-------
Characterization of Coal Combustion Residues
1000
en
_*:
~O)
100 --
10
BPB BPT PPB PPT SHB SHT GAB GAT JAB JAT FLB FLT FLB2 FLT2
Facility C St. Clair
Brayton
Point
Pleasant
Prairie
Salem
Harbor
Facility L Facility L
Run #1 Run #2
Figure 22. Comparison of Total Arsenic Content in Baseline Cases and with Sorbent Injection for CCRs from Different
Facilities. (Facility code suffixes B = baseline and T = treated with sorbent injection; for example, PPB = Pleasant Prairie
baseline, and PPT = Pleasant Prairie treated)
Use of ACI resulted in a substantial decrease in total
arsenic content in CCR for Brayton Point.
There was not a consistent pattern with respect to the
effect of ACI on the range of laboratory extract con-
centrations. For Salem Harbor and slightly for Pleas-
ant Prairie facilities, the cases with ACI had an increase
in the upper bound of extract concentrations compared
to the same facility without ACI. For Facility C and
the Brayton Point and St. Clair facilities, a correspond-
ing decrease was observed.
Very low extract concentrations were observed for the
St. Clair facility without and with B-PAC, even though
the total arsenic content was comparable to several of
the other cases. Conversely, relatively high extract
concentrations were observed for Facility L without
and with B-PAC, even though the total arsenic con-
centration was low compared to the other cases. Thus,
the presence of other constituents in the CCRs or the
formation conditions appears to have a strong influ-
ence on the release of arsenic.
The range of arsenic concentrations observed in the
laboratory extracts is consistent with the range of val-
ues reported for field leachates from landfills and im-
poundments. For some cases, both laboratory (Salem
Harbor, Facility C, Facility L) and field concentrations
exceeded the MCL by more than a factor of 10. The ex-
pected range of arsenic concentrations under field condi-
tions is less than 10 |Jg/L to approximately 1000 |Jg/L.
Arsenic leachate concentrations typically are strongly
a function of pH over the entire pH range examined
and within the pH range observed for field conditions
(for example, see Figure 18). For some cases (for ex-
ample, see St. Clair, Appendix H), measured concen-
trations of arsenic are strongly a function of LS ratio
at the material's natural pH, with much greater con-
centrations observed at low LS ratio. Therefore, test-
ing at a single extraction final pH or LS ratio would
not provide sufficient information to characterize the
range of expected leachate concentrations under field
conditions. Furthermore, for some of the CCRs a shift
from the CCR's natural pH within the range of antici-
pated conditions (e.g., Facility L, Brayton Point with
ACI, Salem Harbor baseline, Facility C baseline) can
result substantial increases in leachate concentrations.
Therefore, co-disposal of these CCRs with other ma-
terials should be carefully evaluated.
46
-------
Characterization of Coal Combustion Residues
10000
1000 --
100 --
C/3
<
0.1
max
• I Natui
10
1 --
Natural pH 95th%
min
--T -sef»%-
5"%)
-MCL
BPB BPT PPB PPT SHB SHT GAB GAT JAB JAT LAB LAT EPA LF IMP
Brayton Pleasant Salem Facility C St. Clair Facility L EPRI
Point Prairie Harbor
Figure 23. Ranges of Laboratory and Field Leachate Arsenic Concentrations Compared with the Drinking Water Maximum
Contaminant Level (MCL). [For laboratory data, symbol represents the concentrations at the natural pH of the CCR
tested, and the error bars represent the minimum and maximum concentrations within the relevant field pH range of 5.8
to 12.09, inclusive. For field data, symbol and error bars represent the 5th, 50th and 95th percentiles of reported values
(EPA = EPA database; LF = landfills from EPRI database; IMP = impoundments from EPRI database). Reliable data for
mercury was not available in the EPA database.]
• For several cases (Brayton Point, Salem Harbor, Fa-
cility C without ACI, Facility L), arsenic concentra-
tions in laboratory extracts appear to be controlled by
solid phase solubility, whereas adsorption processes
appear to play a more important role for other cases
(Pleasant Prairie, Facility C with ACI, St. Clair).
3.3.3. Selenium Results
A comparison of total content and of the range of labora-
tory leach test extract selenium concentrations as a func-
tion of pH and LS ratio for CCRs from different facilities
is provided in Figures 24 and 25, respectively. The approach
used and comparisons made in Figure 25 are the same as
for mercury in Figure 21.
Considering the results provided in Appendices D through
I, and comparisons in Figures 24 and 25, the following
observations for selenium are made:
• For two cases (Brayton Point, Facility C), use of ACI
resulted in a substantial increase in the total selenium
content of the CCR in comparison to the same case
without ACI. For Facility C, this is likely a direct con-
sequence of the COHPAC configuration when ACI is
in use. For the other cases, the change in total sele-
nium content resulting from application of ACI or B-
PAC was minor but increased in all cases.
The range of selenium concentration in laboratory leach
test extracts is not correlated with total selenium con-
tent in the CCRs. For example, Brayton Point with ACI
had much greater total selenium content than the other
cases except Facility C with ACI, but it had only the
fifth highest selenium concentration under the labora-
tory leaching conditions. Conversely, Facility C
baseline had one of the lowest selenium total content
(less than MDL), but it had second greatest selenium
concentration under the laboratory leaching conditions.
The range of selenium concentrations observed in labo-
ratory leach test extracts for Facility C are much greater
than the concentrations observed for other cases and
for field conditions. This is a COHPAC facility, and
field leachate composition data for CCRs from this type
of facility was not available in the EPA or EPRI data-
bases. For all other facilities, the range of concentra-
tions observed from laboratory testing is consistent with
47
-------
Characterization of Coal Combustion Residues
1000
en
_*:
ch
,§
CD
100 v
10 v
Indicates < MDL
BPB BPT PPB PPT SHB SHT GAB GAT JAB JAT FLB FLT FLB2 FLT2
Brayton Pleasant
Point Prairie
Salem Facility C St. Clair Facility L Facility L
Harbor (Run#1) (Run #2)
Figure 24. Comparison of Total Selenium Content in Baseline Cases and with Sorbent Injection for CCRs from Different
Facilities. (Facility code suffixes B = baseline and T = treated with sorbent injection; for example, PPB = Pleasant Prairie
baseline, and PPT = Pleasant Prairie treated)
the range reported in the EPRI database for landfills.
The concentration range reported in the EPA database
for CCR landfills has a much lower upper bound than
reported in the EPRI database.
The concentration range for laboratory extracts and
field observations exceeded the MCL for all cases ex-
cept Facility L. For 5 out of 12 of the cases used for
laboratory evaluation and for some field observations,
the MCL is exceeded by more than a factor of 10.
Selenium concentrations in laboratory leach test ex-
tracts typically are strongly a function of pH over the
entire pH range examined and within the pH range
observed for field conditions (for example, see Brayton
Point, Salem Harbor, Facility C). For some cases (for
example, see Figure 19 or Brayton Point, Salem Har-
bor, St. Clair in Appendices D, F, and H, respectively),
measured concentrations of selenium are strongly a
function of LS ratio at the material's natural pH, with
much greater concentrations observed at low LS ratio.
Therefore, testing at a single extraction final pH or LS
ratio would not provide sufficient information to char-
acterize the range of expected leachate concentrations
under field conditions.
• For several cases (Brayton Point, Salem Harbor, Fa-
cility C, Facility L), selenium concentrations in labo-
ratory extracts appears to be controlled by solid phase
solubility, whereas adsorption processes appear to play
a more important role for other cases (Pleasant Prairie,
St. Clair).
3.4. Long-Term Release Assessment
Cumulative release estimates for CCRs from each facility,
both for the baseline case and the case with enhanced mer-
cury recovery, are presented in Appendices D through I.
One hundred year release estimates of mercury, arsenic
and selenium are presented. One example of long-term re-
lease assessment results for arsenic and selenium is pro-
vided in Figures 26 and 27. For each case, first the polyno-
mial curve fits for solubility as a function of pH are pre-
sented along with the corresponding data from laboratory
leaching test results (SR002.1) and the 5th and 95th percen-
tile of pH and constituent concentration from the U.S. EPA
database. Next, the cumulative probability distribution for
cumulative constituent release is provided from the Monte
Carlo simulation for both the baseline and test cases. Fi-
nally, a bar chart, comparing total content of the constitu-
48
-------
Characterization of Coal Combustion Residues
100000
O)
CD
co
10000 --
1000 --
100 --
10 --
1 --
0.1
-r max
H
Natural pH
95th%
iMCL
BPB BPT PPB PPT SHB SHT GAB GAT JAB JAT LAB LAT EPA LF IMP
Brayton
Point
Pleasant
Prairie
Salem
Harbor
Facility C St. Clair Facility L
EPRI
Figure 25. Ranges of Laboratory and Field Leachate Selenium Concentrations Compared with the Drinking Water
Maximum Contaminant Level (MCL). [For laboratory data, symbol represents the concentrations at the natural pH of the
CCR tested, and the error bars represent the minimum and maximum concentrations within the relevant field pH range
of 5.8 to 12.09, inclusive. For field data, symbol and error bars represent the 5th, 50th and 95th percentiles of reported
values (EPA = EPA database; LF = landfills from EPRI database; IMP = impoundments from EPRI database). Reliable
data for mercury was not available in the EPA database.]
ent evaluated, estimated cumulative release over 100 years,
and percent of total content released is provided for the
baseline and test cases. Similar results are not provided for
mercury because of the simplification used for the assess-
ment based on results and underlying mechanism (see sec-
tion 2.5.1).
3.4.1. Long-term Release Estimates for
Mercury
A comparison of the long-term (100 yr) mercury release
estimates from the Monte Carlo simulation for each case is
presented in Figure 28A on a mass basis (micrograms of
Hg released per kilogram of CCR) and Figure 28B as a
percent of total mercury released. Figure 28A also includes
the total mercury content for each case.
Considering the results provided in Appendices D through
I, and comparisons in Figure 28, the following observa-
tions for mercury are made:
• The estimated mass of mercury released over the as-
sessment period does not correlate with the total mer-
n SR2-BPT-0001-A
o SR2-BPT-0001-B
A SR2-BPT-0001-C
Fit curve
Figure 26. Example Regression Curves of Experimental
Data of Arsenic Solubility as a Function of pH for Brayton
Point.
49
-------
Characterization of Coal Combustion Residues
10000
75 1000
CO
0)
o
o
n
o
1
1 .
'4
nc
nu
DD .t
n A A
A
A
A
t
!l ^ A
^AA^
]
i
0 5% 20
405°% 60
Percentile
nBPB ABPT
Mt min
Mt - 5%
Mt - 50%
Mt - 95%
Mean Mt
Mt max
oro
ng/kg
0.2
0.9
152
2095
468
4693
%
0.0003
0.0011
0.2
2.6
0.6
5.8
or i
ng/kg
0.1
0.1
22
338
90
10157
%
0.0003
0.0005
0.0772
1.2
0.3
36.4
Figure 27. Example 100-Year Arsenic Release Estimates
for Brayton Point as a Function of the Cumulative Probability
for the Scenario of Disposal in a Combustion Waste Landfill.
(Mt refers to the cumulative release over the 100-year
interval.)
cury content of the CCR. This is a consequence of the
relatively constant leaching test extract concentrations
independent of the total mercury content in the CCR.
For all cases, the median expected release over 100
years is less than or equal to 1 |Jg/kg, with the 5th and
95th percentiles less than or equal to 0.005 and 15 |Jg/
kg, respectively.
• The percentage of total mercury estimated to be re-
leased over 100 years ranges from a very small per-
centage (less than 0.002%) to less than 5% for most
cases. From less than a very small percentage (less than
0.03%) to less than 80% of the total mercury may be
released from cases Facility C baseline and Facility L.
The higher percentages for these three cases reflects
the lower total mercury content present in the CCR.
3.4.2. Long-Term Release Estimates for
Arsenic
A comparison of the long-term (100 yr) arsenic release
estimates from the Monte Carlo simulation for each case is
presented in Figure 29A on a mass basis (micrograms As
released per kilogram CCR) and Figure 29B as a percent
of total arsenic released. Figure 29A also includes the total
arsenic content for each case and MCLLS95% for reference.
MCLLS95o/0 is the amount of arsenic that would be released
(1,000 |Jg/kg) if the leachate concentration was equal to
the MCL for arsenic (10 |Jg/L) for the entire 100 year pe-
riod and if the infiltration rate was at the 95th percentile of
reference cases for landfills in the U.S. EPA database. For
the purposes of this study, values that exceed this thresh-
old may warrant further examination as to whether or not
additional management controls should be considered.
Considering the results provided in Appendices D through
I, and comparisons in Figure 29, the following observa-
tions for arsenic are made:
• The estimated mass of arsenic released over the as-
sessment period does not correlate with the total ar-
senic content of the CCR. For all cases except Salem
Harbor, Facility C, and Facility L, less than 0.1% to
5% of the total arsenic content is anticipated to be re-
leased.
• Salem Harbor, Facility C baseline, and Facility L are
cases where up to a very high percentage (more than
30%) of the total arsenic content may be released un-
der some management conditions.
• The cases of Salem Harbor, Facility C, and Facility L
are examples of where more detailed release evalua-
tion is warranted, considering site specific management
practices, infiltration rates, and dilution and attenua-
tion factors.
3.4.3. Long-term Release Estimates for
Selenium
A comparison of the long-term (100 yr) selenium release
estimates from the Monte Carlo simulation for each case is
presented in Figure 30A on a mass basis (micrograms Se
released per kilogram CCR) and Figure 30B as a percent
of total arsenic released. The presentation in Figure 30 is
analogous to the presentation used for arsenic release esti-
mates in Figure 29 and discussed previously.
Considering the results provided in Appendices D through
I, and comparisons in Figure 30, the following observa-
tions for selenium are made:
• For all cases except Brayton Point, from 40% up to
the total content of selenium in the CCR is anticipated
to be released at the 95th percentile, with between 3%
and 20% for the median case (except Facility C
baseline, where the median case is 100% of the total).
For Brayton Point, from 1% to 30% of the total con-
50
-------
Characterization of Coal Combustion Residues
10000 -
1000 -
100 -
10 -
'oi :
en :
0.01 -
0.001 -
0.0001 -
A)
100 -
10 -
1 -
IF 0-1 -
£ •
•5 :
°S? 0.01 -
" 0.001 -
0.0001 -
0.00001 -
• * * * * *
* *
4
95lh% +
"|
(50lh%
4
5th %
4
»
» 4
»
)
4
> 4
> ^
* 4
> <
»
»
^
.A.
<
(
•^
>
i "
r
\
-*-
Median
Total Content
BPB BPT PPB PPT SHB SHT GAB GAT JAB JAT LAB LAT
Brayton Pleasant Salem Facility C St. Clair
Point Prairie Harbor
95th%
4
»
50th%
4
•5th %
4
»
4
1
4
4
>
»
i
1
>
4
4
»
> -r
4
•
BPB BPT PPB PPT SHB SHT GAB GAT JAB JAT
Brayton Pleasant Salem Facility C St. Clair
B) Point Prairie Harbor
Facility L
(
i
4
>
9 Median
LAB LAT
Facility L
Figure 28. Upper Bound of 100 yr Mercury Release Estimates for Landfill Scenario Without and with Activated Carbon
Injection. (A) mass released in ug of mercury released per kg of CCR and total content in ug of mercury per kg of CCR,
(B) percent of total mercury content released. Symbol with error bars represents 5th, 50th and 95th percentiles from Monte
Carlo simulation. (Facility code suffixes B = baseline and T = treated with sorbent injection; for example, PPB = Pleasant
Prairie baseline, and PPT = Pleasant Prairie treated)
51
-------
Characterization of Coal Combustion Residues
O)
_*:
~O)
IUUUUUU 1
100000 i
10000 -
1000 -
100 -
10 -
\ .
1
0.1 -
0.01 -
n nni -
+
- * <
4
95lh%
50lh%-
(
(
5lh%
I '
• Median
^ Total Content
r 4
' <
•
t
I '
<
>
»
j
•
4
(
1
1
4
> ^
I <
»>
»
»
MCL =1000|ig/kg
LS 95% ^a a
A)
BPB BPT PPB PPT SHB SHT GAB GAT JAB JAT LAB LAT
Facility C St. Clair Facility L
Brayton Pleasant
Point Prairie
Salem
Harbor
100 ^
ro
,o
1 -
0.1 ^
0.01 :
0.001 : • -1-
0.0001 :
0.00001
B)
__95lh%
50lh%
Median
BPB BPT PPB PPT SHB SHT GAB GAT JAB JAT LAB LAT
Brayton Pleasant Salem
Point Prairie Harbor
Facility C St. Clair Facility L
Figure 29. Upper Bound of 100 yr Arsenic Release Estimates for Landfill Scenario Without and with Activated Carbon
Injection. (A) mass released in ug of arsenic released per kg of CCR and total content in ug of arsenic per kg of CCR, (B)
percent of total arsenic content released. Symbol with error bars represents 5th, 50th and 95th percentiles from Monte
Carlo simulation. (Facility code suffixes B = baseline and T = treated with sorbent injection; for example, PPB = Pleasant
Prairie baseline, and PPT = Pleasant Prairie treated)
52
-------
Characterization of Coal Combustion Residues
en
CO
1000000
100000 --
10000 --
A)
1000 --
100
10 -f
1
0.1
50th%4 •
<> ,
5th%
O II
• Median
• Total Content
BPB BPT PPB PPT SHB SHT GAB GAT JAB JAT LAB LAT
Brayton Pleasant
Point Prairie
Salem Facility C St. Clair Facility L
Harbor
ro
.o
si
CD
CO
CO
B)
10-
1 -
0.1 -
0.01 -
nn-i -
4
•
95th%
50th%
I
4
5th%
Median
4
I
•
4
' 4
I
4
>
4
1 4
I
4
•
• 4
»
BPB BPT PPB PPT SHB SHT GAB GAT JAB JAT LAB LAT
Brayton
Point
Pleasant
Prairie
Salem
Harbor
Facility C St. Clair Facility L
Figure 30. Upper Bound of 100 yr Selenium Release Estimates for Landfill Scenario Without and with Activated Carbon
Injection. (A) mass released in ug of selenium released per kg of CCR and total content in ug of selenium per kg of CCR,
(B) percent of total selenium content released. Symbol with error bars represents 5th, 50th and 95th percentiles from
Monte Carlo simulation. (Facility code suffixes B = baseline and T = treated with sorbent injection; for example, PPB =
Pleasant Prairie baseline, and PPT = Pleasant Prairie treated)
53
-------
Characterization of Coal Combustion Residues
tent is anticipated to be released for more than half of can be substantially reduced for each CCR case, either
the anticipated conditions. through control of pH or infiltration.
Low fractional releases of selenium (less than 0.1%, • All cases are examples of where more detailed release
except for Facility C baseline) at the 5th percentile sug- evaluation is warranted, considering site specific man-
gest management scenarios where anticipated release agement practices, infiltration rates, and dilution and
attenuation factors.
54
-------
Characterization of Coal Combustion Residues
4. Conclusions and Recommendations
4.1. Assessment of CCRs Without
and With Activated Carbon Injection
Analysis has been completed for CCRs from six coal com-
bustion facilities that control mercury emissions by sor-
bent injection; four using powdered activated carbon in-
jection and two using brominated powdered activated car-
bon injection. For each facility, the evaluation included
assessments of CCRs generated both with and without use
of the activated carbon injection. None of these facilities
had scrubbers as part of their air pollution control technol-
ogy. The following conclusions are drawn for this class of
facilities:
• Application of activated carbon injection substantially
increased the total mercury content in the resulting
CCRs for five of the six facilities evaluated. Substan-
tially increased arsenic and selenium content in the
CCRs was observed at the one facility that employed
COHPAC fabric filter particulate control technology.
This may have resulted from additional arsenic and
selenium adsorption onto the CCR while retained in
the fabric filters. Significant increase in the selenium
content of one additional facility was noted.
• Mercury is strongly retained by the CCR and unlikely
to be leached at levels of environmental concern.
Leaching that did occur did not depend on total mer-
cury content in the CCR, leaching pH, nor liquid to
solid ratio, and mercury concentrations in laboratory
extracts appeared to be controlled by non-linear ad-
sorption equilibrium. Laboratory extract concentrations
ranged between less than the MDL (0.01 |Jg/L) and
0.2 Mg/L.
• Arsenic and selenium may be leached at levels of po-
tential concern from CCRs generated at some facili-
ties both with and without enhanced mercury control
technology. Further evaluation of leaching of arsenic
and selenium from CCRs that considers site specific
conditions is warranted.
• Leachate concentrations and the potential release of
mercury, arsenic and selenium do not correlate with
total content. For many cases, leachate concentrations
observed are a function of final pH over the range of
field conditions, and the observed leaching behavior
implies that solubility in the leachate or aqueous ex-
tract controls observed liquid concentration rather than
linear adsorption equilibrium. For these cases, use of
linear partition coefficients (Kd) in modeling leaching
phenomena does not reflect the underlying processes.
In addition, for many cases, the amount of mercury,
arsenic and/or selenium estimated to be released over
a 100 year interval is a small fraction (less than 0.1%
to 5%) of the total content. For selenium, release from
less than 5% up to the total content of selenium can be
anticipated over the 100 year period. Therefore, it is
not recommended to base landfill management deci-
sions on total content of constituents in CCRs since
total content does not consistently relate to quantity
released.
Results of this assessment also suggest management
conditions (e.g., through control of infiltration and pH)
that may result in reduction releases of arsenic and
selenium by as much as two orders of magnitude in
comparison to upper bound estimated releases.
Use of the Leaching Framework facilitated understand-
ing the variations in anticipated leaching behavior un-
der the anticipated field landfill disposal conditions,
including expected ranges of constituent concentrations
in leachate and cumulative release over a defined time
interval. In addition, insights into the mechanisms con-
trolling constituent leaching were obtained. This depth
of understanding would not have been possible using
leaching tests focused on a single extraction condition
(e.g.,TCLP, SPLP,orSGLP).
This study provides baseline data which allows using
a reduced set of laboratory testing conditions as a
screening leaching assessment for CCRs from coal
combustion facilities employing similar air pollution
control technology. For mercury, extraction only at the
material's natural pH at LS=10 is adequate. For ar-
senic, extraction at four conditions is warranted to de-
55
-------
Characterization of Coal Combustion Residues
fine the range of expected leachate concentrations and
release: (i) pH 5.5-6.0 at LS=10, (ii) pH 7.5-8.5 at
LS=10, (iii) pH 12.0-12.5 at LS=10 and (iv) natural
pH at LS=2. For selenium, either the total content or
the same conditions as recommended for arsenic can
be used. At least duplicate extractions should be used.
Results from this more limited testing can be evalu-
ated in comparison with the results presented in this
report to determine if more extensive evaluation is
warranted.
4.2. Implementation of Leaching Test
Methods
The leaching assessment approach published by Kosson et
al. (2002) and implemented in this report was selected be-
cause after internal EPA review (Office of Research and
Development, Office of Solid Waste) and consultation with
the Environmental Engineering committee of the EPA Sci-
ence Advisory Board, it was considered the only available
peer reviewed and published approach that allowed con-
sideration of the range of potential field management sce-
narios expected for CCRs and that provided a fundamen-
tal foundation for extrapolation of laboratory testing to field
scenarios. Additional development and validation of the
leaching assessment approach through this proj ect provides
the following conclusions:
• Laboratory leaching test results were consistent with
observed ranges of field leachate pH and with mer-
cury, arsenic, and selenium concentrations. Thus, the
leaching test methods employed in this study provide
an appropriate basis for evaluating leaching under the
range of anticipated field management scenarios.
Leaching test methods SR002.1 (Solubility and Re-
lease as a Function of pH) and SR003.1 (Solubility
and Release as a Function of LS ratio) have been suc-
cessfully implemented at the EPANational Risk Man-
agement Research Laboratory. The use of these meth-
ods is now considered near routine methodology for
the laboratory.
QA/QC methodology conforming with EPA Tier 3 re-
quirements has been developed and demonstrated for
the leaching test methods SR002.1 and SR003.1.
Further efficiency in implementation of the QA/QC
methodology may be obtained, based on the results
from testing the initial set of CCRs, by reducing the
number of replicates and control analyses required
under the initial QA/QC plan. These improved project
efficiencies are being implemented for evaluation of
additional CCRs under this project.
A mass balance around the laboratory leaching test pro-
cedures has been completed for mercury and selected
metals of potential concern. These results indicate that
recoveries were between 60% and 91% for mercury
during the leaching tests and subsequent analytical
procedures, which is within the uncertainty resulting
from heterogeneity within the CCR. Additional mass
balance verification may be warranted if future samples
have significantly different characteristics that may
result in greater volatility of the constituents of inter-
est than in the reference sample evaluated.
56
-------
Characterization of Coal Combustion Residues
5. References
ACAA (American Coal Ash Association), 2000. 1999 Coal Combustion Product (CCP) Production and Use (Short Tons),
available at http://www.acaa-usa.org/whatsnew/ccp_surveys.htm (accessed March 2001).
ACAA (American Coal Ash Association), 2003. 2003 Coal Combustion Product (CCP) Production and Use Survey, ACAA,
Alexandria, VA, available at http://www.acaa-usa.org/PDF/2003_CCP_Survey(10-l-04).pdf (accessed January 2006).
Clean Air Mercury Rule: 70 FR 28606; May 18, 2005.
Clean Air Interstate Rule: 70 FR 25162; May 12, 2005.
Duong D. Do., 1998. Adsorption Analysis: Equilibria and Kinetics. Imperial College Press, London, 892 p.
EPA, 1988. Report to Congress-Wastes from the Combustion of Coal by Electric Utility Power Plants. EPA/530/SW-88/002, U.S.
EPA, Office of Solid Waste and Emergency Response, Washington, DC.
EPA, 1996. Method 3052 "Microwave Assisted Acid Digestion of Siliceous and Organically Based Matrices," Test Methods for
Evaluating Solid Waste, Physical/Chemical Methods (SW-846), available at http://www.epa.gov/sw-846/main.htm (accessed
January 2006).
EPA, 1998. Method 7473 "Mercury in Solids and Solutions by Thermal Decomposition, Amalgamation, and Atomic Absorption
Spectrophotometry," Test Methods for Evaluating Solid Waste, Physical/Chemical Methods (SW-846), available at
http://www.epa.gov/sw-846/main.htm (accessed January 2006).
EPA, 1999. Report to Congress-Wastes from the Combustion of Fossil Fuels: Volume 2-Methods, Findings and
Recommendations. EPA/530/R-99/010. U.S. EPA, Office of Solid Waste and Emergency Response, Washington, DC.
EPA, 2000. Characterization and evaluation of landfill leachate. EPA, Draft Report. 68-W6-0068, September 2000.
EPA, 2002. Characterization and Management of Residues from Coal-Fired Power Plants, Interim Report. EPA/600/R-02/083,
December.
EPA, 2003. Technical Support Document for the Assessment of Detection and Quantitation Approaches. EPA/82 l/R-03/005. U.S
EPA, Office of Water, Washington, DC, available at (http://epa.gov/waterscience/methods/det/index.html) [Superceded by
Revised Assessment of Detection and Quantitation Approaches, EPA/82 l/B-004/005, available at
http://www.epa.gov/waterscience/methods/det/rad/rad.pdf (accessed January 2006)].
EPA, 2005. Control of Mercury Emissions from Coal Fired Electric Utility Boilers: An Update, U.S. EPA, Office of Research and
Development, Research Triangle Park, NC, Feb 18, available at
http://www.epa.gov/ttn/atw/utility/ord_whtpaper_hgcontroltech_oar-2002-0056-6141.pdf accessed January 2006.
EPRI, 1999. Guidance for Co-management of Mill Rejects at Coal-Fired Power Plants. Report TR-108994.
EPRI, 2005. Personal communication of EPRI leaching database (as of June 2005) summary information from K. Ladwig to D.
Kosson.
57
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Characterization of Coal Combustion Residues
Kosson, D.S., van der Sloot, H.A., Sanchez, K, and Garrabrants, A.C., 2002. An Integrated Framework for Evaluating Leaching
in Waste management and Utilization of Secondary Materials, Environmental Engineering Science 19:3, 159-204.
MTI (McDermott Technology, Inc.), 2001. Mercury Emissions Predictions, available at
http://www.mtiresearch.con^aecdp/mercury.html#Coal%20Analyses%20and%20Mercury%20Emissions%20Predictions.
accessed November 2002.
Munro, L.J., Johnson, K.J., and Jordan, K.D., 2001. An Interatomic Potential for Mercury Dimmer, J. of Chemical Physics,
114:13, 5545-5551.
Nelson, S., 2004. "Advanced Utility Sorbent Field Testing Program," DOE/NETL Mercury Control Technology R&D Program
Review, Pittsburgh, PA, July 14-15, 2004.
Nelson, S., Landreth, R., Zhou, Q., Miller, J., 2004. "Accumulated Power-Plant Mercury-Removal Experience with Brominated
PAC Injection", Joint EPRI DOE EPA Combined Utility Air Pollution Control Symposium, The Mega Symposium, Washington,
D.C., August 30-September 2.
Rudzinski, W., WA. Steele, and G. Zgrablich, 1997. Equilibria and Dynamics of Gas Adsorption on Heterogeneous Solid
Surfaces. Elsevier, Amsterdam.
Ruthven, D.M., 1984. Principles of Adsorption and Adsorption Processes. Wiley, New York, 433 p.
SAB (EPA Science Advisory Board, Environmental Engineering Committee), 2003. TCLP Consultation Summary, presented at
the SAB Environmental Engineering Committee consultation with EPA, Washington, D.C., June 17-18.
Sanchez, F., Kosson, D.S., 2005. Probabilistic Approach for Estimating the Release of Contaminants under Field Management
Scenarios, Waste Management, 25:5, 643-472.
Senior, C, Bustard, C.J., Baldrey, K., Starns, T. Durham, M., 2003a. "Characterization of Fly Ash From Full-Scale Demonstration
of Sorbent Injection for Mercury Control on Coal-Fired Power Plants," presented at the Combined Power Plant Air Pollutant
Control Mega Symposium, Washington D.C., May 19-22.
Senior, C., Bustard, C.J., Durham, M., Starns, T, Baldrey, K, 2003b. "Characterization of Fly Ash From Full-Scale
Demonstration of Sorbent Injection for Mercury Control on Coal-Fired Power Plants," presented at the Air Quality IV
Conference and Exhibition, Washington D.C, September 22-21.
Senior, C., Bustard, C.J., Durham, M., Baldrey, K., Michaud, D., 2004. Characterization of Fly Ash From Full-Scale
Demonstration of Sorbent Injection For Mercury Control on Coal-Fired Power Plants, Fuel Processing Technology, 85:6-7, 601-
612.
Starns, T, Bustard, J., Durham, M., Lindsey, C., Martin, C., Schlager, R., Donnelly, B., Sjostrom, S., Harrington, P.,
Haythornthwaite, S., Johnson, R., Morris, E., Change, R., Renninger, S., 2002. "Full-Scale Test of Mercury Control with Sorbent
Injection and an ESP at Wisconsin Electric's Pleasant Prairie Power Plant," presented at the Air & Waste Management
Association 95th Annual Conference and Exhibition, Baltimore, MD, June 23-27.
Thorneloe, S., 2003. Presentation to EPA Science Advisory Board (Environmental Engineering Committee), Washington, D.C.,
June 17th.
Vidic, R.D., 2002. Combined Theoretical and Experimental Investigation of Mechanisms and Kinetics of Vapor-Phase Mercury
uptake by Carbonacoues Surfaces. Final Report, Grant No. DE-FG26-98FT40119 to U.S. DOE, National Energy Technology
Laboratory.
58
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Characterization of Coal Combustion Residues
Appendix A
U.S. EPA Science Advisory Board Consultation Summary
This summary was prepared at the close of the June 2003 U.S. EPA OSW and ORD consultation with the Science
Advisory Board, Environmental Engineering Committee Review Panel. These comments do not represent formal con-
sensus of the panel, and no consensus recommendations to the U.S. EPA were prepared. These comments do present
panel members views, with informal consensus on many points.
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Characterization of Coal Combustion Residues
TCLP CONSULTATION SUMMARY
Environmental Engineering Committee
Science Advisory Board
U.S. Environmantal Protection Agency
Washington, DC
June 18, 2003
FOCUS
Alternatives to TCLP test for use in waste and
site situations where TCLP test is not
required by regulation
Focus Areas: contaminated site remediation;
waste material reuse; waste delisting
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Characterization of Coal Combustion Residues
OVERVIEW
Five specific consultation issues
Two general consultation issues
Key findings and recommendations
SPECIFIC CONSULTATION ISSUE 1
Laboratory testing conditions should, to the
degree possible, anticipate the plausible
range of field conditions affecting waste
leaching in disposal and reuse situations.
These conditions will be most realistically
represented by a distribution of values for
factors affecting leaching, and testing should
reflect this range of values to the degree
possible
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Characterization of Coal Combustion Residues
COMMENTS
SPECIFIC CONSULTATION ISSUE 1
Agree with statement; comments that follow represent
consensus of committee
Statement should be related to some contextual use of
leaching test
Could expand probabilistic approach to include distributions
for field property parameters
Range of conditions considered depends on the intended
use of the information; need context
Need to define what the target problems are. What are we
trying to fix? Might be short list.
EPA needs to define better what the objectives are for the
broader leaching framework
COMMENTS
SPECIFIC CONSULTATION ISSUE 1
Unclear what is the cost of making no change.
Unclear to what extent overly conservative
classification affects beneficial reuse
Also need to consider waste material properties,
e.g., physical form, presence of oil, etc.
Need to consider organics as well as metals
Perhaps can group waste materials, consider
categories
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Characterization of Coal Combustion Residues
SPECIFIC CONSULTATION ISSUE 2
Conditions present at the end of a test (rather
than initial test conditions) should be the
basis for comparison with field conditions.
COMMENTS
SPECIFIC CONSULTATION ISSUE 2
Statement indicates application is to dissolution of solids,
and to assessment of max aqueous phase cone of released
species for purposes other than waste classification
To the extent that the test aims to achieve equil conditions,
end measurement is appropriate
Issue motivated by theTCLP test, where final solution pH is
not measured.
Conditions in a reactor at equilibrium or at the end of a fixed
period of time are more relevant to the leaching measured in
the reactor at the time of sampling than the initial condition.
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Characterization of Coal Combustion Residues
SPECIFIC CONSULTATION ISSUE 3
For assessing metals leaching, pH is the strongest
predictor of leaching potential in most cases.
Other important factors include infiltration rate,
liquid/solid ratio, redox environment, effect of
common ions and ionic strength, effects of
external factors (co-disposed waste, biological
activity, etc.), and exposure to ambient air. The
relative importance of these factors is likely to vary
for different wastes.
COMMENTS
SPECIFIC CONSULTATION ISSUE 3
Redox condition (Eh), organic matter, aging-after-
disposal are important factors not in current tests
Microbes important, but not in current tests;
biotransformation can render solid phase metals soluble
Inclusion of microbes difficult for standard tests
pH important; not clear it is "strongest" predictor
Depends on constituent; pure metals, organics
influenced by different factors
R&D needed to be able to rank parameters
Again, need to define objectives better
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Characterization of Coal Combustion Residues
SPECIFIC CONSULTATION ISSUE 4
The development of multiple leaching tests, or a
flexible testing framework is required. Selection of
a suitable leaching test should be made based on a
number of factors: anticipated use of test results,
waste characterization, the range of plausible
disposal or reuse conditions, and previously
available information on the subject waste or similar
wastes. ...
COMMENTS
SPECIFIC CONSULTATION ISSUE 4
Framework of Kosson et al. is flexible tiered approach that encompasses
equilibrium and kinetics and includes a suite of tests to address both, and
allows for site-specific and generic release estimates using mass transfer
modeling
Framework of Kosson et al. is broad and potentially applicable to broad range
of wastes and disposal scenarios
Framework is open ended; it is a huge step beyond a single leach test; the
manner in which it will be implemented by decisionmakers needs to be clarified
Establishment of the framework for implementation will be resource intensive;
EPA needs to justify the value of the information for decisionmaking, as
balanced against other waste regulation needs.
Need systematic approach for applying framework
Need well-defined objectives for framework in order to develop step-by-step
guidance for use
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Characterization of Coal Combustion Residues
SPECIFIC CONSULTATION ISSUE 5
Modeling may also play an important role in
relating laboratory and field conditions to one
another, and in using leach test results to
assess the leaching potential of waste.
COMMENTS
SPECIFIC CONSULTATION ISSUE 5
Concerned about use of deterministic models for prediction of leaching
potential; probabilistic modeling will be more appropriate in some cases, but
is resource intensive
Concern about incorporating modeling into leaching test protocol;
connecting model to field difficult
Modeling of leaching test may be useful for better understanding leach
mechanisms, and connection of test with field
For certain wastes, coupling of leach tests with a model should be
considered to predict solubilization over time, especially for organics
(Multiple equil. states may exist)
Usefulness of modeling depends on question to be answered; goals for
leach eval. need to be defined
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Characterization of Coal Combustion Residues
GENERAL CONSULTATION ISSUE 1
EPA requests SAB reaction to current research,
and the potential to apply it to improve particular
programs, specifically programs that do not now
require the use of TCLP.
COMMENTS
GENERAL CONSULTATION ISSUE 1
Capability to address organics, oily wastes, long-term
reliability need to be incorporated
Framework of Kosson et al. is broadly applicable; more
development work yet needed (guidance for specific
applications, database for field conditions and waste types,
data quality criteria, data interpretation/decisionmaking)
Framework of Kosson et al. is responsive to the 1999 SAB
commentary, but to this point is limited to inorganics
Current research proceeding without clear definition of
problem to be addressed by alternatives to TCLP
EPA should invest in identifying areas where alternative to
TCLP is vitally needed
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Characterization of Coal Combustion Residues
COMMENTS
GENERAL CONSULTATION ISSUE 1
Leaching-related research inside/outside EPA
could be exploited more
COMMENTS
GENERAL CONSULTATION ISSUE 1
Tiered structure of framework: enables tradeoffs in value of
information
EPA should prioritize R&D efforts based on assessment of
the problem most in need of alternatives to the TCLP, e.g.,
- If going to do evaluation of problems driving TCLP
alternatives, try to ascertain value of making a change,
i.e., economic analysis of problem
- Evaluate waste generation and management trends an
projections as well as current situation
- Cost-benefit analysis may be difficult; try to assess
opportunity cost of not pursuing alt. to TCLP
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Characterization of Coal Combustion Residues
GENERAL CONSULTATION ISSUE 2
EPA requests SAB reaction to the direction for long-
term research work to further develop fundamental
understanding of leaching that would improve the
predictive capability of test suites or testing
frameworks.
COMMENTS
GENERAL CONSULTATION ISSUE 2
Goals for long-term research not well defined
Increased fundamental knowledge will yield long-term
advancement in assessment of leaching
Funding priority for leaching research clearly is low.
Long-term ORD research should be better coordinated with
efforts inside/outside EPA, including DOD, FHWA, DOE
Long-term ORD research is responsive to 1999 SAB
commentary in science factors under study, but is focused on
inorganics only and will benefit from clearer objectives
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Characterization of Coal Combustion Residues
COMMENTS
GENERAL CONSULTATION ISSUE 2
Problem definition has two components
- determine waste categories and field situations
most in need of TCLP alternatives
- determine research priorities for the most
important waste/field situations
COMMENTS
GENERAL CONSULTATION ISSUE 2
Organics, manufacturing process wastes, end-of-
life product wastes need to be considered
Industry/government/academic research
consortium on leashing issues would be useful
Industry may be willing to co-fund leaching
evaluation R&D
EPA should investigate collaborative efforts with
European, Canadian, and Japanese researchers
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Characterization of Coal Combustion Residues
KEY FINDINGS AND RECOMMENDATIONS
Alternatives to TCLP for evaluation of leach potential are
needed for some waste and site situations
Not clear if there is large or small number of waste and site
situations for which alternative approach is needed
Framework of Kosson et al. is broadly applicable; more
development work yet needed (guidance for specific
applications, database for field conditions and waste types, data
quality criteria, data interpretation/decisionmaking)
Framework of Kosson et al. is responsive to the 1999 SAB
commentary, but to this point is limited to inorganics
KEY FINDINGS AND RECOMMENDATIONS
Current research needs clear definition of problem
to be addressed by alternative to TCLP
EPA should invest in identifying areas where
alternative to TCLP is vitally needed
The 1999 SAB commentary focused on science-
based issues in leaching: EPA has been
responsive within resource limitations.
Organic waste constituents need to be considered,
and a broader framework should include
assessment or organic constituent leaching
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Characterization of Coal Combustion Residues
KEY FINDINGS AND RECOMMENDATIONS
Research and development should focus on most
applicable waste/site situations, and possible
beneficial reuse scenarios
Given limited R&D resources, EPA should
prioritize research efforts and leverage DOD,
DOE, FHWA interest in leaching through cross-
govt coordination, as well as industrial and
international collaboration
EPA intra-agency efforts should be more closely
linked
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Characterization of Coal Combustion Residues
Appendix B
DOE NETL Full-Scale Test Site Flow Diagrams
73
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Characterization of Coal Combustion Residues
Brayton Point Unit 1
• Carbon injected upstream of second ESP (Research Cottrell). Only !/> of the unit was treated, or carbon was injected
into one of the two new ESPs (Research Cottrell ESPs).
• Hopper IDs also shown. Samples from C-row are from the first row of hoppers in the second ESP.
Gas Flow
Hg
HgS-CEM
Air Preheater
Erst ESP
(Koppers)
Hg S-CEM
Sorbcnt Injection
-Second ESP
(Research-Cottrell)
-Hg S-CEM
Hg S-CEM: Hg Semi Continuous Emission Monitors
74
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Characterization of Coal Combustion Residues
Bird's eye view of second ESP.
Samples taken from C-raw hoppers.
North
New
Precips
Old
Precips
East
West
i
it. -ir.iL.1ii
jssp!p*rfi'"" ""°m3ai
-_
1O
'
—ft—-
_<.l V _„
T*
.^ N
**
x \ 4 1
/• x -^ . -J f
">•
*
4r^
X N
3
—-* \ |—-^
Gas Flow
I!
;
^ ^
ja
75
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Characterization of Coal Combustion Residues
Pleasant Prairie Unit 2
Carbon injected upstream of cold-side ESP. Only % of the unit was treated. Test ESP was ESP 2-4.
76
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Characterization of Coal Combustion Residues
Salem Harbor Unit 1
Carbon injected upstream of cold-side ESP. Row-A hoppers were the front hoppers.
Carbon
Injection Point
Boiler
Long Ai
Heater
=
r Short Air
Heater
II
V
Steam Coils
Facility C
Carbon injected upstream of Unit 3B COHPAC baghouse (in between hot-side ESP and baghouse)
WF
BoBer
Grade Level
HgJF Mercuy Analyzer
Location
•jftftftftfSSS
Activated Carbon Injection
77
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Characterization of Coal Combustion Residues
St. Clair
Total flow from
boiler/econimizer
Facility L
North-Side CS-ESP (ESP B)
T
South-Side CS-ESP (ESP A)
B-PAC injection
B-PAC injection
Total Flow to
Stack
Total flow from
boiler/econimizer
B-Side HS-ESP (ESP B)
A-side HS-ESP (ESP A)
To B Stack
To A Stack
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Characterization of Coal Combustion Residues
Appendix C
Quality Assurance Project Plan
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Characterization of Coal Combustion Residues
U.S. EPA/APPCD
QAPP FDR THE
CHARACTERIZATION
DF COAL COMBUSTION
RESIDUES (WA 4-D4)
CATEGORY HI/APPLIED
RESEARCH
ARCAD1S
80
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Characterization of Coal Combustion Residues
ARCADIS
Susan Thorneloe
EPA WA Manager
QAPP for the
Characterization of Coal
Combustion Residues
(WA 4-4)
Category Ill/Applied
Research
Shirley Wasson
EPA QA Representative
Prepared for:
USEPA/APPCD
Rob Keeney
ARCADIS WA Leader
Laura Nessley
ARCADIS Designated QA Officer
Prepared by:
ARCADIS G&M, Inc.
4915 Prospectus Drive
Suite F
Durham
North Carolina 27713
Tel 919 544 4535
Fax 919 5445690
Our Ref :
RN9902013.0037
Date:
11 January 2006
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Characterization of Coal Combustion Residues
ARCADIS TABLE PF CONTENTS
1 .a PROJECT DESCRIPTION AND OBJECTIVES
1.1 Purpose
1.2 Project Objectives
Z.D PROJECT ORGANIZATION
3.D EXPERIMENTAL APPROACH
3.1 Task I: Characterization of CCRs
3.2 Task II: Chemical Stability of Target Metals
3.3 Task III: Thermal Stability of Target Metals
3.4 Task IV: Biological Transformation and Volatilization of
Organo-Mercury
A.O SAMPLING PROCEDURES
4.1 Sample Custody Procedures
4.2 CCR and SRM Samples
4.2.1 Physical and Chemical Characterization Samples
4.2.2 Leaching Study Samples
4.2.3 Fixed-Bed Reactor Samples
4.3 Leachate Collection
4.3.1 Tier 1 Screening Tests
4.3.2 Tier 2 Solubility and Release as a Function of pH and
LS Ratio
4.3.3 Tier 3 Mass Transfer Rate
4.4 Fixed-Bed, TPD Reactor Sampling
4.4.1 Thermal Desorption Test Plan for High
Temperature CCR Commercial Processes
5.D TESTING AND MEASUREMENT PROTOCOLS
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Characterization of Coal Combustion Residues
ARCADIS TABLE OF CONTENTS
5.1 Physical Characterization
5.1.1 Surface Area and Pore Size Distribution
5.1.2 Density Measurements
5.1.3 pH and Conductivity
5.1.4 Moisture Content
5.2 Chemical Characterization
5.2.1 Carbon Content (TGA)
5.2.2 Mercury (CVAA)
5.2.3 Other Metals (ICP)
5.2.4 Anion Analysis by 1C
5.2.5 X-Ray Fluorescence (XRF) an Neutron Activation
Analysis
6.a QA./QC CHECKS
6.1 Data Quality Indicator Goals
6.2 QC Sample Types
7.a DATA REDUCTION, VALIDATION, AND REPORTING
B.D ASSESSMENTS
9.Q REFERENCES
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Characterization of Coal Combustion Residues
ARCADIS TABLE OF CONTENTS
TABLES
Table 3-1 Summary of testing under Task II to be performed on
theSRM
Table 3-2 Summary of testing under Task II to be performed for
detailed characterization of CCRs
Table 3-3 Summary of testing under Task II to be performed for
screening evaluation of CCRs
Table 4-1 SRM certified values
Table 6-1 Data quality indicator goals
Table 8-1 PEA Parameters and ranges
FIGURES
Figure 2-1- Project organizational chart
in
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Characterization of Coal Combustion Residues
ARCADIS
QAPP FOR THE
CHARACTERIZATION
OF COAL
COMBUSTION
1 .D PROJECT DESCRIPTION AND OBJECTIVES
1 .1 PURPOSE
In December 2000, EPA determined that regulations are needed to control the risks of
mercury (Hg) emissions from coal-fired power plants. A number of Hg control options
are currently being evaluated through bench-scale and full-scale demonstrations. For
each of the technologies that appear to have commercial application, the resulting
residues are to be evaluated to determine any potential cross-media impacts through
either waste management of these residues or use in commercial applications. Coal
combustion residues (CCRs) include bottom ashes, fly ashes, and scrubber sludges
from flue gas desulfurization (FGD) systems. The questions to be addressed through
this research include:
• What are the changes to CCRs resulting from application of control technology at
coal-fired power plants including changes in pH, metals content, and other
parameters that may influence environmental release?
• For CCRs that are land disposed, the questions to be addressed include:
o Will any of these changes result in an increase in the potential for
leaching of Hg and other metals such as As, Se, Pb, and Cd leach
from disposal of CCRs in impoundments, monofills, and minefills?
o What is the fate of Hg and other metals from CCRs that are land
disposed?
o Is there a potential for organo-mercury being formed when anaerobic
decomposition conditions exists?
• For CCRs that are used in commercial applications, the questions to be addressed
include:
o Will any of the changes to CCRs, from application of control
technologies at coal-fired power plants, impact their use in
commercial applications?
o What is the fate of Hg and other metals in CCRs when used in
commercial applications?
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Characterization of Coal Combustion Residues
ARCADIS
QAPP FDR THE
CHARACTERIZATION
DF COAL
COMBUSTION
o What is the extent of Hg, As, Pb, Se and Cd release during high
temperature manufacturing processes used to produce cement clinkers,
asphalt, and wallboard?
o Are Hg and other pollutants such as As, Se, Pb and Cd present in
CCRs that are used in commercial applications such as highway
construction subject to conditions that would result in their release to
the environment?
EPA's Air Pollution Prevention and Control Division (APPCD) through an on-site
laboratory support contract with ARCADIS is to conduct a comprehensive study on the
fate of mercury (Hg), arsenic (As), selenium (Se), lead (Pb) and cadmium (Cd) in
CCRs. This research will be conducted in four tasks. Task I will focus on the
characterization of different CCRs and the impact of Hg control technologies on these
characteristics. Task II will focus on evaluating the potential for leaching of these
toxic metals from CCRs that are generated with and without implementation of Hg
control technologies under a range of management scenarios. Task HI will focus on
the release of these toxic metals during high and low temperature utilization of CCRs
in commercial processes. Task IV will study the potential formation and volatilization
of organo-mercury and inorganic mercury during simulated anaerobic decomposition
processes. The scope of this QAPP covers Task I through Task III. Task IV will be
addressed in a separate document.
1 .2 PROJECT OBJECTIVES
EPA's Office of Solid Waste (OSW) has been asked to provide general guidance on
appropriate testing to evaluate the release potential of Hg and four other metallic
contaminants (As, Se, Pb, and Cd) from CCRs via leaching, run-off, and volatilization
when disposed hi landfills and incorporated into commercial products using high/low
temperature commercial processes. This evaluation in projected disposal and reuse
situations (different waste management scenarios; see Section 1.1) will both help
assess the likely suitability of new or modified wastes for reuse, and ensure that Hg,
As, Se, Pb, and Cd removed from stack emissions are not subsequently released to the
environment in significant amounts as a result of CCR reuse or disposal practices.
The primary objective of this project is to generate a comprehensive database that will
enable EPA/OSW to (1) evaluate changes in CCRs resulting from the implementation
of different Hg control technologies (see Section 3.1), and (2) assess environmental
releases of these toxic metals during CCR management practices including land
Category
86
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Characterization of Coal Combustion Residues
ARCADIS
QAPP FDR THE
CHARACTERIZATION
OF COAL
COMBUSTION
disposal and commercial applications. OSW will be using the results to determine
needs in regard to future policies for managing CCRs whose characteristics are
changing as a result of the MACT under development for coal fired power plants.
OAR will be using the data to determine the potential for cross-media impacts and
potential changes to disposal and reuse practices which impact the economics of
potential regulations for coal-fired power plants. The data will also be used to address
questions raised by Congress and others regarding establishing the net benefit of
potential requirements for reducing emissions from coal-fired power plants.
Data on the chemical stability of these metals (leaching tests) will be generated using
the EPA/OSW recommended methods (EPA, 2002b) developed by Dr. David Kosson
and Dr. Florence Sanchez of Vanderbilt University titled An Integrated Framework for
Evaluating Leaching in Waste Management and Utilization of Secondary Materials
(Kosson et al., 2002a). The ability of these EPA/OSW methods to assess leaching of
the metals of interest will be further demonstrated with the use of a NIST standard
reference material (SRM) with certified amounts of trace metals. Data on the thermal
stability of these toxic metals during CCRs commercial applications will also be
determined by implementing temperature program desorption techniques (see Section
4.4). The time/temperature profiles experienced by CCRs in their commercial
applications (highway construction, cement, asphalt, and wallboard manufacturing) as
determined based on the study conducted by RTI International and presented in the
publication titled Characterization and management of Residues from Coal-Fired
Power Plants/Interim Report, prepared for APPCD/NRMRL/EPA (EPA, 2002a).
Using this comprehensive database, EPA/OSW will determine the feasibility of the
application of the above methods to CCRs and they will assess the environmental
impacts of different types of CCRs' waste management practices.
A secondary objective of this project is to modify and develop a QA/QC framework
for the proposed leaching assessment approach developed by Kosson et al. The
reference fly ash may be an appropriate candidate for a method QC sample. These
activities will be carried out in cooperation with Drs. Kosson and Sanchez during
implementation of the proposed methods (see Task II, Section 3.2).
2.a PROJECT ORGANIZATION
The organizational chart for this project is shown in Figure 2-1. The roles and
responsibilities of the project personnel are discussed in the following paragraphs. In
addition, contact information is also provided.
Category
87
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Characterization of Coal Combustion Residues
ARCADIS QAPP FOR THE
CHARACTERIZATION
OF COAL
COMBUSTION
EPA Work Assignment Manager. Susan Thorneloe: The EPA WA Manager is
responsible for communicating the scope of work, data quality objectives and
deliverables required for this work assignment. The EPA WA Manager is also
responsible for providing ARCADIS with the various types of CCRs to be
characterized.
Phone:(919)541-2709
E-mail: thorneloe.susan@epamail.epa.gov
EPA QA Representative. Shirley Wasson: The EPA QA Representative will be
responsible for reviewing and approving this QAPP. This proj ect has been assigned a
QA category ni and may be audited by EPA QA. Ms. Wasson is responsible for
coordinating any EPA audits.
Phone (919) 541-5510
E-mail: wasson.shirlev@epamail.epa.gov
ARCADIS Work Assignment Leader. Robert Keenev: The ARCADIS WA Leader is
responsible for preparing project deliverables and managing the work assignment. He
will ensure the project meets scheduled milestones and stays within budgetary
constraints agreed upon by EPA. The WA Leader is also responsible for
communicating any delays in scheduling or changes in cost to the EPA WA Manager
as soon as possible.
Phone (919) 541-3284
E-mail: rkeenev@arcadis-us.com
ARCADIS Inorganic Laboratory Manager, Robert Keenev. In addition to being the
work assignment leader, Robert Keeney is also responsible for the operation of EPA's
in-house Inorganic Laboratory. Mr. Keeney will review and validate all analytical data
reports and ensure that the leaching studies are performed properly. He will also
operate the TGA and surface area analyzers. For the leaching studies and mercury and
metals analyses, Mr. Keeney will be supported by one chemist: Gene Gallagher and
one technician: John Foley.
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Characterization of Coal Combustion Residues
ARCADIS gApp FDR THE
CHARACTERIZATION
DF COAL
COMBUSTION
Mr. Gallagher will perform HF extractions of solid CCR and SRM samples and also be
responsible for mercury analysis of samples by CVAA. John Foley will perform the
leaching test. Mr. Keeney and Mr. Gallagher will submit the remaining HF digestates
to the subcontract analytical laboratory, STL-Savannah for ICP/MS analysis of the
other target metals. Mr. Keeney will also be responsible for assisting Drs. Kosson and
Sanchez in the development of appropriate QA/QC procedures for the leaching
assessment methods.
Phone (919) 541-3284
E-mail: rkeenev@arcadis-us.com
STL-Savannah Analytical Manager. Angie Weimerskirk: Ms. Weimerskirk will
review and validate the ICP/MS results and report them to Mr. Keeney.
Phone (912) 354-7858
E-mail: aweimerskirk@stl-inc.com
ARCADIS Thermal Desorption Task Manager (Task HI), Behrooz Ghorishi: The
ARCADIS Thermal Desorption Task Manager is responsible for preparing task El
deliverables and managing task HI. He will ensure the task meets scheduled
milestones. The Thermal Desoption Task Manager is also responsible for
communicating any delays in scheduling to the ARCADIS Work Assignment Leader.
EPA WA Manager as soon as possible. Dr. Ghorishi will be assisted by Jarek
Karwowski. Mr. Karwowski will perform the thermal desorption test and submit the
samples to the laboratory.
ARCADIS Designated QA Officer. Laura Nessley: The ARCADIS QA Manager,
Laura Nessley, has been assigned QA responsibilities for this work assignment. Ms.
Nessley will be responsible for reviewing this QAPP prior to submission to EPA QA
for review. Ms. Nessley will also ensure the QAPP is implemented by project
personnel by performing internal assessments. All QA/QC related problems will be
reported directly to the ARCADIS WAL, Robert Keeney.
Phone: (919) 544-2260 ext. 258
E-mail: lnessley@arcadis-us.com
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Characterization of Coal Combustion Residues
ARCADIS
QAPP FDR THE
CHARACTERIZATION
OF COAL.
COMBUSTION
Vanderbilt University. Methods Development. Professors David Kosson and Florence
Sanchez: Dr. Kosson in cooperation with Dr. Florence Sanchez developed the
leachability methods being evaluated on this project. He will be available to consult
regarding method optimization and development of QA/QC procedures. Dr. Kosson
and Dr. Sanchez will be on-site in the early stages of the project to assist in setting up
the procedures. Phones: (615)322-1064; (615)322-5135
E-mail: David.Kosson@vanderbilt.edu
Florence.Sanchez@vandcrbilt.edu
Category
Figure 2-1- Project Organizational Chart
3-D EXPERIMENTAL APPROACH
3.1 TASK
CHARACTERIZATION OF CCRs
This task will focus on physical and chemical characterization of as-received CCRs.
CCRs from different power plants and various types of control technologies will be
selected and provided to ARCADIS by the EPA WA Manager. These CCRs will
include fly ashes and scrubber sludges from DOE test facilities. These full-scale
facilities are being used to test two different Hg control technologies: activated carbon
injection as an adsorbent and addition of agents to wet scrubbers that maintain Hg in an
oxidized state to facilitate removal by aqueous scrubbing. Physical characteristics of
CCRs to be determined include specific surface area, moisture content and density.
Chemical characterization will include total carbon analysis, pH of extract, total
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Characterization of Coal Combustion Residues
ARCADIS
CJAPP FOR THE
CHARACTERIZATION
OF COAL.
COMBUSTION
concentration of target metals (Hg, As, Se, Pb, and Cd) and principal constituents (i.e., v
Fe, Cl", SO42", COa2")1. The types of analyses and instrumentations used to perform this
characterization are further described in Section 5.0. Identical characterizations will be
performed on the reference fly ash. Task I results will reveal the effect of implementing
the two Hg control technologies on the final characteristics of CCRs. This information
will help in decision-making regarding different waste management scenarios.
3.Z TASK II: CHEMICAL STABILITY QF TARGET METALS
This task will investigate the fate of Hg, As, Se, Cd, and Pb during CCR management
practice of land disposal. Using the recently proposed test methods developed by
Kosson et al in coordination with EPA's Office of Solid Waste, leaching studies will
first be conducted on a reference fly ash. The reference fly ash is a high quantity fly
ash that has been characterized by ICP/MS and CVAA analyses. The ICP/MS and
CVAA analyses will be checked using the NIST SRM 1633b. NIST SRM 1633B is a
bituminous coal fly ash that is fully described in Section 4.2.2. The results obtained
from the reference fly ash leaching studies will be critical in evaluating the
performance of the method. Using a known standard in place of the CCR material,
will also allow optimization of the proposed test methods. The quality control
procedures regarding the reference fly ash tests are described in section 6.
A summary of testing that will be carried out on the reference fly ash is presented in
Table 3-1 along with the number of replicates, the material mass required and the
number of extracts that will be generated. Detailed descriptions of the methods listed
in Table 3-1 can be found in the document titled An Integrated Framework for
Evaluating Leaching in Waste management and Utilization of Secondary materials
(Kosson et al., 2002a).
1 This will provide valuable insights concerning the characteristic behavior of the CCRs.
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Characterization of Coal Combustion Residues
ARCADIS
C?APP FDR THE
CHARACTERIZATION
OF COAL
COMBUSTION
Category
TABLE 3-1. SUMMARY OF TESTING UNDER TASK II TO BE PERFORMED ON THE
REFERENCE FLY ASH
Sample type
Level of testing
Tests
Baseline : Detailed pH001.1 (pH TOration Pretest)
Fly Ash" characterization j
| Moisture Content
I
-•
AV002.1
Material
particle size
<2mm
<2mm
<2mm
Availability at pH 7.5 with EDTA I
(3 target points) |
|
SR002.1
Alkalinity, Solubility and Release
as a Function of pH
(11 pHs tested from 2 to 12)
SR003.1
Solubility and Release as a
Function of LS ratio
(LS=10, 5, 2, 1,0.5mL/g)
LSIOmUg
LSSmUg
LSZmUg
IS 1 mug
LS 0.5 mug
MTO02.1
Mass Transfer Rate in Granular
Materials
(10 extracts in 30 days)
- Optimum moisture content
- Leach test
<2mm
<2mm
<2mm
<2mm
Number of
replicates
2
3
3
3
3
2
S
Mass
material/
aliquot*
(9)
8
8
a
40
40
40
50
100
200
500
500
Mass
material/
test
replicate
(9)
8
8
24
440
430
500
500
Total mass material required (g
Total mass
of material
required
(9)
16
24
72
1320
1290
2500
5222
I
Number of
analytical
samples
NA
NA
3
33
15
30
" Baseline fly ash is a fly ash that will be used as a reference material. Total elemental content will be determined by NAA/XRF analysis. ;
After the proposed test methods have been successfully demonstrated on the reference
fly ash, leaching studies will be conducted on high priority CCRs that will allow
estimating constituent release by leaching for a range of conditions that are likely to
occur during management practices. A separate test plan for the leaching experiments
under this task is provided by its developers (Drs. Kosson and Sanchez). This test plan,
titled "Draft (Revision #2), Sampling and Characterization Plan for Coal Combustion
Residues from Facilities with Enhanced Mercury Emissions Reduction Technology"
(Kosson et al., 2002b) together with this QAPP will cover all the issues regarding Task
II. Two levels of testing will be performed. The first level will provide detailed
8
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ARCADIS
FDR THE
CHARACTERIZATION
OF COAL.
COMBUSTION
characterization of representative samples of CCRs that reflect each dominant CCR
chemistry with respect to mercury release. This will define the behavior of the general
class of CCR chemistry. This detailed characterization would establish a baseline for
comparison of subsequent test results. A summary of testing that will be carried out on
each dominant CCR chemistry is presented in Table 3-2 along with the number of
replicates, the material mass required and the number of extracts that will be generated.
The second level will provide screening evaluation of additional samples anticipated to
be representative of each dominant CCR chemistry. The second level screening will be
used to determine if the CCR being tested exhibits the same leaching behavior as the
general class of CCRs, which is assumed to have the same dominant chemistry. If the
leaching behavior is found to be significantly different than anticipated, then more
complete characterization can be completed. A summary of testing that will be carried
out for the screening level is presented in Table 3-3 along with the number of
replicates, the material mass required and the number of extracts that will be generated.
Residues collected before and after application of enhanced Hg control technologies
will be examined to evaluate the effect of the enhanced systems on the leaching
behavior of CCRs.
Estimates of the extent of release of the metals of concern during management
scenarios that include percolation through the CCRs or infiltration flow around the
CCRs (e.g., when compacted to low permeability or otherwise expected to behave as a
monolithic material) will be determined. These data will be used to determine the risk
of land disposal of the different CCRs. Mass balances for each metal will be
determined using the chemical characterization data obtained in Task I. Utilization of
mass balance as a QA/QC tool is described in section 6. Details of this QA/QC
procedure are outlined hi section 6. In addition to testing of the CCRs as generated,
CCRs as used in commercial products will be examined. Only commercial uses for
which there is a potential for release of Hg during leaching will be considered. One
commercial use of CCRs that may be of concern for Hg leaching is cement-based
materials (i.e., concrete/grout, waste stabilization, road base/subbase). A generic
cement-based product made from samples representative of the major coal fly ash
categories will be examined. A second commercial use of CCRs that may be of
concern is incorporation in gypsum board. In this case leaching of Hg after disposal is
of concern. This task will consider the potential for Hg leaching after disposal from a
representative gypsum board product.
Category
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Characterization of Coal Combustion Residues
ARCADIS
C^APP FDR THE
CHARACTERIZATION
or COAL
COMBUSTION
TABLE 3-2. SUMMARY OF TESTING UNDER TASK II TO BE PERFORMED FDR DETAILED
CHARACTERIZATION OF CCRB
Category
Sample type
Sample reflecting dominant
CCR chemistry
!* Sample size required for each
," Optional
Level of testing
Detailed
characterization
Tests
pHOOI.1 (pH Trtratton Pretatt)
Moisture Content
AV002.1"
Availability at pH 7.S with EOTA
(3 target points)
SROC21
Alkalinity, Solubility and Release
as a Function of pH
(11 pHs tested from 2 to 12)
SR0031
Solubility and Release as a
Function of LS ratio
(LS=10, 5, 2, 1,0.5 mL/g)
LSIOmUg
LS5mUg
LS2mUQ
LS1mL/s
LSO.SmUg
MT002.1
Mass Transfer Rate in Granular
Materials
(10 extracts in 30 days)
-Optimum moisture content
- Leach tost
Material
particle size
< 2mm
< 2mm
< 2mm
< 2mm
< 2mm
<2mm
condttkxi within the test method. For example, one replicate of SRI
'
Number of
replicates
2
3
2
2
2
2
Mass Mass
material/ ^material/
aliquot* test
(g) Implicate
(g)
8
•
1
40
40
40
SO
100-
200
500
500
Total mass material
102.1 requires eleven!
e
a
24
440
430
required (g
Total mass
of material
required
(g)
16
24
46
L~ M0
MO
2000
3821
sample aliquots.
J_ '
Number of)
analytical
samples
NA
NA
2
22
10
20
10
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Characterization of Coal Combustion Residues
ARCADIS
FOR THE
CHARACTERIZATION
OF COAL.
COMBUSTION
TABLE 3-3. SUMMARY OF TESTING UNDER TASK II TO BE PERFORMED FOR SCREENING Category
EVALUATION OF CCRS
Sample type
Additional samples anticipated
to be representative of each
dominant OCR chemistry
Level of testing
Scrawling
Tests
Moisture Content
SR002.1-A
(3 pHs © LS lOmL/g: ack»c,
neutral, alkali)
SRQ03.1-A
(LS - 10, 0.5 mL/g)
LSIOmljS
LSO.SmUg
:
MT0021-A
Material
particle size
<2mm
<2mm
< 1mm
<2mm
(4 extractions In 5 days)
- Optmum moisture content
- Leach test
Number of
replicates
3
3
a
2
3
Mass
material/
aliquot'
(g)
a
40
40
200
500
500
Mass
material/
test
replicate
(g)
8
120
240
h 5001
500
Total mass material required (g
! ]
Total mass
of material
required
(g)
24
360
720
2500
2§£
' Sample size required for each condition within the test method. For example, one replicate of SR002.1-A requires three sample aliquots.
Number of
analytical
samples
MA
3
•
12
_
3.3 TASK III: THERMAL STABILITY OF TARGET METALS
This task will investigate the potential release of the target metals during their
commercial applications such as cement, wallboard and asphalt manufacturing. The
potential long-term evaporation of these metals during low temperature applications
such as structural fills, highway construction, snow/ice control, and soil amendment
will also be determined Representative samples of CCRs will be tested in an in-house,
bench-scale, fixed-bed reactor system called the Thermal Program Desorption (TPD)
system. CCRs will be exposed to conditions that are experienced in actual situations.
The effluent of the fixed-bed reactor will be sampled and analyzed for inorganic Hg
(speciated, elemental and ionic), As, Se, Pb, and Cd using established methods such as
EPA Method 29 for metals and Ontario Hydro Method for mercury. Mass balances for
the metals will be determined using the chemical characterization data obtained in Task
I. The reference fly ash will also be tested in the reactor and the results will be used as
a quality control check (see section 6).
11
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Characterization of Coal Combustion Residues
ARCADIS
QAPP FOR THE
CHARACTERIZATION
OF COAL.
COMBUSTION
3.4 TASK IV: BIOLOGICAL. TRANSFORMATION AND VOLATILIZATION OF DRGANO-
MERCURY
This task will investigate the potential formation and release of organo-mercury during
anaerobic decompositions. This will be simulated in a bioreactor and the effluent will
be sampled for speciated inorganic and organic mercury. The details of these tests will
be described in a separate QAPP. Due to the health and safety related concerns
regarding organo-mercury compounds, prior to preparation of the QAPP, an extensive
literature survey will be performed to select the most appropriate methods for sampling
and analysis of these types of compounds.
4.D SAMPLING PROCEDURES
The following subsections describe the sampling procedures to be used for each task.
Whenever possible, standard methods will be followed. In some cases, draft methods
may be evaluated and implemented. Each method to be used will be cited and any
deviations from the methods will be documented.
4. 1 SAMPLE CUSTODY PROCEDURES
The following types of samples will be generated during these tests:
1- "As-received" CCR samples before and after application of Hg control technologies,
SRM and reference fly ash samples (solid samples) and treated CCR samples as used
in commercial applications
2- Post -leaching and post-thermal desorption CCR, reference fly ash samples and
treated CCR samples (solid samples)
3- Leachate samples (liquid samples)
4- Method 29 and Ontario Hydro Tram samples (liquid samples)
Each sample generated will be analyzed in-house but chain-of-custody procedures .will
be required. CCRs will be logged as they are received by the ARCADIS WAL, Mr.
Robert Keeney. Information regarding where each CCR originated and any other
descriptive information available will be recorded in a dedicated laboratory notebook
by Mr. Keeney. A 200 g grab sample will be taken from each "as-received" CCR and
processed for physical and chemical characterization. All samples will be properly
contained and identified with a unique sample ID and sample label. Sample labels at a
minimum will contain the sample ID, date sampled, and initials of the analyst
Category
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Characterization of Coal Combustion Residues
ARCADIS
QAPP FOR THE
CHARACTERIZATION
OF COAL
COMBUSTION
responsible for preparing the sample. Chain-of-custody forms will be generated for all
samples prior to transfer for analysis.
Handling of CCR samples for the leaching tests (Task II) is described in detail by the
leaching procedure provided by its developers (Kosson et al., 2002a). For Task HI, a
lOg grab sample will be taken from each "as received" CCR and will be subjected to
the TPD procedures (see section 4.2.3)
4.2 CCR, AND REFERENCE FLY ASH SAMPLES
As mentioned, the focus of this program is to obtain information on the effect of Hg
control technologies on the stability of Hg, As, Se, Cd, and Pb in CCRs. Currently, two
different Hg control technologies are being tested in full-scale facilities. The focus of
the first technology is on powdered activated carbon (PAC) injection upstream of
participate matter control devices. The PAC injection technology affects the properties
of fly ashes collected in electrostatic precipitators and baghouses. These facilities are
listed in the Vanderbilt test plan "Draft (Revision #2), Sampling and Characterization
Plan for Coal Combustion Residues from Facilities with Enhanced Mercury Emissions
Reduction Technology" (Kosson et al., 2002b). The second technology focuses on Hg
capture by wet scrubbers. Chemical modifications are being implemented in wet
scrubbers to enhance the Hg capture. The scrubber sludge from these facilities will be
impacted by this control technology. The scrubber sludge samples from these facilities
will be included in this test program.
The Hg control testing facilities will be identified and then" test reports will be obtained
and amended to this QAPP. The test reports will include information on the
history/origin of each CCR sample, facility process description, CCR type, sampling
location, sampling time and method, coal type, operating condition, and sample storage
condition. Section 4.1 describes the sampling custody procedure.
4.2.1 Physical and Chemical Characterization Samples
"As received" CCR will be well mixed prior to taking samples for physical
characterization. Mixing of the sub-samples collected at the site will be done using a
riffle splitter. To ensure a good homogeneity of the final composite sample that will be
used for the study, the first two composite samples exiting the splitter will be
reintroduced at the top of the splitter. This procedure should be repeated at least 6
times. At the end, the two resulting homogeneous composite samples will be combined
in the same bucket and stored until laboratory testing. A 200 g representative sample
Category III
13
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Characterization of Coal Combustion Residues
ARCADIS
QAPP FDR THE
CHARACTERIZATION
OF COAL,
CDMBUBTIDN
will be taken from the "as received" CCR and subjected to physical characterization
measurements. Samples will also be taken of any CCRs that undergo size-reduction
techniques (if size reduction is needed for testing purposes). The reference fly ash
samples will be processed in the same manner as the CCRs. They will be tracked by
lot number and will not require size-reduction.
4.2.2 Leaching Study Samples
CCRs used for leaching studies may undergo size reduction to acquire an adequate
sample for testing. The size reduction method is outlined in the leaching test methods
(Kosson et al., 2002a). If "as-received" CCRs are altered in any way prior to leaching
studies, a representative sample will be submitted for physical and chemical
characterization. SRM samples will not require size reduction. The NIST 1633B SRM
is a bituminous coal fly ash that has been sieved through a nominal sieve opening of 90
[an and blended to assure homogeneity. The certified values for the constituent
elements are given in Table 4-1. The reference fly ash will also be certified using
ICP/MS and CVAA.
4.2.3 Fixed-Bed Reactor Samples
Reactor samples will be essentially the same as the CCR samples used in the leaching
studies. Amount of material may be reduced, but physical and chemical characteristics
will not be affected.
Category
TABLE 4-1. SRM CERTIFIED VALUES
Element
Arsenic
Barium
Cadmium
Chromium
Copper
Lead
Manganese
Mercury
Nickel
Selenium
Concentration (mg/kg)
136.2 ±2.6
709 + 27
0.784 ± O.OO6
198.2 ±4.7
11 2. 8 ±2. 6
68. 2 ± 1.1
131. 8± 1.7
0.141 ±0.019
120.6 ±1.8
10.26±0.17
14
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Characterization of Coal Combustion Residues
ARCADIS qjAFP FOR THE
CHARAtTERIZATION
OF COAL
COMBUSTION
Strontium
Thorium
Uranium
Vanadium
1041 ± 14
25.7 ± 1.3
8.79 ±0.36
295.713.6
Category
4.3 LEACHATE COLLECTION
The proposed test method described in the publication titled An Integrated Framework
for Evaluating Leaching in Waste Management and Utilization of Secondary Materials
(Kosson, et. al., 2002a) will be used to conduct leaching studies. There are three tiers
to this test method:
Tier 1) Screening based assessment (availability)
Tier 2) Equilibrium-based assessment over a range of pH and Liquid/solid (LS) ratios
Tier 3) Mass transfer based assessment
The Tier 1 screening test provides an indication of the maximum potential for release
under the limits of anticipated environmental conditions expressed on a mg
contaminant leached per kg waste basis. Tier 2 defines the release potential as a
function of liquid-to-solid (LS) ratio and pH. Tier 3 uses information on LS
equilibrium in conjunction with mass transfer rate information. As mentioned
previously, prior to testing CCR, a reference fly ash will be used to demonstrate the
effectiveness of the proposed test methods. Procedures for each tier are discussed in
the following subsections.
If needed, prior to tier testing, the "as-received" CCR will be size reduced using the
procedure PS001.1 Particle Size Reduction (Kosson et al., 2002a) to minimize mass
transfer rate limitation through larger particles. The pH will be then tested using the
method pHOOl.O pH Titration Pretest (Kosson et al., 2002a).
4.3.1 Tier 1 Screening Tests
Test Method AV002.1 Availability at pH 7.5 with EDTA (Kosson et al., 2002a) will
be used to perform the screening test. This method measures availability in relation to
the release of anions at an endpoint pH of 7.5±0.5 and cations under enhanced liquid-
phase solubility due to complexation with the chelating agent. Constituent availability
is determined by a single challenge of an aliquot of the reference fly ash or size
15
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Characterization of Coal Combustion Residues
ARCADIS
FDR THE
CHARACTERIZATION
OF COAL.
COMBUSTION
reduced CCR material to dilute acid or base in DI water with the chelating agent,
ethylenediamine-tetraacetic acid (EDTA). Extracts are tumbled end-over-end at 28±2
rpm at room temperature for a contact time of 24 hours. At the end of the 24-hour
period, the leachate pH value of the extraction is measured. The retained extract is
filtered through a 0.45 jam polypropylene filtration membrane and the sample is stored
at 4°C until analysis.
The results from this test are used to determine the maximum quantity, or the fraction
of the total constituent content, of inorganic constituents (Hg, As, Se, Pb, and Cd) in a
solid matrix that potentially can be released from the solid material in the presence of a
strong chelating agent. The chelated availability, or mobile fraction, can be considered
(1) the thermodynamic driving force for mass transport through the solid material, or
(2) the potential long-term constituent release. Also, a mass balance based on the total
constituent concentration provides the fraction of a constituent that may be chemically
bound, or immobile in geologically stable mineral phases.
4.3.2 Tier 2 Solubility and Release as a Function of pH and LS Ratio
Test Method SR002.1 Alkalinity, Solubility and Release as a Function of pH
(Kosson et al., 2002a) is the method to be used for Tier 2 pH Screening. The protocol
consists of 11 parallel extractions of particle size reduced material at a liquid-to-solid
ratio of 10 mL extractant per gram of dry sample. An acid or base addition schedule is
formulated for 11 extracts with final solution pH values between 3 and 12, through
addition of aliquots of HNO3 or KOH as needed. The exact pH schedule is adjusted
based on the nature of the CCR; however, the range of pH values must include the
natural pH of the matrix, which may extend the pH domain. The extraction schedule
and the range of tested pHs are outlined in the developers' leaching test plan, "Draft
(Revision #2), Sampling and Characterization Plan for Coal Combustion Residues
from Facilities with Enhanced Mercury Emissions Reduction Technology" (Kosson et
al., 2002b).
If necessary, the material being evaluated is particle size reduced to <0.3 mm by
sieving to remove any large pebbles present. A mortar and pestle may be used to break
up clumps of material. A 40 g dry sample of the reference fly ash or size reduced CCR
is used for these tests. Using the schedule, equivalents of acid or base are added to a
combination of deionized water and the reference fly ash or particle size reduced CCR.
The final liquid-to-solid (LS) ratio is 10 mL extractant per gram of sample, which
includes DI water, the added acid or base, and the amount of moisture that is inherent
to the waste matrix as determined by moisture content analysis. The 11 extractions are
Category III
16
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Characterization of Coal Combustion Residues
ARCADIS
QAPP FOR THE
CHARACTERIZATION
OF COAL
COMBUSTION
tumbled in an end-over-end fashion at 28 rpm for a contact time of 24 hrs. Following
gross separation of the solid and liquid phases by settling, leachate pH measurements
are recorded and the phases are separated by pressure filtration through 0.45 urn
polypropylene filtration membranes. Analytical samples of the leachates are collected
and preserved as appropriate for chemical analysis. For metal analysis, leachates are
preserved by acidification with HNOs to a pH <2 and stored at 4 °C until analysis. For
anion analysis, leachates are stored at 4°C until analysis.
Test method SR003.1 Solubility and Release as a Function of LS Ratio (Kosson et
al., 2002a) is the method to be used for Tier 2 LS ratio screening. The protocol consist
of five parallel batch extractions over a range of LS ratios (0.5,1,2, 5, and 10 mL/g
dry material) using the particle size reduced CCR and DI water as the extractant.
Extractions are conducted at room temperature in leak-proof vessels that are tumbled at
28±2 rpm for 24 hours. Solid and liquid phases are separated by settling and pH and
conductivity measurements are taken. The liquid is further separated by pressure
filtration using a 0.45 [tin polypropylene filter membrane. Leachates are collected for
each of the 5 LS ratios and preserved as appropriate for chemical analysis. For metal
analysis, leachates are preserved by acidification with HNO3 to a pH <2 and stored at 4
°C until analysis. For anion analysis, leachates are stored at 4°C until analysis. The
range of tested LS ratios is outlined in the leaching test plan, "Draft (Revision #2),
Sampling and Characterization Plan for Coal Combustion Residues from Facilities
with Enhanced Mercury Emissions Reduction Technology" (Kosson et al., 2002b).
4.3.3 Tier 3 Mass Transfer Rate
Test method MT002.1 Mass Transfer Rates in Granular Materials (Kosson et al.,
2002a) is the method to be used for Tier 3 testing. This protocol involves continuous
water-saturation of the reference fly ash or CCR material. Compacted granular
material is contacted with DI water using a liquid to surface area ratio of 10 mL DI
water for every cm2 of exposed solid surface. Fresh DI water is exchanged with
leached material at specific intervals (2, 5 and 8 hours, 1, 2,4, and 8 days). The pH,
and conductivity for each time interval is also recorded. Each leachate sample is
prepared for chemical analysis by pressure filtration through a 0.45 (im polypropylene
filtration membrane and preserved as appropriate for chemical analysis. For metal
analysis, leachates are preserved by acidification with HNO3 to a pH <2 and stored at 4
°C until analysis. For anion analysis, leachates are stored at 4°C until analysis. In some
cases, this test will be extended up to a cumulative leaching tune of ca. 30 days to
provide more information about long-term material behavior.
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Test method MTOO1.1 Mass Transfer in Monolithic Materials will be used on the
treated CCR samples when applicable instead of the MT002.1 protocol (Kosson et al.,
2002a).
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•4.4 FIXED-BED, TPD REACTOR SAMPLING
Data on the thermal stability of toxic metals on CCRs during their commercial
applications will be obtained using simulated conditions in a fixed-bed reactor called
the Thermal Program Desorption (TPD) system. The time/temperature profiles
experienced by CCRs in their commercial applications, type of other materials that
CCRs are mixed with, and the composition of the flue gas that is in contact with CCRs
have been determined by a separate study conducted by RTI International (EPA,
2002a). The information from this report has been used to create simulated conditions
in our in-house, fixed-bed TPD reactor. This reactor is described in detail in the
Mercury Facility Manual. CCRs (mixed with other compounds) will be placed in the
fixed bed reactor (about 10 grams). The simulated flue gas will be passed through the
fixed-bed that is exposed to a specific time/temperature profile. Detailed description of
the simulated flue gas preparation and temperature control of the fixed-bed reactor is
also described in the Mercury Facility Manual. This manual also addresses the QA/QC
issues regarding the operation of this reactor. The flue gas effluent of the fixed-bed
reactor will be sampled for the duration of each test (the time profile) using two
standard methods. EPA method 29 (EPA, 1996c) will be used to sample for As, Se, Pb,
and Cd. Ontario Hydro Method (ASTM, 2002) will be used to sample for elemental
and ionic mercury (inorganic forms of mercury). Since the effluents of the fixed-bed
reactor is free of any entrained particulate matter, only the impinger portions of
Method 29 and Ontario Hydro will be used (filter box will be eliminated). After each
test, the exposed CCR will be recovered and analyzed for Hg, As, Se, Cd, and Pb. The
pre- and post-test analysis results of the CCRs together with the Method 29 and
Ontario Hydro results will be used to determine mass balances for these five metals.
This experiment will also be performed on a sample of the reference fly ash material as
a QC check.
4.4.1 Thermal Desorption Test Plan for High Temperature CCR Commercial
Processes
A- Cement (Clinker) manufacturing:
hi this process, fly ash is used as feed to a cement kiln. Fly ash typically represents a
maximum of about 5% (weight) of the typical raw mix to the kiln. Other inputs include
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limestone (90%), iron ore (3%), and sand (2%), but fly ash can displace other
components of cement kiln like limestone and iron ore, so its percentage can go higher.
Cement kiln residence time is about one hour, temperature is about 1500°C, and the
gas environment is natural gas combustion flue gas. The assumption is that all Hg is
vaporized. Thus, the focus of this section will be on As, Cd, Se, and Pb. The test plan is
as follow:
1- Mix 5g fly ash, with 5g CaCO3 (limestone), 0.2g iron oxide (Fe203) and 0.5g
sand and place the mixture in the fixed-bed reactor.
2- Inlet flue gas consists of 14% CO2, 3% O2,5.3% H2O, and 50 ppm NOX. The
total flow rate will be 400 cc/min.
3- Heat the fixed-bed reactor to its maximum temperature (1000°C). With the
current system, we will not be able to exceed 1000°C. If no evaporation of
these metals is observed at this temperature, we will modify the system to
achieve a desorption temperature of 1500°C.
4- Attach a mini-impinger, EPA Method 29 to the outlet of the fixed-bed reactor
and sample the whole effluent of the fixed-bed reactor for As, Cd, Pb, and Se
for one hour (residence time of cement kilns).
5- Recover the solid residue and the Method 29 train and submit for metal
analysis.
6- Close metals' mass balances across all phases (pre-test fixed bed solid,
exposed solid, and reactor effluent).
B- Wallboard Manufacturing
This process will be simulated using FGD waste (and not fly ash). Wallboard
manufacturing consists of two steps: calcining and drying. FGD waste experiences a
higher temperature during calcining, thus only this step will be simulated. The
calcining kettle temperature is about 310-370°C; but FGD waste temperature never
exceeds 170°C. FGD waste is not mixed with any other compounds, its residence time
in the kettle is about 1 hour and it is in contact with natural gas combustion flue gas.
The test plan will be as follow:
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1- Place lOg of FGD waste in the fixed-bed reactor.
2- Inlet flue gas consists of 14% CO2,3% O2, 5.3% H2O, and 50 ppm NOX. The
total flow rate will be 400 cc/min.
3- Heat the fixed bed reactor to 170°C.
4- Attach a mini-impinger Method 29 train to the outlet of the fixed-bed reactor
and sample for As, Cd, Pb, and Se for one hour (residence time of calcining
kettle); recover the solid residue and the Method 29 train and submit for As,
Se, Pb, and Cd analysis.
5- Repeat steps 1 thru 3 (new batch of sample) and attach a mini-impinger
Ontario Hydro train to the outlet of the reactor and sample for one hour.
Recover solid residue and the train and submit for Hg analysis. Ontario Hydro
sampling will reveal the amount of total Hg, ionic Hg (inorganic Hg), and
elemental Hg evolved from the calcining process simulation.
6- Close metals' mass balances across all phases (pre-test fixed bed solid,
exposed solid, and reactor effluent).
C- Asphalt manufacturing
Asphalt manufacturing consists of two steps: a very short residence time mixing
process (about one minute) and a long residence time storage process (several hours).
The storage process occurs at temperatures of about 5°C higher than the mixing
process. Thus, the most important step (in terms of thermal desorption) is the storage
step. Hot mix asphalt (HMA) is 95% stone, sand, or gravel bound together with asphalt
cement (crude oil); fly ash makes up approximately 5% of this mixture replacing
natural fillers such as hydrated lime or stone. This mixture is hi contact with natural gas
combustion flue gas. Storage temperatures usually range from 130-150°C for binder
grade PG46-28 and 160-170°C for binder grade PG82-22. The test plan for asphalt
manufacturing simulation will be as follow:
1 - Place 1 g of fly ash and 9 g sand in the fixed-bed reactor.
2- Inlet flue gas consists of 14% CO2, 3% O2,5.3% H2O, and 50 ppm NOX. The
total flow rate will be 400 cc/min.
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3- Heat the fixed bed reactor to 170°C.
4- Attach a mini-impinger Method 29 train to the outlet of the fixed-bed reactor
and sample for As, Cd, Pb, and Se for three hours (assumed residence time of
asphalt storage); recover the solid residue and the Method 29 train and submit
for As, Se, Pb, and Cd analysis.
5- Repeat steps 1 thru 3 (new batch of sample) and attach a mini-impinger
Ontario Hydro train to the outlet of the reactor and sample for three hours.
Recover solid residue and the train and submit for Hg analysis. Ontario Hydro
sampling will reveal the amount of total Hg, ionic Hg (inorganic Hg), and
elemental Hg evolved from the asphalt storage process simulation.
6- Close metals' mass balances across all phases (pre-test fixed bed solid,
exposed solid, and reactor effluent).
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5.D TESTING AND MEASUREMENT PROTOCOLS
Whenever possible, standard methods will be used to perform required measurements.
Standard methods are cited in each applicable section. Where standard methods are
not available, operating procedures will be written to describe activities. In situations
where method development is ongoing, activities and method changes will be
thoroughly documented in dedicated laboratory notebooks.
5.1 PHYSICAL CHARACTERIZATION
5.1.1 Surface Area and Pore Size Distribution
A Micromeretics ASAP 2400 Surface Area Analyzer will be used to perform
Brunauer, Emmett, and Teller (BET) method surface area, pore volume, and pore size
distribution analysis on each as-received and size reduced CCR. A 200 mg sample is
degassed at 200 C for at least one hour in the sample preparation manifold. Samples
are then moved to the analysis manifold, which has a known volume. Total gas
volume in the analysis manifold and sample tube is calculated from the pressure
change after release of an N2 and He mixed gas from the analysis manifold known
volume. Report forms are automatically generated after each completed analysis. The
instrument uses successive dosings of N2 while measuring pressure. The surface area
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analyzer is calibrated annually by a Micromeretics service representative. Standards of
known surface area are run with each batch of samples as a QC check. Detailed
instructions for the operation of this instrument are included in the Mercury Facility
Manual.
Category
5.1.2 Density Measurements
The Micromeretics Accupyc 1330, a helium pyncnometer, will be used to determine
CCR density. This is a fully automatic gas displacement pycnometer, which measures
the volume of solids. Instrument operation is based on the ideal gas law. By
measuring the pressure change of He in a calibrated volume, the pycnometer
determines sample volume from which density can be derived automatically if sample
weight is know. Samples must be free of moisture to obtain true sample weight and to
avoid the distorting effect of water vapor on volume measurement. The cell chamber
should be kept closed at all times except when actually inserting or removing a sample.
The size of the cell and expansion chamber is determined by calibration, which is
performed every 10 runs or immediately prior to analysis after two weeks without
operation. The density measuring capacity of the Accupyc is calibrated for each run by
analyzing two steel balls of known density. Detailed instructions for the operation of
this instrument are included in the Mercury Facility Manual.
5.1.3 pH and Conductivity
pH and conductivity will be measured on all aqueous extracts. Conductivity is a
measure of the ability of an aqueous solution to carry an electric current. This ability is
dependent upon the presence of ions; on their total concentration, mobility, and
variance; and on the temperature of the measurement.
pH of the leachates will be measured using a combined pH electrode. A 2-point
calibration will be done using pH buffer solutions. The pH meter will be accurate and
reproducible to 0.1 pH units with a range of 0 to 14.
Conductivity of the leachates will be measured using a standard conductivity probe.
The conductivity probe will be calibrated using appropriate standard conductivity
solutions for the conductivity range of concern. Conductivity meters are typically
accurate to ±1% and have a precision of ±1%. The procedure to measure pH and
conductivity will be as follow:
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Following a gross separation of the solid and liquid phases by centrifugation or
settling, a minimum volume of the supernatant to measure the solution pH and
conductivity will be taken and poured in a test tube. The remaining liquid will be
separated by pressure filtration and filtrates will be accordingly preserved and stored
for subsequent chemical analysis.
Category
5.1.4 Moisture Content
Moisture content of the "as received" CCR, the reference fly ash and SRM samples
will be determined using ASTM D 2216-92 (ASTM, 1992). This procedure supercedes
the method indicated in the leaching procedure (Kosson et al., 2002a). This method,
however, is not applicable to the materials containing gypsum (calcium sulfate
dihydrate or other compounds having significant amounts of hydrated water), since this
material slowly dehydrates at the standard drying temperature (110°C). This slow
dehydration results in the formation of another compound (calcium sulfate
hemihydrate) which is not normally present in natural material. ASTM method C 22-
83 will be used to determine the moisture content of materials containing gypsum
(ASTM, 1983).
5.2 CHEMICAL CHARACTERIZATION
5.2.1 Carbon Content (TGA)
A Micromeretics Thermogravimetric Analyzer (TGA) is used to determine weight loss
due to thermal decomposition. Through knowledge of chemical components in the
sample, composition can be determined based on weight loss, decomposition
stoichiometry, and decomposition temperature. This method is used to estimate carbon
content of the CCR material. Carbon content corresponds to the weight loss in the
temperature range of 400-500°C, when TGA is operated in O2 or air. The TGA
requires temperature and weight calibration. Temperature is calibrated using curie
point transistors of nickel and iron. Weight is calibrated with a 100 mg standard
weight. Values are entered into the TGA whenever configuration is changed or at least
annually. Calcium oxalate monohydrate is analyzed to establish accuracy and is run at
least every 20 runs.
It should be noted that an alternative method for the analysis of carbon, nitrogen, and
sulfur is also available. This method uses a combustion technique followed by mass
spectroscopy. The instrument used in this analysis is a Carlo-Erba NA1500 Series II
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elemental analyzer. Similar instrumentation is also available from LECO Inc.
(www.leco.com).
5.2.2 Mercury (CVAA)
Mercury analysis of each extract and leachate will be carried out by Cold Vapor
Atomic Absorption Spectrometry (CVAA) according to EPA SW846 Method 7470A
Mercury in Liquid Waste (Manual Cold Vapor Technique) (EPA, 1998). Samples
are treated with potassium permanganate to reduce possible sulfide interferences. A
Perkin Elmer FIMS 100 Flow Injection Mercury System is the instrument to be used
for this analysis. The instrument is calibrated with known standards ranging from 0.25
to 10 jag/L mercury. The detection limit for mercury in aqueous samples is 0.05 ug/L.
5.2.3 Other Metals (ICP)
Analysis for arsenic (As), selenium (Se), cadmium (Cd) and lead (Pb) as well as
principal constituents such as iron (Fe), calcium (Ca), phosphorus (P) and sulfur (S)
will be performed on a ICP-MS using Method 3052 (EPA, 1996a). Metals and
estimated instrument detection limits are listed in the method. The ICP will be profiled
and calibrated for the target compounds and specific instrument detection limits will be
determined. Mixed calibration standards will be prepared at least 5 levels. Each target
compound will also be analyzed separately to determine possible spectral interference
or the presence of impurities. Two types of blanks will be run with each batch of
samples. A calibration blank is used to establish the analytical curve and the method
blank is used to identify possible contamination from varying amounts of the acids
used in the sample processing. Additional daily QC checks include an Initial
Calibration Verification (ICV) and a Continuing Calibration Verification (CCV). The
1CV is prepared by combining target elements from a standard source different than
that of the calibration standard and at a concentration within the linear working range
of the instrument. The CCV is prepared in the same acid matrix using the same
standards used for calibration at a concentration near the mid-point of the calibration
curve. A calibration blank and a CCV or ICV are analyzed after every tenth sample
and at the end of each batch of samples. The CCV and ICV results must verify that the
instrument is within 10% of the initial calibration with an RSD < 5% from replicate
integrations. Procedures to incorporate the analysis of a MS/MSD for these CCR
samples will be evaluated.
These analyses will be performed at two different ICP-MS facilities. The first facility
is Severn Trent Laboratories in Savannah, Ga. This laboratory uses a Agilent ICP-MS
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with octopole reaction system (ORS). The second facility is Vanderbilit University
(Department of Civil and Environmental Engineering). This laboratory uses a Perkin
Elmer model ELAN DRCII. Standard analysis mode is used for PB and DRC mode is
used for analysis of As and Se.
5.2.4 Anions Analysis by 1C
Aqueous concentrations of anions (chloride, sulfate, sulfides, carbonate and nitrate)
will be determined using ion chromatography (1C). Standard methods (i.e., USEPA
guideline SW-846) will be used.
5.2.5 X-Ray Fluorescence (XRF) and Neutron Activation Analysis (NAA)
For the five target metals, XRF analysis will be performed on each CCR to provide
additional information on the CCR material. This information will be useful in
supplementing and/or validating CVAA and ICP results and calculating mass balances.
XRF is capable of detection limits in the ug range. If levels are in the ng range, XRF
analysis will not be useful. Considering the high detection limit of the XRF, this
method will be used only as a second validation method or a "referee" method. Details
of XRF analysis are included in the Mercury Facility Manual.
Neutron activation analysis (NAA) is an established analytical technique with
elemental analysis applications. This method will be considered in this test program.
NAA is different than AA or inductively coupled plasma mass spectrometry (ICP-MS)
because it is based on nuclear instead of electronic properties. Neutron activation .
analysis is a sensitive multielement analytical method for the accurate and precise
determination of elemental concentrations in unknown materials. Sensitivities are
sufficient to measure certain elements at the nanogram level and below, although the
method is well suited for the determination of major and minor elemental components
as well. The method is based on the detection and measurement of characteristic
gamma rays emitted from radioactive isotopes produced in the sample upon irradiation
with neutrons. Depending on the source of the neutrons, their energies and the
treatment of the samples, the technique takes on several differing forms. It is generally
referred to as INAA (instrumental neutron activation analysis) for the purely
instrumental version of the technique. RNAA (radiochemical neutron activation
analysis) is the acronym used if radiochemistry is used to separate the isotope of
interest before counting. FNAA (fast neutron activation analysis) is the form of the
technique if higher energy neutrons, usually from an accelerator based neutron
generator, are used.
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6.D QA/QC CHECKS
6.1 DATA DUALITY INDICATOR GOALS
Data quality indicator goals for critical measurements in terms of accuracy, precision
and completeness are shown in Table 6-1.
TABLE 6-1. DATA QUALITY INDICATOR GOALS
Measuremen
t
As, Se, Pb,
Cd, Fe, P, S,
and Ca
Concentratio
n
Hg
Concentratio
n
Anions,
Sulfate,
Carbonates,
Chlorides
PH
Carbon
Content
Surface Area
Density
Moisture
Method
ICP/6010B
CVAA/7470A
IC/SW-846
Electrode
TGA
BET
Pycnometer
ASTM
D2216-92
ASTM C22-
83
Accuracy
10%
10%
1O%
2%
10%
5%
2%
N/A
Precision
10%
10%
10%
2%
1O%
5%
2%
1O%
Completenes
s
>90%
>90%
>9O%
100%
>90%
>90%
100%
N/A
N/A: Not Applicable (see Appendix B)
Accuracy will be determined by calculating the percent bias from a known standard.
Precision will be calculated as relative percent difference (RPD) between duplicate
values and relative standard deviation (RSD) for parameters that have more than two
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replicates. Completeness is defined as the percentage of measurements that meet DQI
goals of the total number measurements taken.
Mass balance calculations will also be used as a data quality indicator. Different mass
balance recovery methods will be examined. The reference fly ash sample will be
used to develop and validate an appropriate mass balance recovery method. Mass
balance will be determined by using the metals concentrations determined by analysis
of the "as-received" reference fly ash as the total. Results from successive leaching
samples and analysis of any solid residues will be combined to determine recoveries.
One approach that will be considered is the use of either total digestion (Method 3052)
or Neutron Activation Analysis (NAA) for the analysis of solid residues.
The mass balance recovery will be only performed on 3 pH points and one low LS
ratio. Uncertainty analysis will be considered for each mass balance. The selection of
the target pH values will be dependent on the natural pH of the material. If the natural
pH is <5, then natural pH, 7 and 9 will be selected as the target pH values. If the
natural pH ranges between 5 and 9, then 5, 7 and 9 will be selected as the target pH
values, and if the natural pH is >9, then 5, 7 and natural pH will selected as the target
pH values, hi addition, an extraction at the natural pH of the material and an LS ratio of
ImL/g will be carried out. At least 4 replicates per extract will be run. In the case
where the mass balance will be performed using total digestion or NAA, at least 3
representative samples per residue will be analyzed.
6.2 DC SAMPLE TYPES
Types of QC samples used in this project will include blanks, spiked samples,
replicates, and mass balance tests on the reference fly ash and the SRM. For physical
characterization testing, duplicate samples of the CCR, reference fly ash and SRM will
be processed through each analysis. Duplicates must agree within ±10% to be
considered acceptable. For the leaching studies, an objective of this project is to
determine the appropriate types of QC samples to incorporate in the proposed leaching
methods. This will be accomplished by subjecting the reference fly ash to the leaching
procedure and determining the metals' mass balances by analyzing the leaching
solution and the post-leachate solids. Initially, mass balances of 70-130% will be
considered as an acceptable QC of the leaching procedure. Further statistical analysis
on available data will be performed to narrow down the range of acceptable mass
balances. This method development will be thoroughly documented in a dedicated
laboratory notebook. Leaching of the reference fly ash samples may also be used as
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method controls during testing of CCR samples. For the fixed-bed reactor testing, one
in every five tests will be run in duplicate. Duplicate results from the reactor testing
are expected to agree within 20% to be considered valid. Identical to the leaching
procedure, the use of the reference fly ash as a baseline QC sample will also be
implemented during TPD tests (initial mass balances of 70-130%). Required QC
samples for metals and mercury sampling trains are detailed in EPA Method 29 (EPA,
1996c) and the Ontario Hydro Methods (ASTM, 2002). QC samples required for ICP,
CVAA, 1C analysis are detailed in Methods 3052, 7470A, and SW-864 respectively.
7.D DATA REDUCTION, VALIDATION, AND REPORTING
Chemical (ICP, CVAA, TGA, XRF, 1C, NAA) and physical (surface area, pore size
distribution and density) characterization data are reduced and reports are generated
automatically by the instrument software. The primary analyst will review 100% of
the report for completeness and to ensure that quality control checks meet established
criteria. If QC checks do not meet acceptance criteria, sample analysis must be
repeated. A secondary review will be performed by the Inorganic Laboratory Manager
to validate the analytical report. If appropriate, certain chemical characterization data
will be compared to the XRF and NAA analyses, In addition, the designated QA
Officer will review at least 10% of the raw data for completeness. Analytical data will
be summarized in periodic reports to the ARCADIS WAL. The procedure for
reduction, validation and reporting of the leaching experiments Task II) are outlined in
Appendix A. ARCADIS WAL is responsible for the implementation of these
procedures. Data reduction and interpretation for the TPD experiments (Task IE) is
included in the Mercury Facility Manual. ARCADIS WAL is responsible for
implementing those procedures. ARCADIS WAL is also responsible for ensuring that
mass balance criteria have been met. Mass balance for task n will be calculated as:
[(metal in leachate + metal in residue)/metal in "as received" CCR]* 100
Mass balance for Task ffl will be calculated as:
[(metal in off gas + metal in thermally exposed sample)/metal in "as received"
CCR]* 100
Hg control benefit calculation for each metal or other parameters (such as carbon
content, surface area, and so on) is:
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[(content in CCR, leachate, or residue)w Hgcontroi/(content in CCR, leachate, or
residue)w/oHgControi]*100
Values greater than 100% indicate an increase in that parameter due to implementation
of the Hg control technology. In summary, the ARCADIS WAL checks to ensure that
the duplicates meet the precision limits and the QC-checks for each run are within
documented data quality indicators. Progress of the research conducted under this
QAPP is reported in written monthly reports by ARCADIS WAL. Weekly verbal and
written progress reports are submitted to the EPA WAM. Efforts will be made to
publish and present results. QA/QC activities will be mentioned in any published
materials. A data quality report will be provided in the final report of this investigation.
B.D ASSESSMENTS
Assessments and audits are an integral part of a quality system. This project is
assigned a QA Category in and, while desirable, doest not require planned technical
systems and performance evaluation audits. EPA will determine external or third-party
audit activities. Internal assessments will be performed by project personnel to ensure
acquired data meets data quality indicator goals established in Section 6. The
ARCADIS Designated QA Officer will perform at least one internal technical systems
audit (TSA) to ensure that this QAPP is implemented and methods are performed
according to the documented procedures. This audit will occur during the early stages
of the project to ensure any necessary corrective actions are implemented before large
amounts of data are collected.
There are currently not planned performance evaluation audits but Table 8-1 lists the
measurement parameters and expected ranges should EPA determine a PEA should be
provided.
Category
B-l. PEA PARAMETERS AND RANGES
Analyte or
Measurement
As, Se, Pb and Cd
Hg
PH
Method
ICP/3052
CVAA/7470A
Electrode
Expected Range
1-100 ug/mL
0.25 to 10ug/L
0-14
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In addition to the TSA, the ARCADIS Designated QA Officer will perform an internal Cate9°rV
data quality audit on at least 10% of the reported data. Reported results will be verified
by performing calculations using raw data and information recorded in laboratory
notebooks.
9.Q REFERENCES
ASTM, 1983. Method C 22-83, "Standard Specification for Gypsum"
ASTM, 1992. Method D 2216-92, "Standard Test Method for Laboratory
Determination of Water (Moisture) Content of Soil and Rock"
ASTM, 2002. Method D 6784-02, "Standard Test Method for Elemental, Oxidized,
Particle-Bound, and Total Mercury in Flue Gas Generated from Coal-Fired Stationary
Sources (Ontario-Hydro Method)"
EPA, 1996a. Method 3052 "Microwave Assisted Acid Digestion of Siliceous and
Organically Based Matrices". Test Methods for Evaluating Solid Waste,
Physical/Chemical Methods (SW-846).
EPA, 1996b. Method 6010 "Inductively Coupled Plasma-Atomic Emission
Spectrometry". Test Methods for Evaluating Solid Waste, Physical/Chemical Methods
(SW-846).
EPA, 1996c . Method 29 "Determination of Metals Emissions from Stationary
Sources." Code of Federal Regulations, Title 40, Part 60, Appendix A, April 1996.
EPA, 1998. Method 7470A "Mercury in Liquid Waste (Manual Cold-Vapor
Technique)". Test Methods for Evaluating Solid Waste, Physical/Chemical Methods
(SW-846).
EPA, 2002a. Characterization and Management of Residues from Coal-Fired Power
Plants, Interim Report. EPA-600/R-02, 083, December 2002.
EPA, 2002b. Reply to comments on EPA/OSW's Proposed Approach to
Environmental Assessment of CCRs. Discussed March 5,2002.
3O
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ARCAD1S QAPP FOR THE
CHARACTERIZATION
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COMBUSTION
Kosson, D.S., van der Sloot, H.A., Sanchez, F. and Garrabrants, A.C., 2002a. An Category 111
Integrated Framework for Evaluating Leaching in Waste management and Utilization
of Secondary materials. Environmental Engineering Science 19(3): 159-204.
Kosson, D.S., and Sanchez, F., 2002b. Draft (Revision #2), Sampling and
Characterization Plan for Coal Combustion Residues from Facilities with Enhanced
Mercury Emissions Reduction Technology. May 2002.
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Appendix D
Brayton Point Fly Ashes
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List of Figures
Figure Page
D-l pH Titration Curves for the Baseline Fly Ash and the Fly Ash with Enhanced Hg Control 118
D-2 pH as a Function of LS Ratio for the Baseline Fly Ash and the Fly Ash with Enhanced Hg Control 118
D-3 Mercury Release (top) and Spike Recoveries (bottom) as a Function of pH for the Baseline Fly Ash and the
Fly Ash with Enhanced Hg Control 119
D-4 Mercury Release (top) and Spike Recoveries (bottom) as a Function of LS Ratio for the Baseline Fly Ash and
the Fly Ash with Enhanced Hg Control 120
D-5 Arsenic Release (top) and Spike Recoveries (bottom) as a Function of pH for the Baseline Fly Ash and the
Fly Ash with Enhanced Hg Control 121
D-6 Arsenic Release (top) and Spike Recoveries (bottom) as a Function of LS Ratio for the Baseline Fly Ash
and the Fly Ash with Enhanced Hg Control 122
D-7 Selenium Release (top) and Spike Recoveries (bottom) as a Function of pH for the Baseline Fly Ash and the
Fly Ash with Enhanced Hg Control 123
D-8 Selenium Release (top) and Spike Recoveries (bottom) as a Function of LS Ratio for the Baseline Fly Ash
and the Fly Ash with Enhanced Hg Control 124
D-9 Regression Curves of Experimental Data of Arsenic Solubility as a Function of pH 125
D-10 Regression Curves of Experimental Data of Selenium Solubility as a Function of pH 126
D-ll 100-Year Arsenic Release Estimates as aFunction of the Cumulative Probability forthe Scenario of Disposal
in a Combustion Waste Landfill 127
D-12 100-Year Selenium Release Estimates as a Function of the Cumulative Probability for the Scenario of Disposal
in a Combustion Waste Landfill 127
D-13 100-Year Arsenic Release Estimates from A) Baseline Fly AshandB) Fly Ash with ACI 128
D-14 100-year Selenium Release Estimates from A) Baseline Fly AshandB) Fly Ash with ACI 129
117
-------
Characterization of Coal Combustion Residues
pH Titration Curves
14 1
12.2
12
10 -
I 8
Q.
6 -
4 -
2
-1
Baseline Fly Ash
&
El
I
* 01
^W
1
:
8
<
\
&
2 -10 -8-6-4-20 24 6 8
meq Acid/g dry
DSR2-BPB-0001 -A
OSR2-BPB-0001 -B
ASR2-BPB-0001 -C
14 -,
12
9.5 10
I 8-
Q.
6
4
2
Fly Ash with ACI
D
D
H
A
. . .5
i
B
0
0*
a
6
2 -1.5 -1 -0.5 0 0.5 1 1.5
meq Acid/g dry
n SR2-BPT-0001 - A
0 SR2-BPT-0001 - B
A SR2-BPT-0001 - C
Figure D-1. pH Titration Curves for the Baseline Fly Ash and the Fly Ash with Enhanced Hg Control.
pH as a Function of LS Ratio
Baseline Fly Ash
Fly Ash with ACI
-1O _
m
6
A
9
" S r
-
:
~
:
i
a
|
t
>
k
]
1?
m
I 0
0. °
A
9 -
-
L
-
~-
\
6
D
\
3
24 6 8 10 12
LS ratio [mL/g]
n SR3-BPB-0001 - A
o SR3-BPB-0001 - B
A SR3-BPB-0001 - C
2 4 6 8 10 12
LS ratio [mL/g]
nSRS-BPT-0001 -A
oSRS-BPT-0001 -B
ASR3-BPT-0001 -C
Figure D-2. pH as a Function of LS Ratio for the Baseline Fly Ash and the Fly Ash with Enhanced Hg Control.
118
-------
Characterization of Coal Combustion Residues
Mercury Release as a Function of pH
Baseline Fly Ash
Hg total content*: 650.6+6.8 ng/g
in *• n
MCL
1
U
"S> « A
Z: °-1
^ 0.035
.01
Onn-i
— . — .
«aw
D Q D
Fly Ash with ACI
Hg total content*: 1529.6+1.1 ng/g
MCL
1
IJ
nrn "Bi 0.1
95% .^
D)
I
k 0 01
0.006
" ~*o/_
, T, n nm
.UU I I I I !'• x.xx i
2 4 5°7§ 8 1095°l212-214
PH
ML ML
— - MDL
nSR2-BPB-0001 - A __ . MDL
OSR2-BPB-0001 - B
ASR2-BPB-0001 - C
*Total content as determined by digestion using method 3052.
1 50 •* cn
140
^ 130
•^ i?n
0) 100
3 90 -
Q.
w 80
D)
1 70 -
60
|
-
n
tr
i
i
:
;
i
T D n
140
• — • i^n
"7"" -ion
n n 110
oj inn
v on
Q.
w on
D) U°
I yn
i i en
2 4 6 8 10 12 14
PH
n SR2-BPB-0001 - A
— .
I I I I I I
2 4 5%
_ . _
- 1
, i ^ i ^J1'0! P
Q5C
H~— 5%
6 8 9-51095%12 14
PH
DSR2-BPT-0001 -A
OSR2-BPT-0001 - B
ASR2-BPT-0001 - C
t
n n
n u
? 4
D
u
LLlJ
] n
m
6 8 10 12 14
PH
SR2-BPT-0001 - A
Figure D-3. Mercury Release (top) and Spike Recoveries (bottom) as a Function of pH for the Baseline Fly Ash and the Fly
Ash with Enhanced Hg Control. 5th and 95th percentiles of mercury concentrations observed in typical combustion waste
landfill leachate are shown for comparison.
119
-------
Characterization of Coal Combustion Residues
Mercury Release as a Function of LS Ratio
Baseline Fly Ash Fly Ash with ACI
MCL 0 02 Mni n no
n ni*i -
IT
^ 001 -
D)
0 00*1
n
ML (
— - MDL
-i en
IDU
140
' — • i^n
>< 120
^
92 110
o
o mn
0> IUU
s~ nn
O> 90 -
.*:
'o_ 80
(/5
0) 70
I
60
en
(
-
L^1
s
n
a
, _ —
i
'.,,
n m ^
IT
™ n m
D)
n nn^
n
[
T,'
]
t
D
• - ^~
[
i
]
',.,
) 2 4 6 8 10 12 0 2 4 6 8 10 12
ML
LS ratio [mL/g] LS ratio [mL/g]
n SR3-BPB-0001 - A
0 SR3-BPB-0001 - B
A SR3-BPB-0001 - C
n SR3-BPT-0001 - A
0 SR3-BPT-0001 - B
A SR3-BPT-0001 - C
ie.n
;
n ,
r
]
140
-i-an
^ -ion
!? 110 -
> mn
> 100
0 90
(D 3U
80
(D uu
-^ 70
•Q. /u
w en
°> en
I 50
>in
4U
•?n
-
'-
:_
-
I
:
=
:
_
:
:
:
, n
c
]
D 2 4 6 8 10 12 0 2 4 6 8 10 12
LS ratio [mL/g] LS ratio [mL/g]
n SR3-BPB-0001 - A
n SR3-BPT-0001 - A
Figure D-4. Mercury Release (top) and Spike Recoveries (bottom) as a Function of LS Ratio for the Baseline Fly Ash and
the Fly Ash with Enhanced Hg Control.
120
-------
Characterization of Coal Combustion Residues
Arsenic Release as a Function of pH
Baseline Fly Ash
As total content*: 80.5+1.9 |jg/g
Fly Ash with ACI
As total content*: 27.9+2.1 |jg/g
1000
100
U MCL10 -
"Bj 6.67
" 1 -
< 0.1 -
0.01 -
0.001
t
\
=
nA
^Q
= AO
-
i_ _ _ _
2
=
-
n
A^ D
_ _ _ _ _ _ _
A
g
—n-S-
_ _
95%
5%
5% ' 95% 12 2
2 4 6 8 10 12 14
1 \J\J\J\J
1000 -
100 -
MCLHn
g> 4.8
— 1 -
< 0.1 -
0.01 -
n nm -
;
1 Bffl
!
5°,
2 4
A
A. tiff^^
/o 95 95%
6 8 10 1
a
2 1
95%
5%
..... ML
— - MDL
PH
DSR2-BPB-0001 -A
OSR2-BPB-0001 -B
ASR2-BPB-0001 -C
ML
— - MDL
PH
DSR2-BPT-0001 -A
OSR2-BPT-0001 -B
ASR2-BPT-0001 -C
*Total content as determined by digestion using method 3052.
140
"
•> nn
> nu
m mn
°J Qn
'Q_
w RO
< yn
cn
/
;
:
:
~
: n
:
:
[
]
D
D
D
Q-
I^IU
14D
" i^n
"C 1?0 -
^> nn
> I IU
CD 100
°J Qn
& 80-
< 70
en
:
:
D
:
u
D
o-ir_
n
]
2 4 6 8 10 12 14 2 4 6 8 10 12 14
pH pH
n SR2-BPB-0001 - A
D SR2-BPT-0001 - A
Figure D-5. Arsenic Release (top) and Spike Recoveries (bottom) as a Function of pH for the Baseline Fly Ash and the Fly
Ash with Enhanced Hg Control. 5th and 95th percentiles of arsenic concentrations observed in typical combustion waste
landfill leachate are shown for comparison.
121
-------
Characterization of Coal Combustion Residues
Arsenic Release as a Function of LS Ratio
Baseline Fly Ash Fly Ash with ACI
4D An
-IK
on
„ OK
_l Z0
2. 20
.— *: ^-U
(/5
<1 ^
MCL
m
r;
0
C
ML
— - MDL
15D
140
" i^n
^ *M
>, -i on
9?
> -i-in
o
£ mn
o>
-^ Qn
Q.
w 80
(/5 OU
< 70
fin
i
: A f
: y 2
^^ i™ i •
^
i
^ T i^
o
S
• i ™i ^™
p i^—
5
^ i—^
i
- 1 ^—i •
oc -
an :
' — ' "y^
_j ^0 :
^. ?o :
(/5 :
<1 K
MCL 10 ;
5-
n •
) 2 4 6 8 10 12 0
LS ratio [mL/g] ML
— - MDL
n SR3-BPB-0001 - A
oSRS-BPB-0001 -B
A SR3-BPB-0001 - C
I
\
-
\
~- n C
I
|
:
I
i
D
c
i
150
140
g 130
>* 190
§ 110 -
£ 100 -
o>
^ 90 -
! 80-
< 70-
en
D
& &
^H • •
• • ^H
A
Q
— ^^m
— ^^m
a
;-—]•—•:
2 4 6 8 10 12
LS ratio [mL/g]
n SR3-BPT-0001 - A
oSRS-BPT-0001 -B
A SR3-BPT-0001 - C
I
:
;
•]
D
[
3
D 2 4 6 8 10 12 0 2 4 6 8 10 12
LS ratio [mL/g] LS ratjo [mL/g]
n SR3-BPB-0001 - A
n SR3-BPT-0001 - A
Figure D-6. Arsenic Release (top) and Spike Recoveries (bottom) as a Function of LS Ratio for the Baseline Fly Ash and
the Fly Ash with Enhanced Hg Control.
122
-------
Characterization of Coal Combustion Residues
Selenium Release as a Function of pH
Baseline Fly Ash
Se total content*: 51.4+1.7 |jg/g
Fly Ash with ACI
Se total content*: 51.4+1.7 |jg/g
1000 -
100
MCL 57
=T 10
— 1 -
W 0.1-
0.01 -
n nm
t
• Sfos.
> A 5%
Z 4
*^ I—I i— i
i
6 8 1095°1
&
"12.2
2 1
95%
507
4
(U
CO
1000
164.3
100
MCL
10
9
i ^
0.1-
0.01
n nni
Sy *
— . — . ,
CO/
« a
^p
'
9.5 qiso/n
*
- —
95%
5%
2 4 ^/U6 8 10^12 14
ML PH
— - MDL
Total content
150 -
140
^ 13° "
^ 120
> no
» 100 -
^ 90
Q.
% 80-
w 70
60 -
n SR2-BPB-0001 -A
0 SR2-BPB-0001 - B
ASR2-BPB-0001 -C
as determined by digestion using method 3C
;
:
i
;
; B
;
:
;
;
:
] n
n
Duc
2 4 6 8 10 12
PH
n SR2-BPB-0001 - A
1
ML
— - MDL
)52.
150
140
^ 130
21
^ 120
I 11°
2 100
3 90
Q.
w 80
(U
w 70
60
4
RO/ 9.5 QRO/
2 4 b/°6 8 10ybl2 14
PH
n SR2-BPT-0001 - A
0 SR2-BPT-0001 - B
A SR2-BPT-0001 - C
-
r
: C
n n
n
c
°°\
D
cP
I 4 6 8 10 12
PH
14
n SR2-BPT-0001 - A
Figure D-7. Selenium Release (top) and Spike Recoveries (bottom) as a Function of pH for the Baseline Fly Ash and the
Fly Ash with Enhanced Hg Control. 5th and 95th percentiles of selenium concentrations observed in typical combustion
waste landfill leachate are shown for comparison.
123
-------
Characterization of Coal Combustion Residues
Selenium Release as a Function of
Baseline Fly Ash
ROD
cnn
/inn
4UU
_i
^ onn
.-V oUU -
, -ion
O>
> -i -in
8 11° "
tu -inn
CD
-2 an
._ 90
w 80
0) OU
W 70
Rn
: fi
;
D
u
Q
l
*
) 2 4 6 8 10 1
LS ratio [mUg]
LS Ratio
600
500
400
u
1 300
O)
W 200
100
MCL
0
ML
— - MDL
n SR3-BPB-0001 - A
0 SR3-BPB-0001 - B
A SR3-BPB-0001 - C
Fly Ash with ACI
: 6
_ D
~
g
6
D
<
I
5
0 2 4 6 8 10 12
LS ratio [mL/g]
n SR3-BPT-0001 - A
o SR3-BPT-0001 - B
A SR3-BPT-0001 - C
icn
:
:
;
1
n c
1
1
3
D
I
|]
140
^F 1^0-
sl I<:3U
^ 120 -
O)
> 110
8
P mn
O)
-^ Qn
Q.
w 80
O) OU
W 70
Rn
[|
D
C
]
D 2 4 6 8 10 12 0 2 4 6 8 10 12
LS ratio [mL/g] LS ratio [mL/g]
nSRS-BPB-0001 -A
n SR3-BPT-0001 - A
Figure D-8. Selenium Release (top) and Spike Recoveries (bottom) as a Function of LS Ratio for the Baseline Fly Ash and
the Fly Ash with Enhanced Hg Control.
124
-------
Characterization of Coal Combustion Residues
Arsenic Solubility
Baseline Fly Ash
10000 -
1000 -
A r\r\
100 -
10 -
1 -
0.1 -
0.01 -
n nm
r
"^SL
^S^^_
>. 4
>— -S^
^^CH!
*i
i i i i
0
6 8 10 1:
A
Jl
n
f
A
, .f&
^9
i» T
95%
I 1
95%
CO/
Ovo
4
2
4 6 8 10 12
PH
n SR2-BPB-0001-A
0 SR2-BPB-0001-B
A SR2-BPB-0001-C
Fit n irxjp
14
Fly Ash with ACI
10000 -
1000 -
100 -
10 -
1 -
0.1 -
0.01 -
n nm -
/
:
i
:
!
.a ...
i N
;
!
:
I
|
' COy
I 4
--^H--#**
6 8 10 1
•ffl-
6
95%
2 1
KO/
Ovo
4
PH
n SR2-BPT-0001-A
o SR2-BPT-0001-B
A SR2-BPT-0001-C
Fit curve
Material
BPB
BPT
0.0004 PH5
-0.8130 pH2
0.0005 pH5
-2.0113 pH2
log As (ng/L)
-0.0135 pH4
1.1609 PH
-0.0207 pH4
5.4552 PH
pH range of
validity
0.1 634 pH3 3-14
2.7085
0.3035 pH3 3-12.5
-2.7126
R2 Number of
points
0.77 27
0.98 33
Figure D-9. Regression Curves of Experimental Data of Arsenic Solubility as a Function of pH.
125
-------
Characterization of Coal Combustion Residues
Selenium Solubility
Baseline Fly Ash Fly Ash with ACI
mnnnn -mnnnn
10000 -
1000-
U 100-
1 10-
-------
Characterization of Coal Combustion Residues
100-Year Arsenic Release Estimates
10000
-5 1000
0
O
O
n
n
1
1 .
L
' 4
LJ
n A i
j A
A
k
DD[
nn° A
AAA*
A
]
L
0 5% 20 405°% 60 80 "" 100
Percentile
Mt min
Mt - 5%
Mt - 50%
Mt - 95%
Mean Mt
Mt max
BF
ng/kg
0.2
0.9
152
2095
468
4693
3B
0.0003
0.0011
0.2
2.6
0.6
5.8
BF
0.1
0.1
22
338
90
10157
DT
%
0.0003
0.0005
0.0772
1.2
0.3
36.4
n BPB
A BPT
Figure D-11.100-Year Arsenic Release Estimates as a Function of the Cumulative Probability for the Scenario of Disposal
in a Combustion Waste Landfill.
100-Year Selenium Release Estimates
O
O
i uuuuu -
mono -
3
D mnn -
100 -
•• 10 -
OA
.1 H
(
!
!
:
I
\t
:
)
AA^1
fl«*
A ™
Q
!i
5%20 40 5C
^i
o/o ' ' 95°/
60 80
'o
1C
30
Mt min
Mt - 5%
Mt - 50%
Mt - 95%
Mean Mt
Mt max
BF
ng/kg
1.5
7.6
1031
16681
3573
45169
3B
%
0.003
0.015
2.0
32.5
7.0
87.9
Bl
ng/kg
5.9
10.0
1661
23931
6038
151900
DT
%
0.004
0.007
1.1
15.8
4.0
100.0
Percentile
nBPB
A BPT
Figure D-12. 100-Year Selenium Release Estimates as a Function of the Cumulative Probability for the Scenario of
Disposal in a Combustion Waste Landfill.
127
-------
Characterization of Coal Combustion Residues
100-Year Arsenic Release Estimates
BPB -Arsenic
80500 |^g/kg
100000 100%
'o) 1 nnnn
1
8i
m mnn -
OJ
.0
c
0)
(/> H flfl
CO
CO
8 10-
1 -
A\
:
Tol
n
1
al cont
1
20
95 ^g/kg 2439 ^g/kg
9fi% 3.0%
105^/kg 83 ng/kg
0.1% 010/0
ent Combustion Default-pH3 Default-pH Default-
Waste Landfill - 12.5 Natural pH
95% confidence ^2
— MCLLS95%=1000|jg/kg
-MCLLS125 = 125ug/kg
BPT - Arsenic
H? 10000 -
^
8i
!J5 -innn
0-year arsenic rele
->• 0 C
DOC
i
1 .
275
•
•
300 |ig
100%
'kg
19
SSSjj/kg
1.2%
81 ng/
7.1%
kg
999 i^g/kg
3.6%
60 ^g/kg
0.2%
Total content Combustion Default-pH3 Default-pH Default-
Waste Landfill - 12.5 Natural pH
95% confidence 9.5
=1000|jg/kg
B)
Figure D-13.100-Year Arsenic Release Estimates from A) Baseline Fly Ash and B) Fly Ash with ACI. Release estimates
for percolation controlled scenario are compared to release estimate based on total content. The amount of the arsenic that
would be released if the release concentration was at the MCL is also shown for comparison (LSdefaultscenario = 12.5 L/kg and
LS95%=100L/kg).
128
-------
Characterization of Coal Combustion Residues
100-Year Selenium Release Estimates
BPB - Selenium
100000
10000
-£ 1000
I 100
CO
CO
I 10
51400
100%
16*
381 u9
32.5%
'kg
2667 ug/kg 3226 ug/kg
5.2% 6.3%
71 3 ug/kg
1.4%
A)
Total content Combustion Default-pH3 Default-pH Default-
Waste Landfill - 12.5 Natural pH
95% confidence 12.2
MCLLS95% = 5000 ug/kg
MCLLS125 = 625 ug/kg
BPT- Selenium
1000000
100000
10000
1000
TO
a>
>,
6
o
100
10
151900 i ia/ka
— •
100%
23931 ,,a/ka 43479 ug/kg
.
15.8%
JC
41-pQL
0.9%
Kg .
28.6%
2054 u9/kg
14%
—
_MCL = 5000 ug/kg
MCLS1 = 625 ug/kg
Total content
B)
Combustion
Waste Landfill -
95% confidence
Default-pH 3
Default-pH
12.5
Default-
Natural pH
9.5
Figure D-14.100-year Selenium Release Estimates from A) Baseline Fly Ash and B) Fly Ash with ACI. Release estimates
for percolation controlled scenario are compared to release estimate based on total content. The amount of the selenium
that would be released if the release concentration was at the MCL is also shown for comparison (LSdefaultscenario = 12.5 L/kg
andl_S95%=100L/kg).
129
-------
Characterization of Coal Combustion Residues
Comments
Figure D-3:
• The fly ash from the test case had greater total Hg
content than the fly ash from the baseline case (by
about 2.5 times).
• Hg release is low (but poor replication) for both baseline
and test cases.
Figure D-5:
• The fly ash from the test case had lower total As con-
tent than the fly ash from the baseline case (by about a
factor of 3).
• The laboratory measurements fit within the 5 -95 % con-
fidence intervals of the field observations.
• As release is most frequently worse in baseline case
than test case and exceeds MCL for many possible
conditions.
Figure D-7:
• The fly ash from the test case had greater total Se
content than the fly ash from the baseline case (by
about a factor of 3).
• The laboratory measurements fit within the 5 % to 95 %
confidence intervals of the field observations.
• Se release substantially exceeds MCL for both baseline
and test cases and is generally worse for test cases.
• The fly ash from the test case resulted in greater Se
concentration at the natural pH of the material than
the baseline case (by about 3 times).
Figures D-11. andD-12:
• The fly ash from the test case would result in As re-
lease less than expected from the baseline case, with a
95% probability to be less than 338 and 2095 |jg/kg,
respectively.
• No significant difference in Se release is expected from
both baseline and test cases.
Figure D-13:
• For the 95% probability scenario, arsenic release from
the baseline case would be greater than the amount
that would be released if the release concentration was
at the MCL.
• For the 95% probability scenario, a lower arsenic re-
lease would be expected from the test case. However,
the fly ash from the test case had lower total As con-
tent than the fly ash from the baseline case (by about a
factor of 3).
• For the default scenario corresponding to disposal in a
monofill (leachate pH controlled by the material being
disposed), no significant difference in arsenic release
between the baseline and the test cases would be ex-
pected. Additionally, arsenic release would be less than
the amount that would be released if the release con-
centration was at the MCL.
• For the default scenario corresponding to the "extreme"
pH of 3, arsenic release would be greater than the
amount that would be released if the release concen-
tration was at the MCL, for both the baseline and the
test cases.
• For the default scenario corresponding to the "extreme"
pH of 12.5, arsenic release is expected to be greater
for the test case than the baseline case.
Figure D-14:
• For the 95% probability case, selenium release would
be greater than the amount that would be released if
the release concentration was at the MCL for both the
baseline and the test cases.
• For the default scenario corresponding to disposal in a
monofill (leachate pH controlled by the material being
disposed), a greater selenium release would be ex-
pected from the test case.
• For the default scenario corresponding to the "extreme"
pH of 12.5, selenium release is expected to be greater
for the test case than the baseline case. Selenium re-
lease from the test case would be greater than the
amount that would be released if the release concen-
tration was at the MCL.
130
-------
Characterization of Coal Combustion Residues
Appendix E
Pleasant Prairie Fly Ashes
131
-------
Characterization of Coal Combustion Residues
List of Figures
Figure Page
E-l pH Titration Curves for the Baseline Fly Ash and the Fly Ash with Enhanced Hg Control 133
E-2 pH as a Function of LS Ratio for the Baseline Fly Ash and the Fly Ash with Enhanced Hg Control 133
E-3 Mercury Release (top) and Spike Recoveries (bottom) as a Function of pH for the Baseline Fly Ash and the
Fly Ash with Enhanced Hg Control 134
E4 Mercury Release (top) and Spike Recoveries (bottom) as a Function of LS Ratio for the Baseline Fly Ash and
the Fly Ash with Enhanced Hg Control 135
E-5 Arsenic Release (top) and Spike Recoveries (bottom) as a Function of pH for the Baseline Fly Ash and the
Fly Ash with Enhanced Hg Control 136
E-6 Arsenic Release (top) and Spike Recoveries (bottom) as a Function of LS Ratio forthe Baseline Fly Ash
and the Fly Ash with Enhanced Hg Control 137
E-7 Selenium Release (top) and Spike Recoveries (bottom) as a Function of pH for the Baseline Fly Ash and the
Fly Ash with Enhanced Hg Control 138
E-8 Selenium Release (top) and Spike Recoveries (bottom) as a Function of LS Ratio for the Baseline Fly Ash
and the Fly Ash with Enhanced Hg Control 139
E-9 Regression Curves of Experimental Data of Arsenic Solubility as a Function of pH 140
E-10 Regression Curves of Experimental Data of Selenium Solubility as a Function of pH 141
E-ll 100-Year Arsenic Release Estimates as a Function of the Cumulative Probability forthe Scenario of Disposal
in a Combustion Waste Landfill 142
E-12 100-Year Selenium Release Estimates as a Function of the Cumulative Probability for the Scenario of Disposal
in a Combustion Waste Landfill 142
E-13 100-Year Arsenic Release Estimates from A) Baseline Fly Ash and B) Fly Ash with ACI 143
E-14 100-year Selenium Release Estimates from A) Baseline Fly AshandB) Fly Ash withACI 144
132
-------
Characterization of Coal Combustion Residues
pH Titration Curves
Baseline Fly Ash
14
1? -
11.2
m
-i- 8
i °
Q.
6 -
4
2 -
:- 4
-
,
$
§ a
o
m.
-r-H-iDj
^
QWS" P
2 0 2 4 6 8 10
meq Acid/g dry
DSR2-PPB-0001 -A
o SR2-PPB-0001 -B
A SR2-PPB-0001 -C
Fly Ash with ACI
14
19
11.9
m
53
I 0 -
a.
-
-\
-t
a
A
)
o
^
D
J^A
DQ
1 -2 0 2 4 6 8
meq Acid/g dry
DSR2-PPT-0001 -A
OSR2-PPT-0001 -B
ASR2-PPT-0001 -C
Figure E-1. pH Titration Curves for the Baseline Fly Ash and the Fly Ash with Enhanced Hg Control.
pH as a Function of LS Ratio
Baseline Fly Ash
Q.
14
12
10
8
6
I
4 6 8 10 12
LS ratio [mL/g]
nSRS-PPB-0001 -A
oSRS-PPB-0001 -B
ASR3-PPB-0001 -C
I
Q.
Fly Ash with ACI
19
m
A
(
i
:
!
0
i
\
D 24 6 8 10 12
LS ratio [mL/g]
n SR3-PPT-0001 - A
oSRS-PPT-0001 -B
A SR3-PPT-0001 - C
Figure E-2. pH as a Function of LS Ratio for the Baseline Fly Ash and the Fly Ash with Enhanced Hg Control.
133
-------
Characterization of Coal Combustion Residues
Mercury Release as a Function of pH
Baseline Fly Ash
Hg total content*: 157.7+0.2 ng/g
Fly Ash with ACI
Hg total content*: 1180.1+1.2 ng/g
B)
D)
MCL
1
0.1
0.011
0.01
.001 -
:
=
; ^
o
p. ,. I-DI-. ••.$
. — ^ — _
B> A
A ,
'"'n , "i
— . . _Q -i —
5%' ' 1 1".2
A
i
1
- —
95%
O)
O)
95% 3:
5%
MCL
1
0.1 -
0.011
OfH
.U1 -
n nm
=
E
u
- O Z&
LOOP V
00 n ° n<
o ,
— - — - — - — j
LJ LJ A ^ £
11.9"
i 9
- —
£a
95%
95%
5%
b% 11.2 9b%
2 4 6 8 10 12 14
PH
ML
— -MDL
Total content <
150
140 -
^ 120 -
> 110
e 100 -
3 90
Q.
w 80 -
D)
x 70
60 -
n SR2-PPB-0001 - A
0 SR2-PPB-0001 - B
A SR2-PPB-0001 - C
2 4 6 8 10 12 14
PH
ML
— -MDL
n SR2-PPT-0001 -A
OSR2-PPT-0001 -B
ASR2-PPT-0001 -C
as determined by digestion using method 3052.
-icn
;
-
i
i
p
i
n
=h r
:
r— i -i -an
"C 190
(D
> 110
0
on
'o.
w an
D)
I 70 -
fin
;
;
; a
;
n n
nn
a D
D
a D
2 4 6 8 10 12 14 2 4 6 8 10 12
pH pH
n SR2-PPB-0001 - A
14
n SR2-PPT-0001 - A
Figure E-3. Mercury Release (top) and Spike Recoveries (bottom) as a Function of pH for the Baseline Fly Ash and the Fly
Ash with Enhanced Hg Control. 5th and 95th percentiles of mercury concentrations observed in typical combustion waste
landfill leachate are shown for comparison.
134
-------
Characterization of Coal Combustion Residues
Mercury Release as a Function of LS Ratio
Baseline Fly Ash
Fly Ash with ACI
0 01 5
n1
?£ n m
O)
Onn^i
n
c
ML
— - MDL
-
-
i
i
r~\"
- o-
- —
,
<
- ^— i
^
>
> —
) 2 4 6 8 10 12
LS ratio [mL/g]
n SR3-PPB-0001 - A
o SR3-PPB-0001 - B
A SR3-PPB-0001 - C
n 01^
IT
§. n m
D)
0 00*1
n
C
ML
— - MDL
A [
D i
]
\
D
- —
,
I
, '
>
]
\
) 2 4 6 8 10 12
LS ratio [mL/g]
n SR3-PPT-0001 - A
o SR3-PPT-0001 - B
A SR3-PPT-0001 - C
140 -
^p1 nn
°l
e^ 1?f) -
o>
^
p mn
O)
1/5 80
O) ou
?n
Rn
;
I
:
;
~
;
~
;
:
u
[
]
I-JU
14H
To1 1 *^n
ll
>< -ion
o>
E-inn
O)
1/5 80 -
O) ou
?n
Rn .
i
;
;
;
;
D
C
]
4 6 8 10
LS ratio [mL/g]
12
2 4 6 8 10 12
LS ratio [mL/g]
DSR3-PPB-0001 -A
DSR3-PPT-0001 -A
Figure E-4. Mercury Release (top) and Spike Recoveries (bottom) as a Function of LS Ratio for the Baseline Fly Ash and
the Fly Ash with Enhanced Hg Control.
135
-------
Characterization of Coal Combustion Residues
Arsenic Release as a Function of pH
Baseline Fly Ash
As total content*: 21.3+0.3 |jg/g
Fly Ash with ACI
As total content*: 24.0+0.8 |jg/g
1000 -
100 -
MCLHn
g_ 4
1 ' 1
< 0.1
0.01
n nm
t
1
i - ^itt&Ki
^^m m ^^H • i
' 5'
> 4
. . . -oa£q£ o 5
_ _ _ _ .
A 112
6 8 10 1
r
— ^^^
95%
2 1
95%
b%
4
1000
100 -
CL10
4 2
1
0.1 -
0.01 -
n nm
f
i
1 - 3«&-
_ _ _ _ ,
5°
2 4
-oao&r -C&-0- -d
_._._._
/ "1 "1 Q
6 8 10 1
C
*>A
- —
95%
2 1
95%
5%
4
Ml
— - MDL
Total content
1^0 -,
140
"T"1 -ion
^_
^ 110
> I IU
8 100
S qo
'o.
w 80
t/>
< 7Q -
fin
/
2 4 6 8 10 12 14
PH
DSR2-PPB-0001 -A
OSR2-PPB-0001 -B
ASR2-PPB-0001 -C
1
ML
^— - IVIUL
2 4 6 8 10 12 14
PH
n SR2-PPT-0001 - A
o SR2-PPT-0001 - B
A SR2-PPT-0001 - C
as determined by digestion using method 3052.
-icn
~
:
:
: ^
[T
1
I
-
]
D
n
B [
D
I 4 6 8 10 12
pH
i4n
" 'ion
o
o
m inn
S qn
w «n
< 7Q
fin
:
; B
i
D D
n n
n
n
_,
D
14 2 4 6 8 10 12
pH
n SR2-PPB-0001 - A
14
n SR2-PPT-0001 - A
Figure E-5. Arsenic Release (top) and Spike Recoveries (bottom) as a Function of pH for the Baseline Fly Ash and the Fly
Ash with Enhanced Hg Control. 5th and 95th percentiles of arsenic concentrations observed in typical combustion waste
landfill leachate are shown for comparison.
136
-------
Characterization of Coal Combustion Residues
Arsenic Release as a Function of LS Ratio
Baseline Fly Ash
20
15
% MC1L0
o
A
ML
MDL
468
LS ratio [mL/g]
10 12
nSRS-PPB-0001 -A
oSRS-PPB-0001 - B
ASR3-PPB-0001 -C
20
15
^ MCL
.3 10
0
• ML
MDL
Fly Ash with ACI
D
fi
468
LS ratio [mL/g]
10 12
n SR3-PPT-0001 - A
oSRS-PPT-0001 -B
ASR3-PPT-0001 -C
£
o
o
£
o>
'5.
(/5
i4n
1?0
nn
100
on
80
70
fin
c
:
|
; D C
;
;
]
D
[
]
D 2 4 6 8 10 12
LS ratio [mL/g]
n SR3-PPB-0001 - A
o>
o
o
£
o>
'o.
150
140
130
120
110
100
90
80
70
60
~_
\
- U J
;
~_
]
D
[
]
D 24 6 8 10 12
LS ratio [mL/g]
n SR3-PPT-0001 - A
Figure E-6. Arsenic Release (top) and Spike Recoveries (bottom) as a Function of LS Ratio for the Baseline Fly Ash and
the Fly Ash with Enhanced Hg Control.
137
-------
Characterization of Coal Combustion Residues
Seleniurr
10000 -
1000
110.9
100
MCL
ZT 10
1 1-
o>
w 0.1
0.01 -
0.001
Ml
— - MDL "
\ Release as a Function of pH
Baseline Fly Ash Fly Ash with ACI
Se total content*: <4.0 ug/g Se total content*: <4.0 ug/g
: D_ <*L
I - Z3QJ -<&
|
i
- - - -o-B A Mi O
1000 -
to QF,%
' ncL100
— 25. 3.
ZT 10
^•y O?
- — CD
w 0.1 -
0.01
I, n nn-i
= RftAl ^7S
-
i
B
on rvKl CA o
'"" ' ' '5% ' '112 95% U'UU1 5%' ' 11.995%
2 4 6 8 10 12 14 2 4 6 8 10 12 14
PH MI PH
n SR2-PPB-0001 - A ~~ ' IVILJL
o SR2-PPB-0001 - B
A SR2-PPB-0001 - C B)
DSR2-PPT-0001 -A
OSR2-PPT-0001 - B
ASR2-PPT-0001 -C
*Total content as determined by digestion using method 3052.
-i en -i en
140
£ 13°
£, 120 -
> 110
8
u 100 -
9 qn
w 80
4 6 8 10 12 14 2 4 6 8 10 12 14
pH pH
n SR2-PPB-0001 - A
a SR2-PPT-0001 - A
Figure E-7. Selenium Release (top) and Spike Recoveries (bottom) as a Function of pH for the Baseline Fly Ash and the
Fly Ash with Enhanced Hg Control. 5th and 95th percentiles of selenium concentrations observed in typical combustion
waste landfill leachate are shown for comparison.
138
-------
Characterization of Coal Combustion Residues
Selenium Release as a Function of LS Ratio
Baseline Fly Ash Fly Ash with ACI
1fiO 'lcn
140
120
U 100
9. 80 -
CD
(/) 60
MCL 1
40
20
Oj
C
ML
— - MDL
•icn
140
•^ 1 30
^
>, -|00
o>
> -i-in
8
P 100
O>
-^ QO
Q.
w 80 -
0) OU
W 70
RO
: 6
A
1
R
u
<
>
) 2 4 6 8 10 1
LS ratio [mL/g]
nSRS-PPB-0001 -A
oSRS-PPB-0001 -B
ASR3-PPB-0001 -C
140
-i on
IZU
i — i mn
9. sn
.^r OU
O)
60
MCL
40
20
A
i
B
E
?
T
2 0 2 4 6 8 10 12
_ _ ML LS ratio [mL/g]
— - MDL
n SR3-PPT-0001 - A
o SR3-PPT-0001 - B
A SR3-PPT-0001 - C
i en
|
: [
;
3
n
r
i
140
^F 1^0
>, -|00
o>
> -I -in
8
P 100
-^ an
._ 90
w 80 -
O) OU
70
en
_
;
;
I
I
; D [
;
;
I
j]
D
C
]
D 2 4 6 8 10 12 0 2 4 6 8 10 12
LS ratio [mL/g] LS ratio [mL/g]
n SR3-PPB-0001 - A
n SR3-PPT-0001 - A
Figure E-8. Selenium Release (top) and Spike Recoveries (bottom) as a Function of LS Ratio for the Baseline Fly Ash and
the Fly Ash with Enhanced Hg Control.
139
-------
Characterization of Coal Combustion Residues
Arsenic Solubility
Baseline Fly Ash
Fly Ash with ACI
\J\J\J\J\J -
10000 -
1000 -
100 -
10 -
1 -
0.1 -
0.01 -
n 001
! ^J^ass
f
10000 -
1000 -
950/0 u 100 -
]t 10 -
5% £ 1
0.1
0.01
n nn-i
|
-%$-<*
ux>o-D95i — ca-a — oS
9
PA f
U'UU1 ' 5% ' ' '95% ' 5% ' ' '95%
2 4 6 8 10 12 14 2 4 6 8 10 12 14
pH pH
n SR2-PPB-0001-A
o SR2-PPB-0001-B
A SR2-PPB-0001-C
Fit rurvp
n SR2-PPT-0001-A
o SR2-PPT-0001-B
A SR2-PPT-0001-C
Fit rurvp
Material log As (|ig/L) pH range of R2 Number of
validity points
PPB 0.0003 pH5 -0.0117 pH4 0.1674 pH3 3-12.5 0.47 33
-1.1600pH2 3.8716 PH -4.2743
PPT 0.0006 pH5 -0.0238 pH4 0.3460 pH3 3-13 0.84 33
-2.3840 pH2 7.7036 PH -8.6786
Figure E-9. Regression Curves of Experimental Data of Arsenic Solubility as a Function of pH.
140
-------
Characterization of Coal Combustion Residues
Selenium Solubility
Baseline Fly Ash Fly Ash with ACI
1 nnnnn •" ^nnnn
10000 -
1000-
:r 100-
.!• 10-
w 1 -
0.1 -
0.01 -
n nni -
3A
&
2 4 &/°6 8 10 ir/01
PH
n SR2-PPB-0001-A
o SR2-PPB-0001-B
A SR2-PPB-0001-C
Fit n \r\fp
10000 -
1000-
95% ^ 100 .
§ 10-
5% » ,
\J j | —
0.1 -
0.01 -
n nm -
4
| £&-<&
i
1
^O-DQS — CA^ r
^*>qj
D
/
2 4 5%6 8 10 il5%1
PH
D SR2-PPT-0001-A
0 SR2-PPT-0001-B
A SR2-PPT-0001-C
Fit n ir\)p
Material log Se (|ig/L) pH range of R2 Number of
validity points
PPB 0.0006 pH5 -0.0234 pH4 0.3605 pH3 3-12.5 0.54 33
-2.6711 pH2 9.4536 PH -10.6432
PPT 0.0012 pH5 -0.0440 pH4 0.6379 pH3 3-13 0.81 33
-4.3855 pH2 14.2483 PH -15.6626
95%
5%
4
Figure E-10. Regression Curves of Experimental Data of Selenium Solubility as a Function of pH.
141
-------
Characterization of Coal Combustion Residues
100-Year Arsenic Release Estimates
Arsenic
IUUUU •
1000 -
^ 100 -
-1— •
s
1_
ro m
(D IU •
O
O
01-
c
5
-[
)
fififi5
HaBUB
!
5%20 40 5(
^
)%60 8095'
)
^(
DO
Mt min
Mt - 5%
Mt - 50%
Mt - 95%
Mean Mt
Mt max
PF
Hg/kg
0.1
0.2
36
473
107
1188
3B
%
0.0006
0.0010
0.2
2.2
0.5
5.6
PF
Jig/kg
0.1
0.2
27
358
81
1049
3T
%
0.0004
0.0007
0.1
1.5
0.3
4.4
Percentile
nPPB
APPT
Figure E-11.100-Year Arsenic Release Estimates as a Function of the Cumulative Probability for the Scenario of Disposal
in a Combustion Waste Landfill.
100-year Selenium Release Estimates
Selenium
IUUUUU •
mnnn -
O)
^B) innn -
-i— •
^ 100 -
CD
(D
>s -in -
o
o
^~ -I .
01-
c
S
)
HfiSaS
HB
ITI
A
1
i i i i i i i i
5% 20 40 5C
BHBHHBBI
?HA
1 1 1 1 1 1 1 1
)% ' ' 95°/
1/0 60 80
g
'o
1(
DO
Mt min
Mt - 5%
Mt - 50%
Mt - 95%
Mean Mt
Mt max
PF
jag/kg
3.0
4.4
733
4000
2254
4000
3B
%
0.1
0.1
18.3
100.0
56.4
100.0
PF
jag/kg
0.9
3.3
516
4000
1599
4000
3T
%
0.0
0.1
12.9
100.0
40.0
100.0
Percentile
nPPB
APPT
Figure E-12. 100-Year Selenium Release Estimates as a Function of the Cumulative Probability for the Scenario of
Disposal in a Combustion Waste Landfill.
142
-------
Characterization of Coal Combustion Residues
100-Year Arsenic Release Estimates
PPB -Arsenic
100000
iP 10000
S 1000
o
TO
0)
100
10
A)
-
-
100%
473 ug/kg
2.2%
104 ug/kg
0 5%
45 |id/kg_ u.^/u 5Q jl0;/kq
0.2%
0.2%
Total content Combustion Default-pH 3 Default-pH Default-
Waste Landfill - 12.5 Natural pH
95% confidence 11.2
-MCI =1000 ug/kg
™-r=P===^P=- MCI =125 ug/kg
100000
5> 10000
-------
Characterization of Coal Combustion Residues
100-Year Selenium Release Estimates
CD
"35
E
2
'c
0)
0)
6
o
10000
1000
100
10
PPB -Selenium
<4000 ug/kg 4000 ug/kg
4000
A)
; 100% 100% 100%
:
_
Tol
al cont
565 ug/kg
14 1%
^l'
B6jjg7
34.7%
— —
ent Combustion Default-pH3 Default-pH Default-
Waste Landfill - 12.5 Natural pH
95% confidence 11.2
— MCLLS95% = 5000 ug/kg
MCLLS125 = 625 ug/kg
PPT-Selenium
0)
(/)
TO
TO
0)
CD
O
10000
1000
100
10
<4000 u9/kg 4000 ug/kg
; 100% 100%
Tol
al cont
.
ent Co
Was
95%
mbust
te Lan
confid
740 ug/kg
448 ug/kg 18.5% 316 ug/kg
J.1.2.%
1.9%
on Default -pH 3 Default -pH Default -
dfill- 12.5 Natural pH
ence 11.9
MCL = 5000 ug/kg
B)
Figure E-14.100-year Selenium Release Estimates from A) Baseline Fly Ash and B) Fly Ash with ACI. Release estimates
for percolation controlled scenario are compared to release estimate based on total content. The amount of the selenium
that would be released if the release concentration was at the MCL is also shown for comparison (LSdefaultscenario = 12.5 L/kg
andl_S95%=100L/kg).
144
-------
Characterization of Coal Combustion Residues
Comments
Figure E-3:
• Fly ash from the test case had greater total Hg content
than the fly ash from the baseline case (by about 7.5
times).
• Hg release is well below levels of potential concern
(but poor replication) for both baseline and test cases.
Figure E-5:
• The fly ash from the test case had similar total As
content than that from the baseline case.
• As release was below the MCL for both the baseline
and the test cases for most pH conditions.
Figure E-7:
• Total selenium content was below detection limits for
Method 3052 for both fly ashes while significant sele-
nium release (ranging from around 30 |Jg/L to around
1000 |Jg/L) as a function of pH was observed. This
result is a consequence of the dilution effects of the
digestion method and analytical requirements.
• Selenium release from both the baseline and the test
cases was close to or exceeded the MCL (50 |Jg/L)
for most pH conditions.
Figures E-11 andE-12:
• The fly ash from the test case would result in As re-
lease slightly less than expected from the baseline case,
with a 95% probability to be less than 358 and 473 |Jg/
kg, respectively.
• The fly ash from the test case would result in Se re-
lease less than expected from the baseline case, with a
95% probability to be less than 4000 |Jg/kg (total con-
tent) in both cases and a 5% possibility that the total
content will be released.
Figure E-13:
• For all scenarios examined, no significant difference in
arsenic release would be observed between the fly ash
from the baseline case and the fly ash from the test
case.
• For the 95% probability scenario, arsenic release from
both cases would be less than the amount that would
be released if the release concentration was at the MCL
and the LS ratio was the resultant LS ratio for the 95%
case (i.e., about 100 L/kg). However, arsenic release
would be greater than the amount that would be re-
leased if the release concentration was at the MCL
and the LS ratio was the LS ratio of the default sce-
nario considered (i.e., 12.5 L/kg).
• For the three default scenarios considered, arsenic re-
lease would most likely be less than the amount that
would be released if the release concentration was at
the MCL.
Figure E-14:
• For scenarios at alkaline pH, lower Se release would
be expected for the test case compared to the baseline
case.
• For the 95 % probability scenario, selenium release from
both cases would be greater than the amount that would
be released if the release concentration was at the
MCL.
• In conclusion, Se release will most likely be greater
than the MCL based on solubility and cumulative re-
lease. Without controls appears worse than with con-
trols.
145
-------
Characterization of Coal Combustion Residues
Appendix F
Salem Harbor Fly Ashes
146
-------
Characterization of Coal Combustion Residues
List of Figures
Figure Page
F-l pH Titration Curves for the Baseline Fly Ash and the Fly Ash with Enhanced Hg Control 148
F-2 pH as a Function of LS Ratio for the Baseline Fly Ash and the Fly Ash with Enhanced Hg Control 148
F-3 Mercury Release (top) and Spike Recoveries (bottom) as a Function of pH for the Baseline Fly Ash and the
Fly Ash with Enhanced Hg Control 149
F4 Mercury Release (top) and Spike Recoveries (bottom) as a Function of LS Ratio for the Baseline Fly Ash and
the Fly Ash with Enhanced Hg Control 150
F-5 Arsenic Release (top) and Spike Recoveries (bottom) as a Function of pH for the Baseline Fly Ash and the
Fly Ash with Enhanced Hg Control 151
F-6 Arsenic Release (top) and Spike Recoveries (bottom) as a Function of LS Ratio for the Baseline Fly Ash
and the Fly Ash with Enhanced Hg Control 152
F-7 Selenium Release (top) and Spike Recoveries (bottom) as a Function of pH for the Baseline Fly Ash and the
Fly Ash with Enhanced Hg Control 153
F-8 Selenium Release (top) and Spike Recoveries (bottom) as a Function of LS Ratio for the Baseline Fly Ash
and the Fly Ash with Enhanced Hg Control 154
F-9 Regression Curves of Experimental Data of Arsenic Solubility as a Function of pH 155
F-10 Regression Curves of Experimental Data of Selenium Solubility as a Function of pH 156
F-ll 100-Year Arsenic Release Estimates as aFunction of the Cumulative Probability forthe Scenario of Disposal
in a Combustion Waste Landfill 157
F-12 100-Year Selenium Release Estimates as a Function of the Cumulative Probability for the Scenario of Disposal
in a Combustion Waste Landfill 157
F-13 100-Year Arsenic Release Estimates from A) Baseline Fly Ash and B) Fly Ash with ACI 158
F-14 100-year Selenium Release Estimates from A) Baseline Fly Ash and B) Fly Ash with ACI 159
147
-------
Characterization of Coal Combustion Residues
pH Titration Curves
Baseline Fly Ash Fly Ash with ACI
14 -1/1
12
11.7
•in
IU
I 8-
Q.
4 -
a
• • •
-1 -0
- S(
j
Q
O
D
.500
A
H
, , a
5
1
12
10.3
•in
IU
I 8-
Q.
6
4
9
; 0
-
-
H
i i i i
52 -2 -1.5 -1 -0
B
" "?
^
-------
Characterization of Coal Combustion Residues
Mercury Release as a Function of pH
Baseline Fly Ash
Hg total content*: 650.6+6.8 ng/g
Fly Ash with ACI
Hg total content*: 1529.6+1.1 ng/g
MCL
1
D) 0.1
0) °-032
I
0.01
0.001
Ml
— -MDL
Total content
150
140
P\
110
u 100
% 90
Q.
w 80
D)
1 70
60
x^_.
:O"
: O O
jTT_A A T!
0 °
______ ^
1
D
- —
MCL
1 -
IT
95% S °-1
5%
n nn-i _
!
E
A A
A
_O - _ -
V 001 <,
A A
K^ LJ ^ 1 LJ ^
AA
DD
«>
95C
5%
5% ' 11.795% W'WW1 5o/n ' ' JOS 95%
2 4S/06 8 10 12 14 2 4 s/0 6 8 10 12 14
pH pH
Ml
D SR2-SHB-0001 - A
0 SR2-SHB-0001 - B
A SR2-SHB-0001 - C
— -MDL
n SR2-SHT-0001 - A
0 SR2-SHT-0001 - B
A SR2-SHT-0001 - C
as determined by digestion using method 3052.
-icn
f
° D J
:
:
D
D
rf
140
— i?n
^T 190,
5 -i -in
i 6 MU
D « 100
Q on
-^ yu
'o.
w sn
ou
"T 7n
/U
— i — i — i— en
|
:n rf.
\
n n n n c
• nn
\j\j
> 4 6 8 10 12 14 2 4 6 8 10 12 14
PH pH
n SR2-SHB-0001 - A
n SR2-SHT-0001 - A
Figure F-3. Mercury Release (top) and Spike Recoveries (bottom) as a Function of pH for the Baseline Fly Ash and the Fly
Ash with Enhanced Hg Control. 5th and 95th percentiles of mercury concentrations observed in typical combustion waste
landfill leachate are shown for comparison.
149
-------
Characterization of Coal Combustion Residues
Mercury Release as a Function of LS Ratio
Baseline Fly Ash
Fly Ash with ACI
008
U 0 OR
O) 0 04
0 02
ML '
— - MDL
-
-
; A I
n
O *
: i
-
_ _ .
]
>
_ _ _
o
D
_ _ _
. _ _
[
L
]
^
D 2 4 6 8 10 12
LS ratio [mL/g]
n SR3-SHB-0001 - A
o SR3-SHB-0001 - B
A SR3-SHB-0001 - C
n DR.
u n OR
D) n 04
I U.U4
n n?
n -
Ml ,
— - MDL
— - 1
i- - -
- 71 —
. _ _
/
• — r!
i
r — '
D 2 4 6 8 10 12
LS ratio [mL/g]
n SR3-SHT-0001 - A
o SR3-SHT-0001 - B
A SR3-SHT-0001 - C
140,
^T 1^0-
o^ I OU
o>
> -i -in
o
o>
-^ Qn
w 80
O) OU
7n
en
(
]
n
[
]
14D
To1 -| *^n
ll
>< -i on
O)
> -i -in
o nu
£ -inn _
o>
1/5 80 -
O) ou
yn
Rn
;
:
;
;
~
;
;
;
:
D
[
]
D 2 4 6 8 10 12 0 2 4 6 8 10 12
LS ratio [mL/g] LS ratio [mL/g]
n SR3-SHB-0001 - A
n SR3-SHT-0001 - A
Figure F-4. Mercury Release (top) and Spike Recoveries (bottom) as a Function of LS Ratio for the Baseline Fly Ash and
the Fly Ash with Enhanced Hg Control.
150
-------
Characterization of Coal Combustion Residues
Arsenic Release as a Function of pH
Baseline Fly Ash Fly Ash with ACI
1 nnnn As total content*; 25.9+0.04 |jg/g ^ nnnn As total content*: 26.0+0.03 |jg/g
1000
100
19.30
_i MCL10 -
— 1 -
in
< 0.1 -
0.01 -
0 001
-w^
•CT i^Xj^Wk
\ L^"<>
;
|
?- - eg
1000 -
1?nn
100 -
i — i MO 1 -i r\
-----^-«, O3
5% ^3 ^
< 0.1 -
0.01 -
iii n nn-i
i A>
r~"
ft* 95
°-001 5% ' 11795% ' 5% ' "103 95%
2 4 6 8 10 12 14 2 4 6 8 10 12 14
ML PH M, PH
— - MDL
n SR2-SHB-0001 - A ~~ " IVIUL
OSR2-SHB-0001 - B
A SR2-SHB-0001 - C
n SR2-SHT-0001 - A
o SR2-SHT-0001 - B
A SR2-SHT-0001 - C
*Total content as determined by digestion using method 3052.
-i en •|cn
•I/in
sE,
§2 nn
> nu
o
m *i nn
-------
Characterization of Coal Combustion Residues
Arsenic Release as a Function of LS
Baseline Fly Ash
co
1 r on
^ oU -
a
MCL 10 -
0 J
C
Ml
— - MDL
1^0
140
^ 1 20
flj
^ *i *i r\
O 1 lu
o
P 100
O>
-*: QO
Q.
w 80
70
RO
(
. A
: D <
J
^^H • ^^^ • ^^^ • ^^^ • ^^^ • ^^^ • ^^^ 1
1 1 1 1 1 1
) 2 4 6 8 10 12
LS ratio [mL/g]
n SR3-SHB-0001 - A
0 SR3-SHB-0001 - B
A SR3-SHB-0001 - C
|
i
|
;
1 c
; D
1
;
|
3
D
[
j]
D 2 4 6 8 10 12
LS ratio [mL/g]
n SR3-SHB-0001 - A
> Ratio
250
200
=J 150
a
^ 100
50
MCL
0
ML
— - MDL
150 -r-
140 -
^ 1 20
> no
o
E100
o>
-^ QO
Q.
w 80
70
0
Fly Ash with ACI
_
T
A
I
k
0 2 4 6 8 10 12
LS ratio [mL/g]
n SR3-SHT-0001 - A
0 SR3-SHT-0001 - B
A SR3-SHT-0001 - C
n
D
r
i
2 46 8 10 12
LS ratio [mL/g]
n SR3-SHT-0001 - A
Figure F-6. Arsenic Release (top) and Spike Recoveries (bottom) as a Function of LS Ratio for the Baseline Fly Ash and
the Fly Ash with Enhanced Hg Control.
152
-------
Characterization of Coal Combustion Residues
Seleniun
10000
1217
1000
100
MCL
5- 10
1 1 1
o>
w 0.1
0.01
0.001
ML
— - MDL
i Release as a Function of pH
Baseline Fly Ash Fly Ash with ACI
Se total content*: 41 .9+0.06 ug/g -mnnn Se total content*; 44.0+0.04 |jg/g
w> DA
"I
-i
£U
fln a- - *i
"
!
B
141?D700 -
95% 100 -
MCL
5- 10 -
5% §. 1
110
8
m ^ nn
9J QO
'o_
w 80
(D
W yn
cn
;n J
n n :
n D
D
n
2 4 6 8 10 12 14 2 4 6 8 10 12 14
pH pH
n SR2-SHB-0001 - A
n SR2-SHT-0001 - A
Figure F-7. Selenium Release (top) and Spike Recoveries (bottom) as a Function of pH for the Baseline Fly Ash and the
Fly Ash with Enhanced Hg Control. 5th and 95th percentiles of selenium concentrations observed in typical combustion
waste landfill leachate are shown for comparison.
153
-------
Characterization of Coal Combustion Residues
Selenium
5000
4000
5* 3000 -
$ 2000 -
1000 -
MCL Q
ML
— - MDL
1 ^n
140
vP 1 ^0
0s" v\J
O>
> -i -in
o
o> mn -
O>
^ 90
Q.
w 80
0> OU
W 70 -
fiO
0
Release as a Function of
Baseline Fly Ash
:
- ** i
n
V
[
1
LS Ratio
Fly Ash with ACI
cnnn
0 24 6 8 10 12
LS ratio [mL/g]
n SR3-SHB-0001 - A
o SR3-SHB-0001 - B
A SR3-SHB-0001 - C
n
[
]
D
[
3
4000
"~T ^000
a
CD onnn
1000
MCL
U H
(
ML
— - MDL
1 'in
140
vP 1 ^0
0s" v\J
>* -ion
O)
> -i -in
o
Q> mn -
o>
-^ Qn
._ yu
w 80
0) OU
W 70 -
«n
\
-
t
-
-
J
^
|
D 2 4 6 8 10 12
LS ratio [mL/g]
n SR3-SHT-0001 - A
0 SR3-SHT-0001 - B
A SR3-SHT-0001 - C
;
;
;
: C
;
;
;
;
;
]
D
n
2 4 6 8 10 12 0 2 4 6 8 10 12
LS ratio [mL/g] LS ratio [mL/g]
n SR3-SHB-0001 - A
nSRS-SHT-0001 -A
Figure F-8. Selenium Release (top) and Spike Recoveries (bottom) as a Function of LS Ratio for the Baseline Fly Ash and
the Fly Ash with Enhanced Hg Control.
154
-------
Characterization of Coal Combustion Residues
Arsenic Solubility
Baseline Fly Ash
Fly Ash with ACI
IUUUUU -
10000 -
1000 -
100 -
10 -
1 -
0.1 -
0.01 -
0.001 -
1
1
_____
&
\\j\j\j\j\j -
10000 -
1000 -
95% _j 100.
^ 10 -
5% < -i .
0.1 -
0.01 -
n nn-i
«*^
jD^-firi^^^Q^Bi
&...
95%
5%
1 ' 5% ' ' '95% ' 5% ' ' '95%
2 4 6 8 10 12 14 2 4 6 8 10 12 14
pH pH
n SR2-SHB-0001-A
0 SR2-SHB-0001-B
A SR2-SHB-0001-C
Fit r\ ir\/p
n SR2-SHT-0001-A
0 SR2-SHT-0001-B
A SR2-SHT-0001-C
Fit rurvp
Material log As (|ig/L) pH range of R2 Number of
validity points
SHE 0.0000 pH5 0.0011 pH4 -0.0428 pH3 3-12.5 0.96 33
0.4859 pH2 -2.2393 PH 5.6031
SHT 0.0003 pH5 -0.0106 pH4 0.1194 pH3 3-13 0.92 33
-0.5142 pH2 0.4220 PH 3.3432
Figure F-9. Regression Curves of Experimental Data of Arsenic Solubility as a Function of pH.
155
-------
Characterization of Coal Combustion Residues
Selenium Solubility
Baseline Fly Ash
Fly Ash with ACI
1 \J\J\J\J\J -
10000 -
1000-
U 100-
S 10-
% 1-
0.1 -
0.01 -
0 001 -
S. ..P.A^i
jfcn-ja rf?
<%^._
*-
2 4 5/°6 8 10 l!5%1
PH
n SR2-SHB-0001-A
o SR2-SHB-0001-B
A SR2-SHB-0001-C
Fit n ir\
-------
Characterization of Coal Combustion Residues
100-Year Arsenic Release Estimates
Arsenic
1 UUUUU -
mono .
D)
7r> innn .
^ mn -
i_
co
CD
>s -in -
0
o
""" 1 .
OH
.1 "I
c
*
)
A Q '-'
A n
A U
A°
iD
5% 2Q 4Q50<
.t
AAAAflc
k n '-'
* 60 80 95°'
!
^c
30
Mt min
Mt - 5%
Mt - 50%
Mt - 95%
Mean Mt
Mt max
Sh
0.8
3.6
546
7922
1749
18969
HB
0.003
0.014
2.1
30.6
6.8
73.2
Sh
2.7
6.1
968
13374
3013
26000
HT
0.01
0.02
3.7
51.4
11.6
100.0
Percentile
nSHB
ASHT
Figure F-11.100-Year Arsenic Release Estimates as a Function of the Cumulative Probability for the Scenario of Disposal
in a Combustion Waste Landfill.
100-Year Selenium Release Estimates
Selenium
IUUUUU -
10000 -
"oS
"TTI 1000 -
i_2T
^ 100 -
CO
CD
^ 10 -
6 IU
o
^~ 1 .
0-1
• T ~\
C
S
)
noHH5
n B
s
JH
5%20 40 5C
naaaHH'
% ' ' 95°/
60 80
l
'o
K
DO
Mt min
Mt - 5%
Mt - 50%
Mt - 95%
Mean Mt
Mt max
Sh
6.6
34.5
5011
41900
17623
41900
HB
0.02
0.08
12.0
100.0
42.1
100.0
Sh
4.7
24.3
3650
44000
14240
44000
HT
0.01
0.06
8.3
100.0
32.4
100.0
Percentile
nSHB
ASHT
Figure F-12. 100-Year Selenium Release Estimates as a Function of the Cumulative Probability for the Scenario of
Disposal in a Combustion Waste Landfill.
157
-------
Characterization of Coal Combustion Residues
100-Year Arsenic Release Estimates
SHE - Arsenic
100000
10000
25900
0)
en
CO
o
'c
0)
CO
CO
CD
O
1000
100
10
A)
100%
7922 |jg/kg
30.6%
19
67|jg/
7.6%
kg
360_ug/kg 241_yg/kg
1.4%
0.9%
Total content Combustion Default-pH3 Default-pH Default-
Waste Landfill - 12.5 Natural pH
95% confidence 1 1 7
MCLLS95%=1000|jg/kg
MCLLS125 = 125ug/kg
SHT - Arsenic
100000
10000
0)
CO
CO
"35
o
0)
CO
CO
CD
O
1000
100
10
26000
100%
13;
374 ^g
51.4%
'kg
3326 ng/kg 2590 ug/kg
12.8%
10%
19
50 j^g/
7.5%
kg
Total content Combustion Default -pH 3 Default -pH Default-
Waste Landfill - 12.5 Natural pH
95% confidence 10.3
B)
Figure F-13.100-Year Arsenic Release Estimates from A) Baseline Fly Ash and B) Fly Ash with ACI. Release estimates
for percolation controlled scenario are compared to release estimate based on total content. The amount of the arsenic that
would be released if the release concentration was at the MCL is also shown for comparison (LSdefaultscenario = 12.5 L/kg and
LS95%=100L/kg).
158
-------
Characterization of Coal Combustion Residues
100-Year Selenium Release Estimates
SHE - Selenium
41900|ig/kg 41900
51 -innnn
O)
QJ
CO
cu 1000
cu
E
'c
cu inn
CO
>s
ci in
0 IU
1
E 100% 100% 20296jig/kg _^,
1572|ig/kg
48.4%
^8^*9
36.3%
*g-
Total content Combustion Default - pH 3 Default -pH Default -
Waste Landfill - 12.5 Natural pH
95% confidence 11.7
-MCLLS95% = 5000ug/kg
MCLLS125 = 625ug/kg
A)
44000
SHT- Selenium
44000 na/ka 24978
S5 -innnn
=L
CO
CO
cu innn
cu
E
^
'c
cu -inn
CO
cu
>s
o in
o IU "
1
D\
E 100% 100% 56.8% 18708|ig/kg
1337|ig/kg
•}<>/„
42.5%
Total content Combustion Default - pH 3 Default -pH Default -
Waste Landfill - 12.5 Natural pH
95% confidence 10.3
- MOI -5000iin/kn
ivioi_Lgg5% — CNJUU |jy/i\y
- MPI RPR i in/kn
ivioLLS125 - D^O ug/Kg
Figure F-14.100-year Selenium Release Estimates from A) Baseline Fly Ash and B) Fly Ash with ACI. Release estimates
for percolation controlled scenario are compared to release estimate based on total content. The amount of the selenium
that would be released if the release concentration was at the MCL is also shown for comparison (LSdefaultscenario = 12.5 L/kg
andLS95%=100l_/kg).
159
-------
Characterization of Coal Combustion Residues
Comments
Figure F-3:
• The fly ash from the test case had similar total Hg
content to that from the baseline case.
• Hg release is greater in baseline than test case, but
both were below MCL.
Figure F-5:
• The fly ash from the test case had similar total As
content than that from the baseline case.
• The laboratory measurements fit within the 5-95% con-
fidence intervals of the field observations.
• Arsenic release is less in baseline than test case, but
both are about 10 times greater than the MCL. Ar-
senic release at pH higher than 9 is much greater for
the test case than the baseline case.
Figure F-6:
• Initial landfill leachate As concentrations will likely be
about 20-30 |Jg/L for the baseline case but at least 100
|Jg/L for the test case.
Figure F-7:
• The fly ash from the test case had similar total Se con-
tent to that from the baseline case.
• Se release is similar in baseline and test cases, but sig-
nificantly above MCL for both cases. The observed
concentrations are greater than reported in the EPA
database but consistent with the EPRI database.
Figure F-8:
• Initial landfill leachate Se concentrations are expected
to be around 200 |Jg/L for the baseline case and in-
creasing with increasing LS ratio, but the initial con-
centrations for the test case are expected to be around
3000 |Jg/L and decreasing with increasing LS ratio.
Figures F-11 andF-12:
• The fly ash from the test case would result in As re-
lease greater than expected from the baseline case,
with a 95% probability to be less than 13,375 and 7,925
|Jg/kg, respectively.
• The fly ash from the test case would result in Se re-
lease less than expected from the baseline case. At
the 95th percentile the total content of Se will be re-
leased (41,900 and 44,000 |Jg/kg, respectively, for the
baseline case and the test case).
• 10-100% of the Se can be anticipated to be leached
from the fly ash for both cases under the projected
landfill conditions.
Figure-13:
• Greater As release would be expected for the test case
compared to the baseline case, for all scenarios exam-
ined.
• For all scenarios examined, Arsenic release from the
test case fly ash would be greater than the amount that
would be released if the release concentration was at
the MCL.
Figure F-14:
• At the 95th percentile, Se release estimate exceeds total
content for both the baseline and the test cases. This is
not physically possible. However, this result indicates
that there is 5% possibility that 100% of the total Se
content would be released.
• For all scenarios examined, Se release would most likely
be greater than the amount that would be released if
the release concentration was at the MCL.
160
-------
Characterization of Coal Combustion Residues
Appendix G
Facility C Fly Ashes
161
-------
Characterization of Coal Combustion Residues
List of Figures
Figure Page
G-l pH Titration Curves for the Baseline Fly Ash and the Fly Ash with Enhanced Hg Control 163
G-2 pH as a Function of LS Ratio for the Baseline Fly Ash and the Fly Ash with Enhanced Hg Control 163
G-3 Mercury Release (top) and Spike Recoveries (bottom) as a Function of pH for the Baseline Fly Ash and the
Fly Ash with Enhanced Hg Control 164
G4 Mercury Release (top) and Spike Recoveries (bottom) as a Function of LS Ratio for the Baseline Fly Ash and
the Fly Ash with Enhanced Hg Control 165
G-5 Arsenic Release (top) and Spike Recoveries (bottom) as a Function of pH for the Baseline Fly Ash and the
Fly Ash with Enhanced Hg Control 166
G6 Arsenic Release (top) and Spike Recoveries (bottom) as a Function of LS Ratio for the Baseline Fly Ash
and the Fly Ash with Enhanced Hg Control 167
G-7 Selenium Release (top) and Spike Recoveries (bottom) as a Function of pH for the Baseline Fly Ash and the
Fly Ash with Enhanced Hg Control 168
GS Selenium Release (top) and Spike Recoveries (bottom) as a Function of LS Ratio for the Baseline Fly Ash
and the Fly Ash with Enhanced Hg Control 169
G-9 Regression Curves of Experimental Data of Arsenic Solubility as a Function of pH 170
G-10 Regression Curves of Experimental Data of Selenium Solubility as a Function of pH 171
G-ll 100-Year Arsenic Release Estimates as aFunction of the Cumulative Probability forthe Scenario of Disposal
in a Combustion Waste Landfill 172
G-12 100-Year Selenium Release Estimates as a Function of the Cumulative Probability for the Scenario of Disposal
in a Combustion Waste Landfill 172
G-13 100-Year Arsenic Release Estimates from A) Baseline Fly Ash and B) Fly Ash with ACI 173
G-14 100-year Selenium Release Estimates from A) Baseline Fly Ash and B) Fly Ash with ACI 174
162
-------
Characterization of Coal Combustion Residues
pH Titration Curves
Baseline Fly Ash
12
11.3
1 n
a _
4 -
9 -
"^
_
~
>
\
1
D
6
,, 1
s
-0.5 0 0.5 1 1.5
meq Acid/g dry
n S R2-GAB - A o SR2-GAB - B
A S R2-GAB - C
I
Q.
14
Fly Ash with ACI
2
^- d
n
3.1
Q
A
9
1
^
cP
I
I
I
I
I
I
t
3
fl
\
.,,.
y
-0.5 0 0.5 1 1.5
meq Acid/g dry
DSR2-GAT-A OSR2-GAT-B
Figure G-1. pH Titration Curves for the Baseline Fly Ash and the Fly Ash with Enhanced Hg Control.
pH as a Function of LS Ratio
Baseline Fly Ash
Fly Ash with ACI
12
m
8
t\
O
(
~
D '
-
-
-
-
1
B
i
12 -
m
5 8
Q. u
4
9
-
:
i
-
-
-
a
3
<
L
•
1
D 2 4 6 8 10 12 0 2 4 6 8 10 12
LS ratio [mL/g] LS ratio [ml_/g]
pSRS-GAB-A <>SR3-GAB-B
^ SR3-GAB - C
n S R3-GAT - A o SR3-GAT - B
Figure G-2. pH as a Function of LS Ratio for the Baseline Fly Ash and the Fly Ash with Enhanced Hg Control.
163
-------
Characterization of Coal Combustion Residues
Mercury
10 -
MCL
1
U
ra 0.1 -
0)
1 0.014
0.01 -
0.001
ML
Release as a Function of pH
Baseline Fly Ash Fly Ash with ACI
Hg total content*: 15.8+0.9 ng/g Hn Hg total content*: 1 150.7+14.4 ng/g
m
:* c
i i i | i i i
D pjn ^ ^
A |0
1
A OA Wk
MCL
1
95% 1 °'1 -
D)
I 0.016
n m
CO/
iii n nni
. _ — D - -
A ri
^H • ^^ •
U U
u
- - -0° D
} ?S«...
U ' U IS
95%
" ~5%
2 4 65% 8 1011-31295%14 ""' 2 4 65% 88'1 10 1295%14
PH -ML PH
Mni
DSR2-GAB -A 0SR2-GAB-B
ASR2-GAB -C
QS R2-G AT - A » S R2-G AT - B
*Total content as determined by digestion using method 3052.
150 'lcn
140
" 130
"I"! -ion
CD
> 110
0 MU
O
CD 100
CD
jZ qn
'a.
« 80 -
O)
1 70
RO
^
n Pn n
u UCI nri cP
1/1 n
I4U
ion
CD
b ' ' u
o
m mn
S qn
'o.
O)
X 70
D
n
q
D
h DnD
Qj
LJ
4 6 8 10 12 14 2 4 6 8 10 12 14
pH pH
p SR2-GAB - A
DSR2-GAT- A
Figure G-3. Mercury Release (top) and Spike Recoveries (bottom) as a Function of pH for the Baseline Fly Ash and the Fly
Ash with Enhanced Hg Control. 5th and 95th percentiles of mercury concentrations observed in typical combustion waste
landfill leachate are shown for comparison.
164
-------
Characterization of Coal Combustion Residues
Mercury Release as a Function of LS Ratio
Baseline Fly Ash Fly Ash with ACI
n 1 n •"
n 08
^ 0 06
O)
,3.
o) n r\A
o n?
n
C
ML
— - MDL
150
140
^o1 -i^n -
>s -ion
>
z 11 n
o
P mn -
O>
-^ Qn
Q.
w 80
0) °U
1 70
60
(
. i
g
& i
^.]_..
Q
0
_ _ —
. _ —
i
-—
) 246 8 10 1
LS ratio [mL/g]
nSR3-GAB-A <>SR3-GAB-B
ASR3-GAB -C
0 08
^ 0 06
O)
^
a) n r\A
0 0?
n
2 (
ML
— - MDL
^~ " L
n — -
D
- » —
. _ —
fe
-;-t"-
D 246 8 10 12
LS ratio [mL/g]
n SR3-GAT - A o SR3-GAT - B
•i^n
;
;
I
:
~
;
I
i ii
i i i
n
C
]
140
^F -i^n
>s -ion
>
^ 11 n
o
P mn
O)
-^ Qn
Q.
w 80
0) °U ~
1 70
Rn
_
;
;
I
:
~
:
:
~
D
C
I I I
]
I I I
D 2 4 6 8 10 12 0 2 4 6 8 10 12
LS ratio [mL/g] LS ratio [mL/g]
OSR3-GAB -A
D SR3-GAT - A
Figure G-4. Mercury Release (top) and Spike Recoveries (bottom) as a Function of LS Ratio for the Baseline Fly Ash and
the Fly Ash with Enhanced Hg Control.
165
-------
Characterization of Coal Combustion Residues
Arsenic Release as a Function of pH
Baseline Fly Ash Fly Ash with ACI
10000 As total content*; 93.6+5.5 |jg/g -innnn As total content*; 506.3+28.7 |jg/g
1000 -
237.37
100 -
-T MCL-io ,
O)
— 1 -
t/5
< 0.1
0.01 -
n nm
I _ ntaaAVn 100°
jaJ^Jrrn^-HH Qfi% 119.67
" IOO
-T Mri m
, 5% 2; 1 -
; tO
i < 0.1
i 0.01
" n nn-i
5% 1 1 3 95%
2 4 6 8 10 12 14
MI nu M|_
— - MDL
*Total content
150 -
140
gr 130-
^ 120
O>
> 110
£ 100
2 90
Q.
w 80 -
t/5
< 70
60
- IVIUL
D SR2-GAB - A 0 SR2-GAB - B
A SR2-GAB - C
!» J
^dra ^i^ n._/v IS
! ^y. . .0*P - 'j-f&Q LQP
'- D 1
E
1
95%
5%
'5% "81 ' '95%
2 4 6 8 10 12 14
PH
DSR2-GAT-A <>SR2-GAT-B
as determined by digestion using method 3052.
150
-MO
" -ion
:n n °1
~ •-! - 19D
Cl n £?
CD
D "=• nn
n n o
_ LJ Q
E ° ° ^00
Cl ^ 30
(rt sn
C/)
-------
Characterization of Coal Combustion Residues
Arsenic Release as a Function of LS Ratio
Baseline Fly Ash
Fly Ash with ACI
tuu
-j 250
"3)
J2 -i en
100 -
50
MCL Q ,
(
ML
— -MDL
1 A
n
E (
J
0
5
!
^-TH OCO
i 200
J2 150
mn
en
MCL „
r
<
]
>
R
D
D 2 4 6 8 10 12 0 2 4 6 8 10 12
LS ratio [mL/g] LS ratio [mL/g]
M_
n SR3-GAB - A o SR3-GAB - B — ' IVDL
A SR3-GAB - C
DSR3-GAT-A <>SR3-GAT-B
o
o
0)
150
140
130
11 n
100
80 -
70 -
RD
_
;
=
=
I
= C
- n
=
i
i
D
[
1
1*50
>* -ion
-i -i n
o
® inn
-^ 90
Q.
< 70 .
Rn _
i i i
i i i
D
i i i
[
]
46 8 10 12
LS ratio [mL/g]
2 4 6 8 10 12
LS ratio [mL/g]
QSR3-GAB-A
nSR3-GAT- A
Figure G-6. Arsenic Release (top) and Spike Recoveries (bottom) as a Function of LS Ratio for the Baseline Fly Ash and
the Fly Ash with Enhanced Hg Control.
167
-------
Characterization of Coal Combustion Residues
Seleniurr
10000
2851.88
1000
^L1°°
IT 10
~D)
a 1
140
" 1 30
0s
>, 120
~2 1 1 n
o
o
ai 1 nn
2 90
'5.
y) on -
0)
co 7n
60
:PJ P
P D
I I
> 4
«n _rl _«
n LJ n n ^n
III III III II
140
" 1 30
0s
>> 120
i_
¥ 1 m
o
o
m 1 nn
^ 90
'5.
y) on
0)
co 7n
fin
a D c
i i
1 n
i i
6 8 10 12 14 24
PH
DSR2-GAB -A
3 ncti 13 D
6 8 10 12 14
PH
DSR2-GAT- A
Figure G-7. Selenium Release (top) and Spike Recoveries (bottom) as a Function of pH for the Baseline Fly Ash and the
Fly Ash with Enhanced Hg Control. 5th and 95th percentiles of selenium concentrations observed in typical combustion
waste landfill leachate are shown for comparison.
168
-------
Characterization of Coal Combustion Residues
Selenium Release as a Function of LS Ratio
Baseline Fly Ash
Fly Ash with ACI
7000
6000
— 5000
<$ 3000
2000
-i nnn
MTI n
C
ML
— - MDL
£
t
i
t
I
B
E
I
i
7000 -
6000 -
5000
m 3000
2000
mnn
MP.I n
=
=
=
=
i
1
I
I
]
>
rj
i
y
3
) 2 4 6 8 10 12 0 2 4 6 8 10 12
LS ratio [mL/g] ML LS ratio [mL/g]
— - MDL
QSR3-GAB -A *SR3-GAB-B
ASR3-GAB -C
QSR3-GAT-A oSRS-GAT-B
o
o
140
130
120
110
100
90
70
60
468
LS ratio [mL/g]
10
12
QSR3-GAB
-A
o
o
P
»
150
140
130
120
110
100
90
80
70
60
468
LS ratio [mL/g]
10 12
QSR3-GAT-A
Figure G-8. Selenium Release (top) and Spike Recoveries (bottom) as a Function of LS Ratio for the Baseline Fly Ash and
the Fly Ash with Enhanced Hg Control.
169
-------
Characterization of Coal Combustion Residues
Arsenic Solubility
Baseline Fly Ash
Fly Ash with ACI
10000
1000
100
10
1
0.1
0.01
0.001
;
Ea-SL— a
19
K*****W
/
10000 -
1000 -
95% „ 10Q.
S 10-
5% w ,
< ' •
0.1 -
0.01 -
n nn-i .
^
P — nd^-*^^
X
1 5%' ' ' '95% ' 5% ' ' '95%
2 4 6 8 10 12 14 2 4 6 8 10 12 V
pH pH
a SR2-GAB - A
o SR2-GAB - B
A SR2-GAB - C
B;
n SR2-GAT-A
o SR2-GAT-B
Fit curv6
Material log As (|jg/L) pH range of R2 Number of
validity points
GAB 0.0012 PH5 -0.0416 PH4 0.5236 PH3 3-12.5 0.78 33
-3.0400 pH2 8.0912 PH -5.3943
GAT -0.0008 pH5 0.0304 pH4 -0.4500 pH3 3-12.5 0.75 22
3.1407 pH2 -10.1848 PH 14.1412
Figure G-9. Regression Curves of Experimental Data of Arsenic Solubility as a Function of pH.
170
-------
Characterization of Coal Combustion Residues
Selenium Solubility
Baseline Fly Ash
100000
10000-
1000-
u 100.
1 10-
CO 1 •
0.1 -
0.01 -
n nm
r3p&&*&flr^
^^^^..
•s.
2 4 5%6 8 10 1295%1
PH
100000
10000
1000
95% :j -i oo
S 10
5%
-------
Characterization of Coal Combustion Residues
100-Year Arsenic Release Estimates
100000
^10000
O)
_
CO
CD
><
6
o
1000
100
10
1
0.1
°"^
0^
•""'
A
[
D S% 20 40 E
0"°°^'
;°"
0%' ' 95 °/
60 80
:
l
'o
1C
Mt min
Mt - 5%
Mt - 50%
Mt - 95%
Mean Mt
Mt max
Gf
|jg/kg
5.8
27.5
4086
59706
13789
93600
\B
%
0.0062
0.0294
4.4
63.8
14.7
100.0
G>
|jg/kg
4.1
7.0
1142
15411
3485
48499
M
%
0.0008
0.0014
0.2
3.0
0.7
9.6
P ere entile
nGAB
A GAT
Figure G-11.100-Year Arsenic Release Estimates as a Function of the Cumulative Probability for the Scenario of Disposal
in a Combustion Waste Landfill.
100-Year Selenium Release Estimates
Selenium
100000
"oS
==£ -innnn
O)
1 — ' mnn
^ IUUU
^
m 100
CD
Mg/kg
24.8
69.6
4000
4000
4000
4000
\B
%
0.6
1.7
100.0
100.0
100.0
100.0
G>
Mg/kg
31.1
142.5
21033
206300
78816
206300
VT
%
0.02
0.1
10.2
100.0
38.2
100.0
Percent! I e
DGAB
kGAT
Figure G-12. 100-Year Selenium Release Estimates as a Function of the Cumulative Probability for the Scenario of
Disposal in a Combustion Waste Landfill.
172
-------
Characterization of Coal Combustion Residues
100-Year Arsenic Release Estimates
GAB -Arsenic
100000
10000
1000
CO
CO
o
o
100
10
93600 ug/kg 93600 ug/kg
100% 59706 M9/kg 1000/0
:
:
!
-
-
:
1
1
Dd S%
4855 |jg/kg
5.2%
2967 ug/kg
3.2%
MCL= 1000 ug/kg
MCLLS1 = 125 ug/kg
Total content Combustion Default- pH 3 Default -pH Default-
Waste Landfill - 12.5 Natural pH
95% confidence H 3
A)
GAT- Arsenic
506300 ug/kg
1000000
1 — ' 1 00000
O)
CD 10000
CO
"CD
o IUUU -
CO
ro -inn
i- 1 00
CO
o
0 10
•1
E 1 00%
:
-
:
=
=
=
15411 ug
3.0%
/kg
2413 ug/kg
1178 ug/kg
0.2%
0.5%
14
96 ug/kg
0.3%
Total content Combustion Default- pH 3 Default-pH Default-
Waste Landfill - 12.5 Natural pH
MCLLS95% = 1000
MCLLS12 = 125 ug/kg
B)
95% confide nee
Figure G-13.100-Year Arsenic Release Estimates from A) Baseline Fly Ash and B) Fly Ash with ACI. Release estimates
for percolation controlled scenario are compared to release estimate based on total content. The amount of the arsenic that
would be released if the release concentration was at the MCL is also shown for comparison (LSd f lt =12.5L/kgand
LS95%=100L/kg).
173
-------
Characterization of Coal Combustion Residues
100-Year Selenium Release Estimates
GAB - Selenium
10000
O)
^5)
CO
CO
cu
CO
CD
cu
>s
I
O
O
1000
100
10
<4000 ug/kg 4000 ug/kg 4000 ug/kg 4000 ug/kg
; 100% 100% 34Z
i/.2ug
80-2%
/k9 100% 100%
MCLLS95% = 5000 ug/kg
MCLLS125 = 625 ug/kg
A)
Total content Com busHon Default - pH 3
Waste Landfill -
95% confidence
Default - pH Default - Natural
12.5 pH
11.3
GAT - Selenium
1000000
0)100000
CO
JD
D
CO
CD
O
O
10000
1000
100
10
E 206300 ug/kg 206300 ug/kg 206300 u
: 100% 100% 100%
:
-
-
=
1
:
:
7191. 3 ug/kg
3.5%
3/kg
41101.1 ug/kg
19.9%
MCLLS95% = 5000 ug/kg
MCLLS125 = 625 ug/kg
Total content
B)
Combustion
Waste Landfill -
95% confidence
Default - pH 3
Default-pH
12.5
Default-
Natural pH
8.1
Figure G-14.100-year Selenium Release Estimates from A) Baseline Fly Ash and B) Fly Ash with ACI. Release estimates
for percolation controlled scenario are compared to release estimate based on total content. The amount of the selenium
that would be released if the release concentration was at the MCL is also shown for comparison (LSdefaultscenario = 12.5 L/kg
andl_S95%=100L/kg).
174
-------
Characterization of Coal Combustion Residues
Comments
Figure G-1:
• All extract Hg concentrations are well below levels of
potential concern.
Figure G-5:
• Arsenics extract concentrations for the baseline case
peak between pH 7 and 9, with maximum concentra-
tions significantly greater than the range reported for
field landfill leachates in the EPA database but consis-
tent with the range of concentrations for field landfill
leachates reported in the EPRI database.
• Arsenic extract concentrations for the test case indi-
cate somewhat lower concentrations than for the
baseline case over the range of pH examined, even
though the test case as around 5 times as much total
As as the baseline case. These results also suggest
different chemistry controlling the aqueous-solid equi-
librium for the two cases.
Figure G-7:
• Se extract concentrations as a function of pH exhibit
similar behavior for the baseline and test cases, even
though the test case has greater than 50 times the
amount of total As than the baseline case.
Figure G-8:
• Initial leachate concentrations for Se are likely to be
ca. 1000-4000 |Jg/L (at LS=2), which is much greater
than reported in the EPA database but consistent with
values reported in the EPRI database for landfill
leachates.
Figures G-11and G-12:
• A much greater percentage and quantity of As can be
anticipated to be released from the baseline case than
for the test case under the scenarios examined.
Figure G13:
• Arsenic release from the base case warrants further
examination.
Figure G-14:
• Se release from the test case warrants further exami-
nation.
175
-------
Characterization of Coal Combustion Residues
Appendix H
St. Clair Fly Ashes
176
-------
Characterization of Coal Combustion Residues
List of Figures
Figure Page
H-l pH Titration Curves for the Baseline Fly Ash and the Fly Ash with Enhanced Hg Control 178
H-2 pH as a Function of LS Ratio for the Baseline Fly Ash and the Fly Ash with Enhanced Hg Control 178
H-3 Mercury Release (top) and Spike Recoveries (bottom) as a Function of pH for the Baseline Fly Ash and the
Fly Ash with Enhanced Hg Control 179
H-4 Mercury Release (top) and Spike Recoveries (bottom) as a Function of LS Ratio for the Baseline Fly Ash and
the Fly Ash with Enhanced Hg Control 180
H-5 Arsenic Release (top) and Spike Recoveries (bottom) as a Function of pH for the Baseline Fly Ash and the
Fly Ash with Enhanced Hg Control 181
H-6 Arsenic Release (top) and Spike Recoveries (bottom) as a Function of LS Ratio for the Baseline Fly Ash
and the Fly Ash with Enhanced Hg Control 182
H-7 Selenium Release (top) and Spike Recoveries (bottom) as a Function of pH for the Baseline Fly Ash and the
Fly Ash with Enhanced Hg Control 183
H-8 Selenium Release (top) and Spike Recoveries (bottom) as a Function of LS Ratio for the Baseline Fly Ash
and the Fly Ash with Enhanced Hg Control 184
H-9 Regression Curves of Experimental Data of Arsenic Solubility as a Function of pH 185
H-10 Regression Curves of Experimental Data of Selenium Solubility as a Function of pH 186
H-ll 100-Year Arsenic Release Estimates as a Function of the Cumulative Probability forthe Scenario of Disposal
in a Combustion Waste Landfill 187
H-12 100-Year Selenium Release Estimates as a Function of the Cumulative Probability for the Scenario of Disposal
in a Combustion Waste Landfill 187
H-13 100-Year Arsenic Release Estimates from A) Baseline Fly AshandB) Fly Ash withACI 188
H-14 100-year Selenium Release Estimates from A) Baseline Fly AshandB) Fly Ash withACI 189
177
-------
Characterization of Coal Combustion Residues
pH Titration Curves
Baseline Fly Ash
12.1
1 9
1 n -
8
A
9
• -PI
I I I I
s
hi
6
I I I I
£
I I I I
6
i i i i
i i i i
:
*n
D
i i i i
i i i i i i i i
-101234567
meq Acid/g dry
n SR2-JAB - A o SR2-JAB - B
Fly Ash with B-PAC
14
12.2
12
10
8
6
-101234567
meq Acid/g dry
D SR2-JAT- A o SR2-JAT - B
Figure H-1. pH Titration Curves for the Baseline Fly Ash and the Fly Ash with Enhanced Hg Control.
pH as a Function of LS Ratio
Baseline Fly Ash
Fly Ash with B-PAC
12
m
8
fi -
/\
9
1 5 i
:
-
:
-
-
E
]
it -
19
m
I 8
Q. °
4
9
1 8 i
1
-
-
-
-
a
E
]
0 24 6 8 10 12
LS ratio [mL/g]
0 24 6 8 10 12
LS ratio [mL/g]
pSRS-JAB-A 0SR3-JAB-B
OSR3-JAT-A <>SR3-JAT-B
Figure H-2. pH as a Function of LS Ratio for the Baseline Fly Ash and the Fly Ash with Enhanced Hg Control.
178
-------
Characterization of Coal Combustion Residues
Mercury
10 -
MCL
1 -
ra 0.1
o, 0.030
I
0.01 -
0.001 -
ML
_ Mm
Release as a Function of pH
Baseline Fly Ash Fly Ash with B-PAC
Hg total content*: 1 10.9+5.8 ng/g ^ n Hg total content*: 1 1 63.0+8.9 ng/g
U. LJ
,9
_ . __ .
06 *
^5o/
' 5% 95% '199
2 4 6 8 10 1212'214
PH
D SR2-JAT - A « SR2-JAT - B
*Total content as determined by digestion using method 3052.
1*50 'l^n
" 130
O>
o
m -inn
£ IUU
* 90
Q.
O)
x 7n
en
[
]
n
a a
an n n
r^' 130 -
t^ -ion
O)
5. -i-i n
0 MU
O
Emn
_ m
a ri on
D in «?n
O)
I 7D
, , , en
:
1° C
n
c
J D 1
ID
cd
4 6 8 10 12 14 2 4 6 8 10 12 14
pH pH
QSR2-JAB-A
QSR2-JAT-A
Figure H-3. Mercury Release (top) and Spike Recoveries (bottom) as a Function of pH for the Baseline Fly Ash and the Fly
Ash with Enhanced Hg Control. 5th and 95th percentiles of mercury concentrations observed in typical combustion waste
landfill leachate are shown for comparison.
179
-------
Characterization of Coal Combustion Residues
Mercury Release as a Function of LS Ratio
Baseline Fly Ash Fly Ash with B-PAC
01 n 1
0 08
— ' 0 06
O)
a) n 04
I U.U4
n no
(
ML
MDL
150
140
2^ ion
o>
> 11 n
o
E-inn
O>
Q.
w sn
0) °U ~
1 70
60
(
;
- D
0 r
3
_ _
-^-
. _ ^_
<
[
_ ^_
>
3
_ ^^
D 246 8 10 12
LS ratio [mL/g]
nSR3-JAB-A oSR3-JAB-B
i
;
;
I
I
~
: O [
:
~
:
D
r
]
I I I
D 2 4 6 8 10 12
LS ratio [mL/g]
DSR3-JAB-A
0 08
— "" n OR -
O)
c5 n n4
I U.U4
n OP
n '
D
771.....
^
_ _ —
. _ —
i
]
__^__
0 246 8 10 12
ML LS ratio [mL/g]
MDL
150
140
^ 130 -
^ 120 -
o>
o 110"
E 100 -
o>
^ 90 -
E 80
1 70
60 -
nSR3-JAT-A oSR3-JAT-B
|
;
;
I
i
~
: 0 I
1
1 II
D
n
i
:
0 2 4 6 8 10 12
LS ratio [mL/g]
DSR3-JAT- A
Figure H-4. Mercury Release (top) and Spike Recoveries (bottom) as a Function of LS Ratio for the Baseline Fly Ash and
the Fly Ash with Enhanced Hg Control.
180
-------
Characterization of Coal Combustion Residues
Arsenic Release as a Function of pH
Baseline Fly Ash
„-.„-. As total content*: 43.4+2.6 |jg/g
w
<
1000
100 -
/ICL-in _
1 -
0.92
0.1 -
0.01 -
o 001 -
*
=
i
i
1
=
= - -x&^c
z
=
=
-
5C
2 4
n n
/o 95%
6 8 10 1
9
12.1
2 1
95%
5%
4
10000
^ MCL-H
^)
Fly Ash with B-PAC
As total content*; 40.8+1 .1 |jg/g
000
100 -
I 10
0.54
0.1 -
3.01 -
!
1
=
r—ds^
=
i
5C
2 4
•— •— • —r *- *&m f *—
j Q i?Eiin QD
/o 95%
6 8 10 1
ti
>- -
21Z21
95%
o/u
4
ML
— - MUL
2 4 6 8 10 12 1'
nH
Pn
d SR2-JA B - A o SR2-JAB - B
1
ML
— - MUL
2 4 6 8 10 12 1
nH
Pn
QSR2-JAT-A <>SR2-JAT-B
*Total content as determined by digestion using method 3052.
"^ i9n
o>
> 11 n
0 MU
m mn
5 qn
'5.
to ftn
60
n
) n
i i i
D
n
" a n
Dl
:P
? 46 8 10 12 14
PH
D SR2-JAB - A
i4n
^! 190
a>
> 11 n
0 MU
" 100
'5.
CO on
60 -
f
-_ C
I II
U L
I I I
n
i i i
=m c
i i i
D
i i
_n
cP
I I I
> 46 8 10 12 14
PH
OSR2-JAT- A
Figure H-5. Arsenic Release (top) and Spike Recoveries (bottom) as a Function of pH for the Baseline Fly Ash and the Fly
Ash with Enhanced Hg Control. 5th and 95th percentiles of arsenic concentrations observed in typical combustion waste
landfill leachate are shown for comparison.
181
-------
Characterization of Coal Combustion Residues
Arsenic F
350 -
300
250
| 200-
7 150
<
1 nn
50
MCL n
Release as a Function of LS Ratio
Baseline Fly Ash Fly Ash with B-PAC
•3 en
: fi
;
i
;
;
1 i
a
0 2 4 6 8 10 1
LS ratio[ml_/g]
MDL
150
140
^ 130
>> -ion
0>
> 11 n
0
£ 100
0>
-* QO
•Q. yU
w 80 -
%
70 -
fin
c
300
250
51 200 -
0)
^.
,n 150
<
100
50 -
MCL
2
ML
— -MDL
p SR3-JAB - A o SR3-JAB - B
:
;
- D
|
;
:
i,,y,,,
0 2 4 6 8 10 12
LS ratio [mL/g]
0 SR3-JAT- A o SR3-JAT- B
i^n
: n I
i
n
r
]
140
^ 130
>> -ion
0)
> 11 n
0
£ 100
0)
-* QO
•Q. yU
w 80 -
w ou
"^ 70-
Rn
D [
1
D
:
124681012 024681
LS ratio [mL/g] LS ratio [mL/g]
QSR3-JAB- A
]
0 12
QSR3^JAT-A
Figure H-6. Arsenic Release (top) and Spike Recoveries (bottom) as a Function of LS Ratio for the Baseline Fly Ash and
the Fly Ash with Enhanced Hg Control.
182
-------
Characterization of Coal Combustion Residues
Seleniui
10000
1000
MCL 50.80
IT 10
— 1
O>
W 0.1
0.01
0.001
MI
MDL
*Total conten
150
140
^ 130
^ 120
0)
> 110
g> 100
5 90
! 8°
w 70
60
n Release as a Function
Baseline Fly Ash
Se total content*: 10.7+0.1 |jg/g
!
T-NfcC
I
1
5%
2 4
DOD {] D)ISI o
a
i
i
I
i
i
i
i
i
Of
95%
5%
95% 12.1
6 8 10 12 14
PH
Q SR2-JAB - A o SR2^JAB - B
t as determined by digestion using
: C
: 1
1 t
3
> 4
D
D
nDD
PH
10000 -
1000
M01 58.85
ZT 10
" 0.1
0.01 -
0.001
f\/|
— -MDL
Fly Ash with B-PAC
Se total content*: 12.6+0.9 ug/g
-: S R2- JAT - B
method 3052.
-icn
D[
6 8 10
PH
f
12 14
08^B-A
™
^_
> 1 m
o ' IU
o
5 90
'5_
«n
; c
: Cl
^
:,-p c
D
4 6 8 10 12 14
PH
0 SR2^JAT - A
Figure H-7. Selenium Release (top) and Spike Recoveries (bottom) as a Function of pH for the Baseline Fly Ash and the
Fly Ash with Enhanced Hg Control. 5th and 95th percentiles of selenium concentrations observed in typical combustion
waste landfill leachate are shown for comparison.
183
-------
Characterization of Coal Combustion Residues
Selenium Release as a Function of LS Ratio
Baseline Fly Ash Fly Ash with B-PAC
Rnn °nn
?nn
finn
1 — • 'inn
5 4nn
co 300
onn
mn
MCL
n
c
ML
— -MDL
1 ^n
140
^F -i-sn
?* i?n
O>
> nn
o
£ mn
O>
-* 90
Q.
w 80
0> OU
W 70 -
60
D
C
\
r
. ^^_,^, .
?nn
ROO
•~r 'inn
_l OUU
5 400 -
to 300
onn
mn
MCL
n
' &
I
[
n
6
, J_,^ .
2 4 6 8 10 12 0 2 4 6 8 10 12
LS ratio [mL/g] ML LS ratio [mL/g]
— -MDL
n SR3-JAB - A o SR3-JAB - B
n S R3- J AT - A o S R3- J AT - B
i en
1
1
: D
[
1
D
D
i
\
140
^p1 -ion
>< -ion
O)
> 1 m
o
P mn
O)
-^ Qn
Q.
w an
0. BU "
w 7n
«n
~
;
~
;
~
;
n [
I
]
D
D 2 4 6 8 10 12 0 2 4 6 8 10 12
LS ratio [mL/g] LS ratio [mL/g]
n SR3-JAB - A
n SR3-JAT - A
Figure H-8. Selenium Release (top) and Spike Recoveries (bottom) as a Function of LS Ratio for the Baseline Fly Ash and
the Fly Ash with Enhanced Hg Control.
184
-------
Characterization of Coal Combustion Residues
Arsenic Solubility
Baseline Fly Ash Fly Ash with B-PAC
mnnnn -innnnn
10000-
1000-
U 100-
1 10-
0.1 -
0.01 -
0 001
n
10000 -
1000-
95% :j 100-
1 10-
5% CO ,
^L I "
0.1 -
0.01 -
n nn-i
0 ,
[___^uim>j IMH^_/
k
95%
5%
0.001 -> , go/- i • i950/0 u.uu, , 50/, , , ,g5%
2 4 6 8 10 12 14 2 4 6 8 10 12 14
pH pH
n SR2-JAB - A
0 SR2-JAB-B
Fit n \r\&*
n SR2-JAT - A
0 SR2-JAT-B
Fit n \r\fp
Material log As (ug/L) pH range of R2 Number of
validity points
JAB 0.0010 pH5 -0.0324 PH4 0.4137 PH3 3-12.5 0.62 22
-2.4547 pH2 6.71 05 PH -6.6563
JAT 0.0025 pH5 -0.0973 pH4 1.4698 pH3 4-12.5 0.81 22
-1 0.6792 pH2 37.241 9 PH -50.3673
Figure H-9. Regression Curves of Experimental Data of Arsenic Solubility as a Function of pH.
185
-------
Characterization of Coal Combustion Residues
Selenium Solubility
Baseline Fly Ash
Fly Ash with B-PAC
IVJVJVJVJVJ -
10000 -
1000-
•-j 100 -
1 10-
o> ,,
w 1 -
0.1 -
0.01 -
n nn-i .
I
!
"^^CE^. n
liiy^*iJ3(>oc^--:
V
95%
5%
i \j\j\j\j\j -
10000 -
1000-
U 100-
1 10-
w 1 -
0.1 -
0.01 -
n nm -
•
;
^0*
w— — ^
>^&&tor
-------
Characterization of Coal Combustion Residues
100-Year Arsenic Release Estimates
Arsenic
10000 -B-
o5 1000
^ 100
CO
(U
10
0.1
1
n°D°i
a A
n AA
D A
• n . f . . . , .
D 5% 20 40 £
[
n -
n D A A
J4A*AA~
. A
)0%' ' 95°.
60 80
n
L
/O
1(
DO
Mt min
Mt - 5%
Mt - 50%
Mt - 95%
Mean Mt
Mt max
JAB
|jg/kg
0.01
0.05
8
110
25
836
%
0.00003
0.0001
0.02
0.3
0.1
1.9
JAT
|jg/kg
0.01
0.01
2
29
1
346
%
0.00001
0.00003
0.01
0.1
0.02
0.8
Percentile
D JAB
A JAT
Figure H-11.100-Year Arsenic Release Estimates as a Function of the Cumulative Probability for the Scenario of Disposal
in a Combustion Waste Landfill.
100-Year Selenium Release Estimates
Selenium
IUUUUU -
mono -
D)
_*:
"a) 1000 -
5 100 -
i_
CO
£ 10-
o
o
^~ 1 -
I
ft'8
a1
i
r
B*11
1H"
g
1
Wn ' ' c;O% ' ' 95% '
0 0/020 40bu/060 80 100
Mt min
Mt - 5%
Mt - 50%
Mt - 95%
Mean Mt
Mt max
J/
^g/kg
1.8
4.5
748
10028
2270
10700
\B
%
0.02
0.04
7.0
93.7
21.2
100.0
J/
|jg/kg
1.9
4.3
710
9602
2172
12600
\T
%
0.01
0.03
5.6
76.2
17.2
100.0
Percentile
D JAB
A JAT
Figure H-12. 100-Year Selenium Release Estimates as a Function of the Cumulative Probability for the Scenario of
Disposal in a Combustion Waste Landfill.
187
-------
Characterization of Coal Combustion Residues
100-Year Arsenic Release Estimates
JAB - Arsenic
100000 43400 ug/kg
o) "innnn
O)
=L
CO
co -innn
"35
o
co 1UU
CO
CO
0)
CD -in
0 1U "
1 -
A \
Tol
100%
1
al cont
110|jg/kg
0.3%
noug/kg
0.3%
18 ug/kg
0.04%
12 |jg/kg
0.03%
—
ent Combustion Default -pH 3 Default -pH Default-
Waste Landfill - 12.5 Natural pH
95% confidence 12. 1
MCLLS95% = 1000ug/kg
-MCLLS125 = 125ug/kg
JAT - Arsenic
100000 4080° Mg/kg
-i nnnn
D)
-3 -i nnn
-------
Characterization of Coal Combustion Residues
100-Year Selenium Release Estimates
JAB - Selenium
'D)
v> -i nnnn
ij 1 UUUU
0)
^=L
0)
(/)
S -i nnn
£
E
^
S 1 nn
0)
en
s_
TO
0)
=r 10
O
-1
A)
: 10700 ug/kg 10028 |jg/kg
100% 93.7% 607° u9/kg
56.7%
727 ug/kg 635 ug/kg
6.8% 5.9%
Total content Combustion Default-pH3 Default-pH Default-
Waste Landfill - 12.5 Natural pH
95% confidence 12.1
MCL. = 5000 ug/kg
MCLLS1 = 625 ug/kg
JAT- Selenium
100000
O)
10000
8> 1000
E
2
TO
0)
B)
100
S 10
o
I
: 12600 ug/kg 9602 ug/kg
100% 76.2% 3243 ug/kg
-
:
5§T^%
778 |jg/kg 736 |jg/kg
6 2% 5. 8%
Total content Combustion Default-pH 3 Default - pH
Waste Landfill - 12.5
95% confidence
Default-
Natural pH
12.2
MCL = 5000 ug/kg
MCLLS125 = 625
Figure H-14. 100-year Selenium Release Estimates from A) Baseline Fly Ash and B) Fly Ash with B-PAC. Release
estimates for percolation controlled scenario are compared to release estimate based on total content. The amount of the
selenium that would be released if the release concentration was at the MCL is also shown for comparison (LSdefaultscenario =
12.5 L/kg and LS95% = 100 L/kg).
189
-------
Characterization of Coal Combustion Residues
Comments
Figure H-3:
• All extract concentrations for Hg are well below lev-
els of potential concern.
• Scatter in the extract concentrations for the cased with
enhanced Hg control most likely results from the ma-
terial heterogeneity associated with addition of particu-
late activated carbon.
Figure H-5:
• All extract concentrations for As are well below levels
of potential concern.
Figure H-6:
• Initial As leachate concentrations from landfills are ex-
pected to be substantially greater (i.e., equal to 50 |Jg/
L at LS=2) than indicated by SR002 (LS=10) because
of other ionic species at higher concentrations present
at low LS ratio typical of landfill scenarios. These an-
ticipated concentrations are consistent with landfill
leachate concentrations reported in the EPRI database.
Figure H-7:
• Extract concentrations of selenium are greater than
the MCL but within the range reported in the EPA and
EPRI databases.
Figure H-8:
• Initial Se leachate concentrations from landfills are ex-
pected to be substantially greater (i.e., more than 200-
300 :g/L at LS=2) than indicated by SR002 (LS=10)
because of other ionic species at higher concentra-
tions present at low LS ratio typical of landfill sce-
narios. These anticipated concentrations are consis-
tent with landfill leachate concentrations reported in
the EPRI database.
Figures H-11 andH-12:
• A much greater percentage and quantity of As can be
anticipated to be released from the baseline case than
for the test case under the scenarios examined.
Figure H-13:
• For the three default scenarios considered and the 95 %
probability scenario, arsenic release would most likely
be less than the amount that would be released if the
release concentration was at the MCL.
Figure H-14:
• For the 95 % probability scenario, selenium release from
baseline and test cases would be greater than the
amount that would be released if the release concen-
tration was at the MCL.
• For the default scenario corresponding to disposal in a
monofill (leachate pH controlled by the material being
disposed) and the default scenario corresponding to
the "extreme" pH of 12.5, no significant difference in
selenium release between the baseline and test cases
would be expected.
• For the default scenario corresponding to the "extreme"
pH of 3, selenium release is expected to be greater for
the baseline case than the test case. In both cases,
selenium release would be at or greater than the amount
that would be released if the release concentration was
at the MCL.
• Se release from the baseline and test cases warrants
further examination.
190
-------
Characterization of Coal Combustion Residues
Appendix I
Facility L Fly Ashes
191
-------
Characterization of Coal Combustion Residues
List of Figures
Figure Page
I-l pH Titration Curves for the Baseline Fly Ash and the Fly Ash with Enhanced Hg Control 193
1-2 pH as a Function of LS Ratio for the Baseline Fly Ash and the Fly Ash with Enhanced Hg Control 193
1-3 Mercury Release (top) and Spike Recoveries (bottom) as a Function of pH for the Baseline Fly Ash and the
Fly Ash with Enhanced Hg Control 194
14 Mercury Release (top) and Spike Recoveries (bottom) as a Function of LS Ratio for the Baseline Fly Ash and
the Fly Ash with Enhanced Hg Control 195
1-5 Arsenic Release (top) and Spike Recoveries (bottom) as a Function of pH for the Baseline Fly Ash and the
Fly Ash with Enhanced Hg Control 1%
1-6 Arsenic Release (top) and Spike Recoveries (bottom) as a Function of LS Ratio forthe Baseline Fly Ash
and the Fly Ash with Enhanced Hg Control 197
1-7 Selenium Release (top) and Spike Recoveries (bottom) as a Function of pH for the Baseline Fly Ash and the
Fly Ash with Enhanced Hg Control 198
1-8 Selenium Release (top) and Spike Recoveries (bottom) as a Function of LS Ratio for the Baseline Fly Ash
and the Fly Ash with Enhanced Hg Control 199
1-9 Regression Curves of Experimental Data of Arsenic Solubility as a Function of pH 200
1-10 Regression Curves of Experimental Data of Selenium Solubility as a Function of pH 201
1-11 100-Year Arsenic Release Estimates as a Function of the Cumulative Probability forthe Scenario of Disposal
in a Combustion Waste Landfill 202
1-12 100-Year Selenium Release Estimates as a Function of the Cumulative Probability for the Scenario of Disposal
in a Combustion Waste Landfill 202
1-13 100-Year Arsenic Release Estimates from A) Baseline Fly AshandB) Fly Ash withACI 203
1-14 100-year Selenium Release Estimates from A) Baseline Fly AshandB) Fly Ash withACI 204
192
-------
Characterization of Coal Combustion Residues
pH Titration Curves
Baseline Fly Ash
14
19
m
-i- 8
i °
Q.
6
5.8
4
o
-0
-
_
^
o
D
*
L
;
\
f
1 1 i i
.5 -0.25 0 0.25 0
meq Acid/g dry
Fly Ash with Enhanced Hg Control
14
19
m
Q.
6
5.0-
4 _
o
5 -0
n SR2-LAB - A o SR2-LAB - B
-
-
:
-
-
-
_
n
*
fi
c
<
?
£"
|Q0
.5 -0.25 0 0.25 0
meq Acid/g dry
5
nSR2-LAT-A oSR2-LAT-B
Figure 1-1. pH Titration Curves for the Baseline Fly Ash and the Fly Ash with Enhanced Hg Control.
pH as a Function of LS Ratio
Baseline Fly Ash
19
m -
in o
Q. °
6
4
o
- D (
J
9
<
i
>
i
0 2 4 6 8 10 12
LS ratio [mL/g]
n SR3-LAB - A o SR3-LAB - B
Fly Ash with Enhanced Hg Control
14
12
10
0 2 4 6 8 10 12
LS ratio [mL/g]
n SR3-LAT - A o SR3-LAT - B
Figure I-2. pH as a Function of LS Ratio for the Baseline Fly Ash and the Fly Ash with Enhanced Hg Control.
193
-------
Characterization of Coal Combustion Residues
Mercury
10
MCL
1
IT
0> 0.1 -
D)
I 0.010
0.01
0.001
ML
— -MDL
Release as a Function of pH
Baseline Fly Ash Fly Ash with Enhanced Hg Control
Hg total content*: 1 3+0.2 ng/g dn Hg total content*: 37.7+1 .3 ng/g
|
-
D
- D C
n
D D '
^^ • ^^m m 1
,? V V V '
D
O
D n
<«> V w
MCL
1
D) 0.1
c>F>% .^
D)
n n-i
> 0.009
i i . n nn-i
5-°5% 35%
2 4 68 10 12 14
PH
ML
— -MDL
n SR2-LAB - A o SR2-LAB - B
; D
13 0 P
• - - - -i
^^H • ^^^ '•
' i? V ^JW
D
D
1 Qn
95%
i
~~ RO/_
C> O O ^> < ^ *" ' "
r, , ,
2 4 ' 6 ° 8 10 12 °14
PH
n SR2-LAT - A o SR2-LAT - B
*Total content as determined by digestion using method 3052.
-i en -I en
-i/in
"ZT ion
^ \AJ
110
0 MU
o
m mo
sj iuu
$ qn
'o_
(/) Qf)
O)
X yn
fin
^
n n
: n
DD
n
D _ °
n
n
„
"
^ 120 -
5 -i -in
0 ' IU
V 100
r - 90
'Q-
M RO
D)
I 70
i en
; nn r
3D
n D
n
D
D
D
> 4 6 8 10 12 14 2 4 6 8 10 12 14
pH pH
n SR2-LAB - A
n SR2-LAT - A
Figure I-3. Mercury Release (top) and Spike Recoveries (bottom) as a Function of pH for the Baseline Fly Ash and the Fly
Ash with Enhanced Hg Control. 5th and 95th percentiles of mercury concentrations observed in typical combustion waste
landfill leachate are shown for comparison.
194
-------
Characterization of Coal Combustion Residues
Mercury Release as a Function of LS Ratio
Baseline Fly Ash
n ns
u n OR
D)
I 0.04 -
n n?
n
- n
o
<
'
D
A
[
<
D
>
0 2 4 6 8 10 12
Ml
— -MDL
-icn
140
0s* ' *-'**
>< -ion
O>
> 110-
o
£ mn
O)
-^ Qn
._ 90
w 80 -
£ 70
en
(
LS ratio [mL/g]
n SR3-LAB - A o SR3-LAB - B
~
:
:
~
:
I
: [
n
;
;
i
D
[
D 2 4 6 8 10 12
LS ratio [mL/g]
n SR3-LAB - A
Fly Ash with Enhanced Hg Control
D)
0.1
0.08
0.06
£ 0.04
0.02
0
ML
— -MDL
~° I
0 24 6 8 10 12
LS ratio [mL/g]
n SR3-LAT - A o SR3-LAT - B
150
140
o>
o
o
e
O>
120
110
100
90
80
60
468
LS ratio [mL/g]
nSRS-LAT-A
10 12
Figure 1-4. Mercury Release (top) and Spike Recoveries (bottom) as a Function of LS Ratio for the Baseline Fly Ash and
the Fly Ash with Enhanced Hg Control.
195
-------
Characterization of Coal Combustion Residues
Arsenic Release as a Function of pH
Baseline Fly Ash Fly Ash with Enhanced Hg Control
.mr,™ As total content*: 20+1 . 1 |jg/g 110
0
» 100 -
$ gn
'5.
CO
< 70
fin
/
|
n n D n
P LJ 1-1 |JLJ Q
a n
D
140
" 190
(D
~> 110
6 ' IU
m 1QO
*• 90
'5.
w
<£ 70
, , , en
~
|
|
~
:
3 n
I
I
|
a c
I 4 6 8 10 12 14 24
PH
n SR2-LAB - A
n°
D
D
D
a
6 8 10 12 14
PH
n SR2-LAT - A
Figure I-5. Arsenic Release (top) and Spike Recoveries (bottom) as a Function of pH for the Baseline Fly Ash and the Fly
Ash with Enhanced Hg Control. 5th and 95th percentiles of arsenic concentrations observed in typical combustion waste
landfill leachate are shown for comparison.
196
-------
Characterization of Coal Combustion Residues
Arsenic Release as a Function of LS Ratio
Baseline Fly Ash
50
Fly Ash with Enhanced Hg Control
40
O)
MCL 10
1
50
40
O)
MCL 10
fi
0 2 4 6 8 10 12
LS ratio [mL/g]
MDL
0 2 4 6 8 10 12
• - - ML LS ratio [mL/g]
-MDL
1cn
140 -
>< -ion
o>
o
£ 100
o>
£
70
fin
n SR3-LAB - A o SR3-LAB - B
nSRS-LAT-A oSR3-LAT-B
•icn
;
:
I
: n C
:
;
1
D
140 -
•xO -I ^O
>< -ion
o>
> no
o
£ 100
o>
w 80
w ou
70
fin
:
;
I
;
- U C
:
;
;
1
n
[
1
2 4 6 8 10 12
LS ratio [mL/g]
4 6 8 10 12
LS ratio [mL/g]
n SR3-LAB - A
nSR3-LAT- A
Figure 1-6. Arsenic Release (top) and Spike Recoveries (bottom) as a Function of LS Ratio for the Baseline Fly Ash and
the Fly Ash with Enhanced Hg Control.
197
-------
Characterization of Coal Combustion Residues
Selenium Release as a Function of pH
Baseline Fly Ash
Se total content*: 4.1+0.1 |jg/g
Fly Ash with Enhanced Hg Control
Se total content*: 4.3+0.2 |jg/g
110 -
0
o
nn
0 MU
o
-------
Characterization of Coal Combustion Residues
Selenium Release as a Function of LS Ratio
Baseline Fly Ash
Fly Ash with Enhanced Hg Control
O)
^.
o> 20
m
:
1
- ft
- (
-
J
J
O)
^.
o> 20
m
r
?
]
>
9
(
>
0 2 4 6 8 10 12
ML LS ratio [mL/g]
— -MDL
0 2 4 6 8 10 12
ML LS ratio [mL/g]
MDL
n SR3-LAB - A o SR3-LAB - B
n SR3-LAT - A o SR3-LAT - B
1 ^n •< cr>
140
^F 1^0
>< -ion
O)
> 1 in
o
E 100
o>
-^ QO
Q.
W 70 -
60
(
I
I
I
;
:
; n [
~
~
~
i
D
[
]
1 AD
^p1 -ion
>< -ion
o>
5 1 1 n
o
Emn
o>
.*: on
w 80
a. °u "
w 7n
cn
-
-
: n E
|
i
u
[
]
D 2 4 6 8 10 12 0 2 4 6 8 10 12
LS ratio [mL/g] LS ratio [mL/g]
n SR3-LAB - A
nSR3-LAT-A
Figure I-8. Selenium Release (top) and Spike Recoveries (bottom) as a Function of LS Ratio for the Baseline Fly Ash and
the Fly Ash with Enhanced Hg Control.
199
-------
Characterization of Coal Combustion Residues
Arsenic Solubility
Baseline Fly Ash Fly Ash with Enhanced Hg Control
100000 -innnnn
10000-
1000-
U 100-
1 10-
< 1 -
0.1 -
0.01 -
Onni
I
^~QO
cKrO-0 — ^
..°S^_
o
X
10000 -
1000-
95% ^ 100 -
1 10-
5% w ,
< I -
0.1 -
0.01 -
n nn-i
|
i
|T3 <> ^
\ Vr^
!
rJ*^**^
y
D
S
95%
5%
2 4 6 8 10 12 14 2 4 6 8 10 12 °14
pH pH
n SR2-LAB - A
o SR2-LAB - B
Fit curve
n SR2-LAT - A
0 SR2-LAT - B
Fit n ir\jp
Material log As (ug/L) pH range of R2 Number of
validity points
LAB 0.0004 pH5 -0.0120 PH4 0.0966 PH3 3-12.5 0.92 22
0.0151 pH2 -2.4406 PH 7.2162
LAT 0.0000 pH5 0.0040 pH4 -0.1157 pH3 3-12.5 0.92 22
1.2681 pH2 -5.5708 PH 9.6784
Figure I-9. Regression Curves of Experimental Data of Arsenic Solubility as a Function of pH.
200
-------
Characterization of Coal Combustion Residues
Selenium Solubility
Baseline Fly Ash Fly Ash with Enhanced Hg Control
lOnnnn -mnnnn
10000 -
1000-
U 100-
1 10-
<° -.
w 1 -
0.1 -
0.01 -
Onm
!
|
>°^^w~-*
10000 -
1000-
95% ^ 100 -
D)
a= 10-
5% 5 1 -
0.1 -
0.01 -
n nm .
"^H
^^-^o—^
/
/
5%
2 4 °6 8 10 12 °14 2 4 °6 8 10 12 14
pH pH
n SR2-LAB - A
0 SR2-LAB-B
Fit curvs
n SR2-LAT - A
0 SR2-LAT - B
Fit r*i ir\*p
Material log Se (ug/L) pH range of R2 Number of
validity points
LAB 0.0007 pH5 -0.0239 pH4 0.3133 pH3 3-12.5 0.94 22
-1.8284pH2 4.4667 PH -1.9621
LAT 0.0007 pH5 -0.0230 PH4 0.2978 PH3 3-12.5 0.81 22
-1.7038pH2 4.0275 PH -1.4335
Figure 1-10. Regression Curves of Experimental Data of Selenium Solubility as a Function of pH.
201
-------
Characterization of Coal Combustion Residues
100-Year Arsenic Release Estimates
IUUUUU -
10000 -
0)
"5) moo -
IE 100 -
CD
* 10-
6 1°
o
^~ 1 .
i
***
B***
\
BBBH
H"*"*
1
O/i | • • • | • • • | • • • i • • • i • • • i
5% 50% 95%
0 20 40 60 80 100
Percentile
Mt min
Mt - 5%
Mt - 50%
Mt - 95%
Mean Mt
Mt max
LAB
|jg/kg
0.83
13.36
2049
20000
10541
20000
%
0.00413
0.0668
10.25
100.0
52.7
100.0
LAT
|jg/kg
1.50
17.38
2471
18700
10090
18700
%
0.00800
0.09296
13.22
100.0
53.96
100.0
nLAB
A LAT
Figure 1-11.100-Year Arsenic Release Estimates as a Function of the Cumulative Probability for the Scenario of Disposal
in a Combustion Waste Landfill.
100-Year Selenium Release Estimates
Selenium
IUUUUU -
10000 -
D)
"3) moo -
S mn -
&_
CD
* 10-
o
o
^~ -1 .
OH
.1 H
(
|
!
:
|
D
D
n ^
i*
11
i
5%20 405C
B1
I-""""1
)% ' ' 95°/
1/0 60 80
\
\(
DO
Mt min
Mt - 5%
Mt - 50%
Mt - 95%
Mean Mt
Mt max
\J
|jg/kg
0.3
1.0
143
2113
484
4100
\B
%
0.01
0.02
3.5
51.5
11.8
100.0
\J
|jg/kg
0.3
1.0
141
2041
466
4300
M
%
0.007
0.02
3.3
47.5
10.8
100.0
Percentile
nLAB
A LAT
Figure 1-12.100-Year Selenium Release Estimates as a Function of the Cumulative Probability for the Scenario of Disposal
in a Combustion Waste Landfill.
202
-------
Characterization of Coal Combustion Residues
100-Year Arsenic Release Estimates
LAB - Arsenic
100000
O)
^
"DJ
O
'c
0)
£
TO
L_
CO
0)
>,
CD
O
10000
1000
100
10
! 20000 |jg/kg 20000 |jg/kg 20000 |jg/kg
: 100% 100% 100%
\
729.3 |jg/kg
3.7%
324.3_yg/kg_
1.6%
-MCLLS95% = 1000ug/kg
MCLLS125 = 125ug/kg
A)
Total content Combustion Default-pH 3 Default-pH
Waste Landfill - 12.5
95% confidence
Default-
Natural pH
5.8
LAT - Arsenic
O)
v -I nnnn
D)
^_
0)
CO
m mnn
0>
O
Si: 1UU -
CO
CO
0)
S -in
1
D \
M87
:
oo |jg/kg 18700 |jg/kg 18700 |jg/kg
100% 100% 100%
468 ug/kg
2.5%
1.7%
Total content Combustion Default -pH 3 Default -pH Default-
Waste Landfill - 12.5 Natural pH
95% confidence 5 Q
Figure 1-13.100-Year Arsenic Release Estimates from A) Baseline Fly Ash and B) Fly Ash with Enhanced Hg Control.
Release estimates for percolation controlled scenario are compared to release estimate based on total content. The
amount of the arsenic that would be released if the release concentration was at the MCL is also shown for comparison
(LSdefaultscenario= 12.5 L/kg and LS95%= 100 L/kg).
203
-------
Characterization of Coal Combustion Residues
100-Year Selenium Release Estimates
LAB - Selenium
10000
1000
4100 ug/kg
CO
Q)
0)
I 100
en
CO
>,
6
o
10
-
100%
0-1
1° R ii'
51. 5°/
i/kn
3 58
7.9 ug
14.3%
'kg 98
9.7 ug/
24.1%
kg
10
3.6 ug/
2.5%
kg
MCLLS125 = 625 ug/kg
A)
Total content Combustion Default -pH 3 Default -pH Default- Natural
Waste Landfill - 12.5 pH
95% confidence 5.8
CO
6
o
LAT- Selenium
10000
D)
j± 1000
0)
CO
E 100
4300 ug/kg
100%
B)
10
22%
559.4 ug/kg
_
_
MCLLS95% = 5000 ug/kg
MCLLS1 = 625 ug/kg
73.1 |jg/kg
1.7%
Total content Combustion Default-pH 3
Waste Landfill -
95% confidence
Default-pH Default-Natural
12.5 pH
5.0
Figure 1-14.100-year Selenium Release Estimates from A) Baseline Fly Ash and B) Fly Ash with Enhanced Hg Control.
Release estimates for percolation controlled scenario are compared to release estimate based on total content. The
amount of the selenium that would be released if the release concentration was at the MCL is also shown for comparison
(LSdefaultscenario= 12.5 L/kg and LS95%= 100 L/kg).
204
-------
Characterization of Coal Combustion Residues
Comments
Figure 1-3:
• Fly ash from the test case had greater total Hg content
than the fly ash from the baseline case (by about 3
times).
• Hg release is low (but poor replication) for both baseline
and test cases.
Figure 1-5:
• The fly ash from the test case had lower total As con-
tent than that from the baseline case (by about 4.5
times).
• Arsenic release was close to or exceeded the MCL
(10 |Jg/L) for both the baseline and the test cases for
all pH conditions.
Figure 1-7:
• Fly ash from the test case had greater total Se content
than the fly ash from the baseline case (by about 4.5
times).
• Selenium release from both the baseline and the test
cases was close to the MCL (50 |Jg/L) for most pH
conditions.
Figures 1-11 and 1-12:
• The fly ash from the test case would result in similar
As release than expected from the baseline case, with
a 95% probability to be less than 18700 and 20000 ug/
kg, respectively.
• The fly ash from the test case would result in similar
Se release than expected from the baseline case, with
a 95% probability to be less than 2115 and 2045 |Jg/kg,
respectively.
Figure 1-13:
• For the 95% probability scenario, arsenic release from
both cases would exceed the amount that would be
released if the release concentration was at the MCL.
• For two of the three default scenarios considered (i.e.,
pH 3 and natural pH), arsenic release would most likely
be less than the amount that would be released if the
release concentration was at the MCL. However, for
the default scenario at pH 12.5, arsenic release would
most likely exceed the amount that would be released
if the release concentration was at the MCL.
Figure 1-14:
• Similar Se release would be expected for the test case
compared to the baseline case for all scenarios exam-
ined.
• For the 95 % probability scenario, selenium release from
both cases would be less than the amount that would
be released if the release concentration was at the MCL
and the LS ratio was the resultant LS ratio for the 95%
case (i.e., around 100 L/kg). However, selenium re-
lease would be greater than the amount that would be
released if the release concentration was at the MCL
and the LS ratio was the LS ratio of the default sce-
nario considered (i.e., 12.5 L/kg).
205
-------