## SBIR Phase I Final Report

Feasibility of Monitoring Heavy Metal Emissions from a CoalFired Thermal Hazardous Waste Incinerator Using a MultiMetal Continuous Emissions Monitor

EPA Contract No.: EP-D-07-026
August 30 th 

### , 2007

Submitted by:
Cooper Environmental Services LLC

10180 SW Nimbus Ave, Ste J6

Portland, OR 972231 

### Project Summary

Combined uncertainties in current techniques for estimating metal concentrations at area sources can be 100% or more. These large uncertainties w ould be eliminated if continuous measurements of emissions were possible. To meet this ne ed, Cooper Environmental Services LLC (CES) has developed a multi-metal continuous emissions mo nitor (the Xact CEMSTM). The Xact CEMS has already been EPA-approved for compliance at a gas-fired hazardous waste incinerator. The objective of this research is to evaluate the feas ibility of using the Xact to measure hazardous metal emissions on a coal-fired hazardous waste in cinerator. Specifically, CES sought to answer three questions regarding th e Xact’s performance at a coal-fired facility:

1. Are Xact measurements impacted by the chemistry of the stack effluent?

2. Can the Xact accurately measure over a concen tration range including the emission limits?

3. Can the techniques used previously to validate the Xact be used on a coal-burning facility?
To answer these questions, CES tested the Xact’s ability to take measurements at the EPA’s Multi-Pollutant Control Research Facility in Re search Triangle Park, No rth Carolina, which was used to simulate a full scale coal-fired hazardous waste incinerator. During testing, the Xact sampled stack gas that was dynamically spiked w ith reference concentra tions of arsenic (As), cadmium (Cd), chromium (Cr), lead (Pb), and mercury (Hg) at three concentration levels spanning existing source emission limits: approximately 27, 92 and 250 μ g/dscm. CES also spiked ambient air at the hi ghest concentration level.

CES used several criteria to help evaluate the Xact’s performance at the test coal-fire incinerator. First, the ratio of Xact measured concentrations to the referen ce concentrations was determined for each data point. Ratios between 0.80 and 1.20 indicate that the accuracy of the Xact’s measurements was not impacted by the chemistr y of the stack effluent. Second, a comparison was made between ratios determined for flue gas and for ambient air. If no significantly difference was detected, than the Xact’s meas urements were not impacted by the chemical characteristics of the coal-fired flue gas. Fi nally, a linear regression analysis was performed on the Xact measured concentrations versus the reference concentrations for the experimental concentration range. If the slope of this line was between 0.85 and 1.15 and the correlation coefficient was greater than 0.90, than the X act’s measurements were accurate over a concentration range that in cluded the emission limit.

The results of the experiment s howed that all criteria were me t: measured-to-reference ratios were between 0.80 and 1.20, linear regression sl opes were between 0.85 and 1.15, correlation coefficients were all 0.99, and there was no difference between measurements taken with flue gas or with ambient air. CES therefore concludes that (1) chem ical composition of the stack gas from a coal-fired facility does not impact the Xact’s measurements, (2) the Xact can accurately measure metals over a concentration range that includes the emission limit, and (3) the validation techniques used in this experiment were successful on a coal-fired fu rnace. It is therefore feasible to use the Xact instrument to measure metal emissions from coal-fir ed sources including: hazardous waste incinerators, coal -fired power plants, municipal and medical waste incinerators, industrial furnaces and boilers, and primary and s econdary metal smelters. Currently, there are no other continuous emissions monitors capable of measuring multiple metals at area sources.2 

### 1.0 Introduction

1.1 Problem Significance
Eight of the 33 hazardous air pollutants (HAP) id entified by the U.S. Environmental Protection Agency (EPA) as posing the greatest potential en vironmental health threat in urban areas are metals and their compounds. 1 Negative environmental and health effects caused by metals include respiratory and pulmonary di sorders, neurotoxicity and cancer. 2,3 Hazardous metals are unique in that they will not biode grade; once released into the environment, they will always be available for re-introduction in to the air, water and food chain. Monitoring HAP emissions, especially metal compounds, is an important part of reducing exposur e pathways and thus protecting human health and the environment.

The Hazardous Waste Combustor Maximum Ac hievable Control Technology (HWC MACT) currently regulates six enumerated metals direc tly (arsenic, beryllium, cadmium, chromium, lead and mercury) and additionally regulates another five “nonenumerated” metals (antimony, cobalt, manganese, nickel, and selenium) using pa rticulate matter (PM) as a surrogate. 4 Unfortunately, the emission levels of these metals from the nation’s hazardous waste incinerators are mostly estimates because of limitati ons in monitoring technology. U nder the current MACT rule, emissions of the enumerated metals are estimated based on control efficiencies determined for each class of metals (mercury, semi-volatile, a nd low volatile) during a performance test and the estimated metal feed rates during normal operati ons. The control efficiency is determined by spiking a known amount of metal(s) at a known rate and measuring the resulting concentration using an EPA reference method, Method 29. 5 The determined control efficiency is then used for the next five years, at the end of which anot her performance test is required. Sources of uncertainty in the control efficiency may resu lt from Method 29, which has a measurement error of about 15%, 6,7 and from the assumption that the control efficiency remains the same over the entire five year span. During normal operations, the feed rate is determined by sampling various drums or solid waste to be burned. The uncer tainties from this process result from two assumptions:

1. That the waste container(s) sampled is repres entative of others from the same source.

2. That the sub-sample taken from a particular wa ste container for analysis is representative of the waste in that container.

Thus, combined uncertainties in control efficien cy and feed rate can result in errors in uncertainties in emission estimates on the order of 100% or more.
These large uncertainties in metals emissions would be eliminated if continuous or nearlycontinuous measurements of emissions were possible. The result would be a better understanding of the contribution of hazardous wa ste incineration to ambient levels of toxic metals and a better understanding of the contribu tion of hazardous waste incinerators’ impact on the health of those in the imme diate vicinity. Cooper Environmental Services LLC (CES) has already developed a multi-metal continuous emissi ons monitor (CEM) that is currently accepted by the U.S. EPA for compliance purpos es at one gas-fired incinerator. 8 Extending the demonstrated capabilities of this instrument to other types of hazardous waste incinerators may3 encourage its use at other facil ities, and in turn contribute to a better understanding of hazardous metals emissions.

1.2 Background
There have been several attempts over the past decade to develop a multi-metal continuous emissions monitoring system. These attempts have included CEMs based on laser-induced breakdown spectroscopy and atomic absorption spectroscopy. 9,10,11 However, none of the CEMs based on these approaches are commercially available nor have they been approved for compliance purposes.

Over the last decade, CES has also devel oped a multi-metal CEM based on X-ray fluorescence (XRF) spectroscopy. This CEM, called the Xact CEMSTM (hereafter referred to as “the Xact”), was recently approved by the EPA for compliance purposes on a gas-fired incinerator as defined in an alternative monitoring petition. 8 To demonstrate the Xact’s abilities on a gas-fired thermal hazardous waste, the instrument was tested with EPA Method 301 12 (M301), the procedure by which new emission technologies ar e validated by the U.S. EPA. For the test, the Xact was challenges with an aerosol c ontaining a known metal concentration generated using CES’ Quantitative reference Aerosol Generator (QAG). The QAG, which itself has been validated using M301, delivers a traceable-to NI ST aerosol into stack effluent. 13 During M301 testing of the Xact, three concentration le vels (20, 60, and 130 μg/dscm) of five metals (arsenic, cadmium, chromium, lead, and mercury) were spiked using the QAG. The average percent relative accuracy and the linearity of the Xact’s res ponse were determined by comparing the Xact’s measured concentrations with the QAG’s refere nce concentrations. The average relative percent accuracy of the Xact for all fi ve metals was less than 8.3%. 13 A linear least squares regression analysis showed that the correla tion coefficient for all five el ements was greater than 0.99 and the average slope was 0.96. 13 The strong linear relationship be tween the concentrations reported by the Xact and the QAG reference concentration c onfirms the linearity of the Xact’s response and demonstrates that the instrument is accurate and precise over a wide range of concentrations.

1.3 Research Objectives
The objective of this experiment is to demonstr ate the feasibility of using the Xact CEMS to measure metals emissions from a coal-burning th ermal hazardous waste faci lity. The ability of the Xact to measure metal emission levels at new types of sources is most likely to be impacted by the trapping efficiency of its reactive filter tape. The trapping effici ency, in turn, is most likely to be affected the followi ng physical and chemical characteri stics of the source effluent:

• SO x and NO x emission levels

• PM levels

• Moisture content

• Acid gas levels (e.g. HCl)

• Temperature
The Xact has already been su ccessfully validated on a gas-fired thermal hazardous waste incinerator, however, in terms of these key effluent characteristics, the facility does not represent4 a particularly “challenging” environment. In th is experiment, CES tested the Xact on a coalfired facility because it is likel y to represent a much more “ch allenging” environment. The levels of SO x , acid gases, and PM are likely to be much higher at a coal-fired incinerator than at a natural gas-fired incinerator. Also, the te mperature and moisture (if a wet scrubber is operating) levels may be higher. CES tested the Xact on a coal -fired thermal hazardous waste incinerator because if the instru ment can operate successfully ther e, it is likely that it would operate successfully on numerous other types of sources that burn coal and are regulated for hazardous metals. These other types of sources include but are not limited to the following:

• Municipal waste incinerators

• Medical waste incinerators

• Coal-fired power plants

• Industrial furnaces and boilers

• Primary and secondary metal smelters

• Sewage sludge incinerators
For this research, CES used procedures similar to those used during th e M301 validation of the Xact on a gas-fired facility. These procedures included spiking the source effluent with the QAG and measuring the resulting concen tration with the Xact. The Phase I feasibility demonstration sought to answer three te chnical questions regarding the func tion and validation of the Xact in the more challenging environmen t of a coal-fired facility.

1. Does the chemistry or physical nature of emissions from coal-fired hazardous waste facilities impact the Xact’s ability to continuously and accurately measure metal emissions?

2. Can the Xact accurately measure metal emissi on levels over a concentration range that includes the emission limit on a coal-fired incinerator?

3. Can the techniques used to validate the X act on a natural gas-fired hazardous waste combustion facility be used on a coal-burning facility?

CES will determine that it is feasible to use th e Xact CEMS for measuring metals at coal-fired hazardous waste facilities if the re sults of this experiment indicate that the Xact is not impacted by the chemical composition of coal-fired incinera tor’s emissions and the instrument can take accurate measurements over a concentration range th at includes the emission limit. Furthermore, if the Xact instrument itself is shown to be a fe asible method of measuring metals in a coal-fired incinerator, than CES will determine it is feas ible to apply the Xact validation techniques previously used natural gas-fired hazardous waste to a coal-fired incinerator.5 

### 2.0 Experimental Design

2.1 Experimental Set-Up

CES used EPA’s Multi-Pollutant Control Resear ch Facility (MPCRF) combustor in Research Triangle Park, NC to simulate a coal-fired hazard ous waste incinerator. The MPCRF is a pilotscale combustor operated by the Air Polluti on Technology Branch (APTB) of the EPA’s National Risk Management Resear ch Laboratory. The MPCRF is ab le to fire pulverized coal, distillate oil, and/or natural gas at 4 m illion Btu/hr, yielding flue gas flow at 300 ο F. The MPCRF is equipped with wet and dry fl ue gas cleaning systems and clos ely simulates full-scale emission sources. During this experiment, the combusto r was run by Arcadis, a contractor sanctioned by the EPA to run this facility for two days, and burned bituminous coal with no additional waste products. CES withdrew a sample of flue gas from the stack at approximately 100 Lpm from a point downstream of all controls, including an electrostatic precipitator (ESP) and a wet scrubber. The sample effluent was trans ported from the sampling point to a location approximately 60 feet away using heat-traced one- inch flexible PFA (pol yfluoroalkoxy) line. Figure 1 shows a schematic of the expe rimental setup at this location.

Figure 1. Experimental Set-Up

With the QAG, CES spiked reference concentra tions of chromium (Cr), arsenic (As), cadmium (Cd), mercury (Hg) and lead (Pb) into the st ack effluent upstream of the Xact at three concentration levels and with a blank (approximately 27, 92 and 250 μ g/dscm). Following spiking of the stack gas, CES also spiked ambi ent air at the highest concentration level. The selected concentration levels thus span a ra nge which includes the existing source emission6 limits for all three categories of metals: 92 μ g/dscm for low volatile metals (As, Cr), 230
μ g/dscm for semi-volatile metals (Pb, Cd), and 130 μ g/dscm for Hg. 4

Because there was likely to be significant blank levels of mercury (and possibly other metals of interest), CES attempted to measure the native concentrations of these metals in the stack effluent upstream of the QAG using a M301-validated X-ray and filter-based method (XFM). 13 Background concentrations for each metal were also measured at the start of each day using the Xact, due to difficulties CES encountered with a new sampling inlet design for the XFM (Section 3.3). During these background measurement peri ods, the system was operated without the addition of any flow from the QAG.

2.2 Aerosol Generation and Sampling

2.2.1 Aerosol Generation with the QAG
The QAG or Quantitative Aerosol Generator produces a reference concentration of aerosolized particulate metals and metal vapors. It was approved by the EPA for the purpose of testing the Xact. 13 The QAG generates an aerosol by nebulizing a solution containing known concentration(s) of metal analyte(s). Nebulized droplets are dried, and th e resulting metal salts and vapors are emitted into stack effluent. The solutions for nebulization are prepared in CES’ laboratory by diluting NIST-traceable stock soluti ons of each metal. The total flow through the system is measured using a 0 to 150 Lpm Rose mount flow meter. The mass loss rate is determined using an analytical balance. The QAG reference aerosol concentration ( QAG i C ) is determined using the analyte concen tration in the nebulized solution ( s i C , μg/g), the solution emission rate ( R m , g/min) corrected for vapor loss ( R v , g/min), and the total volume of gas used to create the aerosol ( t F , Lpm).

) R R ( F C C

v m
t s i QAG i − = (Eq. 1)

2.2.2 Sampling with the XFM
The XFM is a multi-metal grab-sample method based on filter technology similar to the Xact. It was validated using M301 testing at the same time as the Xact. 13 The XFM extracts a small sample (about 1 Lpm) which is diluted approximate ly 1:1 with clean dry air. The sample then passes through two filters contained in a single sampling cassette: a PTFE ( polytetrafluoroethylene ) filter for particulate-phase metals, and a reactive filter for gas-phase metals. Sample volume is then determined by s ubtracting dilution flow from the total flow for the total sampling period. Afte r sampling, the filters are shipped back to CES for analysis by XRF. The concentration of metals in the sampled flue gas ( XFM i C ) is calculated by dividing the XRF-determined mass ( XRF i M ) by the sample volume (

s V ).

s XRF i XFM i V M C = (Eq. 2)7 For this experiment, the XFM sampled from a point in the sample transport line upstream of the QAG and the Xact (Figure 1). An XFM sample was acquired for 45 minutes out of every hour. Additionally, the XFM was equipped with a silica gel water trap. This trap was weighed before and after each run to determine the concentr ation of water in the sampled stack gas.

2.2.3 Sampling with the Xact
The Xact is an X-ray fluorescence (XRF) base d multi-metals CEMS capable of measuring the concentrations of up to 25 different metals at a time. The Xact was recently approved by the EPA as a compliance instrument on a gas-fired ha zardous waste combustor. The Xact extracts a sample of effluent from the sour ce and transports it to a “stilling chamber” where the velocity is slowed or “stilled.” The Xact instrument then extracts a sma ll flow from this chamber (0.5 Lpm), which is diluted and then drawn through a reac tive filter tape that qua ntitatively traps both particulate phase and vapor phase metals. Sa mpling lasts for 15 minutes during which time the sample volume is measured. After sampling, the filte r tape is advanced to the XRF analysis area. The deposit is then analyzed by XRF for 15 minutes while the next sample is being collected. The XRF-determined mass ( Xact i M ) is then divided by the totalized sample volume ( t V ) to give the concentration of the Xact ( Xact i C ) in μg/dscm.

t Xact i Xact i V M C = (Eq. 3)

2.3 Feasibility Evaluation
To determine the feasibility of using the Xact in the more challenging environment of a coalfired facility, the Xact-measured concentrations were evaluated for agreement with a reference concentration (the QAG), and agreement among m easured elements across concentration levels, and linearity over concentration range spanning the emission limits of all measured metals. Evaluation of these parameters allowed CES to answer its three technical questions:

1. Is the Xact’s performance is impacted by the chemistry and physical nature of emissions from coal-fired hazard ous waste facilities?

2. Can the instrument accurately measure metal emission levels over a concentration range that includes the emission limit on a coal-fired incinerator?

3. Can the validation techniques used on the X act at a natural gas-fired incinerator be applied to a coal-fired incinerator?

2.3.1 Agreement with a Reference Concentration
If the Xact is unaffected by the chemical compos ition of the stack gas, than theoretically, the concentration measured by the Xact (adjusted for background ) should equal the reference concentration spiked by the QAG. The ratio ( i R ) of the i th metal as measured by the Xact ( Xact i C ) and adjusted for the background concentration ( i B ; determined by either the XFM or the Xact) to the concentrat ion spiked by the QAG ( QAG i C ) is calculated as follows:8 QAG i i Xact i i C B C R −

= (Eq. 4)

An i R value between 0.80 and 1.20 indicates that th ere is good agreement between the measured Xact concentrations and the refe rence QAG concentrations and that the Xact is unaffected by the chemical composition of the stack gas.
As a further means of determining if Xact meas urements are affected by the chemistry of the stack gas, Xact-to-QAG ratios for the spiked stac k gas were compared with those for the spiked ambient air at the high concentration level. Ratio s within one standard deviation of each other indicate that there is no signi ficant different between measurem ents made with stack gas and measurements made with ambient air, and the Xact therefore is not impacted by stack chemistry.

2.3.2 Inter-Elemental Agreement
To further evaluate the potential impacts of coal -fired incinerator emissions on the Xact’s ability to accurately take measurements over a range of concentrations that includes the emission limit, the ratio ( R Cd ) of the concentration of each element ( C i ) to the concentration of Cd ( C Cd ) was calculated as follows for each concentration level:

Cd i Cd C C R = (Eq. 5)

If inter-elemental ratios generally within one standard deviation of each other across all concentration levels, than the Xact can accurate ly take measurements over the experimental concentration range.

As above for the Xact-to-QAG ratios, inter-eleme ntal ratios for the spiked stack gas were compared with those for the spiked ambient air at the high concentration level. Again, ratios within one standard deviation of each other indicate that there is no significant different between measurements made with stack gas and measur ements made with ambient air. If the measurements made by the Xact are not significa ntly impacted by the chemical composition of the stack gas, one would not expect to see a di fference in the inter-elemental ratios between spiked stack gas and spiked ambient ai r at the high concentration level.

2.3.3 Linearity

For each element across all concentration levels, Xact-reported concentrations for each element were plotted against adjusted QAG reference conc entrations, and a linear least squares regression analysis was performed in the form of y = mx + b . The slope of the line ( m ) and the correlation coefficient ( r ) were used to evaluate linearity. Slope values between 0.85 and 1.15 and correlation coefficient values greater than 0.90 accurate Xact measurements over the experimental concentration range.9 

### 3.0 Pre-Test Laboratory Preparation

3.1 QAG Low Flow Rate Confirmation
The QAG was initially designed to spike into a flow of about 600 Lpm and use about 100 Lpm of spiking gas, giving a spike-to -stack-gas ratio of about 1:6. During testing at the combustor site, a much lower flow rate (around 150 Lpm) wa s needed while maintaining a reasonable ratio of spike to stack gas. To confirm that the QAG could be used at lower flow rates, the QAG was used to spike Cr, As, Cd, Hg, and Pb into an Xact manufactured in 2007 at an operational flow rate of about 125 Lpm. The same Xact instrument was then spiked at 45 and 30 Lpm. For each 15 minute Xact period, the ratio of the Xact re ported concentration was compared to the QAG aerosol concentration. The ratio of the QAG to th e Xact for each element at each QAG flow rate was found to be approximately 1.00 (Table 1). These results show that (1) there was great agreement between the QAG concentration and the reported Xact concen tration and (2) the QAG can generate a quantitative aerosol at the lower flow rates. This test therefore confirmed that it was possible to use a flow rate of ab out 150 Lpm at our combustor test site.

Table 1. Results of Testing QAG at Various Flow Rates

Xact/ QAG STDEV of Xact/Qag Xact/ QAG STDEV of Xact/Qag Xact/ QAG STDEV of Xact/Qag Xact/ QAG STDEV of Xact/Qag Xact/ QAG STDEV of Xact/Qag 125 1.02 0.03 1.01 0.07 1.02 0.03 1.00 0.09 1.04 0.03 45 1.00 0.03 1.08 0.02 1.03 0.03 1.08 0.02 1.03 0.02 30 0.99 0.04 1.06 0.05 1.01 0.05 0.95 0.06 1.03 0.05 Pb

Flow (Lpm) Cr As Cd Hg

3.2 CES Xact Calibration
For the testing at the MPCRF, CES used an Xact manufactured in 2004. This Xact was calibrated with XRF thin film standards typically used for the calibration of instruments for PM 10 and PM 2.5 filter analysis. The Xact was then challenged using the QAG at three different concentration levels (20, 75, and 180 μg/dscm). Linearity was evaluated for each analyte (Cr, As, Cd, Hg, and Pb), according to Section 2.2.3. Fo r this test, slopes ranged for a low of 0.74 for chromium and cadmium to a high of 0.82 for l ead (Pb) with correlation coefficients ( r ) of greater than 0.99 for all elements. The reason for the discrepancy between the Xact and the QAG is not well understood at this time. However, the 2007 Xact (Section 3.1) di d not exhibit this difference. The two units differ in the desi gn of the flow system and the XRF calibration method, indicating two potential sources of the discrepancy. Due to time and cost limitations, the Xact used for testing at th e MPCRF could not be retrofitted with components from the newer Xact design. The calibration of the unit was, therefore, adjusted to match the QAG aerosol similar to the way that mercury or SO 2 CEMS are calibrated. 14 Following recalibration, the unit was again challenged using the QAG. The concen trations reported by the Xact were found to be within 3% of the spiked concentration.

3.3 XFM Adjustments
During testing at the MPCRF, CES used the XFM to determine the native concentrations of metals in the stack. The XFM sampling inlet was re designed to make it usab le for this project.10 CES tested the redesigned sampling inlet by ch allenging the XFM with an aerosol of known concentration at three different concentration levels (30, 70, 110 μ g/m 3 ) using the QAG. The XFM-reported concentrations we re compared with those of the QAG for each sampled element (Cr, As, Cd, Hg, and Pb). Ratios (Table 2) of the XFM-reported concentration to the QAG were found to be less then 1.00 (a value of 1.00 indi cates complete agreement between the XFM and the QAG), with mercury (0.70) and arsenic (0.71) being particularly low. Post-test analyses revealed a likely cold spot and flow disturbance at the point wh ere dilution air enters into the sampling nozzle. This cold spot and flow distur bance causes loss of material to the walls of the sampling inlet tube, particularly for the species mo st likely to exist in the vapor phase (mercury and arsenic). Because of the problems with th e redesigned XFM sampling inlet, CES elected to use the Xact to determine background concentrat ions while the facility was burning coal. The Xact therefore sampled stack gas prior to sp iking on each day of testing at the MPCRF and reported background concentrations. XFM samples were still acquired, ho wever, to check for variability in background concentrat ions while spiking was occurring.

Table 2: QAG Spiked Concentration V ersus XFM Reported Concentration

Cr As Cd Hg Pb Cr As Cd Hg Pb Cr As Cd Hg Pb 31.4 31.4 31.3 31.3 31.3 28.1 25.6 26. 2 27.3 26.7 0.89 0.82 0.84 0.87 0.85 31.6 31.6 31.5 31.5 31.6 28.1 25.4 27. 0 25.4 27.4 0.89 0.80 0.86 0.81 0.87 30.8 30.7 30.7 30.7 30.7 30.7 27.1 30. 8 25.3 29.5 1.00 0.88 1.00 0.82 0.96 30.1 30.1 30.0 30.0 30.0 29.0 24.7 26. 9 22.6 28.2 0.96 0.82 0.90 0.75 0.94 71.8 71.7 71.6 71.6 71.7 67.0 45.5 64. 2 55.1 64.7 0.93 0.63 0.90 0.77 0.90 70.0 69.9 69.8 69.8 69.9 66.3 43.9 65. 5 49.7 64.7 0.95 0.63 0.94 0.71 0.93 68.6 68.6 68.5 68.5 68.5 65.4 45.2 61. 4 50.0 64.6 0.95 0.66 0.90 0.73 0.94 68.6 68.6 68.5 68.5 68.5 66.9 44.6 64. 8 49.6 65.5 0.97 0.65 0.95 0.72 0.96 110.1 110.0 109.8 109.9 109.9 1 06.1 72.7 102.4 75.0 104.0 0.96 0.66 0.93 0.68 0.95 108.0 107.9 107.7 107.7 107.8 1 06.9 71.3 101.8 69.5 104.8 0.99 0.66 0.95 0.65 0.97 108.0 107.9 107.7 107.7 107.8 9 7.3 62.2 83.1 56.2 87.4 0.90 0.58 0.77 0.52 0.81 108.0 107.9 107.7 107.7 107.8 1 03.5 66.2 90.9 56.9 55.4 0.96 0.61 0.84 0.53 0.51 0.95 0.70 0.90 0.71 0.88 Low

Mid

Hi g h QAG Predicted Conc. (μg/m3) XFM -Reported Conc. (μg/m3) XFM/QAG

AVERAGE Concentration Level



### 4.0 Test Results and Discussion

4.1 Xact-to-QAG Agreement
Table 3 shows the results of the ratio comparis on between QAG and the Xact. The ratio of the Xact to the QAG should be close to unity if the Xact is no t significantly impacted by the chemical composition of the stack gas. A value of greater than 1 indicate s that the Xact is high relative to the QAG a value of less than 1 indicates the Xact is lo w relative to the QAG. Table 4 summaries the results with regards to the ag reement criteria establ ished in Section 2.3.Table 3. Xact Concentrations, QAG Concentrations and Xact-to-QAG RatiosCr As Cd Hg Pb CrAs Cd Hg Pb CrAs Cd Hg Pb0 0 0 0 0 0 0.4 1.5 23.1 0.26 NA NA NA NA NA0 0 0 0 0 0 0 0.88 21.31 0.8 NA NA NA NA NA0 0 0 0 0 0 0.33 1.42 14.28 0 NA NA NA NA NA0 0 0 0 0 0 0 0 10.64 0.66 NA NA NA NA NA0 0 0 0 0 0 0.49 0 8.85 0.12 NA NA NA NA NA0 0 0 0 0 0 0.23 0 7.41 0.12 NA NA NA NA NA0 0 0 0 0 0 0.43 1.08 6.28 0.43 NA NA NA NA NA27.58 27.56 27.49 27.53 27.60 29.96 28.21 28.94 31.30 26.17 1.09 1.02 1.05 1.14 0.9527.58 27.56 27.49 27.53 27.60 27.71 28.43 29.86 32.11 26.36 1.00 1.03 1.09 1.17 0.9627.58 27.56 27.49 27.53 27.60 29.35 29.73 31.50 30.45 25.61 1.06 1.08 1.15 1.11 0.9327.58 27.56 27.49 27.53 27.60 31.19 30.32 28.48 30.88 26.50 1.13 1.10 1.04 1.12 0.9627.58 27.56 27.49 27.53 27.60 27.20 30.01 28.57 30.77 25.98 0.99 1.09 1.04 1.12 0.9427.86 27.83 27.76 27.81 27.88 27.28 28.45 29.01 30.68 28.30 0.98 1.02 1.04 1.10 1.0227.86 27.83 27.76 27.81 27.88 28.75 31.08 31.70 29.99 25.63 1.03 1.12 1.14 1.08 0.9227.86 27.83 27.76 27.81 27.88 28.94 30.97 28.70 31.31 28.29 1.04 1.11 1.03 1.13 1.0127.86 27.83 27.76 27.81 27.88 29.29 30.32 30.11 30.16 27.85 1.05 1.09 1.08 1.08 1.0027.86 27.83 27.76 27.81 27.88 30.72 29.38 31.85 29.22 26.65 1.10 1.06 1.15 1.05 0.9692.87 92.84 92.89 92.91 92.87 96.74 102.13 104.27 103.96 91.75 1.04 1.10 1.12 1.12 0.9992.23 92.20 92.25 92.27 92.23 95.40 101.44 96.64 102.73 89.02 1.03 1.10 1.05 1.11 0.9792.23 92.20 92.25 92.27 92.23 97.09 102.63 98.80 104.93 90.84 1.05 1.11 1.07 1.14 0.9892.23 92.20 92.25 92.27 92.23 98.83 104.87 103.73 105.11 90.95 1.07 1.14 1.12 1.14 0.9992.23 92.20 92.25 92.27 92.23 96.78 100.45 99.61 101.80 91.32 1.05 1.09 1.08 1.10 0.9991.01 90.99 91.03 91.06 91.01 97.52 102.01 99.30 102.70 90.42 1.07 1.12 1.09 1.13 0.9991.01 90.99 91.03 91.06 91.01 97.60 101.78 98.58 102.69 89.65 1.07 1.12 1.08 1.13 0.9991.01 90.99 91.03 91.06 91.01 96.32 100.05 94.45 102.48 91.52 1.06 1.10 1.04 1.13 1.0191.01 90.99 91.03 91.06 91.01 99.68 105.65 108.04 104.54 93.53 1.10 1.16 1.19 1.15 1.03248.93 248.78 248.14 248.53 249.08 266.66 279.51 264.46 291.91 248.18 1.07 1.12 1.07 1.17 1.00248.93 248.78 248.14 248.53 249.08 262.46 277.26 264.40 278.69 243.97 1.05 1.11 1.07 1.12 0.98248.93 248.78 248.14 248.53 249.08 273.43 286.62 273.00 292.01 252.36 1.10 1.15 1.10 1.17 1.01248.93 248.78 248.14 248.53 249.08 271.94 289.75 282.36 292.30 252.26 1.09 1.16 1.14 1.18 1.01245.73 245.58 244.95 245.34 245.88 275.05 290.57 289.08 293.00 252.08 1.12 1.18 1.18 1.19 1.03245.73 245.58 244.95 245.34 245.88 266.92 280.31 275.81 282.73 243.49 1.09 1.14 1.13 1.15 0.99245.73 245.58 244.95 245.34 245.88 260.84 272.15 271.73 273.55 236.20 1.06 1.11 1.11 1.11 0.96245.73 245.58 244.95 245.34 245.88 267.62 282.02 273.88 288.64 245.60 1.09 1.15 1.12 1.18 1.00247.62 247.47 246.83 247.22 247.77 267.36 277.35 266.38 287.20 245.43 1.08 1.12 1.08 1.16 0.99107.85 107.79 107.51 107.68 107.92 109.73 119.63 114.98 128.64 102.22 1.02 1.11 1.07 1.19 0.95108.11 108.05 107.76 107.94 108.18 118.75 124.52 122.78 131.76 109.87 1.10 1.15 1.14 1.22 1.02108.11 108.05 107.76 107.94 108.18 114.50 125.23 116.98 127.72 107.74 1.06 1.16 1.09 1.18 1.00110.53 110.46 110.17 110.35 110.59 116.27 124.89 121.82 123.96 106.72 1.05 1.13 1.11 1.12 0.96110.53 110.46 110.17 110.35 110.59 117.46 127.80 123.13 126.67 108.88 1.06 1.16 1.12 1.15 0.98AVE 1.06 1.11 1.09 1.13 0.98STDEV 0.04 0.04 0.04 0.03 0.03%RSD 3.36 3.61 4.00 2.93 2.91AVE 1.06 1.14 1.10 1.17 0.98STDEV 0.03 0.02 0.03 0.04 0.03%RSD 2.73 1.85 2.47 3.28 2.71Conc.LevelXact/QAGLowAmbientAirBlankSpikeQAG Aerosol Conc (אg/m3) Background Corrected Xact Conc. (אg/m3)MidHighHighAmbientFlue Gas

1112 Table 4. Summary of Xact-to-QAG Agreement Criteria and Results

Cr 0.80 to 1.20 1.06 yes As 0.80 to 1.20 1.11 yes Cd 0.80 to 1.20 1.09 yes Hg 0.80 to 1.20 1.13 yes Pb 0.80 to 1.20 0.98 yes Element Xact/QAG Ratio

Criteria Experime ntal Avera g e Criteria Met?

On average, the Xact was sligh tly high relative to the QAG, ranging from a low of 0.98 for lead to 1.13 for mercury. However, all values were within the experimental target range between 0.80 and 1.20. Also shown in Table 3, Xact-to- QAG ratios are not significantly different regardless of whether the Xact was sampling spiked stack effluent or spiked ambient air. These two results indicate that the Xact’s measurement of all five metals of interest (chromium, arsenic, cadmium, mercury, and lead) is un affected by the chemical com position of the stack gas.
A major difficulty with this experiment was th e measurement of the amount of water in the system. The Xact measures metals concentratio ns on a dry basis, however, the QAG spikes into a very “wet” air stream. During testing, it appe ars that CES had a great deal of difficulty accurately measuring the amount of water in th e system. Since sampling took place downstream of a wet scrubber, all of the resu lts assume saturation at a measur ed temperature of 116 °F and an absolute pressure of approximately 27.9 inches of mercury (see appendi x A for a more detailed explanation). 15 The amount of water determined to be present during ambient air spiking was based on nearby meteorological data of the relative humidity.
As noted above, background metal concentratio ns were determined using the Xact. A background level of 6.73 μ g/dscm was used for mercury thr oughout the tests and represents the average of all background measurem ents on the Xact. The mercury is likely due to the coal and was expected. For the lowest spike level, a background c oncentration of 4 μ g/dscm of chromium was subtracted from the Xact results. Duri ng most of the blank spike and the background measurements, CES had observed essentially no background metal concentrations for every element of interest except mercury. However, just prior to the low-level spike, CES observed a jump in the concentration of several me tals of interest including chromium (12 μ g/dscm) and arsenic (20 μ g/dscm). This observed spike coincided w ith a sudden failure in the automatic feed of coal. Spiking was not resumed until the arseni c, lead and cadmium values had returned to zero; however, the chromium numbers did not return to zero. The value of 4 μ g/dscm for chromium was therefore used as an estimate and is slightly lower than the last measured value for chromium of 4.73 μ g/dscm.

4.2 Inter-elemental Agreement

Table 5 shows the ratio of all the elements to cadmium under all four spiking conditions (low concentration with stack gas, medium concentr ation with stack gas, high concentration with stack gas, high concentration with ambient air). Of these five elements, chromium, lead and cadmium are likely to exist in a particle phase, ar senic is likely to be partially in the particle13 phase and partially in vapor phase, and mercury is likely to be entirely in the vapor phase. The inter-elemental ratios serve as an additional confirmation that the Xact’s measurement is unaffected by stack gas composition. If the measur ements made by the Xact were significantly impacted by the chemical composition of the stack gas, one would expect a difference in the inter-elemental ratios between spiked stack gas and spiked ambient air, particularly for the metals likely to have significant vapor phase spec ies (arsenic and mercury). The results in Table 5 indicate that the inter-element al ratios are not significantly di fferent for spiked stack gas or spiked ambient air. Furthermore, the fact that the inter-elemental ratios remain nearly the same across all concentration levels i ndicates that the chemistry and physical characteristics of the stack effluent do not affect the Xact’s measurements at any concentration.14 Table 5. Xact Inter-elemental Ratios

Cr/Cd A s/Cd Hg/Cd Pb/Cd 1 1.04 0.97 1.15 0.90 2 0.93 0.95 1.14 0.88 3 0.93 0.94 1.03 0.81 4 1.10 1.06 1.15 0.93 5 0.95 1.05 1.14 0.91 6 0.94 0.98 1.12 0.98 7 0.91 0.98 1.01 0.81 8 1.01 1.08 1.16 0.99 9 0.97 1.01 1.07 0.92 10 0.96 0.92 0.98 0.84 Average 0.97 1.00 1.09 0.90 STDEV 0.06 0.06 0.07 0.07 %RSD 5.80 5.64 6.38 7.35 1 0.98 1.05 1.06 0.91 2 0.95 1.03 1.05 0.91 3 0.93 0.98 1.02 0.88 4 0.99 1.05 1.08 0.92 5 0.98 1.04 1.08 0.92 6 0.95 1.01 1.03 0.88 7 0.97 1.01 1.04 0.92 8 0.98 1.03 1.05 0.91 9 0.99 1.03 1.06 0.91 10 1.02 1.06 1.11 0.97 11 0.92 0.98 0.99 0.87 Average 0.97 1.02 1.05 0.91 STDEV 0.03 0.03 0.03 0.03 %RSD 2.94 2.66 3.17 3.05 1 0.97 1.02 1.06 0.89 2 1.01 1.06 1.11 0.94 3 0.99 1.05 1.06 0.92 4 1.00 1.05 1.08 0.92 5 0.96 1.03 1.04 0.89 6 0.95 1.01 1.02 0.87 7 0.97 1.02 1.03 0.88 8 0.96 1.00 1.01 0.87 9 0.98 1.03 1.06 0.90 10 1.00 1.04 1.09 0.92 Average 0.98 1.03 1.06 0.90 STDEV 0.02 0.02 0.03 0.02 %RSD 2.09 1.88 2.86 2.65 2 0.97 1.01 1.05 0.89 3 0.98 1.07 1.07 0.92 4 0.95 1.03 0.99 0.88 5 0.95 1.04 1.00 0.88 Average 0.96 1.04 1.03 0.89 STDEV 0.01 0.02 0.03 0.02 %RSD 1.23 2.35 3.40 2.19 0.97 1.02 1.07 0.90 0.04 0.04 0.05 0.04 0.96 1.04 1.03 0.89 0.01 0.02 0.03 0.02 AVE of Stack Gas Spike STDEV of Gas Stack Spike AVE of Ambient Air Spike STDEV of Ambient Air Spike Low Stack Gas

Mid Stack Gas

High Stack Gas

High Ambient Air Interelemental Ratios Concentration Level Run Number15 4.3 Linearity
The results of the linear least squares regression analyses for the Xact reported concentration compared to the QAG reference concentrations ov er the experimental co ncentration range are shown in Figures 2 through 6. The slope of each leas t squares fit is an indi cator of the accuracy of the Xact with a value of un ity indicating complete agreement between the Xact and the QAG. The slopes ranged from a low of 0.99 for lead to a high of 1.14 for arsenic; all elements were thus within the experimental target range for the slope of 0.85 to 1.15. The correlation coefficient ( r ) indicates the amount of scatter in the data with a value of 1 indicating no scatter. The correlation coefficient for all of the elements had values of 0.99, indicating very little scatter and much higher than the experimental target of 0.90. Table 6 summari es the results with regards to the linearity criteria established in Section 2.3. Together, the slope and correlation coefficient values demonstrate that the Xact can accurately take measurements over a concentration range that includes existing source emission limits (92 μ g/dscm for As and Cr, 230
μ g/dscm for Pb, Cd, and 130 μ g/dscm for Hg). 4

Chromium Linearity

y = 1.0858x - 1.035 R 2 = 0.9993

-50

0 50 100 150 200 250 300

0 50 100 150 200 250 300

QAG Cr Conc. (μg/m3)Xact Cr. Conc (μg/m3)

Figure 2. Chromium Linearity r = 0.9916 Arsenic Linearity

y = 1.1432x - 1.3864 R 2 = 0.9991

-50

0 50 100 150 200 250 300 350

0 50 100 150 200 250 300

QAG As Conc. (μg/m3)Xact As. Conc. (μg/m3)

Figure 3. Arsenic Linearity

Cadmium Linearity

y = 1.1091x - 0.4478 R 2 = 0.9978

-50

0 50 100 150 200 250 300 350

0 50 100 150 200 250 300

QAG Cd Conc. (μg/m3)Xact Cd Conc. (μg/m3)

Figure 4. Cadmium Linearity r = 0.99

r = 0.9917 Hg Linearity

y = 1.1365x + 3.7157 R 2 = 0.9959

0 50 100 150 200 250 300 350

0 50 100 150 200 250 300 QAG Hg Conc. (μg/m3)Xact Hg Conc. (μg/m3)

Figure 5. Mercury Linearity

Pb Linearity

y = 0.9977x - 0.4203 R 2 = 0.9993

-50

0 50 100 150 200 250 300

0 50 100 150 200 250 300

QAG Pb Conc. (μg/m3)Xact Pb Conc. (μg/m3)

Figure 6. Lead Linearity r = 0.99

r = 0.9918 Table 6. Summary of Linearity Criteria and Results

Criteria Experimental Result Criteria Met? Criteria Experimental Average Criteria Met? Cr 0.85 to 1.15 1.09 yes >0.90 >0.99 yes As 0.85 to 1.15 1.14 yes >0.90 >0.99 yes Cd 0.85 to 1.15 1.11 yes >0.90 >0.99 yes Hg 0.85 to 1.15 1.14 yes >0.90 >0.99 yes Pb 0.85 to 1.15 1.00 yes >0.90 >0.99 yes Element Slope Linearity Correlation Cooefficient



### 5.0 Experimental Conclusions and Technical Feasibility Assessment

The Phase I feasibility demonstration sought to answer three technical questions regarding the function and validation of the Xact in the more ch allenging environment of a coal-fired facility.

1. Does the chemistry or physical nature of emissions from coal-fired hazardous waste facilities impact the Xact’s ability to continuously and accurately measure metal emissions?

2. Can the Xact accurately measure metal emission levels over a concentration range that includes the emission limit on a coal fired incinerator?

3. Can the techniques used to validate the X act on a natural gas fired hazardous waste combustion facility be used on a coal burning facility?
To answer the first question, CES evaluated the agreement between Xact-measured concentrations and reference concentrations as well as the elemental agreement between measurements made in stack gas and measurem ents made in ambient air. The results demonstrated that there was a high level of agreement between the Xact and the reference aerosol at all concentration leve ls and this level agreement was not affected by sampling stack gas versus ambient air. The results also show ed that measurements made in stack gas and measurements made in ambient air were not significantly different for each element. CES therefore concludes that the Xact ’s measurements are not impact ed by the chemical or physical characteristics of the stack gas.
To answer the second question, CES evaluated the linear response a nd the inter-elemental agreement of the Xact’s measur ements over a concentration range that included existing source emission limits. The results demonstrated excellent agreement between the reference QAG concentrations and the Xact measured concentr ation at all spiking le vels, as well as good elemental agreement across all spiking levels. CE S thus concludes that the Xact can accurately measure metals concentrations over a la rge range including th e emission limit.
Because the results of this experiment indicate that the Xact is not impacted by the chemical composition of coal-fired incinerator’s emi ssions and the instrument can take accurate measurements over a concentrati on range that includes the emissi on limit, CES concludes that it19 is feasible to use the Xact CEMS for measur ing metals at any coal-fired combustion source including: hazardous waste incinerators, m unicipal waste incinerators, medical waste incinerators, and coal-fired power plants. Furthermore, the valid ation techniques us ed previously on a gas-fired hazardous waste incinerator were also successful on a coal-fired furnace. Future work however, should incorporate more accurate methods of measuring stack gas water content should be used.



### 6.0 Commercialization Activities and Plans

An investigation of potential markets for the X act multi-metals monitor during Phase I of this project has revealed several markets for this instrument: the mercury monitoring market, the multi-metal CEMs market, and the multi-metal ambien t monitoring market. At the time of this study, the most significant market for the Xact CEMS is the mercury monitoring market. The mercury monitoring market, estimated at $100 million dollar a year (all goods and services), was created in 2005 with the Clean Air Mercury Rule . 16 This rule requires monitoring of mercury emissions from coal-fired utility boilers. While other technologies exist in this market, the Xact technology is unique in that it uses X-ray fluorescence to measure mercury and thus offers significant benefits over the othe r technologies including measurem ent of more than one metal and reduced cost.

Presently, the multi-metals CEMS and ambient monitoring markets are still emerging. CES continues to pursue possible commercial opportun ities in the multi-metals CEMS market as emission monitors and standards are review ed by the US and Europe. During 2007, CES received and filled orders for two Xact CEMS for the US Army. CES was also approached several times throughout the year by parties potentia lly interested in purc hasing units. In terms of the multi-metal ambient monitoring market, CES has been contacted by foreign and state governments interested in the application of X act technology ambient monitoring. This market should continue to expand as National Ambient Ai r Quality Standards for lead are review by the EPA. In fact, CES has recently received two orders for ambient multi-metals monitors and is expecting a third order in October. At this time, however, there are no regulatory drivers for a multi-metal CEMs or ambient monitors.

Given the strength and significance of the mercur y monitoring market, CES has elected to focus the majority of its commercialization efforts on this market. CES is beginning to optimize the Xact design around mercury monitoring while ma intaining those features that make the instrument applicable to the multi-metals CEMs and ambient monitoring markets as they develop. A sustainable commercia l business is expected with a pplication of Xact technology to the existing mercury market alone. However, this technology will also be applied to additional monitoring markets as they are defined by future regulations.
Progress and our future commercia lization activities in this mon itoring market are summarized below.

1. Optimization of our Xact for the measurement of mercury. The multi-metals Xact used in these Phase I demonstration tests had a singl e excitation condition optimized for mercury20 but used a detector optimized for multi-metal s. Future work will focus on optimization of X-ray optics and use of de tectors best suited for mercury. Currently, CES is working with a detector supplier who has loaned CES an optimum mercury detector. This detector is in the early stag es of evaluation and testing.

2. Establishing opportunities to demonstrate the Xact technology on coal-fired utility boilers. CES has obtained permission from a local coal-fired power plant to test a mercury-optimized monitor on their stac k. With funding, CES plans on installing a mercury-optimized Xact at the local coal-f ired power plant and operating it over an extended period to demonstrate its reliability. If funding is available, this unit would also be tested for accuracy with a comparativ e reference method. CES expects to obtain a commitment to fund reference method testing of the mercury-optimized Xact when the instrument is installed on the stack.

3. Strengthening patent protection. During this past year, CES has obtained a third patent dealing with proprietary filter chemistry. CES submitted two other patent applications this past year dealing with quality assuran ce anticipates submitting an additional patent in 2008.

4. Defining and streamlining th e Xact production supply c hain and cost reduction. In 2007, CES built two new multi-metal Xacts for a US Army conventional weapons incineration application. This opportunity a llowed CES to define its supply chain along with a clearly defined database on costs, vendor, lead times, etc. As a result, CES was also able to more precisely define fabrication costs an d identify areas for cost reduction.

5. Demonstrating the application of the Xact to the ambient ai r monitoring market. With current EPA funding, CES is in the process of demonstrating the applic ability of the Xact technology to fence line monitoring. With potenti al future funding, CES expects to have a unit operating in the field n ear a major source in Portland.

6. Development of an expanding distribution network. This past year, CES has successfully established distribution networks in Korea, Canada and Australia. This distribution network has resulted in two purchase orde rs for ambient multi-metal Xacts from a Korean distributor and str ong leads from a Canadian and Australian distributor. In addition, CES is in the process of expanding th e sales territory of our Korean distributor to the major pacific rim countries as well as developing distributor relations for Europe and India.

7. Developing sales literature. This literature will help support sales and distribution efforts. In addition, CES attendance at seminars will help distributors a nd regulators better understand the Xact technology a nd its broad applications.

8. Looking for partners to help addres s the mercury monitoring market. Discussions with sources of capital are in progress that mi ght provide supplemental resources to more aggressively attack the mercury monitoring market. In addition, CES is currently in discussions with integrators to help serv ice the mercury CEMS market and with key component suppliers to provide support. Thes e discussions have alre ady resulted in labor21 and hardware support from an X-ray detector manufacture in the form of equipment loans and applications development valued on th e order of $100,000 to develop the mercury monitoring application.



### 7.0 References

1. U.S. Environmental Protection Agency. Air Toxics Strategy Fact Sheet. EPA Technology Transfer Network Air Toxics Website. h ttp://www.epa.gov/ttn/atw/urban/strategyfs0303.pdf (accessed September 2006). 2. Prieditis, H.; Adamson, I.Y. 2002. Compara tive Pulmonary Toxicity of Various Soluble Metals Found in Urban Particulate Dust; Exp. Lung. Res.
, 28 , 563-576. 3. Monn, C.; Becker, S. 1999. Cytotoxicity a nd Induction of Proinflammatory Cytokines from Human Monocytes Exposed to Fine (PM 2.5 ) and Coarse Particles (PM 10-2.5 ) in Outdoor and Indoor Air; Tox. Appl. Pharm., 155 , 245-252. 4. U.S. Environmental Protection Agenc y. 2005. National Emissions Standards for Hazardous Air Pollutants for Source Categories; Code of Federal Regulations, 40 CFR 63 ; U.S. Government Printing Office: Washington, DC. 5. U.S. Environmental Protection Agen cy. 2005. Method 29, Determination of Metals Emissions from Stationary Sources; Code of Federal Regulations, 40 CFR 60 ; U.S. Government Printing Office: Washington, DC. 6. Rigo, H.G.; Chandler A.J. 1999. Quantitation Limits for Reference Methods 23, 26, and 29; J. Air & Waste Manage. Assoc
., 49 , 399-411. 7. American Society of Mechanical Engin eers [ASME], Research Committee on Industrial and Municipal Waste. 2001. Reference Method Accuracy and Pr ecision (ReMAP): Phase 1, Precision of Manual Stac k Emission Measurements ; Report No. CRTD-60; ASME International: Washington, DC. 8. Eli Lilly and Company. 2005. Alternativ e Monitoring Petition for the Solid-Liquid Incinerator, Tippecanoe Labor atories: Lafayette, IN. 9. Zhang, H.; Yueh, F.Y.; Singh, J.P. 2002. Ev aluation of the Potential of Laser-Induced Breakdown Spectroscopy for Detection of Trace Element in Liquid; J. Air & Waste Manage. Assoc.
, 51 , 681-687

. 10. Seltzer, M.D. 2000. Performance Testing of a Multimetals Continuous Emissions Monitor; J. Air & Waste Manage. Assoc., 50, 1010-1016. 11. Sky +. 1998. 1997 Performance Testing of Multi-Met al Continuous Emissions Monitors ; DOE/ID-10665. U.S. Department of Energy, Ida ho Operations Office: Idaho Falls, ID. 12. U.S. Environmental Protection Agency. 2005. Method 301, Field Validation of Pollution Measurement Methods for Various Media; Code of Federal Regulations, 40 CFR 56 ; U.S. Government Printing Office: Washington, DC.22 13. Yanca, C.A.; Barth, D.C.; Petterson, K.A.; Nakanishi, M.P.; Johnsen, B.E.; Cooper, J.A.; Lambert, R.H.; Bivins, D.G. 2006. Validation of Three New Methods for Determination of Metal Emissions using a Modified EPA Method 301. J. Air & Waste Manage. Assoc.
, 56
, 1733–1742. 14. U.S. Environmental Protection Agen cy. 2002. Continuous Emissions Monitoring; Code of Federal Regulations, 40 CFR 75 ; U.S. Government Printi ng Office: Washington, DC.

15. Perry, R.H.; Green, D.W; Editors. 1984. Perry ’s Chemical Engin eers’ Handbook. 6th Ed. McGraw-Hill Book Company: New York.

16. U.S. Environmental Protection Ag ency. Clean Air Mercury Rule. http://www.epa.gov/mercuryrule (accessed August 2007).

## Appendix A to the Final Report

Feasibility of Monitoring Heavy Metal Emissions from a CoalFired Thermal Hazardous Waste Incinerator Using a MultiMetal Continuous Emissions Monitor

EPA Contract No.: EP-D-07-026
August 30 th 

### , 2007

Submitted by:
Cooper Environmental Services LLC

10180 SW Nimbus Ave, Ste J6

Portland, OR 97223A-1 

### 1.0 Introduction

The initial results from the testing of the CES Xact at the Multi-Poll utant Control Research Facility (MPCRF) are enumerated in Table 1. These results indicate a significant discrepancy (about 25%) between the Xact and the Quantitat ive Aerosol Generator (QAG) when sampling stack gas and a somewhat smaller discrepancy when sampling ambient air. These results were based on what are now believed to be inaccurate measurements of the amount of water in the stack gas. The Xact dries the sampled flow befo re measurement to give a concentration for each result in terms of dry standard cubic meters (d scm). The QAG, however, was spiking into what should be a wet gas stream (the stack gas samp le into which the QAG aerosol was spiked was taken downstream of a wet scrubber and transpor ted using flex line heated to 250 °F). To accurately compare the Xact and the QAG, the water in the stack gas must be taken into account. This appendix presents evidence in support of the conclusion that the water measurement used to generate these results was inaccurate, and also ou tlines why other possible explanations for this discrepancy were discounted.



### 2.0 Evaluation of Potential Sou rces of QAG-Xact Discrepancy

Of particular interest in examining the diffe rence between the concentration measured by the Xact and that emitted by the QAG is that fact th at the Xact is reporti ng a higher concentration than the QAG is emitting. It is therefore unlikely that much if any of the particulate or vaporphase emissions were being lost to the walls of either the QAG or the transport line. To attempt to explain why the Xact was high relative to the QAG, a list of possible explanations was generated as follows:

1. Inaccurate measurement of QAG flow

2. Problem with the Xact X-ray Fluorescen ce (XRF) calibration or flow calibration

3. Evaporative loss in the QAG

4. Leak in the transport line

5. Matrix (stack gas) effects

6. Inaccurate measurement of moisture in stack gas

2.1 Inaccurate Measurement of QAG Flow

The QAG reference aero sol concentration ( QAG i C ) is determined using the analyte concentration in the nebulized solution ( s i C , μg/g), the solution emission rate ( R m , g/min) corrected for vapor loss ( R v , g/min), and the total volume of gas used to create the aerosol ( t F , slpm).

) R R ( F C C

v m
t s i QAG i − = (Eq. 1)Table 1. Initial Results Uncorrected for MoistureCr As Cd Hg Pb Cr As Cd Hg Pb Cr As Cd Hg Pb10:15 10:30 0.00 0.00 0.00 0.00 0.00 0.00 0.40 1.50 23.10 0.26 NA NA NA NA NA10:30 10:45 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.88 21.31 0.80 NA NA NA NA NA10:45 11:00 0.00 0.00 0.00 0.00 0.00 0.00 0.33 1.42 14.28 0.00 NA NA NA NA NA11:00 11:15 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 10.64 0.66 NA NA NA NA NA11:15 11:30 0.00 0.00 0.00 0.00 0.00 0.00 0.49 0.00 8.85 0.12 NA NA NA NA NA11:30 11:45 0.00 0.00 0.00 0.00 0.00 0.00 0.23 0.00 7.41 0.12 NA NA NA NA NA11:45 12:00 0.00 0.00 0.00 0.00 0.00 0.00 0.43 1.08 6.28 0.43 NA NA NA NA NA2:45 3:00 23.95 23.93 23.87 23.91 23.97 29.96 28.21 28.94 33.21 26.17 1.25 1.18 1.21 1.39 1.093:00 3:15 23.95 23.93 23.87 23.91 23.97 27.71 28.43 29.86 34.02 26.36 1.16 1.19 1.25 1.42 1.103:15 3:30 24.19 24.17 24.11 24.15 24.21 29.35 29.73 31.50 32.36 25.61 1.21 1.23 1.31 1.34 1.063:30 3:45 24.19 24.17 24.11 24.15 24.21 31.19 30.32 28.48 32.79 26.50 1.29 1.25 1.18 1.36 1.093:45 4:00 24.19 24.17 24.11 24.15 24.21 27.20 30.01 28.57 32.68 25.98 1.12 1.24 1.18 1.35 1.074:00 4:15 24.44 24.41 24.35 24.39 24.46 27.28 28.45 29.01 32.59 28.30 1.12 1.17 1.19 1.34 1.164:15 4:30 24.55 24.53 24.47 24.51 24.57 28.75 31.08 31.70 31.90 25.63 1.17 1.27 1.30 1.30 1.044:30 4:45 24.55 24.53 24.47 24.51 24.57 28.94 30.97 28.70 33.22 28.29 1.18 1.26 1.17 1.36 1.154:45 5:00 24.55 24.53 24.47 24.51 24.57 29.29 30.32 30.11 32.07 27.85 1.19 1.24 1.23 1.31 1.135:00 5:15 24.55 24.53 24.47 24.51 24.57 30.72 29.38 31.85 31.13 26.65 1.25 1.20 1.30 1.27 1.089:15 9:30 80.07 80.05 80.09 80.11 80.07 95.03 101.84 97.05 102.81 88.41 1.19 1.27 1.21 1.28 1.109:30 9:45 80.07 80.05 80.09 80.11 80.07 95.36 102.82 99.86 104.43 90.66 1.19 1.28 1.25 1.30 1.139:45 10:00 80.07 80.05 80.09 80.11 80.07 96.74 102.13 104.27 105.87 91.75 1.21 1.28 1.30 1.32 1.1510:00 10:15 79.52 79.50 79.54 79.56 79.52 95.40 101.44 96.64 104.64 89.02 1.20 1.28 1.22 1.32 1.1210:15 10:30 81.56 81.54 81.58 81.60 81.56 97.09 102.63 98.80 106.84 90.84 1.19 1.26 1.21 1.31 1.1110:30 10:45 81.56 81.54 81.58 81.60 81.56 98.83 104.87 103.73 107.02 90.95 1.21 1.29 1.27 1.31 1.1210:45 11:00 81.56 81.54 81.58 81.60 81.56 96.78 100.45 99.61 103.71 91.32 1.19 1.23 1.22 1.27 1.1211:00 11:15 80.49 80.47 80.51 80.53 80.49 97.52 102.01 99.30 104.61 90.42 1.21 1.27 1.23 1.30 1.1211:15 11:30 80.70 80.68 80.72 80.74 80.70 97.60 101.78 98.58 104.60 89.65 1.21 1.26 1.22 1.30 1.1111:30 11:45 80.70 80.68 80.72 80.74 80.70 96.32 100.05 94.45 104.39 91.52 1.19 1.24 1.17 1.29 1.1311:45 12:00 80.70 80.68 80.72 80.74 80.70 99.68 105.65 108.04 106.45 93.53 1.24 1.31 1.34 1.32 1.1612:45 1:00 222.93 222.79 222.21 222.57 223.06 266.75 280.10 275.16 292.08 245.82 1.20 1.26 1.24 1.31 1.101:00 1:15 219.38 219.25 218.68 219.03 219.52 266.66 279.51 264.46 293.82 248.18 1.22 1.27 1.21 1.34 1.131:15 1:30 219.38 219.25 218.68 219.03 219.52 262.46 277.26 264.40 280.60 243.97 1.20 1.26 1.21 1.28 1.111:30 1:45 219.38 219.25 218.68 219.03 219.52 273.43 286.62 273.00 293.92 252.36 1.25 1.31 1.25 1.34 1.151:45 2:00 217.94 217.81 217.24 217.59 218.07 271.94 289.75 282.36 294.21 252.26 1.25 1.33 1.30 1.35 1.162:00 2:15 215.14 215.01 214.45 214.79 215.27 275.05 290.57 289.08 294.91 252.08 1.28 1.35 1.35 1.37 1.172:15 2:30 215.14 215.01 214.45 214.79 215.27 266.92 280.31 275.81 284.64 243.49 1.24 1.30 1.29 1.33 1.132:30 2:45 215.14 215.01 214.45 214.79 215.27 260.84 272.15 271.73 275.46 236.20 1.21 1.27 1.27 1.28 1.102:45 3:00 214.94 214.81 214.25 214.59 215.07 267.62 282.02 273.88 290.55 245.60 1.25 1.31 1.28 1.35 1.143:00 3:15 216.59 216.46 215.89 216.24 216.72 267.36 277.35 266.38 289.11 245.43 1.23 1.28 1.23 1.34 1.133:30 3:45 107.15 107.09 106.81 106.98 107.22 118.75 124.52 122.78 128.68 109.87 1.11 1.16 1.15 1.20 1.023:45 4:00 107.15 107.09 106.81 106.98 107.22 114.50 125.23 116.98 124.64 107.74 1.07 1.17 1.10 1.17 1.004:00 4:15 109.55 109.48 109.20 109.37 109.61 116.27 124.89 121.82 120.88 106.72 1.06 1.14 1.12 1.11 0.974:15 4:30 109.55 109.48 109.20 109.37 109.61 117.46 127.80 123.13 123.59 108.88 1.07 1.17 1.13 1.13 0.99AVE 1.21 1.26 1.24 1.32 1.12SD 0.04 0.04 0.05 0.04 0.03%RSD 0.03 0.03 0.04 0.03 0.03AVE1 081 161 121 11 00Background Corrected Xact Conc. (μg/m3) Xact/QAGQAG Aerosol Conc (μg/m3)BlankSpikeConc.LevelXact StartTimeXact EndTimeHighStack GasFlue GasLowMid

A-2A-3 During the experiments at the MPCRF , the QAG concentration flow ( t F ) was measured in standard liters per minute (slpm) using a newly purchased and calibrated Rosemount orifice plate flow meter. 1 Prior to shipment to the field, this flow meter was compared to Sierra Instruments thermal mass flow meter. 2 The two meters were found to be within 5% of each other. Furthermore, after spiking was completed, the same two meters were compared against each other at a rate of about 140 slpm. The meters differed by less than 1%, both when sampling stack gas and when sampling ambient air. It is therefore highly unlikely that the total QAG flow ( t

F ) is being measured inaccurately.

2.2 Problems with Xact XRF or Flow Calibration
The Xact draws a small sample of stack gas (~ 0.5 Lpm) through a reacti ve filter tape. After sampling for 15 minutes the tape is advanced ab out two inches to the analysis area where the mass of each analyte is determined by XRF while the next sample is being collected. The XRFdetermined mass is then divided by the totalized flow to give the concentration in μg/dscm. Errors in the Xact measurement can result prim arily from errors in the XRF measurement or errors in the flow measurement.
Prior to shipment, the XRF portion of the Xact wa s calibrated using thin-film standards available from Micromatter. 3 These standards are typically used for the calibration of XRF instrumentation used for the chemical speciation of PM 10 and PM 2.5 filters. 4 The XRF calibration was also checked with the same standa rds used for calibration on three different days: twice during set up and one during a day of testing (7/30/07). Table 2 show s the results of these XRF calibration checks. In all cases, the reported concentration differs from the calibrated value by less than two percent, indicating that the Xact’s XRF ca libration was stable and accurate.

Table 2. XRF Calibration Checks with Thin Film Standards

R epor t e d Value

( μ g) % Error R epor t e d Value

( μ g) % Error R epor t e d Value

( μ g) % Error Cr 8.13 8.09 0.44 As 7.25 7.23 0.30 7.25 0.04 7.19 0.89 Cd 5.44 5.54 1.86 5.41 0.55 5.44 0.04 Hg 9.59 9.53 0.67 Pb 8.04 7.99 0.62 Element 7/26/2007 7/28/2007 7/30/2007

Calibrated V alue ( μ g )

The Xact measures two separate flows to calculate the flow of stack gas: the dilution flow (~ 0.20 slpm) and the total flow (~0.70 slpm). The X act’s flow sensors were recalibrated in the field prior to testing using a Dr y Cal from Bios International 5 as a reference flow meter. On the day after testing, the Xact’s flow sensors were again compared against the Dry Cal both when sampling stack gas and when sampling ambient air. The results are shown in Table 3. The error in all cases was less than 3.5 percen t, indicating that the Xact’s fl ow sensors were accurate both when sampling ambient air and when sampling stack gas.A-4 Table 3. Xact Flow Sensor Checks

Dry Cal (slpm) D ry Sample (slpm) % Error Dry Cal (slpm) Dil u ti on Flow (slpm) % Error Sampling Stack Gas 0.64 0.66 3.13 0.202 0.20 0.99

Sampling Ambient Air 0.66 0.68 3.03 0.194 0.20 3.09 Dilution Flow Total Flow

Condition

2.3 Evaporative Loss in the QAG
Equation 1 shows that the nebuli zation rate of soluti on is the difference between the solution mass loss rate ( R m , g/min) as measured by an analytical balance minus the solution evaporation rate (R v , g/min). The evaporation rate for this ex periment was about 0.0005 g/min and is based on a measured temperature difference. The eva poration rate therefore accounts for less than 0.2 percent of the overall solution loss rate, making it an unreas onable source of a 25-percent discrepancy between the QAG and the Xact. Assu ming the evaporation rate was high enough to create a discrepancy between th e Xact and the QAG, the Xact w ould report values lower than those of the QAG because the QAG would be nebu lizing far less solution than measured. Clearly, evaporative loss is not source of the 25% discrepancy because the Xact is reporting a higher concentration than the QAG.

2.4 Leak in the Transport Line
Figure 1 is a schematic showing the experimental set-up used dur ing the testing at the MultiPollutant Control Research Facility.

Figure 1. Experimental Set-upA-5 The flow meter used for the calculation of the QAG aerosol concentration is located downstream of the both the Xact and the QAG. A leak in th e transport line between the Xact and the flow meter could result in the Xact re porting a higher than expected read ing. However, all the seals in this region were checked after te sting and found to be adequate. Furthermore, the leak would need to be on the order of 30 to 40 slpm to ge t the 25-percent discrepanc y observed. A leak of that magnitude would generate a great deal of noi se and be detected almost immediately. It is therefore unlikely that a leak in the transport line is the source of th e difference between the QAG and Xact-reported values.

2.5 Matrix (Stack Gas) Effects
Another potential explanation for the difference between the QAG and the Xact is the effect of the stack gas matrix, which could impact the tr ansport and trapping efficiency of the spiked elements. During the course of the experiment, CES determined the ratio of each spiked element to cadmium when sampling both stack gas and ambien t air. The five elements sampled represent metals in the particle phase (Cd, Cr, and Pb), mixed phase (As) and vapor phase (Hg). If the stack gas matrix inhibited the transport or trappi ng efficiency of the metals, then it is expected that one type of species would be more imp acted than another (e.g., vapor phase species are more impacted than particle phase species). Howe ver, the ratios of each element to cadmium are the same for stack gas and ambient air (Table 4). Therefore, the transpor t and trapping of both particle phase and vapor pha se species are unaffected by the physical and chemical characteristics of the gas matrix.

Table 4. Inter-Elemental Ratios

Cr/Cd As/Cd Hg/Cd Pb/Cd AVE 0.97 1.02 1.07 0.90 STDEV 0.04 0.04 0.05 0.04

AVE 0.96 1.04 1.03 0.89 STDEV 0.01 0.02 0.03 0.02 Ambient Air Matrix Interelemental Ratios

Stack Gas

2.6 Inaccurate Moisture Measurement

The Xact measures metal concentrations on a dry basis. The QAG aerosol, however, is being spiked into a relatively wet air stream. To compare the two concentrations, the QAG concentration must be calculated on a dry basis. The dry QAG flow rate t F is determined using Equation 2. This value can then be used in Equation 1 to calculate the QAG aerosol concentration. 

# ( )

w Q m m t P F F F F

− = (Eq. 2)

Where:

t F = Total QAG flow on a dry basis (slpm)

m F = Total flow as measured by the experimental flow meter (slpm)A-6 Q F = Total flow through the QAG (slpm) (dried compressed air)

w P = The measured fraction of water

During testing, the XFM was used to determine fraction of water. The flow through the XFM filter, about 1 slpm, was dried usi ng a silica gel trap prior to flow measurement. This silica gel trap was weighed before and after each sample and the difference was used to determine the fraction of water vapor in the sampled stack ga s. A problem with this approach was later discovered; the silica gel was unlik ely to trap all of the water in the gas stream. The temperature of the silica gel trap is believed to have been at about 80 to 90 ο F and operating under a significant vacuum (approximately 12 in. Hg vacuum). Silica gel will typically lower the relative humidity to around 40%. 6 Under these cond itions, air escaping the trap could still contain almost 10% moisture. 7 Therefore, the accuracy of this approach is questionable and could be the source of the observed di screpancy between the Xact and QAG.
To estimate the actual fraction of water present in the gas stream, it is reasonable to assume that the gas was saturated at temperatures and pre ssures present at the sampling point because the stack effluent was withdrawn from the duct imme diately downstream of a wet scrubber,. The temperature in the duct was monitored througho ut the experiment and averaged about 116 ο F. The pressure in the duct was not measured; how ever, the pressure in the transport line was measured on a continuous basis using the Rosemo unt flow meter. During stack gas sampling and spiking, the pressure at that point was about 13.5 psia. The pressure in the duct would be somewhat higher and was estimated to be about 13.8 psia. This value corresponds well with engineering estimates of the pressure in the duct at minus 30 inches of water. 8 At this temperature and pressure, the mo isture content of the duct woul d be about 26% by volume. The QAG flow rate was therefore adju sted based on this assumed mois ture content in lieu of the potentially inaccurate XFM moisture measurement. For ambient spiking, the QAG flow rate was adjusted based on relative humidity as determined by a nearby meteorological station for the date and time of the experiment. 9 Experimental results with the adjusted QAG flow rates are shown in Table 5.



### 3.0 Conclusions

The most likely cause of the discrepancy betw een the QAG aerosol concen tration and the Xact reported concentration is inaccuracy in the moisture measurement because (1) other possible sources for this error can be discounted, (2) ther e is ample reason to doubt the accuracy of the moisture measurement as it was made, and (3 ) it makes good engineering sense to assume saturation downstream of a wet scr ubber. Future experiments of th is nature should either find a more accurate way of measuring moisture conten t, or remove all moisture prior to the QAG concentration flow measurement.Table 5. Results Assuming Saturation Downstream of Wet ScrubberCrAs Cd Hg Pb CrAs Cd Hg Pb CrAs Cd Hg Pb0 0 0 0 0 0 0.4 1.5 23.1 0.26 NA NA NA NA NA0 0 0 0 0 0 0 0.88 21.31 0.8 NA NA NA NA NA0 0 0 0 0 0 0.33 1.42 14.28 0 NA NA NA NA NA0 0 0 0 0 0 0 0 10.64 0.66 NA NA NA NA NA0 0 0 0 0 0 0.49 0 8.85 0.12 NA NA NA NA NA0 0 0 0 0 0 0.23 0 7.41 0.12 NA NA NA NA NA0 0 0 0 0 0 0.43 1.08 6.28 0.43 NA NA NA NA NA27.58 27.56 27.49 27.53 27.60 29.96 28.21 28.94 31.30 26.17 1.09 1.02 1.05 1.14 0.9527.58 27.56 27.49 27.53 27.60 27.71 28.43 29.86 32.11 26.36 1.00 1.03 1.09 1.17 0.9627.58 27.56 27.49 27.53 27.60 29.35 29.73 31.50 30.45 25.61 1.06 1.08 1.15 1.11 0.9327.58 27.56 27.49 27.53 27.60 31.19 30.32 28.48 30.88 26.50 1.13 1.10 1.04 1.12 0.9627.58 27.56 27.49 27.53 27.60 27.20 30.01 28.57 30.77 25.98 0.99 1.09 1.04 1.12 0.9427.86 27.83 27.76 27.81 27.88 27.28 28.45 29.01 30.68 28.30 0.98 1.02 1.04 1.10 1.0227.86 27.83 27.76 27.81 27.88 28.75 31.08 31.70 29.99 25.63 1.03 1.12 1.14 1.08 0.9227.86 27.83 27.76 27.81 27.88 28.94 30.97 28.70 31.31 28.29 1.04 1.11 1.03 1.13 1.0127.86 27.83 27.76 27.81 27.88 29.29 30.32 30.11 30.16 27.85 1.05 1.09 1.08 1.08 1.0027.86 27.83 27.76 27.81 27.88 30.72 29.38 31.85 29.22 26.65 1.10 1.06 1.15 1.05 0.9692.87 92.84 92.89 92.91 92.87 96.74 102.13 104.27 103.96 91.75 1.04 1.10 1.12 1.12 0.9992.23 92.20 92.25 92.27 92.23 95.40 101.44 96.64 102.73 89.02 1.03 1.10 1.05 1.11 0.9792.23 92.20 92.25 92.27 92.23 97.09 102.63 98.80 104.93 90.84 1.05 1.11 1.07 1.14 0.9892.23 92.20 92.25 92.27 92.23 98.83 104.87 103.73 105.11 90.95 1.07 1.14 1.12 1.14 0.9992.23 92.20 92.25 92.27 92.23 96.78 100.45 99.61 101.80 91.32 1.05 1.09 1.08 1.10 0.9991.01 90.99 91.03 91.06 91.01 97.52 102.01 99.30 102.70 90.42 1.07 1.12 1.09 1.13 0.9991.01 90.99 91.03 91.06 91.01 97.60 101.78 98.58 102.69 89.65 1.07 1.12 1.08 1.13 0.9991.01 90.99 91.03 91.06 91.01 96.32 100.05 94.45 102.48 91.52 1.06 1.10 1.04 1.13 1.0191.01 90.99 91.03 91.06 91.01 99.68 105.65 108.04 104.54 93.53 1.10 1.16 1.19 1.15 1.03248.93 248.78 248.14 248.53 249.08 266.66 279.51 264.46 291.91 248.18 1.07 1.12 1.07 1.17 1.00248.93 248.78 248.14 248.53 249.08 262.46 277.26 264.40 278.69 243.97 1.05 1.11 1.07 1.12 0.98248.93 248.78 248.14 248.53 249.08 273.43 286.62 273.00 292.01 252.36 1.10 1.15 1.10 1.17 1.01248.93 248.78 248.14 248.53 249.08 271.94 289.75 282.36 292.30 252.26 1.09 1.16 1.14 1.18 1.01245.73 245.58 244.95 245.34 245.88 275.05 290.57 289.08 293.00 252.08 1.12 1.18 1.18 1.19 1.03245.73 245.58 244.95 245.34 245.88 266.92 280.31 275.81 282.73 243.49 1.09 1.14 1.13 1.15 0.99245.73 245.58 244.95 245.34 245.88 260.84 272.15 271.73 273.55 236.20 1.06 1.11 1.11 1.11 0.96245.73 245.58 244.95 245.34 245.88 267.62 282.02 273.88 288.64 245.60 1.09 1.15 1.12 1.18 1.00247.62 247.47 246.83 247.22 247.77 267.36 277.35 266.38 287.20 245.43 1.08 1.12 1.08 1.16 0.99107.85 107.79 107.51 107.68 107.92 109.73 119.63 114.98 128.64 102.22 1.02 1.11 1.07 1.19 0.95108.11 108.05 107.76 107.94 108.18 118.75 124.52 122.78 131.76 109.87 1.10 1.15 1.14 1.22 1.02108.11 108.05 107.76 107.94 108.18 114.50 125.23 116.98 127.72 107.74 1.06 1.16 1.09 1.18 1.00110.53 110.46 110.17 110.35 110.59 116.27 124.89 121.82 123.96 106.72 1.05 1.13 1.11 1.12 0.96110.53 110.46 110.17 110.35 110.59 117.46 127.80 123.13 126.67 108.88 1.06 1.16 1.12 1.15 0.98AVE 1.06 1.11 1.09 1.13 0.98STDEV0.04 0.04 0.04 0.03 0.03%RSD 3.36 3.61 4.00 2.93 2.91AVE 1.06 1.14 1.10 1.17 0.98STDEV0.03 0.02 0.03 0.04 0.03%RSD 2.73 1.85 2.47 3.28 2.71Conc.LevelXact/QAGLowAmbientAirBlankSpikeQAG Aerosol Conc (μg/m3) Background Corrected Xact Conc. (μg/m3)MidHighHighAmbientFlue Gas

A-7A-8 

### 4.0 References

1. Rosemount Inc, PO Box 70114, Chicago, IL 60673-0114 2. Sierra Instruments, 5 Harris Court Building L, Monterey, CA 93940 3. Micromatter Co., 18218 18 th Ave. NW, Arlington, WA 98223
4. U.S. Environmental Protection Agency. 1999. Compendium Method IO-3.3 - Determination of Metals in Ambient Pa rticulate Matter Using X-Ray Fluorescence (XRF) Spectroscopy. In Compendium of Methods for th e Determination of Inorganic Compounds in Ambient Air; EPA/625/R-96/010a. U.S. Gove rnment Printing Office: Washington, DC. 5. Bios International Corporat ion, 10 Park Place, Butler, NJ 07405 6. Desiccants Global. Types of Desiccants. http:// desiccants.cn/products.htm (accessed August 2007). 7. Perry, R.H.; Green, D.W; Editors. 1984. Perry’s Chemical Engineers’ Handbook. 6th Ed. McGraw-Hill Book Company: New York. 8. Serre, S. February 27 th , 2007. U.S. Environmental Protection Agency, ORD/National Risk Management Research Labor atory [Personal communication]. 9. National Oceanic and Atmospheric A ssociation (NOAA) Coope rative Institute for Regional Prediction. Real-Time Observat ion and Analysis Network (ROMAN). http://raws.wrh.noaa.gov/roman/i ndex.html (accessed August 2007)