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LEACHING BEHAVIOR OF PERSONAL COMPUTER CENTRAL PROCESSING
UNITS (CPUs) USING STANDARDIZED AND MODIFIED TOXICITY CHARACTERISTIC LEACHING PROCEDURE (TCLP) TESTS
By
KEVIN N. VANN
A THESIS PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT
OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF ENGINEERING
UNIVERSITY OF FLORIDA
2003
Copyright 2003
by
Kevin N. Vann
iii
ACKNOWLEDGMENTS
I would like to thank Dr. Timothy Townsend for giving me the opportunity to work
on this research and pursue my graduate education. I thank all of the graduate students in
the Solid and Hazardous Waste Management research group who provided technical
assistance and advice throughout this research, specifically Jenna Jambeck, Belinda
Grothpietz, Dr. Yong-Chul Jang, Brajesh Dubey, Pradeep Jain, Lakmini Wadanambi,
Thabet Tolaymat, and Sarvesh Mutha.
This research was sponsored by Regions 4 and 5 of the US Environmental
Protection Agency (USEPA). Special thanks are extended to Pamela Swingle of the
USEPA Region 4 and Ray Moreau of the Southern Waste Information eXchange
(SWIX). Special thanks are also extended to Kurt Seaburg of Alachua County
Household Hazardous Waste Center, Secure Environmental Electronic Recycling
(SEER), and James Wood of RecycledPCParts.com, Inc. for providing computer CPUs;
and the folks at Concurrent Technologies Corporation for shredding the CPUs that were
tested during the research.
iv
TABLE OF CONTENTS Page ACKNOWLEDGMENTS ................................................................................................. iii
LIST OF TABLES............................................................................................................. vi
LIST OF FIGURES ......................................................................................................... viii
ABSTRACT....................................................................................................................... ix
CHAPTER
1 INTRODUCTION ........................................................................................................1
1.1 Problem Statement .............................................................................................1 1.2 Objectives ..........................................................................................................2 1.3 Research Approach ............................................................................................3 1.4 Thesis Organization ...........................................................................................3
2 FACTORS AFFECTING TOXICITY CHARACTERISTIC LEACHING
PROCEDURE (TCLP) LEAD LEACHABILITY FROM COMPUTER CPUs..........5
2.1 Introduction........................................................................................................5 2.2 Materials and Methods.......................................................................................7
2.2.1 Sample Collection and Processing.........................................................7 2.2.2 Leaching and Analysis Methods............................................................8 2.2.3 TCLP on Printed Wiring Boards..........................................................10 2.2.4 TCLP on Synthetic Computer CPU Mix .............................................11 2.2.5 Component Impact...............................................................................11 2.2.6 Impact of Head Space ..........................................................................12
2.3 Results and Discussion ....................................................................................13 2.3.1 Lead Leachability from PWBs.............................................................13 2.3.2 Predicting the TC of an Electronic Device ..........................................15 2.3.3 Synthetic Computer CPU Mix.............................................................16 2.3.4 Component Impact...............................................................................18 2.3.5 Impact of Head Space ..........................................................................20 2.3.6 Comparison of Filtered vs. Nonfiltered Samples.................................21
2.4 Discussion........................................................................................................23 2.5 Implications......................................................................................................27
v
3 EVALUATION OF A LARGE-SCALE MODIFIED TCLP FOR RESOURCE CONSERVATION AND RECOVERY ACT (RCRA) TOXICITY CHARACTERIZATION OF COMPUTER CPUs.....................................................29
3.1 Introduction.....................................................................................................29 3.2 Materials and Methods.....................................................................................31
3.2.1 Research Approach ..............................................................................31 3.2.2 Sample Collection and Processing.......................................................32 3.2.3 Modified Leaching Procedure..............................................................32 3.2.4 Impact of Extractor Speed ...................................................................34 3.2.5 Time Studies ........................................................................................35 3.2.6 Methodology Comparison ...................................................................35
3.3 Results..............................................................................................................37 3.3.1 Impact of Extractor Speed ...................................................................37 3.3.2 Time Studies ........................................................................................38 3.3.3 Methodology Comparison ...................................................................43
3.4 Implications......................................................................................................49 4 SUMMARY, CONCLUSIONS, AND RECOMMENDATIONS .............................52
4.1 Summary ..........................................................................................................52 4.2 Conclusions......................................................................................................54 4.3 Recommendations............................................................................................54
APPENDIX A LABORATORY DATA.............................................................................................56
B QA/QC DATA............................................................................................................77
C METHODOLOGY COMPARISON SAMPLE SEQUENCE ...................................96
D CHEMISTRY .............................................................................................................98
LIST OF REFERENCES...................................................................................................99
BIOGRAPHICAL SKETCH ...........................................................................................102
vi
LIST OF TABLES
Table page 2-1 CPU Material Impact Samples............................................................................11
2-2 Ferrous Metal Impact Sample Compositions......................................................12
2-3 Impact of Vessel Headspace Sample Composition ............................................13
2-4 Average TCLP Leachate Concentrations from PWBs........................................15
2-5 TCLP Results of Synthetic Computer CPU Mixture..........................................17
2-6 Component Impact TCLP Results ......................................................................19
2-7 Impact of Head Space Results ............................................................................20
2-8 Analysis of Fe2+ as Percentage of Total Iron ......................................................22
3-1 Testing Methodologies........................................................................................36
3-2 Methodology Comparison Results......................................................................44
A-1 TCLP Concentrations in Filtered Samples .........................................................56
A-2 Time Study Concentrations in Filtered Samples ................................................58
A-3 Methodology Comparison Concentrations in Filtered Samples .........................59
A-4 TCLP Concentrations in Nonfiltered Samples ...................................................62
A-5 Methodology Comparison Concentrations in Nonfiltered Samples ...................64
A-6 Time Study Concentrations in Nonfiltered Samples ..........................................66
A-7 TCLP pH, DO, and ORP Measurements ............................................................67
A-8 Time Study pH, DO, and ORP Measurements ...................................................69
A-9 Methodology Comparison pH, DO, and ORP Measurements............................70
A-10 TCLP Ferrous Iron (Fe2+) ...................................................................................73
vii
A-11 Methodology Comparison Ferrous Iron (Fe2+) in Filtered Samples...................75
A-12 Methodology Comparison Ferrous Iron (Fe2+) in Nonfiltered Samples.............76
B-1 Laboratory Blanks...............................................................................................77
B-2 Lead Matrix Spike Recovery ..............................................................................79
B-3 Iron Matrix Spike Recovery................................................................................82
B-4 Copper Matrix Spike Recovery ..........................................................................84
B-5 Zinc Matrix Spike Recovery...............................................................................86
B-6 Lead Concentrations of TCLP Sample Replicates..............................................88
B-7 Lead Concentrations of Modified Large-Scale TCLP Methodology Comparison Sample Replicates...............................................................................................89
B-8 Iron Concentrations of TCLP Sample Replicates...............................................90
B-9 Iron Concentrations of Modified Large-Scale TCLP Methodology Comparison Sample Replicates...............................................................................................91
B-10 Copper Concentrations of TCLP Sample Replicates..........................................92
B-11 Copper Concentrations of Modified Large-Scale TCLP Methodology Comparison Sample Replicates ..........................................................................93
B-12 Zinc Concentrations of TCLP Sample Replicates ..............................................94
B-13 Zinc Concentrations of Modified Large-Scale TCLP Methodology Comparison Sample Replicates...............................................................................................95
C-1 TCLP Methodology Comparison Sampling Sequence .......................................96
viii
LIST OF FIGURES
Figure page 2-1 Average CPU Composition of 29 Computer CPUs by Weight ............................8
2-2 Effects of Component Mixture on Lead Leachability ........................................17
2-3 Dissolved Oxygen and ORP Results from Head Space Impact Study ...............21
2-4 Lead Results from Head Space Impact Study.....................................................22
3-1 Impact of Rotation Speed Results.......................................................................38
3-2 Comparison of Metals Results from TCLP Time Study Experiments. ..............40
3-3 Sample 2 Filtered vs. Nonfiltered Metals Concentrations. .................................42
3-4 Metal Concentrations from Methodology Comparison for CPU #1...................45
3-5 Laboratory Measurements from Methodology Comparison for CPU #1.. .........46
ix
Abstract of Thesis Presented to the Graduate School
of the University of Florida in Partial Fulfillment of the Requirements for the Master of Engineering
LEACHING BEHAVIOR OF PERSONAL COMPUTER CENTRAL PROCESSING UNITS (CPUs) USING STANDARDIZED AND MODIFIED TOXICITY
CHARACTERISTIC LEACHING PROCEDURE (TCLP) TESTS
By
Kevin N. Vann
December 2003
Chair: Timothy G. Townsend Major Department: Environmental Engineering Sciences
Research was conducted to address environmental and regulatory issues related to
the management of discarded electronic equipment, a topic of major discussion in the
solid waste industry today. One objective of the research was to investigate the factors
that impact lead leachability from CPUs during the TCLP. A second objective was to
develop and assess the applicability of an alternative methodology for performing the
TCLP on computer CPUs.
In one study, several CPUs were sampled, size-reduced, and mixed to create a
composite CPU mixture. Several different TCLP tests were performed on the mixture,
all within the constraints of the US Environmental Protection Agency (USEPA) method,
but slightly varied to assess the impact of different leaching conditions (e.g., particle size,
head space). Results indicated that particle size did not impact lead leachability from the
composite CPU mixture tested in this study. The head space above the leaching solution,
however, did impact lead leachability. Results indicated that a large head space increased
x
the lead concentrations that were measured in the TCLP leachate. The impact of
computer CPU composition on lead leachability during the TCLP was examined by
leaching different combinations of CPU components (e.g., PWB, metal, plastic,
cable/wire). The results indicated that metallic iron decreased the dissolved oxygen (DO)
and oxidation-reduction potential (ORP) of the TCLP leaching solution; and therefore
decreased the lead concentrations measured in the leachate. It appeared that metallic iron
and zinc also reduced the lead that was leached during the TCLP, which also resulted in
low concentrations of lead being measured in the leachate.
A second study evaluated a large-scale modified TCLP methodology for
performing the TCLP on CPUs. The large-scale modified TCLP involved using a drum
rotator and a 55-gallon drum to perform a TCLP, which enabled an entire CPU to be
tested. The CPUs were disassembled and leached while maintaining as many of the
requirements of the methodology as possible. Identical CPU models were also tested
using the standard TCLP methodology to assess the applicability of the large-scale
modified TCLP. Results of this study indicated that lead leachability from CPUs was
greater when using the large-scale modified TCLP method than when using the standard
TCLP method. The leachate of the TCLP appeared to have lower DO and ORP than the
large-scale modified TCLP. As a result, higher lead concentrations were measured in the
samples that were tested using the large-scale modified TCLP than those that were tested
using the standard TCLP. The size reduction requirement of the TCLP may have been the
cause for the higher lead concentrations being measured in the samples that were tested
using the large-scale modified TCLP.
1
CHAPTER 1 INTRODUCTION
1.1 Problem Statement
The rapid progress in technological development in recent years has resulted in
electronic devices continuously being updated and replaced by newer, faster, cheaper,
and more efficient models. This results in obsolete devices being discarded at an
increasing rate. According to the US Environmental Protection Agency (USEPA),
approximately 1.9 million tons of consumer electronics (video, audio, and information
products) were discarded in 2000 (USEPA, 2002a). This growing waste stream has
raised concerns within the solid waste industry with respect to the proper regulation and
management of discarded electronic devices (BAN, 2002; USEPA, 2002a; SVTC et al.
2001, SVTC, 2002). Discarded electronic devices such as televisions, computers and
computer peripherals, VCRs, cellular phones and a variety of other electronic devices and
accessories are often referred to as E-waste. Increasingly, US landfills are the last stop
for electronic waste. According to the USEPA (2002a), approximately 1.2% of the US
municipal solid waste stream is composed of discarded consumer electronics.
Several reports document that electronic equipment contains many toxic chemicals
including heavy metals, brominated flame-retardants (BFRs), and polychlorinated
biphenyls (PCBs) (BAN, 2002; BSEF, 2000; FWI, 2001; MCC, 1996; NCM, 1995,
SVTC, 2002). It has been estimated that approximately 70% of all heavy metals found in
landfills come from electronic equipment wastes (GFF, 2001). Printed wiring boards
(PWBs), cathode ray tubes (CRTs), plastic and metal housings, batteries, and flat panel
2
displays can contain a variety of heavy metals such as arsenic, barium, cadmium,
chromium, copper, lead, mercury, zinc, and other rare earth metals. Several of these
heavy metals may potentially cause an electronic device to be classified as a hazardous
waste.
Hazardous wastes are managed under the Resource Conservation and Recovery
Act (RCRA) Subtitle C regulations. One way a solid waste can be classified as a
hazardous waste is if it exhibits the toxicity characteristic (TC) using the Toxicity
Characteristic Leaching Procedure (TCLP). The TCLP is the standard test required by
the USEPA to determine if a solid waste is an RCRA TC hazardous waste (USEPA,
1999). If a solid waste is found to exhibit the TC, it must be managed under RCRA
Subtitle C hazardous waste regulations (unless otherwise excluded). Previous studies
have found that PWBs usually exceed the 5mg/L TC limit for lead (Environment
Australia, 1999; Yang, 1993). However, relatively little information is available on
whether complete electronic devices (of which PWBs are only a fraction) are RCRA TC
hazardous wastes.
1.2 Objectives
One objective of the research reported here was to investigate the factors that
impact lead leachability from computer central processing units (CPUs) during the TCLP.
Because of the difficulties with applying the TCLP test to whole electronic devices, a
second objective was to develop and assess the applicability of an alternative
methodology for performing the TCLP on a computer CPU (and possibly other similar
devices). This work is part of an overall effort to assess the TC status of discarded
electronic devices. An understanding of the physical and chemical processes that impact
heavy metal leaching during the TCLP is useful for selecting and developing the
3
appropriate testing procedures and for understanding how results may differ among
devices.
1.3 Research Approach
In one study, several personal computer CPUs were sampled, size-reduced, and
mixed to create a composite CPU mixture. Several different TCLP tests were performed
on the mixture, all within the constraints of the USEPA method, but slightly varied to
assess the impact of different leaching conditions (e.g., particle size, head space). The
impact of computer CPU composition on lead leachability during the TCLP was
examined by leaching different combinations of CPU components (e.g., PWB, metal,
plastic, cable/wire).
A second study evaluated an alternative methodology for performing the TCLP on
computer CPUs. The alternative methodology involved using a drum rotator and a
55-gallon drum to perform a TCLP. This method enabled an entire computer CPU to be
tested. Computer CPUs were disassembled and leached while maintaining as many of
the requirements of the methodology as possible. Identical CPU models were also tested
using the standard TCLP methodology to assess the applicability of the large-scale
modified TCLP.
1.4 Thesis Organization
This thesis includes two studies. Chapter 2 provides an overview of the TCLP and
presents the results of an investigation of the factors affecting lead leachability from
computer CPUs. Chapter 3 provides the results of an evaluation of an alternative TCLP
for RCRA toxicity characterization of computer CPUs. Chapter 4 summarizes the
research. Raw data are presented in Appendix A; quality assurance data are presented in
4
Appendix B; a sampling sequence for the TCLP methodology comparison is presented in
Appendix C, and chemical reactions are presented in Appendix D.
5
CHAPTER 2 FACTORS AFFECTING TOXICITY CHARACTERISTIC LEACHING PROCEDURE
(TCLP) LEAD LEACHABILITY FROM COMPUTER CPUs
2.1 Introduction
The toxicity characteristic leaching procedure (TCLP) is the US Environmental
Protection Agency (USEPA) method required to determine whether a solid waste is a
hazardous waste by the toxicity characteristic (TC). The TCLP is performed by leaching
100 grams of size-reduced waste for 18 hours in a synthetic landfill leachate. The results
are compared to TC limits provided in the federal regulations (USEPA, 1999); if the
concentrations in the leachate are greater than the TC limits, the waste is hazardous
(unless otherwise excluded). The TCLP is a relatively easy method to perform on liquid,
semi-solid, and granular wastes. Even monolithic waste forms can be crushed with fairly
standard laboratory tools. Testing of manufactured articles such as electrical equipment,
however, can be more troublesome. The heterogeneous nature of large bulky electronic
devices often makes it difficult to obtain a size-reduced representative sample for testing.
Discarded electronic devices are a growing segment of the solid waste stream; and
as a result of the toxic chemicals they often contain (e.g., lead), their status as TC
hazardous wastes is questioned (BAN, 2002; FWI, 2001; GFF, 2001; SVTC et al. 2001,
SVTC, 2002). Personal computers are one example of discarded electronics that pose a
concern. They are becoming obsolete at a growing rate, increasing the rate at which they
are being discarded. Computers, which had an average lifetime of 4 to 5 years in 1992,
are projected to have an average lifetime of 2 years by 2005 (NSC, 1999). The National
6
Safety Council reports that more than 20 million personal computer central processing
units (CPUs) became obsolete in 1998; and that approximately 500 million computers
will become obsolete between 1997 and 2007 (NSC, 1999).
Estimates show that approximately 6.3% of a typical computer is composed of
lead, most of which is attributed to the monitor’s cathode ray tube (CRT) (MCC, 1996).
One recent study showed that color CRTs from televisions and computer monitors
usually did exceed the Resource Conservation and Recovery Act (RCRA) TC limits for
lead (Musson et al., 2000; Townsend et al., 1999). A recent Federal Register notice
proposed to exclude CRTs and CRT glass being sent for recycling from the definition of
a solid waste, thus simplifying RCRA management requirements (USEPA, 2002b). In
this notice, the USEPA stated “we are not currently aware of any non-CRT computer
components or electronic products that would generally be hazardous waste.” Lead is
also found in other components of a computer such as printed wiring boards (PWBs).
Tin/lead solder (63% tin and 37% lead) is the most common solder alloy used in
electronics (NCM, 1995). While some studies have reported TCLP lead concentrations
from PWBs to exceed the 5 mg/L TC limit (Environment Australia, 1999; Yang, 1993),
shredded and whole PWBs that are reclaimed are excluded from the definition of solid
waste (USEPA, 1997; USEPA, 1998). Although tests performed on PWBs indicate that
electronic devices such as computer CPUs have the potential to fail the TCLP, there are
no reports that assess the TC of an entire computer CPU.
Research was performed to examine the factors that impact lead leachability from
computer CPUs. This work was conducted as part of a larger effort to assess the TC
status of discarded electronic devices. Because computer CPUs consist of several distinct
7
materials with different physical and chemical properties, an understanding of the
processes impacting heavy metal leaching are useful for developing the appropriate
testing procedures and for understanding how results may differ among devices. Slight
changes in the TCLP methodology, which still meet the requirements of the method, can
impact results. For example, Meng et al. (2001) found that changing the head space
above the TCLP leaching fluid during the test greatly impacted the amount of arsenic that
leached from water treatment sludges. This paper provides the details of an experiment
where several personal computer CPUs were sampled, size-reduced, and mixed to create
a composite CPU mixture that was leached under a variety of conditions. Lead, iron,
copper, and zinc results are presented. Although lead is the primary chemical of interest,
the analysis of iron, copper, and zinc can be used to describe the processes (reduction by
metallic iron and sorption by hydrous ferric oxide) that have been documented to impact
lead leachability (Kendall, 2003). The objective of the research reported here was to
investigate the factors that impact lead leachability from computer CPUs during the
TCLP, not to provide a definitive study on the hazardous waste characterization of
computer CPUs.
2.2 Materials and Methods
2.2.1 Sample Collection and Processing
Computer CPUs were collected from variety of sources including electronics
demanufacturing facilities, individuals, and a local hazardous waste collection center. A
total of 29 computer CPUs were completely disassembled and separated into five
material categories: PWBs, ferrous metals, nonferrous metals, wires/cables, and plastics.
Figure 2-1 presents the average composition (by weight) of all the CPUs. Five of the
CPUs were selected at random as the source of materials to create a synthetic CPU
8
mixture. In order to obtain enough sample to create a mixture with a composition the
same as Figure 2-1 for all the tests desired, approximately 500 g of PWB, 240 g of
plastic, 2,200 g of ferrous metal, 170 g of nonferrous metal, and 100 g of wires were
collected from each of the five CPUs. These pieces were selected at random from each
CPU, and the materials collected were size-reduced by hand (i.e., using shears) so they
would pass a 0.95-cm sieve (a requirement of the TCLP). Similar materials from each
CPU were combined and mixed. The “synthetic” CPU samples were prepared by mixing
representative subsamples of each material type. Since the total weight required for a
TCLP is 100 g, the “synthetic” CPU mix was composed of 15.8 g of PWB, 7.5 g of
plastic, 68.2 g of ferrous metal, 5.4 g of nonferrous metal, and 3.1 g of wires/cables.
Plastic7.5%
Ferrous Metals68.2%
Printed Wiring Boards15.8%
Nonferrous Metals5.4%
Wires3.1%
Figure 2-1. Average CPU Composition of 29 Computer CPUs by Weight
2.2.2 Leaching and Analysis Methods
The TCLP, USEPA Method 1311, is the USEPA prescribed test for determining
whether a solid waste is a TC hazardous waste (USEPA, 1996). The TCLP, in this study,
was performed by manually size reducing (i.e., hand cutting) the CPU components using
9
shears so they would pass a 0.95-cm sieve. One hundred-gram samples of the size-
reduced materials were placed into 2-L TCLP extraction vessels (high-density
polyethylene (HDPE)). Two liters of TCLP extraction fluid #1, which consists of
11.4 mL of glacial acetic acid and 128.6 mL of 1 N sodium hydroxide solution diluted to
2 L with reagent water, were added to the extraction vessel. The initial pH of the TCLP
extraction fluid was 4.93±0.05. Initial measurements of the pH, oxidation-reduction
potential (ORP), and dissolved oxygen (DO) were recorded. All pH and ORP
measurements were made using an Orion Model 710A+ benchtop meter equipped with an
Orion Model 91-55 combination pH electrode and a Orion Model 91-79 ORP platinum
triode. The pH probe and meter were calibrated with standard buffer solutions (4.0, 7.0,
and 10.0) with a three-point calibration. The ORP probe and meter were calibrated using
a reference standard (475 mV) in the relative millivolt (RMV) mode and all
measurements were in RMV. Dissolved oxygen measurements were collected using an
YSI Inc. Model 55 handheld dissolved oxygen meter.
All samples were performed in triplicate and a TCLP blank was included for each
set of leaching extractions. The samples were rotated at 30±2 rpm for 18±2 hours in a
12-vessel rotary extractor (Analytical Testing Corporation). After rotation, the final pH,
DO, and ORP of the leachates were recorded. The TCLP leachates were filtered through
a glass fiber filter (0.7 µm pore size) using pressure filtration and preserved by adding
concentrated nitric acid until the pH of the filtrate was below 2. In addition to collecting
the filtered leachate, samples of nonfiltered leachates were also collected. All samples
were then placed in HDPE bottles and stored until acid digestion. Specific experimental
details of the TCLP methodologies performed will be described in the following sections.
10
Ferrous iron (Fe2+) analysis was performed on nonpreserved samples using a
HACH Model DR/4000 spectrophotometer using the 1,10 phenanthroline method
(HACH program 2150). The spectrophotometer was zeroed with reagent water and a
1-mg/L standard was used to check the machine calibration. Samples were added to
glass vials and ferrous iron reagent powder pillows were added to the sample and were
allowed to react for three minutes. The glass vials were cleaned to remove any surface
contamination and then placed into the spectrophotometer. The ferrous iron (Fe2+)
concentration was recorded. Readings were taken before and after the addition of the
ferrous iron reagent powder pillows for the nonfiltered samples to account for any
absorbance caused by particulates in the sample. Analysis of lead, iron, copper, and zinc
were performed by digesting the samples using the hotplate acid digestion procedure,
USEPA Method 3010A. The digested samples were then analyzed using USEPA
Method 6010B (Inductively Coupled Plasma-Atomic Emissions Spectrometry) on a
Thermo Terrell Ash Trace Analyzer ICP (USEPA, 1996).
2.2.3 TCLP on Printed Wiring Boards
The TCLP was performed on the PWB pieces described earlier; 100 g of the size-
reduced PWBs were leached in triplicate. In addition, the TCLP was performed on
smaller amounts of PWBs, namely 70 g, 30 g, and 15.8 g, respectively. The same
volume of leaching fluid, 2 L, was used in each case. Thus the liquid-to-solid ratio of the
smaller masses leached were greater than the standard 20:1 for TCLP. The purpose of
these tests was to provide a set of data that could be compared to mixed component
samples, which can contain various amounts of PWBs.
11
2.2.4 TCLP on Synthetic Computer CPU Mix
The TCLP was performed on a 100-g sample of the “synthetic” CPU mixture
prepared in Section 2.2.1 to evaluate lead leachability from a computer CPU. It is noted
that the TCLP does not limit the extent of size reduction of the solid sample. To address
the issue of how size reduction impacts lead leachability from CPUs, a second sample of
the “synthetic” CPU mixture was collected and further processed. This sample was
manually size reduced (i.e., hand cut) using shears to a size capable of passing through a
0.2-cm sieve. The TCLP was then performed to evaluate the impact of sample size on
lead leachability during the TCLP.
2.2.5 Component Impact
An investigation of the impact of computer CPU composition on lead leachability
during the TCLP was performed by leaching different mixtures of the CPU components.
Samples were prepared by mixing size-reduced PWBs with ferrous metal, nonferrous
metal, and plastic, to examine the impact of each material on lead leachability from the
PWBs during the TCLP. The materials were obtained from the CPU components
described in Section 2.2.1. The component mixtures evaluated are listed in Table 2-1.
Table 2-1. CPU Material Impact Samples
Sample PWB (g)
Ferrous Metal (g)
Nonferrous Metal (g)
Plastic (g)
PWB Only 50 - - -
PWB & Ferrous 50 50 - -
PWB & Nonferrous 50 - 50 -
PWB & Plastic 50 - - 50
12
The impact of CPU composition was also evaluated by conducting TCLPs with
constant PWB quantity, but with varying fractions of ferrous metal. In addition to the
“synthetic” CPU mixture (68.2% ferrous metal), three other samples were prepared with
fractions of ferrous metal of 40%, 20% and 0%. The total mass of each sample was
maintained at 100 g; additional plastic was substituted for the respective fractions of
ferrous metal. The sample masses are presented in Table 2-2.
Table 2-2. Ferrous Metal Impact Sample Compositions
% Ferrous Metal
PWB (g)
Plastic (g)
Ferrous Metal
(g)
Nonferrous Metal
(g)
Wires/Cables (g)
Total Mass (g)
68.2 15.8 7.5 68.2 5.4 3.1 100
40 15.8 35.7 40 5.4 3.1 100
20 15.8 55.7 20 5.4 3.1 100
0 15.8 75.7 0 5.4 3.1 100
2.2.6 Impact of Head Space
As discussed in Section 2.1, slight changes in the TCLP methodology can impact
results. An investigation was conducted to evaluate whether the head space above the
TCLP leaching fluid impacts lead leachability from computer CPUs during the TCLP. A
2-L extraction vessel was used during the standard TCLP method that had an actual total
volume of 2.34 L, which leaves approximately 0.34 L of head space above the TCLP
extraction fluid. The volume occupied by the 100-g CPU sample itself was
approximately 0.023 L. The actual volume of head space (Va) and extraction fluid (Vl) in
the vessel was 0.317 L and 2.023 L, respectively. This results in an air-to-liquid ratio
(volume of air to volume of liquid (Va/Vl)) of 0.16. In order to determine if the vessel
13
head space significantly impacts lead leachability three additional samples were
evaluated in this study with head space ratios (Va/Vl) of approximately 0, 0.5, and 1. It is
noted that the zero head space samples were not truly free of air due to a small amount of
air leakage into the vessel. The sample materials were obtained from the CPU
components prepared in Section 2.2.1. The liquid-to-solid ratio was maintained at 20:1.
The relative material fractions remained identical to the synthetic CPU sample. The
sample masses were adjusted (considering the volume occupied by the sample itself) to
achieve the appropriate air-to-liquid ratios. The sample compositions and volumes of the
TCLP extraction fluid are presented in Table 2-3.
Table 2-3. Impact of Vessel Headspace Sample Composition
Sample PWB (g)
Ferrous Metal
(g)
Nonferrous Metal
(g)
Plastic (g)
Wires(g)
Total Mass (g)
Solution (mL)
Va/Vl~0 18.3 79.0 6.3 8.7 3.6 115.8 2315
Va/Vl=0.16 15.8 68.2 5.4 7.5 3.1 100.0 2000
Va/Vl=0.5 12.3 53.2 4.2 5.9 2.4 78.0 1560
Va/Vl=1 9.2 39.9 3.2 4.4 1.8 58.5 1160
2.3 Results and Discussion
2.3.1 Lead Leachability from PWBs
The average TCLP lead concentration from the 100-g sample of PWBs was
151 mg/L. Other studies have reported TCLP lead concentrations for PWBs to range
from 56 mg/L to 1,350 mg/L (Environment Australia, 1999; Yang, 1993). Typical PWB
TCLP lead concentrations measured in other studies by the authors have been in the
range of 100 mg/L to 200 mg/L (Jang, Y. and T. Townsend, 2003 “Leaching of Lead
14
from Computer Printed Wire Boards and Cathode Ray Tubes by Municipal Solid Waste
Landfill Leachates,” Submitted for publication.; Townsend et al., 2001). All of the
samples tested in this study exceeded the RCRA TC limit for lead. This was not
unexpected since the USEPA excludes PWBs that are being recycled from the definition
of a solid waste; they are exempt from the RCRA hazardous waste regulations. In
general, lead concentration increased with an increase in sample mass. The maximum
lead concentration was reached at the 70-g sample. The lead concentration from the
15.8-g PWB sample gave an indication of the expected lead leachability from the PWBs
alone in the “synthetic” CPU mixture. The lead, iron, copper, and zinc results from the
TCLPs that were performed on the PWBs are presented in Table 2-4.
The final pH of all of the samples did not vary greatly and did not change much
from the initial pH (4.93±0.05), whereas the DO and ORP tended to decrease with an
increase in the mass of PWB in the sample. The results also showed a general increase in
iron, copper, and zinc concentrations as the mass of the sample increased. There was no
significant difference (t-test, α=0.5 using Microsoft Excel) in the lead, iron, copper, and
zinc concentrations between the 70-g and 100-g samples. The averages and standard
deviations of the iron and zinc concentrations measured in the 30-g and 100-g samples,
respectively, were impacted by one sample (an outlier) out of the three that were
analyzed. This caused the standard deviation to be higher than the average concentration
of the three samples. If the outlier is removed and only two samples are used the average
iron concentration in the 30-g sample is 1 mg/L with a standard deviation of 0.04 mg/L
while the average zinc concentration in the 100-g sample is 0.3 mg/L with a standard
deviation of 0.03 mg/L.
15
Table 2-4. Average TCLP Leachate Concentrations from PWBs (average of three samples)
Mass (g)
Final pH
Lead (mg/L)
Iron (mg/L)
Copper (mg/L)
Zinc (mg/L)
15.8 4.91±0.01 39±7 1±0.5 0.3±0.1 0.14±0.1
30 4.92±0.01 61±3 3±4 0.5±0.1 0.2±0.05
70 4.93±0.01 161±6 8±2 0.7±0.2 0.3±0.18
100 4.91±0.01 151±10 5±0.6 0.5±0.2 3±4
2.3.2 Predicting the TC of an Electronic Device
One possible approach to determine the TCLP results for a heterogeneous
manufactured device is to use TCLP results from the suspected hazardous component of
the device and assume that the rest of the device does not impact leaching. This was
performed using the data in Table 2-4 following two methods. The first method is to
calculate a predicted TCLP concentration for the entire device based on the TCLP results
from the hazardous components only. For example, the suspected hazardous component
in a computer CPU is the PWB; therefore the TCLP can be performed on the PWB only.
A predicted TCLP lead concentration for the entire CPU can then be calculated based
upon the fraction of PWB in the CPU and the results from the TCLP performed on the
PWB. Equation 2-1 presents the equation that was used to calculate a predicted TCLP
concentration for a computer CPU.
Total
PWBPWB
MM TCLP
TCLP = (2-1)
The TCLPPWB term represents the TCLP lead concentration from the PWB, MPWB
is the mass of PWB in the CPU, and MTOTAL is the total mass of the CPU. Using this
procedure showed that if the TCLP lead concentration from the PWBs is 151 mg/L and
16
PWBs make up 15.8% (MPWB/MTotal=0.158) of the CPU composition then the predicted
TCLP lead concentration would be 24 mg/L, which exceeds the TC limit.
A second method in predicting the TC of an electronic device is to perform the
TCLP on the relative fraction of the suspected hazardous component only. For example,
the results showed that the TCLP lead concentrations from the 15.8-g PWB sample was
39 mg/L. The predicted lead leachability from the “synthetic” CPU mixture during the
TCLP was expected to be 39 mg/L, assuming the other components did not impact lead
leaching.
2.3.3 Synthetic Computer CPU Mix
Results of this study showed that the lead, iron, and zinc concentrations in the
TCLP leachates from the “synthetic” CPU mixture were 0.3 mg/L, 19 mg/L, and
136 mg/L, respectively. Copper was not detected (MDL=0.05 mg/L). The results are
presented in Table 2-5. The lead leachability from the 15.8-g sample of PWB was
39 mg/L; however, only 0.32 mg/L of lead was leached from the “synthetic” CPU
mixture sample, which also contained 15.8 g of PWB, during the TCLP. This indicated
that the various components of the CPU impacted lead leachability from the PWBs.
Figure 2-2 illustrates a comparison of the average lead concentration from the “synthetic”
CPU mixture samples, the weighted average TCLP lead concentration, and the lead
concentration from the 15.8-g sample of PWB. This confirmed that there was indeed an
impact on lead leachability during the TCLP when the other components of the CPU
were mixed with the PWBs. This comparison also demonstrated that testing the PWBs
alone did not accurately predict the lead leachability from a representative sample of the
“synthetic” CPU mixture. A Student’s t-test (α=0.5 using Microsoft Excel) performed on
17
the results shows that the two methods of predicting the TCLP lead concentration were
significantly different in this sample. Predicting the TC of an entire device by testing the
hazardous component only, as discussed in Section 2.3.2, may not be the most reliable
option.
Table 2-5. TCLP Results of Synthetic Computer CPU Mixture (average of 3 Samples)
Size (cm) pH Lead
(mg/L) Iron
(mg/L) Copper (mg/L)
Zinc (mg/L)
<0.95 5.16±0.01 0.3±0.2 19±9 BDL 136±24
<0.20 5.20±0.02 0.3±0.03 52±6 BDL 144±3
0.01
0.1
1
10
100
TCLP <0.95 cm TCLP <0.20 cm Predicted TCLP(Method 1)
Predicted TCLP(Method 2)
Pb C
once
ntra
tion
(mg/
L)
.
Figure 2-2. Effects of Component Mixture on Lead Leachability
Particle size can impact the amount of metals that leach from a waste; as particle
size decreases, leaching typically increases. This was observed for CRT glass (Musson et
al. 2000). Two sample sizes (<0.95 cm and <0.20 cm) of the “synthetic” CPU mixture
were tested to evaluate the impact of particle size on lead leachability from CPUs. No
significant difference (Student’s t-test, α=0.05 using Microsoft Excel) was observed
among the TCLP lead and zinc concentrations between the particle sizes used to test the
18
“synthetic” CPU mixture. Iron however was significantly greater in the smaller sample.
The heterogeneity of a device such as a computer CPU often makes obtaining a
representative sample difficult; therefore size reducing the device helps increase the
surface area for leaching and to homogenize the material in order to get a representative
sample. However, size reduction had little impact on the surface area of the lead in
computer CPUs since the lead typically only exists in small amounts as tin/lead solder
used on the surface of the PWBs. Size reduction of the sample did increase the surface
area of the ferrous metal component and as a result, higher iron concentrations were
measured in the small (<0.20 cm) sample. The impact of size reduction on lead
leachability may have been counteracted by the higher iron concentrations in the small
sample, which resulted in a concentration nearly the same as the larger sample. The final
pH, DO, and ORP of the leachate did not differ greatly between the two samples. The
DO and ORP data are presented in Appendix A.
2.3.4 Component Impact
Table 2-6 presents a summary of the results of an investigation of material impact
on lead leachability during the TCLP. The TCLP lead, iron, copper, and zinc
concentrations from the 50-g PWB sample were 83 mg/L, 6 mg/L, 0.3 mg/L, and 1 mg/L,
respectively. The lead concentration in the sample that contained PWB mixed with
ferrous metal (3 mg/L) was significantly less (Student’s t-test, α=0.5 using Microsoft
Excel) than the sample containing PWB alone (83 mg/L). This indicated that lead
leachability was impacted by the ferrous metal component during the TCLP. Other
studies have also documented that iron impacts lead leachability during the TCLP.
Kendall (2003) reported that adding iron metal shavings to brass foundry casting sand
19
significantly decreases lead leachability during the TCLP. The results of Kendall’s study
will be discussed in more detail in the following sections. This provides some
explanation to why lead leachability from the “synthetic” CPU mixture was significantly
different than the results obtained from the 15.8-g PWB sample and the weighted average
TCLP concentration. Lead leachability was not greatly impacted by the addition of
nonferrous metal. The lead concentration measured in the TCLP leachate was
significantly higher (Student’s t-test, α=0.05 using Microsoft Excel) in the sample that
contained PWB and plastic. Copper leachability was also impacted (decreased) by the
addition of ferrous metal. It is noted that the minimum detection limit for copper was
0.05 mg/L. Iron in all of the samples existed mostly as Fe2+. Also, the pH was not
greatly impacted by the ferrous metal; however, the pH was much higher in the samples
that contained nonferrous metal and plastic.
Table 2-6. Component Impact TCLP Results
pH Lead (mg/L)
Iron (mg/L)
Copper (mg/L)
Zinc (mg/L)
Material Impact PWB 4.74±0.01 83±5 6±4 0.3±0.02 1±2
PWB & Ferrous 4.78±0.01 3±2 21±9 BDL 110±3 PWB & Nonferrous 5.10±0.07 69±8 10±7 BDL 0.2±0.3
PWB & Plastic 5.01±0.01 113±6 8±7 1±0.4 0.3±0.1 Ferrous Impact
0% Ferrous 4.87±0.02 44±5 5±9 2±0.2 1±2 20% Ferrous 4.97±0.002 7±2 69±7 BDL 57±4 40% Ferrous 4.99±0.02 2±1 40±9 0.1±0.01 101±10
68.2% Ferrous 5.16±0.01 0.3±0.2 19±9 BDL 136±24
A further investigation of ferrous metal impact on lead leachability during the
TCLP was conducted. The results of this investigation are presented in Table 2-6. The
20
results showed that as the fraction of ferrous metal in the “synthetic” CPU mixture
decreased, the lead concentration in the TCLP leachate increased. The lead
concentrations in these samples ranged from 0.3 mg/L in the standard “synthetic” CPU
mixture (68.2% ferrous metal) to 44 mg/L in the zero ferrous “synthetic” CPU mixture
(0% ferrous). The pH was observed to slightly increase while the DO and ORP
decreased with an increase in the fraction of ferrous metal in the sample. The DO and
ORP measurements are included in Appendix A. This indicated that there was some
relationship between the redox potential of the solution and lead and iron leachability
during the TCLP.
2.3.5 Impact of Head Space
Table 2-7 presents the results from an investigation of the impact of head space
above the leaching fluid on lead leachability. In general, the pH, DO, and ORP increased
as the head space above the leaching fluid increased. The DO and ORP data are
presented in Figure 2-3. The results showed that the leachability of lead and iron from
the “synthetic” CPU mixture increased as the head space in the leaching vessel increased.
Copper was not detected (MDL=0.05 mg/L). Additionally, an increase in the percentage
of Fe2+ (decrease in Fe3+) was observed as the head space above the leaching fluid
increased. The impact of ferric iron (Fe3+) on lead leachability during the TCLP will be
discussed in the following sections.
Table 2-7. Impact of Head Space Results
Va/Vl pH Lead (mg/L)
Iron (mg/L)
Copper (mg/L)
Zinc (mg/L)
0 5.05±0.01 0.6±0.03 7±0.2 BDL 112±5 0.17 5.16±0.01 0.3±0.2 19±9 BDL 136±24 0.5 5.37±0.01 0.9±0.2 200±15 BDL 138±8 1 5.36±0.03 2.5±0.7 217±39 BDL 134±11
21
0.00
0.20
0.40
0.60
0.80
0.00 0.17 0.50 1.00Va/Vl
DO
(mg/
L)
.
-600
-400
-200
0
200
RM
V
DO ORP
Figure 2-3. Dissolved Oxygen and ORP Results from Head Space Impact Study
2.3.6 Comparison of Filtered vs. Nonfiltered Samples
Lead, copper, and zinc has been reported to adsorb to hydrous ferric oxide
(Kendall, 2003). Kendall reported that solution concentrations of lead, copper, and zinc
decreased and that sorption increased as pH increased and that lead was the most strongly
adsorbed. In Kendall’s study half of the lead, copper, and zinc that were originally in
solution was adsorbed at pH values of 4, 6, and 7, respectively. Sorption to hydrous
ferric oxide would cause the adsorbed lead, copper, and zinc to be filtered out during the
filtration process thus resulting in lower concentrations being measured in the leachates
of the filtered samples. An evaluation of the difference in lead, iron, copper, and zinc
concentrations between the filtered and nonfiltered samples was conducted to determine
if these metals were filtered out during the filtration process. Overall, there was not a
great difference in the iron and zinc concentrations between the filtered and nonfiltered
samples. When the headspace above the leaching fluid exceeded a head space ratio
(Va/Vl) of 0.5 the difference in lead concentrations between the filtered and nonfiltered
samples was significantly higher (Student’s t-test, α=0.5 using Microsoft Excel), as
22
presented in Figure 2-4. Copper was not detected in the filtered samples, however, the
copper concentrations in the nonfiltered samples increased from 2.5 mg/L in the Va/Vl=0
to 4.3 mg/L in the Va/Vl=1 sample. Results of the ferrous iron analysis (Fe2+) indicated
that as Va/Vl increased the percentage of ferrous iron (a portion of the total iron)
increases, as discussed in Section 2.3.5. Also, when Va/Vl was greater than 0.16, Fe3+
constituted a large portion of the total iron in the nonfiltered samples whereas Fe2+
constituted approximately 100% of the total iron in the filtered samples. The Fe2+ results
are presented in Table 2-8.
0.01
0.10
1.00
10.00
100.00
0 0.16 0.5 1Va/Vl
Pb C
once
ntra
tion
(mg/
L)
.
FilteredNonfiltered
Figure 2-4. Lead Results from Head Space Impact Study
Table 2-8 Analysis of Fe2+ as Percentage of Total Iron (average of 3 samples)
Filtered Nonfiltered
Va/Vl Total Iron
(mg/L) % Fe2+ Total Iron (mg/L) % Fe2+
0 7 44 8 48
0.16 19 10 23 5
0.5 200 100 218 70
1 217 100 386 53
23
2.4 Discussion
Results of this study indicated that lead leachability from computer CPUs depended
on several factors: mass of PWB in the sample, composition of the CPU, and the head
space above the leaching fluid in the extraction vessel. Lead leachability from PWBs
during the TCLP was generally in the range of 100 mg/L to 200 mg/L and decreased as
the mass of PWB in the sample decreased. This indicated that CPUs that contain a high
fraction of PWB tend to leach more lead than CPUs that contain a small fraction.
However, the mass of PWB in the computer CPU was not the only factor that impacted
lead leachability during the TCLP. The components of the CPU themselves can greatly
impact the lead concentration in the leachate during the TCLP. For example, the TCLP
lead concentration from the “synthetic” CPU mixture was 0.3 mg/L; however the lead
concentration from the 15.8-g sample of PWB (equal mass of PWB as the “synthetic”
CPU mixture) was 39 mg/L. Additionally, the predicted TCLP lead concentration (based
on the TCLP results from testing the PWBs only) was 24 mg/L. This comparison
demonstrated that the composition of the CPU did indeed impact the lead leachability
from the computer CPU.
Because computer CPUs consist of several components (PWBs, ferrous metals,
nonferrous metals, plastics, and wires/cables) it was important to determine how each
component impacted lead leachability during the TCLP. An investigation on material
impact indicated that the ferrous metal component of the CPU significantly decreased
lead leachability. Other studies have documented that iron impacts lead leachability
during the TCLP. Kendall found that adding iron metal shavings to brass foundry casting
sand significantly decreased lead leachability during the TCLP (Kendall, 2003). Kendall
24
explains that the iron metal caused the TCLP leaching fluid to become reducing therefore
decreasing lead leachability. Also, lead and copper ions that are in solution will be
reduced by the iron, which will cause the concentrations of lead and copper measured in
the TCLP leachate to remain low provided that metallic iron is present (Kendall, 2003).
Results of the material impact also indicated that plastic increased lead leachability from
the PWBs. This is believed, however, to be a physical process rather than a chemical
reaction since plastic is generally considered to be chemically inert with respect to lead
leachability.
An investigation of ferrous metal impact on lead leachability from computer CPUs
indicated that the fraction of ferrous metal (i.e., steel) in the sample significantly
impacted the lead concentration in the leachate. Reaction D-1 in Appendix D
demonstrates the reduction of lead by metallic iron, which appears to have occurred
(Snoeyink et al. 1980). The galvanic series shows that the greater the difference in
electrode potential the greater the potential for corrosion to occur (Snoeyink et al. 1980).
Iron can reduce lead ions in solution since iron has a greater electrode potential (+0.44 V)
than lead (+0.126 V) with respect to oxidation of the metal to the divalent ions. As iron
dissolved from the steel, Fe2+ ions were released into solution and a negative charge was
produced on the steel by the remaining electrons. The Pb2+ ions that leached into solution
were attracted to the negatively charged steel, which resulted in lead plating out onto the
steel. Zinc, which has an electrode potential of +0.76 with respect to oxidation of the
metal to the divalent ion, also appears to have reduced the lead that was leached into
solution as demonstrated in Reaction D-2 (Snoeyink et al. 1980). The source of zinc in
the samples is from the thin layer of zinc applied to the steel during the galvanizing
25
process. This also caused lead to plate out onto the metallic zinc as zinc ions were
released into solution.
Lead, iron, and copper leachability tended to decrease as the fraction of ferrous
metal in the sample increased. This can be explained by the increase in pH and the
decrease in DO and ORP of the TCLP leachates as the fraction of ferrous metal in the
sample increased. It appears that when the iron leached and dissolved into solution, DO
and H+ were consumed as Fe2+ ions were released. This reaction is demonstrated in
Reaction D-4 (Snoeyink et al. 1980). This confirms Kendall’s findings that the ferrous
metal (i.e., steel) in the sample changed the TCLP leaching fluid from oxidizing to
reducing. In a reducing environment lead, iron, and copper are not oxidized; therefore do
not readily leach into the solution. Furthermore, metallic iron and zinc reduced some of
the lead and copper ions that were in solution, which also attributed to the lower
concentrations being measured in the leachate as the fraction of ferrous metal increased.
Zinc leachability was observed to increase as the fraction of ferrous metal in the
sample increased. Based on the electrode potentials, zinc (+0.76 V) can reduce iron
(+0.44 V), lead (+0.126 V), and copper (-0.345 V) (Snoeyink et al. 1980). Reaction D-3
demonstrates the reduction of Fe2+ by metallic zinc. This explained why the iron
concentration decreased from 69 mg/L in the 20% ferrous sample to 19 mg/L in the
68.2% ferrous sample. Increasing the amount of ferrous metal (i.e., steel) in the sample
also increased the amount of zinc since the steel was coated with a thin layer of zinc for
galvanic protection. It is believed the metallic zinc reduced the Fe2+ ions that were
leached into solution, which resulted in a decrease in the iron concentrations measured in
the leachate as the fraction of steel in the sample increased. This also confirmed
26
Kendall’s finds that zinc was not reduced by iron and remained at high concentrations in
the TCLP leachate (Kendall, 2003).
The third factor that can impact lead leachability from computer CPU during the
TCLP is the head space above the leaching fluid in the extraction vessel. The results
indicated that as the head space to liquid ratio (Va/Vl) increased, the pH, DO, and ORP
generally tended to increase. This suggested that the TCLP leaching fluid became more
oxidizing as Va/Vl increased. The leachability of lead and iron increased as the
environment of the leaching fluid became more oxidizing. An analysis of the nonfiltered
samples showed that as Va/Vl increased the difference in the lead, iron, and copper
concentrations between the filtered and nonfiltered samples also increased. Zinc was not
greatly impacted by a change in the head space above the leaching fluid. This indicated
that although more lead was being leached as Va/Vl increased, more of the lead was
sorbed or precipitated as Va/Vl increased. Lead leachability has been reported to adsorb
to hydrous ferric oxide (Kendall, 2003). Kendall reported that solution concentrations of
lead, copper, and zinc decreased and that sorption increased as pH increased and that lead
was the most strongly adsorbed. In Kendall’s study half of the lead, copper, and zinc that
was originally in solution was adsorbed at pH values of 4, 6, and 7, respectively.
Increasing Va/Vl tended to increase the difference in the lead and copper concentrations
between the filtered and nonfiltered samples. These results can be explained by the
formation of hydrous ferric oxide as presented in Reaction D-5. It is believed that the
TCLP solution, which is oxygenated, caused the Fe2+ ions to further oxidize to Fe3+
which then formed ferric hydroxide. Through hydrolysis the ferric hydroxide was then
converted to hydrous ferric oxide. The pH values measured during the evaluation of the
27
impact of head space ranged from 5.05 to 5.36, which explains why zinc was not
impacted by the change in Va/Vl. When Va/Vl > 0.16, Fe3+ composed a large fraction of
the total iron in the nonfiltered samples, whereas, Fe2+ composed approximately 100% of
the total iron in the filtered samples. It appears that the lead and copper adsorbed to
hydrous ferric oxide and was filtered out during the filtration process thus resulted in the
difference in the lead and copper concentrations between the filtered and nonfiltered
samples.
2.5 Implications
This study was designed to investigate the factors that impact lead leachability
from computer CPUs and no interpretations of the TC status of CPUs are made.
However, several observations from the results of this study can be utilized in
determining the appropriate TCLP methodology for testing computer CPUs (and other
electronic devices). One observation was that the TCLP results from the “synthetic”
CPU mixture tested in this study indicated that this particular CPU did not exceed the 5
mg/l TC limit for lead. This was attributed to the high percentage of ferrous metal in the
sample. The presence of large amounts of ferrous metal in the sample tended to decrease
the amount of lead that was measured in the TCLP leachate. Computer CPUs that
contain a large percentage of ferrous metal are less likely to exceed the TC limit for lead
than those that contain smaller amounts. The components of today’s computers CPUs are
typically being constructed with more plastic than in the past. This may result in CPUs
being more likely to exceed the TC limit for lead. Also, laptop computers, which are
constructed mostly of plastic, may tend to leach lead more than standard desktop
computer CPUs. This study did not provide an evaluation of lead leachability with
respect to CPU composition.
28
Another observation was that size reduction of the CPU sample had little effect on
lead leachability as long as the TCLP particle size requirement was met. The amount of
lead measured in the TCLP leachate may indeed decrease in some CPUs because iron
leachability, which has a strong impact, tends to increase when the particle size is small.
The purpose of the research presented here is part of an overall effort to assess the
TC status of discarded computer CPUs and other electronic devices. No definitive
hazardous waste characterization of discarded electronic devices was made from the
results of this research.
29
CHAPTER 3 EVALUATION OF A LARGE-SCALE MODIFIED TCLP FOR RESOURCE
CONSERVATION AND RECOVERY ACT (RCRA) TOXICITY CHARACTERIZATION OF COMPUTER CPUS
3.1 Introduction
The growing need for cheap, reliable, and efficient computing power has resulted in
an increasing amount of computer CPUs entering the waste stream. The average lifetime
of a computer is projected to decrease from 4-5 years in 1992 to 2 years by 2005. The
National Safety Council reports that more than 20 million personal computer CPUs
became obsolete in 1998 and that approximately 500 million computers will become
obsolete between 1997 and 2007 (NSC, 1999). Computer CPUs have the potential to be
classified as RCRA toxicity characteristic (TC) hazardous wastes due to the toxic
chemicals they are known to contain such as arsenic, barium, cadmium, chromium, lead,
mercury, and silver. Reports document that approximately 6.3% of a typical computer is
composed of lead, a majority of which is attributed to the cathode ray tube (CRT) (MCC,
1996). Lead is also found in other components of a computer such as printed wiring
boards (PWBs). Tin/lead solder (63% tin and 37% lead) is the most common solder alloy
used in electronics (NCM, 1995).
The TCLP (USEPA Method 1311) is the test prescribed by the US Environmental
Protection Agency (USEPA) for determining the RCRA TC of a solid waste (USEPA,
1999). The TCLP has several requirements such as sample mass (100 g), particle size
(<0.95 cm), liquid-to-solid ratio (20:1), speed of the rotary extractor (30±2 rpm), time on
the extractor (18±2 hours), volume (2 L), and extraction fluid (glacial acetic acid and 1 N
30
sodium hydroxide; pH=4.93±0.05). For some waste streams, the single largest challenge
in performing the test is obtaining a representative size-reduced sample. The TCLP
requires size reduction of the waste material so that it is capable of passing through a
0.95-cm sieve. This size reduction requirement is difficult to meet for bulky
manufactured devices such as an electronic device. Electronic equipment recycling
facilities may use large-scale industrial equipment (e.g., shear shredders) to size reduce
electronic devices. However, the use of industrial shear shredders often leads to cross
contamination between samples and loss of sample mass in addition to not size reducing
the material to the required size. Another option would be to fabricate a laboratory-size
shredder that could process electronic devices. This option would be expensive and may
require multiple shredders due to the heterogeneous nature of a computer CPU. Manual
size reduction using small-scale laboratory equipment (e.g., shears) is likely to be the
only reasonable option. Manual size reduction, however, is very time consuming and
may introduce human bias into the sample collection process. In addition, selecting a
representative sample of the entire CPU is a difficult task when performing TCLP on
computer CPUs. Computer CPUs have several components made of various materials
(e.g., printed wiring boards, metals, plastics, wires/cables). Selecting the materials to be
tested is often left to the technician collecting the sample, which may introduce further
human bias.
The objective of the work presented here was to develop an alternative
methodology that would resolve some of the issues faced when conducting a TCLP on a
device such as a computer CPU. A large-scale modified TCLP method was developed in
which an entire electronic device, such as a computer CPU, is placed into a large
31
extraction vessel and leached while maintaining the TCLP requirements for the liquid-to-
solid ratio and the extraction fluid. Size reduction is not performed in this method; the
CPU is simply disassembled and placed into the extraction vessel and rotated for
18 hours. Leaching the entire device eliminates any human bias that is introduced during
sample processing and collection.
This paper presents the results of the efforts to access the applicability of a large-
scale modified TCLP for the toxicity characterization of computer CPUs. No
interpretations of the results are made on the hazardous waste characterization of
computer CPUs.
3.2 Materials and Methods
3.2.1 Research Approach
A modified TCLP was developed and evaluated using computer CPUs. In this
method, computer CPUs were completely disassembled and leached using a methodology
similar to the TCLP. The procedure was scaled up so the entire computer CPU could be
tested. A preliminary investigation was conducted to evaluate the impact of the rotation
speed on lead leachability during the TCLP, because the extractor used in the proposed
large-scale modified TCLP rotates at half the speed (13 rpm) of the standard TCLP rotary
extractor (28 rpm). A series of experiments that evaluated the leachability of lead, iron,
copper, and zinc during both the standard TCLP and the large-scale modified TCLP
methods as a function of time was performed. The purpose of these experiments was to
provide a set of data that would be used to evaluate the chemical properties of the
leaching solution and metal concentrations measured in the leachate to determine if the
time requirement of the TCLP (18 hours) was sufficient to achieve chemical equilibrium
in the large-scale modified method. This data was also used to determine if any physical
32
or chemical differences existed between the standard TCLP method and the proposed
large-scale modified TCLP method. A methodology comparison was also performed to
evaluate the results of the large-scale modified TCLP as compared to the standard TCLP.
Results of this study were used to assess the applicability of a large-scale modified
TCLP for the hazardous waste determination of computer CPUs. Lead, iron, copper, and
zinc results are presented. Although lead is the primary chemical of interest, the analysis
of iron, copper, and zinc can be used to describe the processes that have been
documented to impact lead leachability: reduction by metallic iron and sorption by
hydrous ferric oxide (Kendall, 2003). An evaluation was conducted to determine the
similarities (or lack thereof) between the results of the large-scale modified TCLP and
standard TCLP methods
3.2.2 Sample Collection and Processing
Computer CPUs were collected from a demanufacturing facility and a local
household hazardous waste collection center. A total of 43 personal computer CPUs
were collected. Each CPU was completely disassembled and separated into five material
categories: printed wiring boards (PWBs), ferrous metals, nonferrous metals, plastics, and
wires/cables to determine the CPU composition and total weight.
3.2.3 Modified Leaching Procedure
The modified TCLP was performed by leaching an entire disassembled computer
CPU using a scaled up version of the TCLP method. A 55-gallon extraction vessel (high
density polyethylene (HDPE) drum) was placed on a Morse 1-300 Series, Endover Drum
Rotator (Morse Manufacturing). The TCLP extraction fluid #1 was mixed in the
extraction vessel by adding 114 mL of glacial acetic acid and 129 mL of 10 N sodium
hydroxide solution, diluted to 20 L. The amount of extraction fluid was dependent on the
33
mass of the solid sample in order to maintain a 20:1 liquid to solid ratio. For example, a
10-kg CPU requires 200 L of extraction fluid. The maximum sample mass for the large-
scale modified TCLP was 10 kg due to volume required by the extraction fluid; therefore,
representative fractions of each material type for that particular CPU were chosen at
random to obtain a 10-kg sample. The CPUs were not size reduced but were
disassembled. The extraction fluid was mixed by rotating the solution on the drum
rotator. Initial measurements of the pH, oxidation-reduction potential (ORP), and
dissolved oxygen (DO) were recorded. The initial pH of the TCLP extraction fluid #1
was 4.93±0.05. All pH and ORP measurements were made using an Orion Model 710A+
benchtop meter equipped with an Orion Model 91-55 combination pH electrode and an
Orion Model 91-79 ORP platinum triode. The pH probe and meter were calibrated with
standard buffer solutions (4.0, 7.0, and 10.0) with a three-point calibration. The ORP
probe and meter were calibrated using a reference standard (475 mV) in the relative
millivolt (RMV) mode and all measurements were in RMV. DO measurements were
collected using an YSI Inc. Model 55 handheld dissolved oxygen meter. A blank sample
of the TCLP extraction fluid was collected for each leaching extraction.
The disassembled computer CPU was placed into the extraction fluid and rotated
end-over-end at a speed of 13 rpm for 18 hours. After rotation, the samples were drained
from the bottom of the extraction drum and the final pH, DO, and ORP of the leachates
were recorded. The TCLP leachates were filtered through a glass fiber filter (0.7 µm pore
size) using pressure filtration and preserved by adding concentrated nitric acid until the
pH of the filtrate was below 2. In addition to collecting the filtered leachate, samples of
nonfiltered leachates were also collected. All samples were then placed in HDPE bottles
34
and stored until acid digestion. Specific experimental details of the TCLP methodologies
performed will be described in the following sections.
Ferrous iron (Fe2+) analysis was performed on nonpreserved samples of the filtered
leachate using a HACH Model DR/4000 spectrophotometer using the 1,10
phenanthroline method (HACH program 2150). The spectrophotometer was zeroed with
reagent water and a 1-mg/L standard was used to check the machine calibration. Samples
were added to glass vials and ferrous iron reagent powder pillows were added to the
sample and were allowed to react for three minutes. The glass vials were cleaned to
remove any surface contamination and then placed into the spectrophotometer. The
ferrous iron (Fe2+) concentration was recorded. Analysis of lead, iron, copper, and zinc
were performed by digesting the samples using the hotplate acid digestion procedure,
USEPA Method 3010A. The digested samples were then analyzed using USEPA
Method 6010B (Inductively Coupled Plasma-Atomic Emissions Spectrometry) on a
Thermo Terrell Ash Trace Analyzer ICP (USEPA, 1996).
3.2.4 Impact of Extractor Speed
The TCLP requires that the rotary extractor rotate the samples at 30± rpm.
However, the rotator used in the large-scale modified TCLP was only rated at 13 rpm.
To evaluate the impact of the extractor speed on lead leachability during the TCLP three
samples of a “synthetic” CPU mixture were leached at 0, 13, and 28 rpm, respectively.
The TCLP, USEPA Method 1311, was performed by manually size reducing (i.e., hand
cutting with shears) 100-g samples of the “synthetic” CPU mixture so they were capable
of passing a 0.95-cm sieve (USEPA, 1996). The reader is referred to Chapter 2 for a
description of the preparation of the “synthetic” CPU mixture. The samples were placed
into a 2-L extraction vessel. Two liters of the TCLP extraction fluid #1 were added to
35
each sample and then the samples were placed on a rotary extractor (Analytical Testing
Corporation). The samples were performed in triplicate and a TCLP blank was included
for each set of leaching extractions. The three samples were rotated at 0, 13 and 28 rpm,
respectively, for 18 hours. The TCLP leachates were filtered through a glass fiber filter
of 0.7 µm pore size using the pressure filtration procedure and preserved by adding
concentrated nitric acid until the pH of the filtrate is below 2. In addition to collecting
the filtered leachate, samples of nonfiltered leachates were also collected. The samples
were then placed in HDPE bottles and stored until acid digestion.
3.2.5 Time Studies
A series of time studies were conducted to investigate lead leachability from
computer CPUs as a function of time for the large-scale modified TCLP method. Three
CPUs (2 different models) were tested in this series of time studies. Throughout the
period of the time study (approximately 90 hours); 2 L of the leachate were collected
approximately every 9 hours for metals analysis. Fresh extraction fluid was not added to
the sample to maintain the 20:1 liquid-to-solid ratio, thus the liquid-to-solid ratio of the
sample gradually decreased over the period of the experiment.
3.2.6 Methodology Comparison
A total of 40 CPUs were tested to compare the results between the TCLP and the
large-scale modified TCLP. The CPUs were split up into eight model types. Three
testing methodologies were performed on each CPU model: large-scale modified TCLP
on disassembled CPUs, TCLP on shredded CPUs, and TCLP on manually size-reduced
(i.e., hand cut) samples of selected CPU components. A detailed sampling sequence for
the methodology comparison testing is presented in Appendix C. Table 3-1 summarizes
36
the testing methodologies. The large-scale modified TCLP was performed, as described
in Section 3.2.3, on 17 of the CPUs.
Table 3-1. Testing Methodologies Time Studies Sample Model Testing Method 1 A Large-Scale/ Disassembled 2 A Large-Scale/ Disassembled 3 B Large-Scale/ Disassembled Methodology Comparison
# of CPUs Model Testing Methods 8 1 3-Shredded, 2-Hand Cut, 3-Large-Scale
4 2 2-Shredded, 1-Hand Cut, 1-Large-Scale 4 3 1-Shredded, 1-Hand Cut, 2-Large-Scale 4 4 1-Shredded, 2-Hand Cut, 1-Large-Scale 8 5 2-Shredded, 2-Hand Cut, 4-Large-Scale 4 6 1-Shredded, 1-Hand Cut, 2-Large-Scale 4 7 1-Shredded, 2-Hand Cut, 1-Large-Scale 4 8 1-Hand Cut, 3-Large-Scale
Two techniques for conducting the standard TCLP, each meeting the requirements
of the method, were performed on 23 of the CPUs tested in this study. Eleven of these
were shredded by passing the entire CPU through an industrial shear shredder, which was
located at an electronic equipment demanufacturing facility in Largo, FL, equipped with
2-inch blades (SSI Series 40H Model 2000-H). Since the materials did not meet the
TCLP size requirements after being passed through this shredder, each CPU was passed
through second shear shredder, which was located at SSI Shredding Systems Inc.
headquarters in Oregon, that was capable of size reducing the material down to 3/4 inch
(SSI Series 22Q Model Q55ED(40)). Each CPU was stored in plastic storage containers
and transported to the laboratory. Six 100-g samples were collected from each CPU that
37
was shredded. Each sample was then placed on a 0.95-cm sieve and the material that was
retained on the sieve was further processed by manually size reducing (i.e., hand cutting)
the pieces until they were capable of passing the 0.95-cm sieve as required by the TCLP
method. The remaining 12 CPUs were disassembled and representative fractions of the
major material types were selected at random. The materials were then manually size
reduced (hand cut) using shears to a size capable of passing the 0.95-cm sieve.
Each sample was placed into a 2-L extraction vessel. Two liters of the TCLP
extraction fluid #1 were added to each sample. The samples were placed on a rotary
extractor and rotated for 18 hours. The leachates were then filtered through a 0.7-µm
glass fiber filter using the pressure filtration technique and preserved with nitric for metal
analysis (USEPA, 1996)
3.3 Results
3.3.1 Impact of Extractor Speed
Results of the extractor speed study are presented in Figure 3-1. The TCLP
requires that the samples be rotated at 30±2 rpm; however, the extractor used in the large-
scale modified TCLP was only rated at 13 rpm. A Student’s t-test (α=0.5 using
Microsoft Excel) performed on the results indicated that lead and iron concentration in
the TCLP leachate was not significantly different between the samples rotated at 28 rpm
and the samples rotated at 13 rpm. Therefore, the speed of the large-scale extractor was
not expected to be a factor. Results also showed that the lead concentration measured in
the TCLP leachate was significantly higher in the sample that was not rotated (0 rpm).
This was attributed to the fact that the iron concentration in 0-rpm sample was
significantly lower (Student’s t-test, α=0.05 using Microsoft Excel) than the 13-rpm and
38
28-rpm samples. A previous study (Chapter 2) by the author showed that iron impacted
lead leachability from computer CPUs during the TCLP. The presence of ferrous metal
in the sample tended to decrease the amount of lead that was measured in the TCLP
leachate. The TCLP leaching solution tended to become more reducing as iron leached
into solution thus reduced the amount of lead measured in the leachate. The higher lead
concentration in the 0-rpm sample was attributed to lower iron concentration. It appears
that the iron did not reduce the lead to the extent that it did in the 13-rpm and 28-rpm
samples.
0.01
0.10
1.00
10.00
100.00
0 RPM 13 RPM 28 RPM
Con
cent
ratio
n (m
g/L)
.
Pb Fe
Figure 3-1. Impact of Rotation Speed Results
3.3.2 Time Studies
The lead and iron concentrations ranged from 1 mg/L to 10 mg/L and 13 mg/L to
341 mg/L, respectively. The highest lead concentrations measured in the filtered
leachates of the three samples ranged from 6 mg/L to 10 mg/L between 18 hours and
27 hours. After 27 hours the lead concentration tended to decrease below the 5 mg/L TC
limit. The lead concentration was observed to increase again after 80 hours of rotation.
39
Iron leachability tended to peak between 45 hours and 60 hours. Iron concentrations in
the filtered leachates tended to increase with time and peaked between 45 hours and
60 hours at concentrations ranging from 292 mg/L to 341 mg/L. After approximately
60 hours, the iron concentrations in all three samples tended to decrease with time. The
lead and iron results of the modified large-scale TCLP time study samples are presented
in Figure 3-2. This figure provides a comparison of the filtered and nonfiltered results.
The TCLP leachate of all of the samples was visually observed to change from a
gray color initially to an orange (rust) color as time progressed, which indicated that the
iron was being oxidized. The copper concentrations measured in the leachate of all of the
samples generally were not detected (MDL=0.1 mg/L) in the filtered samples. The zinc
concentration measured in the leachate of the large-scale modified TCLP time study
samples varied between 116 mg/L and 167 mg/L and did not change greatly with time.
The pH of the TCLP leachate that was measured in Samples 1, 2, and 3 ranged
from 5.01 to 5.47 with the highest values, 5.47, 5.42, and 5.44, respectively, occurring
between 45 hours and 60 hours. After 60 hours the pH tended to decrease with time to
values ranging from 5.22 to 5.30 at approximately 90 hours. The ORP of the leaching
solution tended to fluctuate throughout the time period of the study and peaked between
9 hours and 27 hours, ranging from 55 RMV to 153 RMV. Results of these samples
indicated that the TCLP leaching fluid in the large-scale modified TCLP remained
oxidizing during the duration of the experiment.
40
A
Hours
0 20 40 60 80 100
Con
cent
ratio
n (m
g/L)
0.1
1
10
100
1000
10000 B
Hours
0 20 40 60 80 100
Con
cent
ratio
n (m
g/L)
0.1
1
10
100
1000
10000
C
Hours
0 20 40 60 80 100
Con
cent
ratio
n (m
g/L)
0.1
1
10
100
1000
10000
Pb Concentration Filtered SamplesPb Concentration Nonfiltered SamplesFe Concentration Filtered SamplesFe Concentration Nonfiltered Samples
Figure 3-2. Comparison of Metals Results from TCLP Time Study Experiments.
A) Sample 1. B) Sample 2. C) Sample 3.
Results presented in Figure 3-2 showed that the impact of lead leachability appears
to have been dominated by an oxidation-reduction process (reduction by metallic iron) in
the beginning of the time studies. This is evidenced by the small difference in the
concentrations of lead and iron measured in the leachates of the filtered and nonfiltered
41
samples. A previous study (Chapter 2) indicated that metallic iron and zinc reduced lead
during the TCLP. Reaction D-1 (Appendix D) demonstrates the reduction of lead ions by
metallic iron. This oxidation-reduction reaction indicated that the metallic iron and zinc
reduced the lead that was leached into solution, which resulted in the relatively low lead
concentrations that were measured in the leachate. As time progressed beyond
approximately 30 hours it appeared that lead leachability was primarily impacted by the
adsorption by hydrous ferric oxide process. The formation of hydrous ferric oxide during
the TCLP can cause lead, copper, and zinc to be removed from solution by adsorption. A
recent study showed that solution concentrations of lead, copper, and zinc decrease and
sorption increases as pH increases in the presence of hydrous ferric oxide (Kendall,
2003). Kendall found that lead was the most strongly adsorbed followed by copper and
zinc. In Kendall’s study half of the lead, copper, and zinc originally in solution were
adsorbed at pH values of 4, 6, and 7, respectively. Reaction D-5 shows that in an
oxidizing environment iron is oxidized and forms hydrous ferric oxide, which can adsorb
lead. As time progressed beyond 30 hours iron continued to oxidize and form hydrous
ferric oxide, which adsorbed the lead that was leached, which allowed additional lead to
leach into solution as evidenced by the nearly constant lead concentration measured in
the leachates of the filtered samples. Results indicated that lead adsorbed to the hydrous
ferric oxide and was filtered out during the filtration process.
42
A
Hours0 20 40 60 80 100
Pb (m
g/L)
0
5
10
15
20
25
30
35 B
Hours0 20 40 60 80 100
Fe (m
g/L)
0
200
400
600
800
1000
1200
C
Hours0 20 40 60 80 100
Cu
(mg/
L)
0.01
0.1
1
10
100
FilteredNonfiltered
D
Hours0 20 40 60 80 100
Zn (m
g/L)
100
120
140
160
180
200
Figure 3-3. Sample 2 Filtered vs. Nonfiltered Metals Concentrations. A) Lead. B) Iron. C) Copper. D) Zinc.
Analysis of the nonfiltered samples also indicated that copper was adsorbed during
the large-scale modified TCLP. The lead, iron, copper, and zinc concentrations from
Sample 2 are presented in Figure 3-3. These results also showed that as time increased
the difference in the lead, iron, and copper concentrations between the filtered and
nonfiltered samples increased. It is noted that copper in the filtered samples was only
detected in the 88 hour sample. This further confirmed Kendall’s findings. It appeared
that the iron was oxidized over the entire duration of the experiment and formed hydrous
ferric oxide, which absorbed a portion of the lead and copper that was leached. The
43
hydrous ferric oxide was filtered out during the filtration procedure, thus removing the
adsorbed lead and copper from the leachate. As time progressed lead and copper
continued to adsorb to the hydrous ferric oxide, which resulted in the large difference in
concentrations of the filtered and nonfiltered samples at the end of the experiments. The
zinc concentrations measured in the filtered and nonfiltered samples did not greatly
differ, which indicated that zinc was not adsorbed. This was not unexpected since the pH
of the solution was below 7.
3.3.3 Methodology Comparison
The lead concentrations measured in all of the leachates ranged from 0.2 mg/L to
21.4 mg/L with 14 of the 40 CPUs tested exceeding the 5 mg/L TC limit. Of the 14
CPUs that exceed the TC lead limit 13 were tested using the large-scale modified TCLP
method and one was tested using the standard TCLP method (shredded). The results also
showed that shredding the CPUs did not greatly impact the lead concentration in the
leachate when compared to the samples that were hand cut. Iron concentrations ranged
from 6 mg/L to 255 mg/L, copper concentrations ranged from below the detection limit
(0.05 mg/L) to 0.31 mg/L, and zinc concentrations ranged from 27 mg/L to 156 mg/L.
Based on the ferrous iron (Fe2+) analysis the iron that was measured in the leachate
ranged from 2% Fe2+ to 100% Fe2+ and was greater than 50% Fe2+ on a majority of
occasions. Results of the TCLP methodology comparison are presented in Table 3-2.
The pH measurements of the leachate from the standard TCLP ranged from 4.99 to
5.26 and from 5.03 to 5.32 in the large-scale modified TCLP. The ORP and DO
measurements indicated that the large-scale modified TCLP produced a more oxidizing
environment than the standard TCLP method. The ORP and DO measurements of the
leachate from the standard TCLP ranged from -42 RMV to -318 RMV and 0.25 mg/L to
44
1.14 mg/L, respectively. The ORP and DO measurements from the large-scale modified
TCLP ranged from -84 RMV to 170 RMV and 2.95 mg/L to 4.92 mg/L, respectively.
The ORP measurements from the large-scale TCLP were positive in a majority of
occasions.
Table 3-2. Methodology Comparison Results CPU Model Processing/ TCLP Method Lead
(mg/L) Iron
(mg/L) Copper (mg/L)
Zinc (mg/L)
1 1 Shredded/ Standard 1.4 92 BDL 112 2 1 Shredded/ Standard 6.0 38 BDL 107 3 1 Shredded/ Standard 1.00 86 BDL 103 4 1 Disassembled/ Large 9.0 104 BDL 143 5 1 Disassembled/ Large 9.0 94 BDL 153 6 1 Disassembled/ Large 8.0 93 BDL 156 7 1 Manual/ Standard 0.5 50 BDL 105 8 1 Manual/ Standard 0.4 11 BDL 118 9 2 Shredded/ Standard 1.1 106 BDL 84
10 2 Shredded/ Standard 0.9 85 BDL 122 11 2 Disassembled/ Large 5.5 255 BDL 128 12 2 Manual/ Standard 0.3 18 BDL 147 13 3 Shredded/ Standard 3.2 84 BDL 128 14 3 Disassembled/ Large 21.4 117 0.05 81 15 3 Disassembled/ Large 16.4 132 0.2 92 16 3 Manual/ Standard 2.3 20 BDL 147 17 4 Shredded/ Standard 1.0 119 BDL 99 18 4 Disassembled/ Large 9.5 127 BDL 103 19 4 Manual/ Standard 0.4 24 BDL 130 20 4 Manual/ Standard 0.5 31 BDL 122 21 5 Shredded/ Standard 3.6 96 BDL 43 22 5 Shredded/ Standard 1.5 136 BDL 52 23 5 Disassembled/ Large 5.3 65 BDL 21 24 5 Disassembled/ Large 3.1 24 0.06 33 25 5 Disassembled/ Large 15.5 131 0.08 27 26 5 Disassembled/ Large 4.0 62 0.05 34 27 5 Manual/ Standard 0.3 5 BDL 172 28 5 Manual/ Standard 3.1 59 0.06 115 29 6 Shredded/ Standard 1.3 111 BDL 111 30 6 Disassembled/ Large 0.6 44 BDL 99 31 6 Disassembled/ Large 0.5 50 BDL 101 32 6 Manual/ Standard 0.3 35 BDL 106 33 7 Shredded/ Standard 0.5 147 BDL 111 34 7 Disassembled/ Large 9.1 189 0.07 114 35 7 Manual/ Standard 0.2 6 BDL 168 36 7 Manual/ Standard 0.1 19 0.32 129 37 8 Disassembled/ Large 8.4 201 0.08 215 38 8 Disassembled/ Large 7.1 253 0.13 160 39 8 Disassembled/Large 6.6 267 0.14 134 40 8 Manual/ Standard 0.5 44 BDL 220
45
The lead, iron, and zinc data from CPU #1 are presented in Figure 3-4. These
figures represent a typical example of the data from the TCLP methodology comparison.
In general, the lead concentrations measured in the leachate of samples that were leached
using the large-scale modified TCLP method were higher than those leached using the
standard TCLP method. The iron and zinc concentrations measured in the leachate from
the large-scale modified TCLP were equal to or greater than the standard TCLP methods
in a majority of occasions. Copper was not detected (MDL=0.05) in any of the filtered
samples for CPU #1. The iron measured in the leachate existed mostly as Fe2+, indicating
that hydrous ferric oxide did not form. In general, the zinc concentrations varied between
all of the samples that were tested and did not tend to be impacted by the testing
methodology.
A
Shredded Large Hand Cut
Pb (m
g/L)
0
2
4
6
8
10B
Shredded Large Hand Cut
Fe (m
g/L)
0
20
40
60
80
100
120
C
Shredded Large Hand Cut
Zn (m
g/L)
0
20
40
60
80
100
120
140
160
180
Figure 3-4. Metal Concentrations from Methodology Comparison for CPU #1.
A) Lead Concentration. B) Iron Concentration. C) Zinc Concentration.
46
The pH, ORP, and DO data from CPU #1 are presented in Figure 3-5. The pH
measured in the leachates from CPU #1 ranged from 5.04 to 5.19 and did not greatly
differ between the testing methods. However, DO and ORP were impacted by the testing
methodology. The DO measurements from the large-scale modified TCLP ranged from
2.95 mg/L to 3.85 mg/L, whereas the DO from the standard TCLP tests ranged from 0.25
mg/L to 0.42 mg/L. The ORP ranged from 14.5 RMV to 124.1 RMV in the large-scale
modified TCLP and from -98 RMV to -310 RMV in the standard TCLP tests. These
results indicated that the leaching solution in the large-scale modified TCLP test was
more oxidizing than the leachate of the standard TCLP, as previously reported.
A
Shredded Large Hand Cut
pH
5.00
5.05
5.10
5.15
5.20B
Shredded Large Hand Cut
OR
P (R
MV
)
-300
-200
-100
0
100
C
Shredded Large Hand Cut
DO
(mg/
L)
0
1
2
3
4
Figure 3-5. Laboratory Measurements from Methodology Comparison for CPU #1.
A) Final pH. B) Final ORP. C) Final DO.
Previous work (Chapter 2) that evaluated the factors that affect lead leachability
from computer CPUs during the TCLP showed that the head space above the leaching
47
fluid can impact lead leachability from computer CPUs. Results from that study showed
as the head space-to-liquid ratio (Va/Vl) increased, the pH, DO, and ORP increased, thus
indicated that the TCLP leaching fluid became more oxidizing as Va/Vl increased. The
leachability of lead and iron increased as the environment of the leaching fluid became
more oxidizing. However, the Va/Vl ratio in the large-scale modified TCLP method was
not greatly different from the standard Va/Vl ratio of 0.16. For example, the mass of CPU
1 was 8,418 g, which resulted in 168.4 L of the TCLP leaching fluid being used in the
extraction based on a 20:1 liquid-to-solid ratio. The Va/Vl ratio of the large-scale
modified TCLP method was then estimated by assuming that the total volume of the
extraction drum was 55 gallons (208 L) and the volume taken up by the CPU itself was
1.85 L. This resulted in a Va/Vl ratio of approximately 0.22. This showed that there were
other factors that impacted the leaching solution in the large-scale modified TCLP
method that caused it to be a more oxidizing environment.
The difference between the TCLP and the large-scale modified TCLP can be
explained by understanding reduction by metallic iron and zinc. The electrode potentials,
with respect of oxidization of the metal to divalent ions, of zinc(+0.76 V) and iron
(+0.44 V) are higher than lead (+0.126 V), which means that both metallic zinc and
metallic iron can reduce Pb2+ ions that are leached into solution (Snoeyink et al. 1980).
The reduction of Pb2+ ions by metallic iron and zinc, which appears to have occurred, is
demonstrated in Reactions D-1 and D-2. Metallic iron can also cause the TCLP leaching
solution to become more reducing by consuming DO and H+ as iron dissolves and
releases Fe2+ ions into solution, as demonstrated in Reaction D-4 (Snoeyink et al. 1980).
In the TCLP methodology the CPU components are size reduced so that they are capable
48
of passing through a 0.95-cm sieve, while the components of the large-scale modified
TCLP are not size reduced. Size reduction of the components greatly increased the
surface area of the iron that was exposed to the leaching solution, which would otherwise
be protected by the galvanizing. Galvanizing (coating with a thin layer of zinc) is a form
of cathodic protection that is typically applied to steel to prevent corrosion (Snoeyink et
al. 1980). Exposing the raw iron to the leaching solution allowed it to dissolve into
solution more readily than the non-size reduced components. In this study metallic iron
appears to have caused the leachate of the TCLP to become more reducing by consuming
the DO and H+ that was in the leaching solution, which lowered the ORP. This was
evidenced by the negative ORP measurements and the relatively low DO concentrations
in the samples that were tested using the TCLP. The leachates of the large-scale modified
TCLP, however, were more oxidizing than the standard TCLP as evidenced by the
positive ORP measurements and relatively high DO concentrations. This may be
attributed to the fact that the components were not sized reduced, which limited the
amount of iron that was leached. An evaluation of the impact of size reduction on lead
and iron leachability during the large-scale modified TCLP would be beneficial.
Analysis of the nonfiltered samples indicated that the lead, iron, and zinc
concentrations did not greatly differ, on a majority of occasions, from the concentration
measured in the filtered samples during both TCLP methods evaluated in this study.
Copper on the other hand tended to only be present in the nonfiltered samples. This
indicated that although the large-scale modified TCLP produced a more oxidizing
environment, lead leachability appears to not have been impacted by adsorption by
49
hydrous ferric oxide. This was not unexpected since the time study results indicated that
adsorption by hydrous ferric oxide did not occur until after 30 hours of rotation.
3.4 Implications
Results of the work presented in this paper are intended to provide an overview of
the efforts to assess the applicability of an alternative method to the TCLP for the toxicity
characterization of computer CPUs. This research is part of an overall effort to assess the
RCRA TC of computer CPUs. It is noted that no interpretations of the results from this
study are made on the hazardous waste characterization of computer CPUs.
The standard TCLP method has requirements that often make it difficult to perform
the test on electronic devices, such as size reduction and mass of the sample being tested.
The biggest issue with performing the TCLP on electronic devices is obtaining a
representative size-reduced sample of the device. In addition, size reducing an electronic
device such as a CPU is difficult due the large bulky nature of the components. For
example, computer CPUs are composed of a high percentage of steel and other metals
that are difficult to cut. The use of industrial shredders for processing electronic devices
is not practical because they often lead to sample loss and cross contamination in addition
to not meeting the size requirements. Manual size reduction (i.e., hand cutting) using
small-scale laboratory equipment is the only reasonable option, which is very time
consuming. It is often left to the technician that is performing test to select the
components and process them for testing, which can introduce human bias into the
results.
There are several advantages to using the proposed large-scale modified TCLP
methodology. The first advantage is that it would allow an entire electronic device to be
tested, which would eliminate any human bias that is introduced when collecting the
50
sample and processing it for testing. The second advantage of the large-scale modified
TCLP is that a representative sample would be obtained since the entire device (or a
majority of it due to volume constraints) would be tested. Electronic devices, such as
computer CPUs, are composed of several components including: ferrous metals,
nonferrous metals, PWBs, plastics, and wires/cables. Obtaining a 100-g representative
sample (as required by the TCLP) that contains all of the components is not easily
accomplished and can lead to inaccurate results. The third advantage of the proposed
methodology is that it is more time efficient since the device being tested does not need
to be size reduced. As previously stated, size reducing an electronic device is difficult
and very time consuming. In the proposed large-scale TCLP the device would simply be
disassembled and placed into the extractor.
Although there are several advantages to the large-scale modified TCLP, there are
also some disadvantages. More chemicals are required to perform the large-scale
modified TCLP than the standard TCLP thus increasing the cost per sample. Another
disadvantage is that only one sample can be collected since the entire device is used in
the test.
Questions remain on the validity of the proposed large-scale TCLP. Although the
proposed method maintains the liquid-to-solid ratio and pH requirements of the TCLP, it
is not practical to size reduce an electronic device to meet the requirements of the TCLP.
The large-scale modified TLCP however, may be more realistic simulation of the
physical and chemical environment experienced in a municipal solid waste landfill. The
results show that the large-scale modified TCLP tends to produce an oxidizing leachate,
which provides a condition for lead, iron, and zinc to leach, whereas the standard TCLP
51
tended to produce a reducing environment. Also, iron can reduce the lead that is leached
into solution which results in low lead concentrations being measured in the leachate.
Research has show that the addition of iron filings to brass foundry waste reduces the
amount of lead that leaches by causing a reducing environment in the TCLP leachate
(Kendall, 2003). Another report also concluded that the addition of iron filings to the
foundry waste artificially alters the environmental character of the TCLP test by
increasing pH and lowering Eh and DO (Drexler, J., “Phase I: Characterization of Iron
Filings Treatment Method of Foundry Sands,” Expert Witness Report, Complaint 3007,
Boulder, Colorado, 1996). However, in a landfill environment Kendall explains that once
the iron is not available for reduction, copper and lead will leach from the waste at a rate
dependent on the local climate at the landfill. Kendall concluded that metallic iron or
iron oxides are not a reliable way to stabilize wastes in an uncontrolled environment such
as a landfill. The USEPA has recently decided that treating foundry waste with iron
filings constituted impermissible dilution, because the waste was treated by an ineffective
method (USEPA, 2001). The iron component of an electronic device will cause the
standard TCLP to become reducing and not provide accurate results. The leaching
solution in the large-scale modified TCLP does not tend to be impacted by the iron and
remains oxidizing, which allows the test to evaluate the leachability of the metals as it
was designed to do.
52
CHAPTER 4 SUMMARY, CONCLUSIONS, AND RECOMMENDATIONS
4.1 Summary
A study was performed to investigate the factors that impact lead leachability from
computer CPUs during the TCLP. Results of this study showed that several factors
impacted the leachability of lead during the TCLP. The biggest factor was the
composition of the CPU. Computer CPUs contain various materials including ferrous
metals, nonferrous metals, printed wiring boards (PWBs), plastics, and wires/cables.
Lead leachability was dependent on the amount of PWB in the CPU, which contains a
majority of the lead, and the amount of ferrous metal (i.e., galvanized steel) that was in
the sample. Results showed that the steel component of the CPU caused the leaching
solution to become more reducing. As the iron leached and dissolved into solution DO
and H+ were consumed as Fe2+ was released into the leachate, which resulted in an
decrease in the DO concentrations and ORP values of the leachate. As the fraction of
ferrous metal in the sample increased the solution became more reducing. In a reducing
environment lead, iron, and copper are not oxidized; they therefore do not leach into the
solution. Furthermore, metallic iron and zinc appears to have reduced the lead and copper
ions in the leachate.
Another factor that impacted lead leachability from CPUs during the TCLP was the
head space above the leaching solution. Results of the CPU leaching indicated that the
formation of hydrous ferric oxide also reduced the amount of lead in the TCLP leachate
when there was a large head space above the leaching solution. When there was a large
53
head space above the leaching fluid the solution became more oxidizing, which allowed
hydrous ferric oxide to form. Analysis of the nonfiltered samples suggested that a large
portion of the lead had been adsorbed and removed from solution.
This research also evaluated the applicability of a large-scale modified TCLP for
the toxicity characterization of computer CPUs. Results of this study showed that the
large-scale modified TCLP produced a more oxidized environment in the leaching
solution than the standard TCLP. This caused the lead concentrations measured in the
large-scale TCLP solution to be higher than the standard TCLP on a majority of
occasions. Analysis of the nonfiltered samples also indicated that lead was not adsorbed
and remained dissolved in the solution.
It appears that the difference between the results obtained from testing CPUs using
the TCLP and those tested using the large-scale modified TCLP can be explained by
understanding reduction by metallic iron. Metallic iron caused the TCLP leaching
solution to become more reducing by decreasing the DO concentrations and ORP values.
This was not quite the case; however, in the large-scale modified TCLP method. The
solution in the large-scale modified TCLP was more oxidizing than the standard TCLP.
In the TCLP methodology the CPU components are size reduced so that they are capable
of passing through a 0.95-cm sieve, while the components of the large-scale modified
TCLP are not size reduced. Size reduction of the components greatly increased the
surface area of the iron that was exposed to the leaching solution. It appeared that
exposing more surface area of iron to the leaching solution allowed it to dissolve into
solution more readily in the samples that were tested using the TCLP than the non-size
reduced samples that were tested using large-scale modified TCLP.
54
Analysis of the nonfiltered samples indicated that adsorption by hydrous ferric
oxide did not appear to have any major impact on lead leachability. This was not
unexpected since the time study results indicated that adsorption by hydrous ferric oxide
did not appear to occur until after 30 hours of rotation.
4.2 Conclusions
The conclusions of this research were as follows:
• The ferrous metal (i.e., steel) component impacted lead leachability from CPUs during the TCLP
• Lead concentrations in TCLP remained relatively low due to reduction by metallic
iron and zinc • The more steel that was present the less lead leached • Head space can impact lead leachability from computer CPUs due to adsorption by
hydrous ferric oxide • In general, the large-scale modified TCLP leached more lead than the standard TCLP • The large-scale modified TCLP appears to be a more practical way to characterize
large devices such as computer CPUs
4.3 Recommendations
This research was performed in support of an overall effort to assess the TC status
of discarded computer CPUs. The work presented here was not used to provide a
definitive answer as to whether computer CPUs are a RCRA TC hazardous waste. An
additional study should include leaching size-reduced CPUs using the large-scale
modified TCLP to evaluate of the impact of size reduction on lead and iron leachability
during this method. This would help determine if size reduction would cause the large-
scale modified TCLP to be reducing as seen in the standard TCLP. Further testing should
be performed to assess the RCRA TC status of computer CPUs when using the modified
55
large-scale TCLP method. Research should also focus on the applicability of the large-
scale modified TCLP for the RCRA toxicity characterization of other electronic devices
other than computer CPUs.
56
APPENDIX A LABORATORY DATA
Table A-1. TCLP Concentrations in Filtered Samples
Sample Name Material Pb (mg/L)
Fe (mg/L)
Cu (mg/L)
Zn (mg/L)
PWB 100g #1 PWB 155 5.0 0.7 0.3 PWB 100g #2 PWB 159 5.1 0.4 0.3 PWB 100g #3 PWB 140 6.1 0.5 7.5 PWB 70g #1 PWB 168 9.1 0.9 0.2 PWB 70g #2 PWB 158 5.9 0.6 0.2 PWB 70g #3 PWB 158 10.0 0.5 0.5 PWB 30g #1 PWB 58 0.9 0.6 0.2 PWB 30g #2 PWB 61 7.4 0.6 0.1 PWB 30g #3 PWB 63 1.4 0.4 0.1 PWB 15.8g #1 PWB 45 2.4 0.4 0.1 PWB 15.8g #2 PWB 33 1.6 0.3 0.1 PWB 15.8g #3 PWB 33 1.23 0.3 0.1 Standard #1 Synthetic Mix 0.6 18 BDL 161 Standard #2 Synthetic Mix 0.2 11 BDL 112 Standard #3 Synthetic Mix 0.2 28 BDL 135 Standard Small #1 Synthetic Mix 0.2 49 BDL 143 Standard Small #2 Synthetic Mix 0.3 59 BDL 147 Standard Small #3 Synthetic Mix 0.3 48 BDL 142 Material Impact #1 PWB 89 1.4 0.2 0.2 Material Impact #2 PWB 82 5.7 0.2 0.2 Material Impact #3 PWB 80 10.1 0.3 3.1 Material Impact #4 PWB & Ferrous 1.8 24 BDL 107 Material Impact #5 PWB & Ferrous 5.0 27 BDL 111 Material Impact #6 PWB & Ferrous 1.6 10.0 BDL 114 Material Impact #7 PWB & Nonferrous 60 7.9 BDL BDL Material Impact #8 PWB & Nonferrous 77 17 0.03 0.53 Material Impact #9 PWB & Nonferrous 69 4.0 0.004 0.015 Material Impact #10 PWB & Plastic 112 5.8 1.0 0.3 Material Impact #11 PWB & Plastic 120 16 1.8 0.2 Material Impact #12 PWB & Plastic 108 3.1 1.4 0.2 Ferrous Impact 0% #1 Synthetic Mix 40 0.9 2.1 0.2 Ferrous Impact 0% #2 Synthetic Mix 42 1.23 1.7 0.2 Ferrous Impact 0% #3 Synthetic Mix 52 18 2.2 4.0 Ferrous Impact 20% #1 Synthetic Mix 8.9 72 BDL 56
57
Table A-1 continued
Sample Name Material Pb (mg/L)
Fe (mg/L)
Cu (mg/L)
Zn (mg/L)
Ferrous Impact 20% #2 Synthetic Mix 5.9 61 BDL 61 Ferrous Impact 20% #3 Synthetic Mix 6.8 74 BDL 53 Ferrous Impact 40% #1 Synthetic Mix 1.2 29 0.06 113 Ferrous Impact 40% #2 Synthetic Mix 3.1 46 BDL 93 Ferrous Impact 40% #3 Synthetic Mix 1.6 46 BDL 99 Va/Vl=0 #1 Synthetic Mix 0.6 6.8 BDL 106 Va/Vl=0 #2 Synthetic Mix 0.6 6.5 BDL 115 Va/Vl=0 #3 Synthetic Mix 0.5 6.7 BDL 114 Va/Vl=0.5 #1 Synthetic Mix 1.1 209 BDL 129 Va/Vl=0.5 #2 Synthetic Mix 0.7 190 BDL 142 Va/Vl=0.5 #3 Synthetic Mix 0.7 185 BDL 147 Va/Vl=1 #1 Synthetic Mix 3.3 175 0.1 139 Va/Vl=1 #2 Synthetic Mix 2.2 250 BDL 141 Va/Vl=1 #3 Synthetic Mix 2.0 227 BDL 141 0 RPM #1 Synthetic Mix 1.3 0.8 0.06 29 0 RPM #2 Synthetic Mix 1.5 0.5 0.08 28 0 RPM #3 Synthetic Mix 1.2 0.7 0.08 42 13 RPM #1 Synthetic Mix 0.1 26 BDL 145 13 RPM #2 Synthetic Mix 0.2 22 BDL 142 13 RPM #3 Synthetic Mix 0.4 29 BDL 132
58
Table A-2. Time Study Concentrations in Filtered Samples
Time Study Sample Method Hour Pb (mg/L)
Fe (mg/L)
Cu (mg/L)
Zn (mg/L)
1 Large 9 2.3 27 BDL 116 1 Large 18 6.2 98 BDL 138 1 Large 27 6.8 187 BDL 143 1 Large 36 2.0 268 BDL 146 1 Large 45 1.7 341 BDL 151 1 Large 57 1.0 322 BDL 146 1 Large 66 1.4 249 BDL 142 1 Large 76 1.5 189 BDL 140 1 Large 85 4.4 150 BDL 141 1 Large 93 5.1 121 BDL 136 2 Large 9 3.1 26 BDL 125 2 Large 18 3.4 87 BDL 151 2 Large 27 5.9 178 BDL 160 2 Large 36 3.2 269 BDL 163 2 Large 45 5.2 291 BDL 165 2 Large 59 1.1 304 BDL 165 2 Large 66.5 2.6 245 BDL 160 2 Large 75 3.8 176 BDL 150 2 Large 85 3.5 134 BDL 140 2 Large 88 6.7 135 0.2 141 3 Large 9 4.7 12.9 BDL 123 3 Large 18 9.9 76 BDL 141 3 Large 27 7.2 174 BDL 155 3 Large 37 2.7 261 BDL 167 3 Large 45.5 2.6 292 BDL 167 3 Large 60 2.3 275 BDL 160 3 Large 69.5 1.5 235 BDL 158 3 Large 81.5 1.3 177 BDL 145 3 Large 90.5 3.1 164 0.1 166 3 Large 92 2.8 176 0.4 164
59
Table A-3. Methodology Comparison Concentrations in Filtered Samples
CPU Model Processing Method
TCLP Method
Pb (mg/L)
Fe (mg/L)
Cu (mg/L)
Zn (mg/L)
1 1 Shredded #1 Standard 0.3 89 0.6 105 1 1 Shredded #2 Standard 5.5 103 BDL 104 1 1 Shredded #3 Standard 0.5 84 BDL 93 1 1 Shredded #4 Standard 1.3 106 BDL 118 1 1 Shredded #5 Standard 0.2 76 BDL 129 1 1 Shredded #6 Standard 0.3 97 BDL 124 2 1 Shredded #1 Standard 5.9 56 BDL 80 2 1 Shredded #2 Standard 7.1 79 BDL 93 2 1 Shredded #3 Standard 5.2 23 BDL 135 2 1 Shredded #4 Standard 3.6 29 BDL 115 2 1 Shredded #5 Standard 10.2 16 BDL 114 2 1 Shredded #6 Standard 4.0 23 BDL 103 3 1 Shredded #1 Standard 0.2 109 BDL 111 3 1 Shredded #2 Standard 3.0 85 BDL 72 3 1 Shredded #3 Standard 0.9 80 BDL 106 3 1 Shredded #4 Standard 0.1 66 BDL 122 3 1 Shredded #5 Standard 1.2 92 BDL 109 3 1 Shredded #6 Standard 0.6 81 BDL 95 4 1 Disassembled Large 8.6 104 BDL 143 5 1 Disassembled Large 8.9 94 BDL 153 6 1 Disassembled Large 8.3 93 BDL 156 7 1 Manual #1 Standard 0.7 56 BDL 101 7 1 Manual #2 Standard 0.5 43 BDL 107 7 1 Manual #3 Standard 0.4 50 BDL 107 8 1 Manual #1 Standard 0.4 12 BDL 108 8 1 Manual #2 Standard 0.3 5.3 BDL 133 8 1 Manual #3 Standard 0.4 17 BDL 112 9 2 Shredded #1 Standard 0.8 111 BDL 69 9 2 Shredded #2 Standard 1.6 117 BDL 81 9 2 Shredded #3 Standard 0.5 82 BDL 98 9 2 Shredded #4 Standard 0.5 102 BDL 80 9 2 Shredded #5 Standard 0.2 120 BDL 85 9 2 Shredded #6 Standard 3.1 104 BDL 90 10 2 Shredded #1 Standard 2.2 106 BDL 110 10 2 Shredded #2 Standard 0.6 71 BDL 122 10 2 Shredded #3 Standard 0.1 86 BDL 132 10 2 Shredded #4 Standard 1.1 83 BDL 138 10 2 Shredded #5 Standard 0.1 61 BDL 132 10 2 Shredded #6 Standard 1.0 104 BDL 108 11 2 Disassembled Large 5.5 255 BDL 128 12 2 Manual #1 Standard 0.4 20 BDL 151 12 2 Manual #2 Standard 0.3 18 BDL 144
60
Table A-3 continued
CPU Model Processing Method
TCLP Method
Pb (mg/L)
Fe (mg/L)
Cu (mg/L)
Zn (mg/L)
12 2 Manual #3 Standard 0.2 14 BDL 145 13 3 Shredded #1 Standard 5.4 116 BDL 132 13 3 Shredded #2 Standard 0.9 61 BDL 184 13 3 Shredded #3 Standard 4.3 74 BDL 113 13 3 Shredded #4 Standard 3.5 73 BDL 122 13 3 Shredded #5 Standard 0.5 112 BDL 92 13 3 Shredded #6 Standard 4.6 68 BDL 124 14 3 Disassembled Large 21 117 0.05 81 15 3 Disassembled Large 16 132 0.2 92 16 3 Manual #1 Standard 3.1 25 BDL 153 16 3 Manual #2 Standard 1.4 5.1 BDL 157 16 3 Manual #3 Standard 2.3 28 BDL 130 17 4 Shredded #1 Standard 0.4 141 BDL 85 17 4 Shredded #2 Standard 0.5 124 BDL 94 17 4 Shredded #3 Standard 0.9 85 BDL 116 17 4 Shredded #4 Standard 1.2 132 BDL 106 17 4 Shredded #5 Standard 1.0 117 BDL 89 17 4 Shredded #6 Standard 1.7 115 BDL 106 18 4 Disassembled Large 9.5 127 BDL 103 19 4 Manual #1 Standard 0.4 23 BDL 134 19 4 Manual #2 Standard 0.4 22 BDL 129 19 4 Manual #3 Standard 0.5 26 BDL 126 20 4 Manual #1 Standard 0.6 29 BDL 128 20 4 Manual #2 Standard 0.3 36 BDL 121 20 4 Manual #3 Standard 0.7 29 BDL 116 21 5 Shredded #1 Standard 4.3 93 BDL 43 21 5 Shredded #2 Standard 3.0 76 BDL 60 21 5 Shredded #3 Standard 2.7 93 BDL 62 21 5 Shredded #4 Standard 1.7 110 BDL 21 21 5 Shredded #5 Standard 6.5 102 BDL 37 21 5 Shredded #6 Standard 3.3 103 BDL 35 22 5 Shredded #1 Standard 2.5 132 BDL 61 22 5 Shredded #2 Standard 1.5 129 BDL 39 22 5 Shredded #3 Standard 1.3 151 BDL 44 22 5 Shredded #4 Standard 1.8 146 BDL 30 22 5 Shredded #5 Standard 0.8 131 BDL 70 22 5 Shredded #6 Standard 1.1 123 BDL 71 23 5 Disassembled Large 5.3 65 BDL 21 24 5 Disassembled Large 3.1 24 0.06 33 25 5 Disassembled Large 16 131 0.08 27 26 5 Disassembled Large 4.0 62 0.05 34 27 5 Manual #1 Standard 0.3 5.4 BDL 177
61
Table A-3 continued
CPU Model Processing Method
TCLP Method
Pb (mg/L)
Fe (mg/L)
Cu (mg/L)
Zn (mg/L)
27 5 Manual #2 Standard 0.3 4.9 BDL 173 27 5 Manual #3 Standard 0.2 4.2 BDL 165 28 5 Manual #1 Standard 3.9 57 0.08 123 28 5 Manual #2 Standard 2.8 56 BDL 115 28 5 Manual #3 Standard 2.5 64 0.06 108 29 6 Shredded #1 Standard 2.5 92 BDL 97 29 6 Shredded #2 Standard 0.5 133 BDL 75 29 6 Shredded #3 Standard 0.3 130 BDL 79 29 6 Shredded #4 Standard 0.7 115 BDL 79 29 6 Shredded #5 Standard 2.2 111 BDL 92 29 6 Shredded #6 Standard 1.5 85 BDL 94 30 6 Disassembled Large 0.6 44 BDL 99 31 6 Disassembled Large 0.5 50 BDL 101 32 6 Manual #1 Standard 0.4 39 BDL 103 32 6 Manual #2 Standard 0.3 27 BDL 107 32 6 Manual #3 Standard 0.3 40 BDL 107 33 7 Shredded #1 Standard 0.7 132 BDL 111 33 7 Shredded #2 Standard 0.2 174 BDL 127 33 7 Shredded #3 Standard 0.1 123 BDL 90 33 7 Shredded #4 Standard 0.6 111 BDL 99 33 7 Shredded #5 Standard 1.1 165 BDL 121 33 7 Shredded #6 Standard 0.4 179 BDL 120 34 7 Disassembled Large 9.1 189 0.07 114 35 7 Manual #1 Standard 0.2 6.6 BDL 160 35 7 Manual #2 Standard 0.2 5.6 BDL 174 35 7 Manual #3 Standard 0.3 6.3 0.08 171 36 7 Manual #1 Standard 0.2 22 0.9 127 36 7 Manual #2 Standard 0.1 22 BDL 132 36 7 Manual #3 Standard 0.1 13 BDL 129 37 8 Disassembled Large 8.4 201 0.08 215 38 8 Disassembled Large 7.1 253 0.13 160 39 8 Disassembled Large 6.6 267 0.14 134 40 8 Manual #1 Standard 0.5 38 0.07 235 40 8 Manual #2 Standard 0.4 27 BDL 213 40 8 Manual #3 Standard 0.5 68 BDL 211
62
Table A-4. TCLP Concentrations in Nonfiltered Samples
Sample Name Material Pb (mg/L)
Fe (mg/L)
Cu (mg/L)
Zn (mg/L)
PWB 100g #1 PWB 156 5.3 5.8 0.3 PWB 100g #2 PWB 158 5.3 4.5 0.2 PWB 100g #3 PWB 140 15 11.3 7.3 PWB 70g #1 PWB 167 9.9 6.4 0.3 PWB 70g #2 PWB 164 7.0 10.4 0.3 PWB 70g #3 PWB 163 13 12 0.8 PWB 30g #1 PWB 60 1.2 1.5 0.1 PWB 30g #2 PWB 54 6.9 1.8 0.2 PWB 30g #3 PWB 65 1.8 1.6 0.2 PWB 15.8g #1 PWB 47 3.0 0.8 0.08 PWB 15.8g #2 PWB 33 2.00 0.7 0.08 PWB 15.8g #3 PWB 37 2.0 0.8 0.2 Standard #1 Synthetic Mix 0.6 21 1.1 159 Standard #2 Synthetic Mix 0.5 20 1.1 142 Standard #3 Synthetic Mix 0.3 29 0.8 133 Standard Small #1 Synthetic Mix 0.4 52 1.3 146 Standard Small #2 Synthetic Mix 0.4 58 1.8 140 Standard Small #3 Synthetic Mix 1.0 50.2 1.1 140 Material Impact #1 PWB 90.69 1.4 2.2 0.2 Material Impact #2 PWB 85 6.2 2.9 0.2 Material Impact #3 PWB 82 10.9 2.4 3.1 Material Impact #4 PWB & Ferrous 2.1 28 2.4 107 Material Impact #5 PWB & Ferrous 5.3 27 2.6 108 Material Impact #6 PWB & Ferrous 4.0 18 1.7 114 Material Impact #7 PWB & Nonferrous 64 11.5 3.6 0.6 Material Impact #8 PWB & Nonferrous 82 20 4.0 0.6 Material Impact #9 PWB & Nonferrous 71 7.2 4.2 0.02 Material Impact #10 PWB & Plastic 110 6.2 3.3 0.3 Material Impact #11 PWB & Plastic 116 16 4.6 0.2 Material Impact #12 PWB & Plastic 109 3.5 4.1 0.3 Ferrous Impact 0% #1 Synthetic Mix 40.8 1.2 7.0 0.3 Ferrous Impact 0% #2 Synthetic Mix 42 2.0 4.4 0.2 Ferrous Impact 0% #3 Synthetic Mix 53 19 5.3 4.0 Ferrous Impact 20% #1 Synthetic Mix 9.5 74 5.1 54 Ferrous Impact 20% #2 Synthetic Mix 7.4 77 8.8 52 Ferrous Impact 20% #3 Synthetic Mix 6.3 63 4.5 58 Ferrous Impact 40% #1 Synthetic Mix 1.6 32 0.6 113 Ferrous Impact 40% #2 Synthetic Mix 3.5 48 0.05 93 Ferrous Impact 40% #3 Synthetic Mix 2.2 51 0.04 99 Va/Vl=0 #1 Synthetic Mix 0.7 9.5 3.7 102 Va/Vl=0 #2 Synthetic Mix 0.8 7.6 1.5 113 Va/Vl=0 #3 Synthetic Mix 0.8 8.1 2.4 113
63
Table A-4 continued
Sample Name Material Pb (mg/L)
Fe (mg/L)
Cu (mg/L)
Zn (mg/L)
Va/Vl=0.5 #1 Synthetic Mix 2.2 233 3.1 132 Va/Vl=0.5 #2 Synthetic Mix 1.4 213 2.6 145 Va/Vl=0.5 #3 Synthetic Mix 1.8 208 3.3 149 Va/Vl=1 #1 Synthetic Mix 17 417 6.1 142 Va/Vl=1 #2 Synthetic Mix 14 295 3.5 143 Va/Vl=1 #3 Synthetic Mix 12 446 3.5 143 0 RPM #1 Synthetic Mix 1.3 0.7 0.07 27 0 RPM #2 Synthetic Mix 1.4 0.5 0.08 25 0 RPM #3 Synthetic Mix 1.1 0.7 0.09 37 13 RPM #1 Synthetic Mix 0.2 28 1.8 144 13 RPM #2 Synthetic Mix 0.6 24 1.2 137 13 RPM #3 Synthetic Mix 0.7 30 0.6 129
64
Table A-5. Methodology Comparison Concentrations in Nonfiltered Samples
CPU Model Processing Method
TCLP Method
Pb (mg/L)
Fe (mg/L)
Cu (mg/L)
Zn (mg/L)
1 1 Shredded #1 Standard 0.9 94 5.9 102 1 1 Shredded #2 Standard 12 132 7.4 98 1 1 Shredded #3 Standard 1.0 87 3.5 89 2 1 Shredded #1 Standard 26 66 7.9 79 2 1 Shredded #2 Standard 15 118 9.3 91 2 1 Shredded #3 Standard 20 235 10.6 130 3 1 Shredded #1 Standard 0.5 105 0.9 101 3 1 Shredded #2 Standard 3.4 87 1.1 72 3 1 Shredded #3 Standard 1.4 83 2.1 102 4 1 Disassembled Large 9.9 118 1.1 142 5 1 Disassembled Large 10 108 1.0 152 6 1 Disassembled Large 9.4 104 1.3 153 7 1 Manual #1 Standard 1.1 56 1.2 99 7 1 Manual #2 Standard 0.9 45 1.3 107 7 1 Manual #3 Standard 0.8 50 0.2 105 8 1 Manual #1 Standard 0.8 13 1.2 108 8 1 Manual #2 Standard 0.4 6.1 0.8 132 8 1 Manual #3 Standard 0.7 18 1.0 113 9 2 Shredded #1 Standard 1.3 114 2.0 69 9 2 Shredded #2 Standard 3.0 123 3.4 79 9 2 Shredded #3 Standard 0.7 84 1.3 96 10 2 Shredded #1 Standard 5.7 122 6.8 113 10 2 Shredded #2 Standard 1.1 78 3.1 123 10 2 Shredded #3 Standard 0.3 87 1.2 119 11 2 Disassembled Large 7.6 283 0.7 128 12 2 Manual #1 Standard 0.5 23 0.7 145 12 2 Manual #2 Standard 0.7 28 0.9 143 12 2 Manual #3 Standard 0.7 17 1.1 141 13 3 Shredded #1 Standard 10.4 147 10.6 126 13 3 Shredded #2 Standard 4.3 66 2.4 177 13 3 Shredded #3 Standard 9.1 82 6.1 116 14 3 Disassembled Large 22 122 10.2 80 15 3 Disassembled Large 17 138 2.7 93 16 3 Manual #1 Standard 3.2 25 0.9 150 16 3 Manual #3 Standard 3.1 32 0.9 139 17 4 Shredded #1 Standard 1.0 144 3.7 81 17 4 Shredded #2 Standard 0.9 136 2.8 91 17 4 Shredded #3 Standard 2.5 98 4.2 116 18 4 Disassembled Large 10.4 137 0.4 102 19 4 Manual #1 Standard 0.9 23 0.7 132 19 4 Manual #2 Standard 1.0 24 1.1 131 19 4 Manual #3 Standard 1.1 28 1.3 127
65
Table A-5 continued
CPU Model Processing Method
TCLP Method
Pb (mg/L)
Fe (mg/L)
Cu (mg/L)
Zn (mg/L)
20 4 Manual #1 Standard 0.8 30 1.1 123 20 4 Manual #2 Standard 0.4 36 1.3 119 20 4 Manual #3 Standard 2.0 31 1.6 119 21 5 Shredded #1 Standard 8.2 97 2.0 44 21 5 Shredded #2 Standard 4.2 81 3.2 60 21 5 Shredded #3 Standard 3.1 100 1.2 63 22 5 Shredded #1 Standard 4.6 141 0.2 60 22 5 Shredded #2 Standard 2.7 135 4.0 38 22 5 Shredded #3 Standard 2.3 166 5.5 44 23 5 Disassembled Large 6.3 68 1.1 21 27 5 Manual #1 Standard 0.5 6.6 0.7 175 27 5 Manual #2 Standard 0.6 5.4 0.7 163 27 5 Manual #3 Standard 0.4 6.2 0.6 173 29 6 Shredded #1 Standard 3.5 97 3.3 95 29 6 Shredded #2 Standard 1.9 138 5.9 72 29 6 Shredded #3 Standard 0.8 145 3.8 77 30 6 Disassembled Large 0.8 47 0.3 99 31 6 Disassembled Large 1.2 53 1.3 100 32 6 Manual #1 Standard 0.8 42 1.6 103 32 6 Manual #2 Standard 0.5 29 1.5 107 32 6 Manual #3 Standard 0.6 41 1.1 107 33 7 Shredded #1 Standard 3.5 97 3.3 95 33 7 Shredded #2 Standard 1.9 138 5.9 720 33 7 Shredded #3 Standard 0.8 145 3.8 77 34 7 Disassembled Large 10.8 211 0.6 113 35 7 Manual #1 Standard 2.4 12 2.5 161 35 7 Manual #2 Standard 0.4 7.0 1.2 176 35 7 Manual #3 Standard 0.7 10.3 2.6 167 36 7 Manual #1 Standard 0.2 26 1.5 131 36 7 Manual #2 Standard 0.2 23 1.0 131 36 7 Manual #3 Standard 0.3 24 8.8 129
66
Table A-6. Time Study Concentrations in Nonfiltered Samples
Time Study Sample Method Hour Pb (mg/L)
Fe (mg/L)
Cu (mg/L)
Zn (mg/L)
1 Large 9 2.6 33 0.3 114 1 Large 18 7.8 119 1.0 141 1 Large 27 10.2 235 1.9 148 1 Large 36 6.7 364 2.5 157 1 Large 45 8.7 453 2.6 145 1 Large 57 10.8 599 4.3 158 1 Large 66 13 627 4.8 144 1 Large 76 16 851 7.2 171 1 Large 85 21 759 6.8 154 1 Large 93 26 1044 6.9 170 2 Large 9 3.7 36 0.4 126 2 Large 18 5.3 119 1.3 163 2 Large 27 8.7 214 1.8 156 2 Large 36 8.4 353 2.6 165 2 Large 45 14 464 3.1 178 2 Large 59 9.7 434 3.7 111 2 Large 66.5 20 746 5.9 181 2 Large 75 23 815 6.6 171 2 Large 85 24 960 8.2 171 2 Large 88 32 1080 9.7 171 3 Large 9 5.2 19 0.4 129 3 Large 18 13 105 1.0 175 3 Large 27 9.6 200 2.3 162 3 Large 37 6.7 316 4.1 168 3 Large 45.5 9.2 363 4.6 150 3 Large 60 13 499 6.9 169 3 Large 69.5 17 616 9.4 180 3 Large 81.5 18 660 9.1 172 3 Large 90.5 26 750 11.5 172
67
Table A-7. TCLP pH, DO, and ORP Measurements Final
Sample Name Material pH DO (mg/L)
ORP (RMV)
PWB 100g #1 PWB 4.909 3.10 214.5 PWB 100g #2 PWB 4.913 2.60 213.1 PWB 100g #3 PWB 4.901 3.07 208.4 PWB 70g #1 PWB 4.946 3.80 88.7 PWB 70g #2 PWB 4.923 3.83 84.4 PWB 70g #3 PWB 4.925 3.32 63.7 PWB 30g #1 PWB 4.918 6.55 126.1 PWB 30g #2 PWB 4.918 6.16 135.2 PWB 30g #3 PWB 4.923 6.41 146.1 PWB 15.8g #1 PWB 4.919 6.83 126.8 PWB 15.8g #2 PWB 4.913 6.90 124.9 PWB 15.8g #3 PWB 4.908 6.84 125.0 Standard #1 Synthetic Mix 5.168 0.23 -403.2 Standard #2 Synthetic Mix 5.157 0.26 -161.4 Standard #3 Synthetic Mix 5.155 0.24 -123.5 Standard Small #1 Synthetic Mix 5.176 0.24 -410.2 Standard Small #2 Synthetic Mix 5.199 0.26 -384.8 Standard Small #3 Synthetic Mix 5.158 0.32 -402.7 Material Impact #1 PWB 4.732 - - Material Impact #2 PWB 4.738 - - Material Impact #3 PWB 4.745 - - Material Impact #4 PWB & Ferrous 4.789 - - Material Impact #5 PWB & Ferrous 4.777 - - Material Impact #6 PWB & Ferrous 4.768 - - Material Impact #7 PWB & Nonferrous 5.169 - - Material Impact #8 PWB & Nonferrous 5.023 - - Material Impact #9 PWB & Nonferrous 5.119 - - Material Impact #10 PWB & Plastic 5.003 - - Material Impact #11 PWB & Plastic 5.016 - - Material Impact #12 PWB & Plastic 4.997 - - Ferrous Impact 0% #1 Synthetic Mix 4.853 6.60 219.5 Ferrous Impact 0% #2 Synthetic Mix 4.867 6.92 195.5 Ferrous Impact 0% #3 Synthetic Mix 4.892 5.43 125.5 Ferrous Impact 20% #1 Synthetic Mix 4.966 0.61 -110.9 Ferrous Impact 20% #2 Synthetic Mix 4.968 0.56 -131.3 Ferrous Impact 20% #3 Synthetic Mix 4.969 0.54 -74.0 Ferrous Impact 40% #1 Synthetic Mix 4.988 0.42 -154.4 Ferrous Impact 40% #2 Synthetic Mix 4.993 0.50 -96.6
68
Table A-7 continued Final
Sample Name Material pH DO (mg/L)
ORP (RMV)
Ferrous Impact 40% #3 Synthetic Mix 4.991 0.49 -111.4 Va/Vl=0 #1 Synthetic Mix 5.068 0.36 -514.5 Va/Vl=0 #2 Synthetic Mix 5.053 0.43 -518.8 Va/Vl=0 #3 Synthetic Mix 5.039 0.44 -517.8 Va/Vl=0.5 #1 Synthetic Mix 5.369 0.56 171.0 Va/Vl=0.5 #2 Synthetic Mix 5.366 0.62 88.3 Va/Vl=0.5 #3 Synthetic Mix 5.377 0.70 62.0 Va/Vl=1 #1 Synthetic Mix 5.321 0.95 -31.6 Va/Vl=1 #2 Synthetic Mix 5.378 0.63 -2.4 Va/Vl=1 #3 Synthetic Mix 5.382 0.53 -35.1 0 RPM #1 Synthetic Mix 5.016 6.27 25.3 0 RPM #2 Synthetic Mix 5.016 6.41 38.0 0 RPM #3 Synthetic Mix 5.019 6.17 21.1 13 RPM #1 Synthetic Mix 5.173 0.23 -393.5 13 RPM #2 Synthetic Mix 5.168 0.29 -358.6 13 RPM #3 Synthetic Mix 5.160 0.30 -330.4
69
Table A-8. Time Study pH, DO, and ORP Measurements Final
Time Study Sample Method Hour pH DO (mg/L)
ORP (RMV)
1 Large 9 5.039 - 25.2 1 Large 18 5.160 - 117.2 1 Large 27 5.218 - 108.7 1 Large 36 5.329 - 95.1 1 Large 45 5.472 - 76.1 1 Large 57 5.442 - 60.5 1 Large 66 5.343 - 85.6 1 Large 76 5.328 - 79.3 1 Large 85 5.231 - 96.4 1 Large 93 5.241 - 110.6 2 Large 9 5.041 - 92.8 2 Large 18 5.158 - 122.3 2 Large 27 5.277 - 104.3 2 Large 36 5.353 - 94.3 2 Large 45 5.423 - 51.5 2 Large 59 5.392 - 70.2 2 Large 66.5 5.344 - 90.4 2 Large 75 5.333 - 107.2 2 Large 85 5.260 - 116.3 2 Large 88 5.298 - 117.7 3 Large 9 5.011 - 152.7 3 Large 18 5.165 - 135.8 3 Large 27 5.226 - 110.8 3 Large 37 5.369 - 94.9 3 Large 45.5 5.397 - 85.3 3 Large 60 5.436 - 55.0 3 Large 69.5 5.288 - 67.9 3 Large 81.5 5.212 - 82.0 3 Large 90.5 5.218 - 87.5 3 Large 92 5.286 - 58.8
70
Table A-9. Methodology Comparison pH, DO, and ORP Measurements Final
CPU Model Processing Method
TCLP Method pH DO
(mg/L) ORP
(RMV) 1 1 Shredded #1 Standard 5.094 0.55 -171.1 1 1 Shredded #2 Standard 5.131 0.17 -281.3 1 1 Shredded #3 Standard 5.073 0.33 -242.4 1 1 Shredded #4 Standard 5.163 0.22 -193.4 1 1 Shredded #5 Standard 5.132 0.29 -239.5 1 1 Shredded #6 Standard 5.219 0.26 -252.4 2 1 Shredded #1 Standard 5.052 0.19 -129.5 2 1 Shredded #2 Standard 5.083 0.23 -170.4 2 1 Shredded #3 Standard 5.079 0.28 -233.8 2 1 Shredded #4 Standard 5.046 0.28 -219.4 2 1 Shredded #5 Standard 5.037 0.21 -292.1 2 1 Shredded #6 Standard 5.035 0.31 -309.7 3 1 Shredded #1 Standard 5.135 0.67 -188.1 3 1 Shredded #2 Standard 5.064 0.29 -183.5 3 1 Shredded #3 Standard 5.089 0.30 -216.8 3 1 Shredded #4 Standard 5.116 0.49 -199.5 3 1 Shredded #5 Standard 5.116 0.33 -231.6 3 1 Shredded #6 Standard 5.088 0.46 -163.7 4 1 Disassembled Large 5.191 3.85 76.5 5 1 Disassembled Large 5.134 3.44 14.5 6 1 Disassembled Large 5.140 2.95 124.1 7 1 Manual #1 Standard 5.101 0.36 -172.1 7 1 Manual #2 Standard 5.147 0.25 -191.6 7 1 Manual #3 Standard 5.150 0.28 -156.6 8 1 Manual #1 Standard 5.018 0.41 -160.8 8 1 Manual #2 Standard 5.052 0.36 -185.4 8 1 Manual #3 Standard 5.040 0.26 -115.8 9 2 Shredded #1 Standard 5.125 0.37 -172.5 9 2 Shredded #2 Standard 5.147 0.20 -126.1 9 2 Shredded #3 Standard 5.110 0.35 -166.2 9 2 Shredded #4 Standard 5.127 0.30 -152.7 9 2 Shredded #5 Standard 5.140 0.58 -133.4 9 2 Shredded #6 Standard 5.145 0.26 -197.0 10 2 Shredded #1 Standard 5.224 0.21 -291.6 10 2 Shredded #2 Standard 5.176 0.36 -225.7 10 2 Shredded #3 Standard 5.187 0.37 -183.5 10 2 Shredded #4 Standard 5.205 0.23 -265.0 10 2 Shredded #5 Standard 5.175 0.32 -233.8 10 2 Shredded #6 Standard 5.187 0.18 -165.4 11 2 Disassembled Large 5.319 4.92 82.5
71
Table A-9 continued Final
CPU Model Processing Method
TCLP Method pH DO
(mg/L) ORP
(RMV) 12 2 Manual #1 Standard 5.061 0.37 -97.7 12 2 Manual #2 Standard 5.218 0.18 -106.4 12 2 Manual #3 Standard 5.209 0.20 -89.8 13 3 Shredded #1 Standard 5.250 0.14 -387.7 13 3 Shredded #2 Standard 5.275 0.31 -326.5 13 3 Shredded #3 Standard 5.150 0.31 -305.6 13 3 Shredded #4 Standard 5.189 0.25 -251.9 13 3 Shredded #5 Standard 5.160 0.30 -283.9 13 3 Shredded #6 Standard 5.115 0.26 -354.9 14 3 Disassembled Large 5.086 3.17 -83.6 15 3 Disassembled Large 5.107 3.95 113.8 16 3 Manual #1 Standard 5.239 0.55 -217.8 16 3 Manual #2 Standard 5.263 0.78 -199 16 3 Manual #3 Standard 5.284 0.42 -325.7 17 4 Shredded #1 Standard 5.184 0.24 -304.9 17 4 Shredded #2 Standard 5.170 0.26 -352.3 17 4 Shredded #3 Standard 5.154 0.43 -301.1 17 4 Shredded #4 Standard 5.224 0.24 -343.8 17 4 Shredded #5 Standard 5.134 0.24 -293.4 17 4 Shredded #6 Standard 5.185 0.20 -317.9 18 4 Disassembled Large 5.056 - -44.6 19 4 Manual #1 Standard 5.091 0.94 -20.3 19 4 Manual #2 Standard 5.113 0.97 -54.3 19 4 Manual #3 Standard 5.108 1.15 -52.2 20 4 Manual #1 Standard 5.093 0.86 -51.3 20 4 Manual #2 Standard 5.086 1.15 -55.7 20 4 Manual #3 Standard 5.061 0.99 -67.3 21 5 Shredded #1 Standard 5.047 0.66 -96.5 21 5 Shredded #2 Standard 5.066 0.23 -188.6 21 5 Shredded #3 Standard 5.081 0.34 -183.4 21 5 Shredded #4 Standard 5.066 0.33 -127.1 21 5 Shredded #5 Standard 5.082 0.46 -122.5 21 5 Shredded #6 Standard 5.088 0.35 -108.4 22 5 Shredded #1 Standard 5.104 0.26 -252.5 22 5 Shredded #2 Standard 5.080 0.22 19.3 22 5 Shredded #3 Standard 5.102 0.26 -159.3 22 5 Shredded #4 Standard 5.092 0.37 -383.5 22 5 Shredded #5 Standard 5.146 0.49 -190.4 22 5 Shredded #6 Standard 5.117 0.31 -337.7 23 5 Disassembled Large 5.026 3.45 169.9 24 5 Disassembled Large 5.031 - -
72
Table A-9 continued Final
CPU Model Processing Method
TCLP Method pH DO
(mg/L) ORP
(RMV) 25 5 Disassembled Large 5.070 - - 26 5 Disassembled Large 5.112 - - 27 5 Manual #1 Standard 5.286 0.21 -120.1 27 5 Manual #2 Standard 5.094 0.30 -101.7 27 5 Manual #3 Standard 5.264 0.29 -70.3 28 5 Manual #1 Standard 5.063 - - 28 5 Manual #2 Standard 5.071 - - 28 5 Manual #3 Standard 5.081 - - 29 6 Shredded #1 Standard 5.132 0.29 -276.9 29 6 Shredded #2 Standard 5.147 0.49 -228.7 29 6 Shredded #3 Standard 5.162 0.54 -177.4 29 6 Shredded #4 Standard 5.142 0.31 -274.3 29 6 Shredded #5 Standard 5.150 0.28 -308.6 29 6 Shredded #6 Standard 5.110 0.30 -279.2 30 6 Disassembled Large 5.043 3.44 154.1 31 6 Disassembled Large 5.074 3.8 64.9 32 6 Manual #1 Standard 5.196 1.21 -76.4 32 6 Manual #2 Standard 5.234 1.22 -93.8 32 6 Manual #3 Standard 5.136 1.00 -92.2 33 7 Shredded #1 Standard 5.124 0.17 -195.2 33 7 Shredded #2 Standard 5.228 0.29 -246.6 33 7 Shredded #3 Standard 5.105 0.29 -169.5 33 7 Shredded #4 Standard 5.114 0.44 -258.7 33 7 Shredded #5 Standard 5.207 0.22 -239.4 33 7 Shredded #6 Standard 5.202 0.29 -189.5 34 7 Disassembled Large 5.235 3.38 -64.7 35 7 Manual #1 Standard 4.983 0.40 -154 35 7 Manual #2 Standard 4.988 0.25 -198 35 7 Manual #3 Standard 5.076 0.25 -190.9 36 7 Manual #1 Standard 4.976 0.30 -165.3 36 7 Manual #2 Standard 5.008 0.22 -114.5 36 7 Manual #3 Standard 4.978 0.25 -92.9 37 8 Disassembled Large 5.306 - - 38 8 Disassembled Large 5.227 - - 39 8 Disassembled Large 5.232 - - 40 8 Manual #1 Standard 5.066 - - 40 8 Manual #2 Standard 5.028 - - 40 8 Manual #3 Standard 5.074 - -
73
Table A-10. TCLP Ferrous Iron (Fe2+)
Sample Ferrous Iron (mg/L)
Total Iron (mg/L)
% Ferrous
Iron Standard #1 Filtered 10.11 18.39 54.95 Standard #2 Filtered 9.99 10.55 94.69 Standard #3 Filtered 5.48 27.83 19.67 Standard #1 Nonfiltered 16.75 20.51 81.67 Standard #2 Nonfiltered 17.35 19.53 88.84 Standard #3 Nonfiltered 30.28 29.26 103.47 Standard Small #1 Filtered 66.35 48.91 135.7 Standard Small #2 Filtered 66.85 58.78 113.7 Standard Small #3 Filtered 55.9 48.06 116.3 Standard Small #1 Nonfiltered 12.35 51.95 23.8 Standard Small #2 Nonfiltered 46.4 58.23 79.7 Standard Small #3 Nonfiltered 34.55 50.15 68.9 PWB 100g #1 Filtered 5.49 5.01 109.6 PWB 100g #2 Filtered 5.95 5.10 116.6 PWB 100g #3 Filtered 6.96 6.14 113.3 PWB 100g #1 Nonfiltered 6.53 5.29 123.3 PWB 100g #2 Nonfiltered 5.41 5.32 101.7 PWB 100g #3 Nonfiltered 7.27 15.0 48.5 PWB 70g #1 Filtered 11.61 9.1 127.6 PWB 70g #2 Filtered 7.69 5.89 130.6 PWB 70g #3 Filtered 6.15 10.04 61.3 PWB 70g #1 Nonfiltered 9.76 9.94 98.1 PWB 70g #2 Nonfiltered 7.07 7.02 100.7 PWB 70g #3 Nonfiltered 12.64 12.85 98.4 PWB 30g #1 Filtered 2.77 0.89 311.7 PWB 30g #2 Filtered 5.34 7.37 72.4 PWB 30g #3 Filtered 3.58 1.41 253.5 PWB 30g #1 Nonfiltered 0.93 1.21 76.7 PWB 30g #2 Nonfiltered 3.88 6.85 56.7 PWB 30g #3 Nonfiltered 1.53 1.77 86.2 PWB 15.8g #1 Filtered 3.88 2.38 162.9 PWB 15.8g #2 Filtered 4.13 1.62 254.7 PWB 15.8g #3 Filtered 3.75 1.27 294.3 PWB 15.8g #1 Nonfiltered 2.68 2.96 90.6 PWB 15.8g #2 Nonfiltered 1.83 2.0 91.4 PWB 15.8g #3 Nonfiltered 1.62 1.95 83.1 13 RPM #1 Filtered 32.4 26.5 122.4 13 RPM #2 Filtered 27.4 22.5 121.7 13 RPM #3 Filtered 36.5 28.5 127.8 13 RPM #1 Nonfiltered 33.8 27.9 121.1 13 RPM #2 Nonfiltered 23.9 24.0 99.9
74
Table A-10 continued
Sample Ferrous Iron (mg/L)
Total Iron (mg/L)
% Ferrous
Iron 13 RPM #3 Nonfiltered 26.5 30.0 88.4 Va/Vl=0 #1 Filtered 3.6 6.8 53.2 Va/Vl=0 #2 Filtered 3.3 6.5 50.5 Va/Vl=0 #3 Filtered 1.8 6.7 26.4 Va/Vl=0.5 #1 Filtered 245.8 209.3 117.4 Va/Vl=0.5 #2 Filtered 223.8 190.3 117.6 Va/Vl=0.5 #3 Filtered 221.5 184.9 119.8 Va/Vl=1 #1 Filtered 174.8 174.8 100 Va/Vl=1 #2 Filtered 271.0 250.1 108.4 Va/Vl=1 #3 Filtered 220.0 226.8 97 Va/Vl=0 #1 Nonfiltered 3.8 9.45 40.4 Va/Vl=0 #2 Nonfiltered 4.1 7.6 53.9 Va/Vl=0 #3 Nonfiltered 4.1 8.1 50.3 Va/Vl=0.5 #1 Nonfiltered 98.3 233.3 42.1 Va/Vl=0.5 #2 Nonfiltered 196.3 212.9 92.2 Va/Vl=0.5 #3 Nonfiltered 161.8 208.1 77.7 Va/Vl=1 #1 Nonfiltered 148.5 20.5 724 Va/Vl=1 #2 Nonfiltered 206.8 19.5 1058.6 Va/Vl=1 #3 Nonfiltered 254.5 29.3 869.8
75
Table A-11. Methodology Comparison Ferrous Iron (Fe2+) in Filtered Samples
CPU Model Processing Method
TCLP Method
Ferrous Iron (mg/L)
Total Iron (mg/L)
% Ferrous Iron
1 1 Shredded Standard 62.8 92.3 68.0 2 1 Shredded Standard 32.6 37.7 86.4 3 1 Shredded Standard 59.8 85.7 69.9 4 1 Disassembled Large 105.2 104.0 101.1 5 1 Disassembled Large 100 93.8 106.7 6 1 Disassembled Large 91.2 92.6 98.5 7 1 Manual Standard 1.5 49.6 3.1 8 1 Manual Standard 15 11.4 131.4 9 2 Shredded Standard 125.3 105.9 118.3 10 2 Shredded Standard 67.3 85.2 79.0 11 2 Disassembled Large 253.1 254.6 99.4 12 2 Manual # Standard 17.8 17.5 101.4 13 3 Shredded Standard 48.0 84.1 57.0 14 3 Disassembled Large 57.6 116.6 49.4 15 3 Disassembled Large 48.6 132.0 36.8 16 3 Manual Standard 14.5 19.6 74.0 17 4 Shredded Standard 50.1 119.2 42.0 18 4 Disassembled Large 81.2 127.2 63.8 19 4 Manual Standard 27.3 23.8 114.8 20 4 Manual Standard 1.3 31.2 4.2 21 5 Shredded Standard 66.2 96.2 68.8 23 5 Disassembled Large 0.9 64.7 1.5 24 5 Disassembled Large 44.4 24.3 182.7 27 5 Manual Standard 5.5 4.9 112.8 29 6 Shredded Standard 43.3 110.9 39.1 30 6 Disassembled Large 9.4 44.3 21.2 31 6 Disassembled Large 14.2 49.7 28.6 32 6 Manual Standard 25.2 35.4 71.0 33 7 Shredded Standard 180.7 147.4 122.6 34 7 Disassembled Large 11.7 189.4 6.2 35 7 Manual Standard 7.2 6.1 117.8 36 7 Manual Standard 22.7 19.3 117.4
76
Table A-12. Methodology Comparison Ferrous Iron (Fe2+) in Nonfiltered Samples
CPU Model Processing Method
TCLP Method
Ferrous Iron (mg/L)
Total Iron (mg/L)
% Ferrous Iron
4 1 Disassembled Large 117.9 118.1 99.8 5 1 Disassembled Large 94.3 107.9 87.3 6 1 Disassembled Large 113.4 104.4 108.6 11 2 Disassembled Large 130.3 282.9 46.0 14 3 Disassembled Large 15.3 121.9 12.5 15 3 Disassembled Large 55.5 138.2 40.1 16 3 Manual Standard 4.6 28.4 16.4 18 4 Disassembled Large 33.0 136.7 24.2 23 5 Disassembled Large 1.0 67.7 1.4 30 6 Disassembled Large 6.7 47.2 14.2 31 6 Disassembled Large 8.1 52.7 15.4 32 6 Manual Standard 39.7 37.4 106.2 34 7 Disassembled Large 36.5 210.6 17.3 35 7 Manual Standard 0.8 9.8 8.4 36 7 Manual Standard 2.1 24.6 8.5
77
APPENDIX B QA/QC DATA
Table B-1. Laboratory Blanks
Sample Lead (mg/L)
Iron (mg/L)
Copper (mg/L)
Zinc (mg/L)
9/30/02 TCLP Blank 2 BDL BDL BDL BDL 10/3/02 TCLP Blank 2 BDL BDL BDL BDL 10/7/02 TCLP Blank 2 BDL BDL BDL BDL 10/17/02 TCLP Blank 2 0.19 BDL 0.11 0.11 10/22/02 TCLP Blank 2 BDL BDL BDL BDL 11/12/02 TCLP Blank 2 BDL BDL BDL BDL 11/16/02 TCLP Blank 2 BDL BDL BDL BDL 11/23/02 TCLP Blank 2 0.09 BDL 0.07 BDL 5/5/02 Time #1 TCLP Blank 1 BDL BDL BDL BDL 5/13/02 Time #2 TCLP Blank 1 BDL 0.53 BDL BDL 3/28/02 Time #3 TCLP Blank 1 BDL BDL BDL BDL 8B1 7/17/02 TCLP Blank 1 BDL BDL BDL BDL 8B2 7/18/02 TCLP Blank 1 BDL BDL BDL BDL 8B3 7/19/02 TCLP Blank 1 BDL BDL BDL 0.12 8C1 7/20/02 TCLP Blank 1 BDL BDL BDL BDL 5B2 7/23/02 TCLP Blank 1 BDL BDL BDL BDL 5B3 7/21/02 TCLP Blank 1 BDL BDL BDL BDL 5B4 7/22/02 TCLP Blank 1 BDL BDL BDL BDL 5C2 7/23/02 TCLP Blank 1 BDL BDL BDL BDL 11/7/02 7B1 TCLP Blank 2 0.06 BDL BDL 0.16 12/19/02 6B1 TCLP Blank 2 BDL BDL BDL BDL 12/21/02 3B1 TCLP Blank 2 BDL BDL BDL BDL 12/22/02 3B2 TCLP Blank 2 BDL BDL BDL BDL 12/23/02 2B1 TCLP Blank 2 BDL BDL 0.08 BDL 1/6/03 4B1 TCLP Blank 2 BDL BDL BDL BDL 12/06/02 6B2 TCLP Blank 2 BDL BDL BDL BDL 1/9/03 1B1 TCLP Blank 2 BDL BDL BDL BDL 1/10/03 7C1, 7C2 TCLP Blank 2 BDL BDL BDL BDL 1/10/03 1B2 TCLP Blank 2 BDL BDL BDL 0.14 1/11/02 1B3 TCLP Blank 2 BDL BDL BDL 0.13 1/13/03 5B1 TCLP Blank 2 BDL BDL BDL BDL 1/16/03 3C1, 6C1 TCLP Blank 2 BDL BDL BDL BDL 1/19/02 5A2 TCLP Blank 2 BDL BDL BDL BDL 1/20/03 1C1, 1C2, 1A3, 5A1 TCLP Blank 2 BDL BDL BDL BDL 1/22/03 4A1, 6A1 TCLP Blank 2 BDL BDL BDL BDL 1/23/03 3A1, 1A2 TCLP Blank 2 BDL BDL BDL BDL
78
Table B-1 continued
Sample Lead (mg/L)
Iron (mg/L)
Copper (mg/L)
Zinc (mg/L)
1/23/03 4C1, 4C2 TCLP Blank 2 BDL 0.23 BDL 0.16 1/24/03 1A1, 2A2 TCLP Blank 2 BDL BDL BDL BDL 1/25/03 2A1, 7A1 TCLP Blank 2 BDL BDL BDL BDL 2/3/03 2C1, 5C1 TCLP Blank 2 BDL BDL BDL 0.16 7/24/02 Digestion Blank 2 BDL BDL BDL BDL 10/10/02 Digestion Blank 2 BDL BDL BDL BDL 10/18/02 Digestion Blank 2 BDL BDL BDL BDL 10/22/02 Digestion Blank 2 BDL BDL BDL BDL 10/23/02 Digestion Blank 2 BDL BDL BDL BDL 11/23/02 Digestion Blank # 21 BDL BDL BDL BDL 11/23/02 Digestion Blank #2 2 BDL BDL BDL BDL 5/14/02 Digestion Blank 1 BDL BDL BDL BDL 5/16/02 Digestion Blank 1 BDL BDL 0.13 BDL 5/17/02 Digestion Blank 1 BDL BDL BDL BDL 5/29/02 Digestion Blank 1 BDL BDL BDL BDL 3/21/02 Digestion Blank 1 BDL BDL BDL BDL 4/5/02 Digestion Blank 1 BDL BDL BDL BDL 1/27/03 Digestion Blank 2 BDL BDL BDL BDL 1/28/03 Digestion Blank 2 BDL BDL BDL BDL 1/29/03 Digestion Blank 2 BDL BDL BDL BDL 1/30/03 Digestion Blank 2 BDL BDL BDL BDL 2/1/03 Digestion Blank 2 BDL BDL BDL BDL 2/2/03 Digestion Blank 2 BDL BDL BDL BDL 2/4/03 Digestion Blank 2 BDL BDL BDL BDL 1 Pb=0.1 mg/L, Fe=0.2 mg/L, Cu=0.1 mg/L, Zn=0.1 mg/L 2 Pb=0.05 mg/L, Fe=0.2 mg/L, Cu=0.05 mg/L, Zn=0.1 mg/L
79
Table B-2. Lead Matrix Spike Recovery
Sample Spike
Response (mg/L)
Spike Added (mg/L)
Sample Conc. (mg/L)
Spike Recovery
(%) 7/24/02 Digestion Blank MS 5.608 5 BDL 112.2 7/24/02 Digestion Blank MSD 5.436 5 BDL 108.7 10/10/02 Digestion Blank MS 2.488 2.5 BDL 99.5 10/10/02 Digestion Blank MSD 2.498 2.5 BDL 99.9 10/18/02 Digestion Blank MS 4.915 5 BDL 98.3 10/18/02 Digestion Blank MSD 4.976 5 BDL 99.5 10/22/02 Digestion Blank MS 52.13 52.5 BDL 99.3 10/22/02 Digestion Blank MSD 52.7 52.5 BDL 100.4 10/23/02 Digestion Blank MS 53.39 52.5 BDL 101.7 10/23/02 Digestion Blank MSD 54.56 52.5 BDL 103.9 11/23/02 Digestion Blank #1 MS 50.86 50 BDL 101.7 11/23/02 Digestion Blank #1 MSD 50.14 50 BDL 100.3 11/23/02 Digestion Blank #2 MS 5.257 5 BDL 105.1 11/23/02 Digestion Blank #2 MSD 5.282 5 BDL 105.6 1/27/03 Digestion Blank MS 20.1 20 BDL 100.5 1/27/03 Digestion Blank MSD 19.98 20 BDL 99.9 1/28/03 Digestion Blank MS 19.79 20 BDL 99 1/28/03 Digestion Blank MSD 19.56 20 BDL 97.8 1/29/03 Digestion Blank MS 19.49 20 BDL 97.5 1/29/03 Digestion Blank MSD 19.46 20 BDL 97.3 1/30/03 Digestion Blank MS 20.51 20 BDL 102.6 1/30/03 Digestion Blank MSD 20.92 20 BDL 101 2/1/03 Digestion Blank MS 21.17 20 BDL 97.3 2/1/03 Digestion Blank MSD 20.36 20 BDL 96.9 2/2/03 Digestion Blank MS 19.45 20 BDL 97.3 2/2/03 Digestion Blank MSD 19.38 20 BDL 96.9 2/4/02 Digestion Blank MS 19.27 20 BDL 96.4 2/4/02 Digestion Blank MSD 19.15 20 BDL 95.8 5/13/02 Digestion Blank MS 112.7 101 BDL 111.6 5/13/02 Digestion Blank MSD 99.5 101 BDL 98.5 5/16/02 Digestion Blank MS 106.1 100 BDL 106.1 5/16/02 Digestion Blank MSD 104.0 100 BDL 104 5/17/02 Digestion Blank MS 99.97 100 BDL 99.97 5/17/02 Digestion Blank MSD 100.7 100 BDL 100.7 5/29/02 Digestion Blank MS 11.95 12.5 BDL 95.6 5/29/02 Digestion Blank MSD 12.09 12.5 BDL 96.7 3/21/02 Digestion Blank MS 108.0 105 BDL 102.9 3/21/02 Digestion Blank MS 111.3 105 BDL 106 4/5/02 Digestion Blank MS 114.9 105 BDL 109.4 4/5/02 Digestion Blank MSD 118 105 BDL 112.4 Standard #1 Filtered MS 3.208 2.5 .5869 104.8 Standard #1 Filtered MSD 3.226 2.5 .5869 105.5
80
Table B-2 continued
Sample Spike
Response (mg/L)
Spike Added (mg/L)
Sample Conc. (mg/L)
Spike Recovery
(%) Standard #1 Nonfiltered MS 5.826 5 .6113 104.3 Standard #1 Nonfiltered MSD 5.838 5 .6113 104.5 PWB 100g #1 Filtered MS 306.4 102.5 155 147.7 PWB 100g #1 Filtered MSD 258.9 102.5 155 101.4 PWB 100g #1 Nonfiltered MS 260.9 102.5 156 102.3 PWB 100g #1 Nonfiltered MSD 259.2 102.5 156 100.7 PWB 30g #1 Filtered MS 112.1 52.5 58 103 PWB 30g #1 Filtered MSD 112.8 52.5 58 104.4 Material Impact #1 Filtered MS 136.0 50 89 94 Material Impact #1 Filtered MSD 134.6 50 89 91.2 Ferrous Impact 20% #1 Filtered MS 58.33 52.5 8.9 94.1 Ferrous Impact 20% #1 Filtered MSD 59.42 52.5 8.9 96.2 13 RPM #1 Filtered MS 3.706 3.5 0.1 103 13 RPM #1 Filtered MSD 5.132 5 0.1 100.6 Time #1 18 hrs Filtered MS 113.2 101 6.2 105.9 Time #1 18 hrs Filtered MSD 103.4 101 6.2 96.2 Time #2 18 hrs Filtered MS 112.5 100 3.4 109.1 Time #2 18 hrs Filtered MSD 112.8 100 3.4 109.4 Time #1 18 hrs Nonfiltered MS 108.3 100 7.8 100.5 Time #1 18 hrs Nonfiltered MSD 106.3 100 7.8 98.5 Time #3 18 hrs Filtered MS 129.9 105 9.9 114.3 Time #3 18hrs Filtered MSD 131.1 105 9.9 115.4 CPU 1A1 #1 Filtered MS 18.86 20 0.3 92.8 CPU 1A1 #1 Filtered MSD 19.21 20 0.3 94.6 CPU 1A3 #1 Filtered MS 19.09 20 0.2 94.5 CPU 1A3 #1 Filtered MSD 19.10 20 0.2 94.5 CPU 1B1 #1 Nonfiltered MS 29.33 20 10.1 96.2 CPU 1B1 #1 Nonfiltered MSD 29.42 20 10.1 96.6 CPU 1C1 #1 Nonfiltered MS 20.09 20 1.1 94.95 CPU 1C1 #1 Nonfiltered MSD 20.46 20 1.1 96.8 CPU 2A1 #1 Filtered MS 20.56 20 0.8 98.8 CPU 2A1 #1 Filtered MSD 20.16 20 0.8 96.8 CPU 2A2 #1 Nonfiltered MS 23.91 20 5.7 91.1 CPU 2A2 #1 Nonfiltered MSD 23.94 20 5.7 91.2 CPU 2B1 #1 Filtered MS 25.61 20 5.4 101.1 CPU 2B1 #1 Filtered MSD 24.85 20 5.4 97.3 CPU 2C1 #1 Filtered MS 19.46 20 0.4 95.3 CPU 2C1 #1 Filtered MSD 18.99 20 0.4 92.95 CPU 3A1 #1 Filtered MS 24.55 20 5.4 95.75 CPU 3A1 #1 Filtered MSD 24.51 20 5.4 95.55 CPU 3A1 #1 Nonfiltered MS 29.09 20 10.4 93.45 CPU 3A1 #1 Nonfiltered MSD 29.7 20 10.4 96.5
81
Table B-2 continued
Sample Spike
Response (mg/L)
Spike Added (mg/L)
Sample Conc. (mg/L)
Spike Recovery
(%) CPU 3B1 #1 Nonfiltered MS 41.63 20 22.0 98.15 CPU 3B1 #1 Nonfiltered MSD 41.58 20 22.0 97.9 CPU 6B2 #1 Nonfiltered MS 19.50 20 1.2 91.5 CPU 6B2 #1 Nonfiltered MSD 20.09 20 1.2 94.45 CPU 7C1 #1 Filtered MS 18.44 20 0.2 91.2 CPU 7C1 #1 Filtered MSD 18.24 20 0.2 90.2 CPU 7C2 #1 Nonfiltered MS 18.54 20 2.4 80.7 CPU 7C2 #1 Nonfiltered MSD 18.27 20 2.4 79.35 CPU 8B1 #1 MS 14.1 5 8.6 110 CPU 8B1 #1 MSD 13.67 5 8.6 101.4
82
Table B-3. Iron Matrix Spike Recovery
Sample Spike
Response (mg/L)
Spike Added (mg/L)
Sample Conc. (mg/L)
Spike Recovery
(%) 10/10/02 Digestion Blank MS 105.1 100 BDL 105.1 10/10/02 Digestion Blank MSD 104.1 100 BDL 104.1 10/18/02 Digestion Blank MS 53.84 55 BDL 97.9 10/18/02 Digestion Blank MSD 54.21 55 BDL 98.6 10/22/02 Digestion Blank MS 53.33 52.5 BDL 101.6 10/22/02 Digestion Blank MSD 53.5 52.5 BDL 101.9 10/23/02 Digestion Blank MS 50.56 52.5 BDL 96.3 10/23/02 Digestion Blank MSD 51.58 52.5 BDL 98.2 11/23/02 Digestion Blank #1 MS 105.0 100 BDL 105 11/23/02 Digestion Blank #1 MSD 103.5 100 BDL 103.5 11/23/02 Digestion Blank #2 MS 57.21 50 BDL 114.4 11/23/02 Digestion Blank #2 MSD 57.48 50 BDL 114.96 1/27/03 Digestion Blank MS 48.46 50 BDL 96.9 1/27/03 Digestion Blank MSD 48.83 50 BDL 97.7 1/28/03 Digestion Blank MS 47.93 50 BDL 95.86 1/28/03 Digestion Blank MSD 47.75 5050 BDL 95.5 1/29/03 Digestion Blank MS 48.49 50 BDL 96.98 1/29/03 Digestion Blank MSD 48.61 50 BDL 97.2 1/30/03 Digestion Blank MS 49.67 50 BDL 99.3 1/30/03 Digestion Blank MSD 50.4 50 BDL 100.8 2/1/03 Digestion Blank MS 50.82 50 BDL 101.6 2/1/03 Digestion Blank MSD 49.37 50 BDL 98.7 2/2/03 Digestion Blank MS 48.41 50 BDL 96.8 2/2/03 Digestion Blank MSD 47.08 50 BDL 94.2 2/4/02 Digestion Blank MS 47.98 50 BDL 95.96 2/4/02 Digestion Blank MSD 48.26 50 BDL 96.52 3/21/02 Digestion Blank MS 4.959 5 BDL 99.2 3/21/02 Digestion Blank MS 5.164 5 BDL 103.3 4/5/02 Digestion Blank MS 4.831 5 BDL 96.6 4/5/02 Digestion Blank MSD 5.065 5 BDL 101.3 Standard #1 Filtered MS 112.8 100 18.39 94.4 Standard #1 Filtered MSD 112.7 100 18.39 94.3 Standard #1 Nonfiltered MS 72.78 55 20.51 95.0 Standard #1 Nonfiltered MSD 73.63 55 20.51 96.6 PWB 100g #1 Filtered MS 8.721 2.5 5.0 148.8 PWB 100g #1 Filtered MSD 7.28 2.5 5.0 90.0 PWB 100g #1 Nonfiltered MS 7.442 2.5 5.3 85.7 PWB 100g #1 Nonfiltered MSD 7.82 2.5 5.3 100.8 PWB 30g #1 Filtered MS 47.8 52.5 0.9 89.3 PWB 30g #1 Filtered MSD 47.92 52.5 0.9 89.6 Material Impact #1 Filtered MS 91.69 100 1.4 90.29 Material Impact #1 Filtered MSD 89.16 100 1.4 87.8
83
Table B-3 continued
Sample Spike
Response (mg/L)
Spike Added (mg/L)
Sample Conc. (mg/L)
Spike Recovery
(%) Ferrous Impact 20% #1 Filtered MS 114.1 52.5 72 80.1 Ferrous Impact 20% #1 Filtered MSD 114.8 52.5 72 81.5 13 RPM #1 Filtered MS 76.28 50 26 100.6 13 RPM #1 Filtered MSD 75.69 50 26 99.4 Time #3 18 hrs Filtered MS 97.7 25 76.0 87 Time #3 18hrs Filtered MSD 95.48 25 76.0 79 CPU 1A1 #1 Filtered MS 128.1 50 89.0 78.2 CPU 1A1 #1 Filtered MSD 128.3 50 89.0 78.6 CPU 1A3 #1 Filtered MS 149.7 50 109.1 81.2 CPU 1A3 #1 Filtered MSD 150.1 50 109.1 82.0 CPU 1B1 #1 Nonfiltered MS 159 50 117.0 84.0 CPU 1B1 #1 Nonfiltered MSD 156.1 50 117.0 78.2 CPU 1C1 #1 Nonfiltered MS 100.2 50 56.0 88.4 CPU 1C1 #1 Nonfiltered MSD 150.6 50 56.0 89.2 CPU 2A1 #1 Filtered MS 150.6 50 110.7 79.8 CPU 2A1 #1 Filtered MSD 148.4 50 110.7 75.4 CPU 2A2 #1 Nonfiltered MS 160.0 50 122.2 75.6 CPU 2A2 #1 Nonfiltered MSD 160.4 50 122.2 76.4 CPU 2B1 #1 Filtered MS 289.7 50 252.5 74.4 CPU 2B1 #1 Filtered MSD 290.5 50 252.5 76.0 CPU 2C1 #1 Filtered MS 62.67 50 19.94 85.46 CPU 2C1 #1 Filtered MSD 61.20 50 19.94 82.5 CPU 3A1 #1 Filtered MS 156.5 50 116.4 80.2 CPU 3A1 #1 Filtered MSD 157.2 50 116.4 81.6 CPU 3A1 #1 Nonfiltered MS 186.2 50 147.3 77.8 CPU 3A1 #1 Nonfiltered MSD 189.7 50 147.3 84.8 CPU 3B1 #1 Nonfiltered MS 161.8 50 122.1 79.4 CPU 3B1 #1 Nonfiltered MSD 162.6 50 122.1 81.0 CPU 6B2 #1 Nonfiltered MS 94.27 50 52.2 84.1 CPU 6B2 #1 Nonfiltered MSD 94.14 50 52.2 83.9 CPU 7C1 #1 Filtered MS 46.77 50 6.6 80.3 CPU 7C1 #1 Filtered MSD 46.86 50 6.6 80.52 CPU 7C2 #1 Nonfiltered MS 66.20 50 25.8 80.8 CPU 7C2 #1 Nonfiltered MSD 65.41 50 25.8 79.22
84
Table B-4. Copper Matrix Spike Recovery
Sample Spike
Response (mg/L)
Spike Added (mg/L)
Sample Conc. (mg/L)
Spike Recovery
(%) 10/10/02 Digestion Blank MS 2.565 2.5 BDL 102.6 10/10/02 Digestion Blank MSD 2.592 2.5 BDL 103.7 10/18/02 Digestion Blank MS 5.023 5 BDL 100.5 10/18/02 Digestion Blank MSD 5.025 5 BDL 100.5 10/22/02 Digestion Blank MS 2.489 2.5 BDL 99.6 10/22/02 Digestion Blank MSD 2.456 2.5 BDL 98.2 10/23/02 Digestion Blank MS 2.264 2.5 BDL 90.6 10/23/02 Digestion Blank MSD 2.322 2.5 BDL 92.9 11/23/02 Digestion Blank #2 MS 4.977 5 BDL 99.5 11/23/02 Digestion Blank #2 MSD 4.911 5 BDL 98.2 1/27/03 Digestion Blank MS 1.080 1 BDL 108.0 1/27/03 Digestion Blank MSD 1.071 1 BDL 107.1 1/28/03 Digestion Blank MS 1.047 1 BDL 104.7 1/28/03 Digestion Blank MSD 1.041 1 BDL 104.1 1/29/03 Digestion Blank MS 1.078 1 BDL 107.8 1/29/03 Digestion Blank MSD 1.055 1 BDL 105.5 1/30/03 Digestion Blank MS 0.9014 1 BDL 90.1 1/30/03 Digestion Blank MSD 1.118 1 BDL 111.8 2/1/03 Digestion Blank MS 1.112 1 BDL 111.2 2/1/03 Digestion Blank MSD 1.099 1 BDL 109.9 2/2/03 Digestion Blank MS 0.9715 1 BDL 97.15 2/2/03 Digestion Blank MSD 0.9811 1 BDL 98.1 2/4/02 Digestion Blank MS 1.016 1 BDL 101.6 2/4/02 Digestion Blank MSD 1.019 1 BDL 101.9 5/13/02 Digestion Blank MS 1.134 1 BDL 113.4 5/13/02 Digestion Blank MSD 1.033 1 BDL 103.3 5/16/02 Digestion Blank MS 2.429 2.5 0.1304 91.9 5/16/02 Digestion Blank MSD 2.337 2.5 0.1304 88.3 5/17/02 Digestion Blank MS 2.257 2.5 BDL 90.3 5/17/02 Digestion Blank MSD 2.28 2.5 BDL 91.2 3/21/02 Digestion Blank MS 4.422 5 BDL 88.4 3/21/02 Digestion Blank MS 4.624 5 BDL 92.5 4/5/02 Digestion Blank MS 4.998 5 BDL 99.96 4/5/02 Digestion Blank MSD 5.154 5 BDL 103.1 Standard #1 Filtered MS 2.404 2.5 BDL 96.2 Standard #1 Filtered MSD 2.417 2.5 BDL 96.7 Standard #1 Nonfiltered MS 5.927 5 1.127 96.0 Standard #1 Nonfiltered MSD 5.975 5 1.127 96.96 PWB 100g #1 Filtered MS 3.924 2.5 0.7 128.96 PWB 100g #1 Filtered MSD 3.231 2.5 0.7 104.8 PWB 100g #1 Nonfiltered MS 7.923 2.5 5.8 84.9 PWB 100g #1 Nonfiltered MSD 7.868 2.5 5.8 82.7
85
Table B-4 continued
Sample Spike
Response (mg/L)
Spike Added (mg/L)
Sample Conc. (mg/L)
Spike Recovery
(%) PWB 30g #1 Filtered MS 2.911 2.5 0.6 92.44 PWB 30g #1 Filtered MSD 2.928 2.5 0.6 93.12 Ferrous Impact 20% #1 Filtered MS 2.132 2.5 BDL 85.3 Ferrous Impact 20% #1 Filtered MSD 2.139 2.5 BDL 85.6 13 RPM #1 Filtered MS 3.145 3.5 BDL 89.9 13 RPM #1 Filtered MSD 4.475 5 BDL 89.5 Time #1 18 hrs Filtered MS 1.099 1 BDL 109.9 Time #1 18 hrs Filtered MSD 0.713 0.7 BDL 101.9 Time #2 18 hrs Filtered MS 2.53 2.5 BDL 101.2 Time #2 18 hrs Filtered MSD 2.53 2.5 BDL 101.2 Time #1 18 hrs Nonfiltered MS 3.049 2.5 1.0 81.96 Time #1 18 hrs Nonfiltered MSD 2.921 2.5 1.0 76.84 Time #3 18 hrs Filtered MS 5.181 5 BDL 103.6 Time #3 18hrs Filtered MSD 5.257 5 BDL 105.1 CPU 1A1 #1 Filtered MS 1.017 1 0.06 95.7 CPU 1A1 #1 Filtered MSD 1.012 1 0.06 95.2 CPU 1A3 #1 Filtered MS 1.047 1 BDL 104.7 CPU 1A3 #1 Filtered MSD 1.048 1 BDL 104.8 CPU 1B1 #1 Nonfiltered MS 2.165 1 1.15 101.5 CPU 1B1 #1 Nonfiltered MSD 2.118 1 1.15 96.8 CPU 1C1 #1 Nonfiltered MS 2.304 1 1.24 106.4 CPU 1C1 #1 Nonfiltered MSD 2.294 1 1.24 105.4 CPU 2A1 #1 Filtered MS 1.059 1 BDL 105.9 CPU 2A1 #1 Filtered MSD 1.050 1 BDL 105.0 CPU 2A2 #1 Nonfiltered MS 7.548 1 6.8 74.8 CPU 2A2 #1 Nonfiltered MSD 7.519 1 6.8 71.9 CPU 2B1 #1 Filtered MS 1.061 1 BDL 106.1 CPU 2B1 #1 Filtered MSD 1.056 1 BDL 105.6 CPU 2C1 #1 Filtered MS 0.96 1 BDL 96.0 CPU 2C1 #1 Filtered MSD 0.9502 1 BDL 95.02 CPU 3A1 #1 Filtered MS 1.067 1 BDL 106.7 CPU 3A1 #1 Filtered MSD 1.081 1 BDL 108.1 CPU 3A1 #1 Nonfiltered MS 11.14 1 10.6 54.0 CPU 3A1 #1 Nonfiltered MSD 11.35 1 10.6 75.0 CPU 3B1 #1 Nonfiltered MS 10.83 1 10.2 63.0 CPU 3B1 #1 Nonfiltered MSD 10.92 1 10.2 72.0 CPU 6B2 #1 Nonfiltered MS 2.257 1 1.3 95.7 CPU 6B2 #1 Nonfiltered MSD 2.273 1 1.3 97.3 CPU 7C1 #1 Filtered MS 0.9104 1 BDL 91.04 CPU 7C1 #1 Filtered MSD 0.9146 1 BDL 91.46 CPU 7C2 #1 Nonfiltered MS 2.4 1 1.5 90.0 CPU 7C2 #1 Nonfiltered MSD 2.417 1 1.5 91.7
86
Table B-5. Zinc Matrix Spike Recovery
Sample Spike
Response (mg/L)
Spike Added (mg/L)
Sample Conc. (mg/L)
Spike Recovery
(%) 10/10/02 Digestion Blank MS 2.648 2.5 BDL 105.9 10/10/02 Digestion Blank MSD 2.638 2.5 BDL 105.5 10/18/02 Digestion Blank MS 5.19 5 BDL 103.8 10/18/02 Digestion Blank MSD 5.26 5 BDL 105.2 10/22/02 Digestion Blank MS 2.63 2.5 BDL 105.2 10/22/02 Digestion Blank MSD 2.667 2.5 BDL 106.7 10/23/02 Digestion Blank MS 2.655 2.5 BDL 106.2 10/23/02 Digestion Blank MSD 2.705 2.5 BDL 108.2 11/23/02 Digestion Blank #2 MS 5.217 5 BDL 104.3 11/23/02 Digestion Blank #2 MSD 5.322 5 BDL 106.4 1/27/03 Digestion Blank MS 0.9893 1 BDL 98.9 1/27/03 Digestion Blank MSD 0.9592 1 BDL 95.9 1/28/03 Digestion Blank MS 0.9404 1 BDL 94.0 1/28/03 Digestion Blank MSD 0.9398 1 BDL 93.98 1/29/03 Digestion Blank MS 1.035 1 BDL 103.5 1/29/03 Digestion Blank MSD 1.043 1 BDL 104.3 1/30/03 Digestion Blank MS 0.8406 1 BDL 84.06 1/30/03 Digestion Blank MSD 1.051 1 BDL 105.1 2/1/03 Digestion Blank MS 1.059 1 BDL 105.9 2/1/03 Digestion Blank MSD 0.9883 1 BDL 98.83 2/2/03 Digestion Blank MS 1.005 1 BDL 100.5 2/2/03 Digestion Blank MSD 0.9454 1 BDL 94.5 2/4/02 Digestion Blank MS 0.9417 1 BDL 94.17 2/4/02 Digestion Blank MSD 0.9366 1 BDL 93.66 5/13/02 Digestion Blank MS 1.209 1 BDL 120.9 5/13/02 Digestion Blank MSD 1.068 1 BDL 106.8 5/16/02 Digestion Blank MS 2.894 2.5 BDL 115.8 5/16/02 Digestion Blank MSD 2.798 2.5 BDL 111.9 5/17/02 Digestion Blank MS 2.644 2.5 BDL 105.8 5/17/02 Digestion Blank MSD 2.721 2.5 BDL 108.8 3/21/02 Digestion Blank MS 4.677 5 BDL 93.5 3/21/02 Digestion Blank MS 4.471 5 BDL 89.4 4/5/02 Digestion Blank MS 5.051 5 BDL 101.0 4/5/02 Digestion Blank MSD 5.186 5 BDL 103.7 Standard #1 Filtered MS 161.3 2.5* 161 12.0 Standard #1 Filtered MSD 160.7 2.5* 161 0 Standard #1 Nonfiltered MS 161.2 5* 158.9 46.0 Standard #1 Nonfiltered MSD 162.5 5* 158.9 72.0 PWB 100g #1 Filtered MS 3.47 2.5 0.3 126.8 PWB 100g #1 Filtered MSD 2.828 2.5 0.3 101.1 PWB 100g #1 Nonfiltered MS 2.804 2.5 0.3 100.2 PWB 100g #1 Nonfiltered MSD 2.783 2.5 0.3 99.32
87
Table B-5 continued
Sample Spike
Response (mg/L)
Spike Added (mg/L)
Sample Conc. (mg/L)
Spike Recovery
(%) PWB 30g #1 Filtered MS 2.585 2.5 0.2 95.4 PWB 30g #1 Filtered MSD 2.615 2.5 0.2 96.6 Ferrous Impact 20% #1 Filtered MS 57.08 2.5* 56 43.2 Ferrous Impact 20% #1 Filtered MSD 57.08 2.5* 56 43.2 13 RPM #1 Filtered MS 150.9 3.5* 145 168.6 13 RPM #1 Filtered MSD 148.7 5* 145 74.0 Time #1 18 hrs Filtered MS 146.8 1* 138 880.0 Time #1 18 hrs Filtered MSD 135.3 0.7* 138 0 Time #2 18 hrs Filtered MS 160.1 2.5* 151 364 Time #2 18 hrs Filtered MSD 160.4 2.5* 151 376 Time #1 18 hrs Nonfiltered MS 144.8 2.5* 141 152 Time #1 18 hrs Nonfiltered MSD 142.1 2.5* 141 44 Time #3 18 hrs Filtered MS 177.9 5* 141 738 Time #3 18hrs Filtered MSD 173.3 5* 141 646 CPU 1A1 #1 Filtered MS 107.3 1* 104.8 250 CPU 1A1 #1 Filtered MSD 107.9 1* 104.8 310 CPU 1A3 #1 Filtered MS 112.9 1* 111.3 160 CPU 1A3 #1 Filtered MSD 113.7 1* 111.3 240 CPU 1B1 #1 Nonfiltered MS 142.4 1* 143.1 0 CPU 1B1 #1 Nonfiltered MSD 139.8 1* 143.1 0 CPU 1C1 #1 Nonfiltered MS 104.6 1* 99.2 540 CPU 1C1 #1 Nonfiltered MSD 104.9 1* 99.2 570 CPU 2A1 #1 Filtered MS 68.71 1* 69.2 0 CPU 2A1 #1 Filtered MSD 67.81 1* 69.2 0 CPU 2A2 #1 Nonfiltered MS 117.0 1* 112.5 450 CPU 2A2 #1 Nonfiltered MSD 116.4 1* 112.5 390 CPU 2B1 #1 Filtered MS 126.6 1* 128.2 0 CPU 2B1 #1 Filtered MSD 127.2 1* 128.2 0 CPU 2C1 #1 Filtered MS 152.9 1* 151.1 180 CPU 2C1 #1 Filtered MSD 149.4 1* 151.1 0 CPU 3A1 #1 Filtered MS 128.6 1* 131.6 0 CPU 3A1 #1 Filtered MSD 129.4 1* 131.6 0 CPU 3A1 #1 Nonfiltered MS 129.8 1* 126.3 350 CPU 3A1 #1 Nonfiltered MSD 132.4 1* 126.3 610 CPU 3B1 #1 Nonfiltered MS 79.88 1* 79.98 0 CPU 3B1 #1 Nonfiltered MSD 80.48 1* 79.98 50 CPU 6B2 #1 Nonfiltered MS 101.5 1* 99.32 218 CPU 6B2 #1 Nonfiltered MSD 101.3 1* 99.32 198 CPU 7C1 #1 Filtered MS 164.7 1* 160.3 440 CPU 7C1 #1 Filtered MSD 166.3 1* 160.3 600 CPU 7C2 #1 Nonfiltered MS 133.0 1* 130.9 210 CPU 7C2 #1 Nonfiltered MSD 129.8 1* 130.9 0
*Note: Poor recoveries due to inappropriate zinc spike concentration.
88
Table B-6. Lead Concentrations of TCLP Sample Replicates
Sample Leachable
Lead (mg/L)
Replicate Leachable Lead
(mg/L) PWB 15.8g #1 Filtered 44.92 46.16 Ferrous Impact 0% #1 Filtered 40.46 42.28 Va/Vl=0.5 #1 Filtered 1.054 1.084 Time #1 9hrs Filtered 2.249 2.361 Time #1 18hrs Filtered 6.151 6.214 Time #1 27hrs Filtered 6.882 6.805 Time #1 36hrs Filtered 1.867 2.056 Time #1 45hrs Filtered 1.764 1.702 Time #1 57hrs Filtered 0.9931 1.034 Time #1 66hrs Filtered 1.384 1.472 Time #1 76hrs Filtered 1.519 1.478 Time #1 85hrs Filtered 4.438 4.455 Time #1 93hrs Filtered 5.293 4.904 Time #2 9hrs Filtered 3.107 3.103 Time #2 18hrs Filtered 3.413 3.365 Time #2 27hrs Filtered 6.053 5.829 Time #2 36hrs Filtered 3.225 3.189 Time #2 45hrs Filtered 5.339 5.129 Time #2 59hrs Filtered 1.159 1.135 Time #2 66.5hrs Filtered 2.517 2.627 Time #2 75hrs Filtered 3.720 3.856 Time #2 85hrs Filtered 3.525 3.565 Time #2 88hrs Filtered 6.836 6.624 Time #3 27hrs Filtered 7.019 7.414 Time #3 37hrs Filtered 2.696 2.644 Time #3 45.5hrs Filtered 2.621 2.503 Time #3 60hrs Filtered 2.279 2.365 Time #3 69.5hrs Filtered 1.496 1.591 Time #3 81.5hrs Filtered 1.062 1.591 Time #3 90.5hrs Filtered 2.986 3.133
89
Table B-7. Lead Concentrations of Modified Large-Scale TCLP Methodology Comparison Sample Replicates
CPU Model Processing Method
Filtered/ Nonfiltered
Leachable Lead
(mg/L)
Replicate Leachable
Lead (mg/L)
Replicate Leachable
Lead (mg/L)
4 1 Disassembled Filtered 8.44 8.49 8.72 4 1 Disassembled Nonfiltered 9.82 10.05 9.83 5 1 Disassembled Filtered 9.04 8.79 8.93 5 1 Disassembled Nonfiltered 10.29 10.26 10.13 6 1 Disassembled Filtered 8.21 8.21 8.35 6 1 Disassembled Nonfiltered 9.52 9.45 9.33 11 2 Disassembled Filtered 5.40 5.43 5.55 11 2 Disassembled Nonfiltered 7.53 7.78 7.54 14 3 Disassembled Filtered 21.73 21.18 21.28 14 3 Disassembled Nonfiltered 22.04 22.63 21.69 15 3 Disassembled Filtered 16.3 16.57 16.25 15 3 Disassembled Nonfiltered 16.86 16.89 17.09 18 4 Disassembled Filtered 9.42 9.54 9.64 18 4 Disassembled Nonfiltered 10.35 10.42 10.52 23 5 Disassembled Filtered 5.28 5.14 5.32 23 5 Disassembled Nonfiltered 6.29 6.18 6.31 24 5 Disassembled Filtered 3.07 3.00 3.12 25 5 Disassembled Filtered 15.45 15.35 15.79 26 5 Disassembled Filtered 4.50 3.75 3.87 30 6 Disassembled Filtered 0.64 .059 .057 30 6 Disassembled Nonfiltered 0.77 0.76 0.77 31 6 Disassembled Filtered 0.49 0.49 0.48 31 6 Disassembled Nonfiltered 1.21 1.24 1.22 34 7 Disassembled Filtered 8.98 9.17 9.22 34 7 Disassembled Nonfiltered 10.99 10.64 10.75 37 8 Disassembled Filtered 8.57 8.06 8.58 38 8 Disassembled Filtered 7.15 7.13 7.02 39 8 Disassembled Filtered 6.70 6.45 6.63
90
Table B-8. Iron Concentrations of TCLP Sample Replicates
Sample Leachable
Iron (mg/L)
Replicate Leachable Iron
(mg/L) Va/Vl=0.5 #1 Filtered 209.3 217.1 PWB 15.8g #Filtered 2.380 2.321 Ferrous Impact 0% #1 Filtered 0.8770 0.8935 Time #1 9hrs Filtered 26.75 27.82 Time #1 18hrs Filtered 97.89 97.87 Time #1 27hrs Filtered 186.1 188.3 Time #1 36hrs Filtered 259.5 277.3 Time #1 45hrs Filtered 338.3 343.4 Time #1 57hrs Filtered 322.5 322.1 Time #1 66hrs Filtered 244.5 254.3 Time #1 76hrs Filtered 194.2 183.0 Time #1 85hrs Filtered 149.2 150.7 Time #1 93hrs Filtered 124.6 116.9 Time #2 9hrs Filtered 25.68 25.72 Time #2 18hrs Filtered 86.12 87.35 Time #2 27hrs Filtered 178.5 177.0 Time #2 36hrs Filtered 270.1 267.0 Time #2 45hrs Filtered 293.3 289.2 Time #2 59hrs Filtered 306.9 300.9 Time #2 66.5hrs Filtered 241.9 248.0 Time #2 75hrs Filtered 177.0 175.9 Time #2 85hrs Filtered 134.8 132.8 Time #2 88hrs Filtered 138.4 131.4 Time #3 27hrs Filtered 169.1 179.5 Time #3 37hrs Filtered 260.8 261.8 Time #3 45.5hrs Filtered 294.8 289.0 Time #3 60hrs Filtered 266.4 283.2 Time #3 69.5hrs Filtered 228.2 241.7 Time #3 81.5hrs Filtered 144.1 210.6 Time #3 90.5hrs Filtered 162.2 164.8
91
Table B-9. Iron Concentrations of Modified Large-Scale TCLP Methodology Comparison Sample Replicates
CPU Model Processing Method
Filtered/ Nonfiltered
Leachable Iron
(mg/L)
Replicate Leachable
Iron (mg/L)
Replicate Leachable
Iron (mg/L)
4 1 Disassembled Filtered 103.4 103.0 105.6 4 1 Disassembled Nonfiltered 117 119 118.3 5 1 Disassembled Filtered 94.53 93.22 93.5 5 1 Disassembled Nonfiltered 108 108.5 107.2 6 1 Disassembled Filtered 91.94 92.57 93.15 6 1 Disassembled Nonfiltered 105.2 104.3 103.7 11 2 Disassembled Filtered 252.5 252.9 258.5 11 2 Disassembled Nonfiltered 279.9 287.6 281.2 14 3 Disassembled Filtered 117.8 115.2 116.7 14 3 Disassembled Nonfiltered 122.1 124.1 119.4 15 3 Disassembled Filtered 131.4 133.7 131.0 15 3 Disassembled Nonfiltered 138.1 137.3 139.2 18 4 Disassembled Filtered 125.9 127.0 128.7 18 4 Disassembled Nonfiltered 136 136.5 137.7 23 5 Disassembled Filtered 64.78 63.81 65.49 23 5 Disassembled Nonfiltered 67.68 66.7 68.8 24 5 Disassembled Filtered 24.9 24.07 23.91 25 5 Disassembled Filtered 131.2 129.3 133.5 26 5 Disassembled Filtered 65.3 60.46 61.69 30 6 Disassembled Filtered 44.53 44.56 43.93 30 6 Disassembled Nonfiltered 47.15 47.09 47.42 31 6 Disassembled Filtered 50.36 49.72 49.12 31 6 Disassembled Nonfiltered 52.22 53.13 52.81 34 7 Disassembled Filtered 187.2 190.2 190.9 34 7 Disassembled Nonfiltered 214.2 208.3 209.4 37 8 Disassembled Filtered 204.5 194.0 205.5 38 8 Disassembled Filtered 252.8 253.6 252.0 39 8 Disassembled Filtered 271.1 261.0 269.4
92
Table B-10. Copper Concentrations of TCLP Sample Replicates
Sample Leachable
Copper (mg/L)
Replicate Leachable Copper
(mg/L) Va/Vl=0.5 #1 Filtered BDL BDL PWB 15.8g #Filtered 0.4173 0.4235 Ferrous Impact 0% #1 Filtered 2.087 2.150 Time #1 9hrs Filtered BDL BDL Time #1 18hrs Filtered BDL BDL Time #1 27hrs Filtered BDL BDL Time #1 36hrs Filtered BDL BDL Time #1 45hrs Filtered BDL BDL Time #1 57hrs Filtered BDL BDL Time #1 66hrs Filtered BDL BDL Time #1 76hrs Filtered BDL BDL Time #1 85hrs Filtered BDL BDL Time #1 93hrs Filtered BDL BDL Time #2 9hrs Filtered BDL BDL Time #2 18hrs Filtered BDL BDL Time #2 27hrs Filtered BDL BDL Time #2 36hrs Filtered BDL BDL Time #2 45hrs Filtered BDL BDL Time #2 59hrs Filtered BDL BDL Time #2 66.5hrs Filtered BDL BDL Time #2 75hrs Filtered BDL BDL Time #2 85hrs Filtered BDL BDL Time #2 88hrs Filtered .2012 0.2014 Time #3 27hrs Filtered BDL BDL Time #3 37hrs Filtered BDL BDL Time #3 45.5hrs Filtered BDL BDL Time #3 60hrs Filtered BDL BDL Time #3 69.5hrs Filtered BDL BDL Time #3 81.5hrs Filtered BDL 0.1883 Time #3 90.5hrs Filtered .1500 0.1352
93
Table B-11. Copper Concentrations of Modified Large-Scale TCLP Methodology Comparison Sample Replicates
CPU Model Processing Method
Filtered/ Nonfiltered
Leachable Copper (mg/L)
Replicate Leachable
Copper (mg/L)
Replicate Leachable
Copper (mg/L)
4 1 Disassembled Filtered BDL BDL BDL 4 1 Disassembled Nonfiltered 1.13 1.147 1.136 5 1 Disassembled Filtered BDL BDL BDL 5 1 Disassembled Nonfiltered 1.021 1.023 1.009 6 1 Disassembled Filtered BDL BDL BDL 6 1 Disassembled Nonfiltered 1.356 1.332 1.322 11 2 Disassembled Filtered BDL BDL BDL 11 2 Disassembled Nonfiltered 0.6493 0.6712 0.6562 14 3 Disassembled Filtered 0.0501 BDL BDL 14 3 Disassembled Nonfiltered 10.2 10.34 9.963 15 3 Disassembled Filtered 0.1724 0.177 0.1741 15 3 Disassembled Nonfiltered 2.692 2.673 2.709 18 4 Disassembled Filtered BDL BDL BDL 18 4 Disassembled Nonfiltered 0.4329 0.4316 0.4344 23 5 Disassembled Filtered BDL BDL BDL 23 5 Disassembled Nonfiltered 1.095 1.079 1.084 24 5 Disassembled Filtered 0.0667 0.0576 0.0549 25 5 Disassembled Filtered 0.059 0.1001 0.0836 26 5 Disassembled Filtered 0.0669 0.0471 0.0479 30 6 Disassembled Filtered BDL BDL BDL 30 6 Disassembled Nonfiltered 0.3241 0.3203 0.3276 31 6 Disassembled Filtered BDL BDL BDL 31 6 Disassembled Nonfiltered 1.298 1.317 1.316 34 7 Disassembled Filtered 0.0759 0.069 0.0682 34 7 Disassembled Nonfiltered 0.6394 0.63 0.6283 37 8 Disassembled Filtered 0.0666 0.0788 0.0979 38 8 Disassembled Filtered 0.1386 0.1374 0.111 39 8 Disassembled Filtered 0.1292 0.1326 0.1476
94
Table B-12. Zinc Concentrations of TCLP Sample Replicates
Sample Leachable
Zinc (mg/L)
Replicate Leachable Zinc
(mg/L) Va/Vl=0.5 #1 Filtered 129.1 132.8 PWB 15.8g #Filtered 0.1121 0.3025 Ferrous Impact 0% #1 Filtered 0.2382 0.2302 Time #1 9hrs Filtered 113.9 118.5 Time #1 18hrs Filtered 137.8 137.4 Time #1 27hrs Filtered 142.3 142.8 Time #1 36hrs Filtered 141.3 150.9 Time #1 45hrs Filtered 150.5 152.1 Time #1 57hrs Filtered 145.2 146.1 Time #1 66hrs Filtered 138.9 145.0 Time #1 76hrs Filtered 143.7 135.6 Time #1 85hrs Filtered 139.5 141.7 Time #1 93hrs Filtered 140.8 131.4 Time #2 9hrs Filtered 125.0 125.2 Time #2 18hrs Filtered 150.7 151.9 Time #2 27hrs Filtered 161.6 158.8 Time #2 36hrs Filtered 163.2 162.0 Time #2 45hrs Filtered 166.3 163.0 Time #2 59hrs Filtered 166.3 162.8 Time #2 66.5hrs Filtered 158.1 161.0 Time #2 75hrs Filtered 150.0 150.5 Time #2 85hrs Filtered 141.0 139.6 Time #2 88hrs Filtered 143.8 137.6 Time #3 27hrs Filtered 154.5 163.7 Time #3 37hrs Filtered 167.1 166.6 Time #3 45.5hrs Filtered 168.2 165.3 Time #3 60hrs Filtered 154.4 164.0 Time #3 69.5hrs Filtered 153.5 162.9 Time #3 81.5hrs Filtered 117.5 172.1 Time #3 90.5hrs Filtered 163.8 167.2
95
Table B-13. Zinc Concentrations of Modified Large-Scale TCLP Methodology Comparison Sample Replicates
CPU Model Processing Method
Filtered/ Nonfiltered
Leachable Zinc
(mg/L)
Replicate Leachable
Zinc (mg/L)
Replicate Leachable
Zinc (mg/L)
4 1 Disassembled Filtered 142.4 141.3 145.2 4 1 Disassembled Nonfiltered 141.1 143.1 143.2 5 1 Disassembled Filtered 153.9 152.3 152.0 5 1 Disassembled Nonfiltered 151.9 152.0 151.1 6 1 Disassembled Filtered 156.2 156.1 156.2 6 1 Disassembled Nonfiltered 153.6 153.7 152.6 11 2 Disassembled Filtered 128.2 126.7 130.0 11 2 Disassembled Nonfiltered 127.2 128.9 127.6 14 3 Disassembled Filtered 81.77 80.35 81.37 14 3 Disassembled Nonfiltered 79.98 81.43 78.59 15 3 Disassembled Filtered 92.19 93.22 91.27 15 3 Disassembled Nonfiltered 92.99 92.5 93.91 18 4 Disassembled Filtered 102.1 102.5 104.4 18 4 Disassembled Nonfiltered 101.6 102.2 103.1 23 5 Disassembled Filtered 20.62 20.28 21.02 23 5 Disassembled Nonfiltered 20.61 20.32 21.44 24 5 Disassembled Filtered 34.04 33.15 33.22 25 5 Disassembled Filtered 26.91 26.67 27.6 26 5 Disassembled Filtered 35.78 33.26 33.96 30 6 Disassembled Filtered 99.17 99.64 98.81 30 6 Disassembled Nonfiltered 99.02 97.72 99.38 31 6 Disassembled Filtered 102.3 100.4 100.0 31 6 Disassembled Nonfiltered 99.32 101.0 100.3 34 7 Disassembled Filtered 112.5 114.0 114.4 34 7 Disassembled Nonfiltered 115.0 111.5 112.1 37 8 Disassembled Filtered 218.4 207.2 220.1 38 8 Disassembled Filtered 160.0 160.6 159.4 39 8 Disassembled Filtered 135.9 132.1 135.0
96
APPENDIX C METHODOLOGY COMPARISON SAMPLE SEQUENCE
Table C-1. TCLP Methodology Comparison Sampling Sequence Sample Model Sample Collection Sample Processing Leaching Method
#1 1 Entire CPU Shredded Standard #2 1 Entire CPU Shredded Standard #3 1 Entire CPU Shredded Standard #4 1 Entire CPU Disassembled Large #5 1 Entire CPU Disassembled Large #6 1 Entire CPU Disassembled Large #7 1 Selected Components Manual Standard #8 1 Selected Components Manual Standard #9 2 Entire CPU Shredded Standard #10 2 Entire CPU Shredded Standard #11 2 Entire CPU Disassembled Large #12 2 Selected Components Manual Standard #13 3 Entire CPU Shredded Standard #14 3 Entire CPU Disassembled Large #15 3 Entire CPU Disassembled Large #16 3 Selected Components Manual Standard #17 4 Entire CPU Shredded Standard #18 4 Entire CPU Disassembled Large #19 4 Selected Components Manual Standard #20 4 Selected Components Manual Standard #21 5 Entire CPU Shredded Standard #22 5 Entire CPU Shredded Standard #23 5 Entire CPU Disassembled Large #24 5 Entire CPU Disassembled Large #25 5 Entire CPU Disassembled Large #26 5 Entire CPU Disassembled Large #27 5 Selected Components Manual Standard #28 5 Selected Components Manual Standard #29 6 Entire CPU Shredded Standard #30 6 Entire CPU Disassembled Large #31 6 Entire CPU Disassembled Large #32 6 Selected Components Manual Standard #33 7 Entire CPU Shredded Standard #34 7 Entire CPU Disassembled Large
97
Table C-1 continued Sample Model Sample Collection Sample Processing Leaching Method
#35 7 Selected Components Manual Standard #36 7 Selected Components Manual Standard #37 8 Entire CPU Disassembled Large #38 8 Entire CPU Disassembled Large #39 8 Entire CPU Disassembled Large #40 8 Selected Components Manual Standard
98
APPENDIX D CHEMISTRY
Reaction D-1
(s)22
(s)
(s)-2
-2(s)
PbFePbFe
Pb2ePb
2e FeFe
+→+
→+
+→
++
+
+
Reaction D-2
(s)2
(s)
(s)-2
-2(s)
PbZnPbZn
Pbe2Pb
e2ZnZn
+→+
→+
+→
+
+
+
Reaction D-3
(s)22
(s)
(s)-2
-2(s)
FeZnFeZn
Fee2Fe
e2ZnZn
+→+
→+
+→
++
+
+
Reaction D-4
OH2Fe2O4HFe2
OH2O4He4
4eFe2Fe2
22
2(aq)(s)
22(aq)-
-2(s)
+→++
→++
+→
++
+
+
Reaction D-5
O3H OFe Fe(OH)
Fe(OH)3OHFe
O2H4FeO4HFe4
23(s)2 Hydrolysis
3(s)
3(s)-3
23
22
⋅ →
⇔+
+⇔+++
+++
99
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BIOGRAPHICAL SKETCH
Kevin Vann graduated from the University of Florida in August of 2001 with a
Bachelor of Science degree in environmental engineering. After receiving his bachelor’s
degree, Kevin continued his studies at the University of Florida to pursue a Master of
Engineering degree in environmental engineering sciences, specializing in solid and
hazardous waste management.
