste fuel)
could not account for all the S02 meas-
ured. Sulfur-out divided by  sulfur-in
ranged from 3.3 to 12. It is likely that the
aggregate contributed S02 to the flue
gas. Sulfur removal efficiencies of  the
wet scrubber could not be calculated
because of lack of sulfur measurements
in the flue gas entering the scrubber or
the waste discharge stream from  the
scrubber.
  Particulate emissions were signifi-
cantly higher for site II by as  much as
two orders of magnitude than for site I.
This result is attributed primarily to a
lower collection  efficiency  of the wet
scrubber compared to the fabric filter of
site I. Furthermore, higher participate
emissions for the cofired tests at site II
were  the result of flyash contribution
from  pulverized coal and scrubber
water entrainment detected during
tesfl.

 Volatile Organic Emissions and
 ORE
   Figure 3 illustrates the volatile POHC
 ORE results obtained at both sites. Each
 bar is indicative of the range in ORE ob-
 tained  for the major volatile POHCs.
 Bars with upper dashed lines  corre-
 spond to ORE results greater than the
 indicated level.
   DREs for site I POHCs failed to meet
 the 99.99 percent level, the current regu-
 latory level for hazardous waste inciner-
 ators. Several of the components failed
 to  meet the 99.9 percent level as well.
 The low DREs are attributable primarily
 to  the relatively low process tempera-
 tures in the kiln. However, test results
 also  point out the  likelihood that  low
 concentration POHCs would fail to
 achieve high DREs, possibly because of
 the sensitivity of state-of-the-art sam-
 pling and analytical techniques in
 measuring low concentration organics
 as  well as the susceptibility of back-
 ground contamination of these results.
 More importantly, the contribution of
 99.999990 -
 99.99990
   99.9990

*
Q   39.990
     99.90
      99.0
      90.0
                     Freon 113
                   MEK, PCE. TCE
                   and1,1.1-TCA
                 Chlorobenzene
                 Toluene
               Benzene
                                        —1TCE
                                              Freon
                                              113.
                                              MEK,
                                              1,1,1-TCA
                                               Toluene
                                            PCE
                 PCE.
                 TCE. and
                 Toluene
                              MEK. Freon
                              113, and
                              1.1.1-TCA
     Chlorobenzene
                                      Carbon
                                      Tetrachloride
                                 L Benzene
                          Chlorobenzene


                        Carbon
                        Tetrachloride
                   L Benzene
                  Site I
Site II (Cofire)
Site II (Waste Fuel Only)
Figure 3.    Summary of site I and site II ORE results.
 PIC formation to total POHC emissions
 may play a greater role in determining
 the ORE results of low-concentration
 POHCs. DREs for the spiked Freon 113
 were the highest of any of the volatile
 organic compounds detected in the
 waste fuel at site I, exceeding the 99.990
 percent level on the average. The firing
 rate or concentration in the waste fuel of
 Freon 113 was the  highest of any of the
 other volatile POHCs.
  Site II DRE results indicate destruction
 efficiencies exceeding 99.99 percent for
 most volatile POHCs  except for  ben-
 zene, Chlorobenzene, and carbon tetra-
 chloride (cofiring tests only). These high
 DREs were obtained for both the cofir-
 ing and waste-fuel-only test conditions
 and are attributable  to the  high  kiln
 process temperatures compared to
    site I.  Low DREs were  obtained for
    volatile POHCs present in the fuel in the
    lowest concentrations, generally less
    than 150 ppm corresponding  to firing
    rates lower than 58 mg/s. Again, this re-
    sult of lower DREs associated with low
    POHC  concentrations may indicate the
    significance  of background  organic
    emission  levels in combustion prod-
    ucts. DREs for Freon 113 at site II also
    exceeded  DREs for any of the other
    POHCs.

    Products of Incomplete
    Combustion
      Table 5 summarizes emission results
    of volatile  organics that were not de-
    tected  in the waste fuels of site I or site
    II. These compounds are identified as
    products  of incomplete combustion
                                   6

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 Table S.    Volatile PIC Emissions, \ig/s

                                 Site I
                              Site II
Compound
Carbon tetrachloride
Chloromethane
Bromomethane
Vinylchloride
Dichloromethane
1, 1-dichloroethane
Chloroform
Chloroethane
1 ,2-dichloropropane
1, 1,2,2-tetrachloroethane
Waste fuel only
(tests 1, 2, and 3)
4.1 to 494
(173)*
Oto67
(30)
5.2-11
(8.0)
18 to 44
(28)
Oto72
(30)
Oto55
(18)
0 to 3.9
(2.5)
0 to 4.1
(1.4)
0 to 2.8
(0.9)
0 to 2.6
(0.9)
Cofiring
(tests 1 and 2)
NA
156 to 547
(350)
7.2 to 37
(22)
12 to 19
(16)
NA
—
2.5 to 8.6
(5.5)
—
NA
—
Waste fuel only
(tests 3 and 4)
NA
600 to 968
(780)
8. 1 to 8.9
(8.4)
13 to 14
(14)
NA
—
5. 1 to 6.4
(5.8)
—
NA
—
 1,1-dichloroethylene
 Trans- 1,2-dichloroethylene
                  1.9 to 4.0
                  (3.0)

                  0.5 to 1.4
                  (1.0)
                 2.0 to 2.8
                 (2.4)

                 1.0 to 1.1
                 (1.1)
 Total PICs
  PICsfZPOHCsb
51 to 670
(290)

0.14 to 0.30
(0.25)
190 to 610
(400)

0.64 to 0.91
(0.83)
630 to 1,000
(810)

0.72 to 0.83
(0.76)
  aEach entry is the arithmetic average of the measurements for each test. Number in paren-
   theses is the average for number of tests indicated.
  bSum of PIC emissions divided by the sum of breakthrough volatile POHC emissions includ-
   ing toluene and benzene.
 —Dashes indicate emission level or blank corrected emissions were below detection limits.
NA—Not applicable. Compound was a POHC.
(PICs). For site I, highest PIC emissions
were contributed by carbon tetrachlo-
ride. These high average emissions are
attributed to test 1  results, which indi-
cate high carbon tetrachloride emis-
sions of about 500 |jig/s. DREs for test 1
were also lower than DREs measured
during the remaining two tests. Total
volatile PIC emissions  accounted for
about 14 to 30 percent of the total POHC
breakthrough measured.
  For site II, Chloromethane emissions
accounted for nearly all the PICs de-
tected with 570 >i,g/s on the average for
all tests. Higher Chloromethane emis-
          sions were measured for the waste fuel
          firing tests 3 and 4. The ratio of total
          PICs to total POHC breakthrough ranged
          from 0.76 to 0.83.

          Trace Metal Emissions
            Selected trace metals were sought in
          the analysis of fuels and flue gas emis-
          sions to quantitate the emissions of the
          inorganics from the two process kilns
          burning hazardous liquid wastes. Anal-
          ysis of metals was generally limited to
          the 13 EPA-designated priority pollutant
          elements. Table 6 summarizes the re-
          sults of these measurements.
  For site I, copper, lead, and zinc con-
stituted the major metals, heaving con-
centrations of 400 to 700 ppm  in the
waste fuel. Other detected metals were
cadmium, chromium, and  nickel, all
having fuel concentrations of less than 5
ppm. Emissions ranged from nonde-
tected for cadmium to 130 ^g/s for zinc.
Lead emissions were found to be about
80 M-g/s on the average. Emissions  of
these trace metals generally constituted
less  than 1 percent  of the total  input
rate. This was found to be especially the
case for lead, copper, and zinc. It is likely
that most of these metals were ab-
sorbed on baghouse-collected flyash  or
trapped in the clay product of the kiln.
  Lead and zinc were the major metals
in the waste fuel at site II, with average
concentrations of 860  ppm and 210
ppm, respectively. Chromium  also ex-
ceeded 100 ppm. During cofiring (tests 1
and  2), pulverized coal contributed a
minor fraction of these metals. Highest
emissions were measured for lead (7.6
mg/s), followed by chromium (1.5 mg/
s), and zinc (1.0 mg/s). On the average,
the measured emissions of all  trace
metals accounted for  1.7 to 8.0 percent
of the total input rate.
  Results of  waste firing only, tests 3
and 4 for site II, indicate an increase  in
lead emissions to 25 mg/s, followed by
zinc  at 4.4 mg/s, and chromium at 1.3
mg/s. With the exception of mercury,
nickel, and antimony, which were not
detected,  total  metal emissions ac-
counted for 3.9 to 17 percent of the total
input rate on the average. Therefore, the
results obtained during this test pro-
gram indicate that, although the site II
kiln was more efficient  in thermal de-
struction  of organics, it had a higher
percentage of trace metals emissions.
This result is attributed to the higher
process temperatures, which may pre-
vent metal adsorption on the flue gas
entrained particulate matter combined
with the  lower efficiency of the wet
scrubber in controlling particulate emis-
sions. The increase in lead  and  other
metal emissions during the waste-fuel-
only tests may be the result of reduced
entrained particulate/metal interaction.
Coal flyash generated during the cofired
tests may have contributed to metal ad-
sorption.

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Table 6. Trace Element Emissions
Site 1
Element3
Antimony
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Zinc
Waste
Flue gas
emissions
(W/s)
—
<5.S
10 to 29
(20)
12 to 92
(52)
66 to 96
(81)
—
5.0 to 35
(20)
59 to 130
(95)
fuel only
Mass balance
out/in
(percent)
—
<2.5
1.2 to 2.9
(2.1)
0.01 to 0.11
(0.05)
0.05 to 0.07
(0.06)
—
20 to 13
(7.5)
0.05 to 0.11
(0.08)
Cofiring
Flue gas
emissions
(\ig/s)
<5.7
100 to 174
(140)
1,290 to 1,740
(1,500)
260 to 430
(350)
6,300 to 8,850
(7,600)
<0.6
<14to 190
(<100)
690 to 1,310
(1,000)
Site II

Mass balance
out/in
(percent)
NA
6.4 to 9.5
(8.0)
5.7 to 5.8
(5.8)
1.4 to 2.0
(1.7)
3.6 to 5.4
(4.5)
NA
<1.1 to 11
«5.5)
1.5 to 3.2
(2.4)
Waste
Flue gas
emissions
(pg/s)
<5.8
440 to 450
(450)
1,1 70 to 1,400
(1,300)
1,020 to 1,120
(1,070)
25,000
<0.6
<14
4,290 to 4,570
(4,400)
fuel only
Mass balance
out/in
(percent)
<0.2S
16 to 18
(17)
3.2 to 4.8
(4.0)
3.5 to 4.3
(3.9)
9.4 to 9.9
(9.7)
<0.5
<1.8
5.3 to 5.9
(5.6)
 s'Analysis was limited to priority pollutant elements. Metals listed are those that were detected in the fuels and flue gas emission stream.
 bNumber in parentheses is the arithmetic average of three test measurements for site I and two test measurements for site II. Averages are
  generally rounded to two significant figures.
—Dashes indicate element not detected in the fuels or flue gas at site I.
NA—Not available. Mass balance cannot be computed because of unknown element contribution from coal.
   A. W. Wyss, C. Castaldini, and M.  M. Murray are with Acurex Corporation,
     Mountain View, CA 94039.
   Robert E. Mournighan is the EPA Project Officer (see below).
   The complete report, entitled "Field Evaluation of Resource Recovery of Hazardous
     Wastes,"(Order No. PB 86-211 869/AS; Cost: $ 16.95, subject to change) will
     be available only from:
           National Technical Information Service
           5285 Port Royal Road
           Springfield, VA 22161
           Telephone: 703-487-4650
   The EPA Project Officer can be contacted at:
           Hazardous Waste Engineering Research Laboratory
           U.S. Environmental Protection Agency
           Cincinnati, OH 45268

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United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
Official Business
Penalty for Private Use $300

EPA/600/S2-86/059

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