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Low waste feed concentrations and destruction removal efficiency
WASTE MANAGEMENT Waste Management 18 (1998) 453±459
Low waste feed concentrations and destruction removal eciency James J. Cudahy* Focus Environmental, Inc., Knoxville, TN, USA
Abstract In the early 1980s, the Environmental Protection Agency (EPA) funded research on destruction and removal eciencies (DREs) at eight hazardous waste incinerators. This research appeared to show that DREs of 99.99% could not be achieved at low waste feed principal hazardous organic constituent (POHC) concentrations. During the mid 1980s and 1990s however, testing at Superfund sites has indicated that DREs of 99.9999% or greater can be achieved at low waste feed POHC concentrations. This paper will summarize testing which includes 32 test runs at ®ve Superfund sites and the EPA's incineration research facility. The tests include POHC concentrations from 6552 parts per million down to 28 parts per million at typical DREs of 6±9 s or greater. # 1999 Elsevier Science Ltd. All rights reserved.
1. Introduction In the early 1980s, the Environmental Protection Agency (EPA) funded an extensive research project to perform an evaluation test program at eight hazardous waste incinerators [1]. Table 1 summarizes the design parameters of these eight systems [1]. This test program was implemented by the Midwest Research Institute (MRI) and involved waste feed, ash, scrubber water and stack testing on particulate, HCl, dioxins and furans, other products of incomplete combustion (PICs), metals and carbon monoxide emissions. The test program also involved destruction and removal eciency (DRE) testing for many principle organic hazardous constituents (POHCs) at all eight incinerators. During resource conservation and recovery act (RCRA) DRE testing as de®ned by 40 CFR 264.343(a)(1) and 40 CFR 270.62, one or more POHCs are selected from the Appendix VIII list in 40 CFR 261 and used to calculate POHC DREs for the incinerator being tested. A RCRA incinerator must achieve a DRE of at least 99.99% for each POHC designated in the facility trial burn plan. In the MRI study, the authors developed statistical correlations for both volatile and semi-volatile organics which appeared to show that DREs of 99.99% could not be achieved at waste feed POHC concentrations below 1000 ppm [2]. The MRI volatile organic plot appeared to show that DREs of 99.9999% could not be achieved at waste feed POHC concentrations below approximately 10,000 ppm [2]. * Tel.: +1-423-694-7517; fax: +1-423-531-8854; e-mail: jjcudahy@ focusenv.com
An EPA study performed by Energy and Environmental Research Corporation (EER) and published in 1989, also researched low DREs in relation to low waste feed POHC concentrations [3]. A small 100,000 Btu per hour liquid spray combustor with no secondary combustion and with water-cooled walls surrounding the ¯ame zone was used for the experimental work. The spray combustor waste feed was either No. 2 fuel oil or n-heptane doped with a `soup' of ®ve test compounds. The test `soup' was an equimolar mixture of acrylonitrile, toluene, chlorobenzene, chloroform and 1,1,1-trichloroethane. The test `soup' was added to the No. 2 fuel oil or the n-heptane at various concentrations ranging from 30 parts per million (ppm) to 30% by weight. The spray combustor with the fuel oil `soup' was tested at 120 and 150% excess air, and the n-heptane and `soup' mixture was tested without chloroform at 150% excess air [3]. In the EER study, the authors, based on the MRI study and their research, stated that incineration has diculty meeting the 99.99% DRE permitting requirement when the waste represents less than 1000 ppm of the feed stream [3]. 2. PIC to POHC formation hypothesis Since these two studies were done, testing with mobile incinerators at Superfund sites and at the EPA's incineration research facility (IRF) during the mid 1980s and 1990s has shown that not only are DREs above 99.99% achievable with waste feed POHC concentrations below 1000 ppm but that DREs of 99.9999% or greater
0956-053X/99/$ - see front matter # 1999 Elsevier Science Ltd. All rights reserved PII: S0956 -0 53X(98)00129-9
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J.J. Cudahy/Waste Management 18 (1998) 453±459
Table 1 Design parameters of hazardous waste incinerators tested by MRI Incinerator Ross Incineration Services Trade Waste Incineration Upjohn Company Zapata Industries American Cyanamid Mitchell Systems Dupont Plant B (con®dential)
Location
Type
HWI size (MW Btu/h)
APC
Grafton, OH Sauget, IL LaPorte, TX Butner, NC Willow Island, WV Spruce Pine, NC LaPlace, LA
Rotary kiln Solid hearth Liquid injection Controlled air Liquid injection Solid hearth Rotary kiln and liquid
90 10 6 2 5 10 40
Wet None Wet None None None Wet
can be achieved at waste feed POHC concentrations not only below 10,000 ppm, but also below 100 ppm. The objective of this paper was to evaluate why the MRI and EER data indicated low DREs at low waste POHC concentrations, but the Superfund and IRF test data do not show this. An analysis of the data in Refs. [1] and [3] shows that many of the POHCs used for DRE determinations in these studies are compounds that can form PICs which also happen to be compounds present in the waste feeds as other POHCs. A reasonable hypothesis to explain the MRI and EER low DRE with low waste feed POHC concentration data is that a high concentration waste feed POHC, such as carbon tetrachloride, will form chloroform as a PIC. If chloroform is also present in the waste as a POHC, but at a much lower concentration than the carbon tetrachloride, then the chloroform formed as a PIC is analyzed in the stack gas as if it were the undestroyed chloroform POHC. The sampling methods used for POHC determination in a stack gas can not distinguish between chloroform fed as a POHC or formed as a PIC from another POHC. The additional chloroform generated as a PIC from the carbon tetrachloride can reduce the apparent chloroform DRE relative to what it would have been if only the chloroform POHC in the original waste feed were considered in the DRE equation. This formation of chloroform as a PIC from carbon tetrachloride has been clearly shown to occur in testing at a full scale incinerators [4]. This concept of PICs contributing to the mass emission rate of other POHCs was not well understood in the early 1980s when the MRI study was done, but it is still mentioned in the MRI study as a possible factor in the low DRE±low waste feed concentration correlation [5]. Throughout the mid to late 1980s, as a database of RCRA trial bum test data developed, it became clear that certain chemicals such as chlorinated methanes, triand tetrachlorinated ethanes and ethenes, chlorinated benzenes, and benzene and toluene should not be used as multiple POHCs in a single RCRA trial burn, because of the potential impact of the PICs on the target POHC DRE [6]. Fig. 1 illustrates some of the possible PIC formation mechanisms that probably occurred during the MRI study. The chlorinated methane, chlorinated
benzene and toluene PIC reactions illustrated in Fig. 1 have been shown to occur in laboratory and full scale studies involving the formation of PIC [4,7±9]. The MRI and EER studies are discussed in relation to the PIC to POHC formation hypothesis in the following sections. 2.1. MRI study The MRI report has numerous cases where the target waste feed POHCs generated PICs which are other waste feed POHCs, thereby resulting in the apparent reduction of DREs. A speci®c example of this situation is shown in Table 2. The DRE and waste feed concentration data in Table 2 was taken from Appendix E of Volume IV of the MRI study [10]. The incineration of the high concentration p-dichlorobenzene and o-dichlorobenzene appears to have resulted in the formation of m-dichlorobenzene, monochlorobenzene and 1,2,4-trichlorobenzene as PICs at high enough concentrations to reduce the DREs of the lower concentration compounds. The formation of monochlorobenzene and trichlorobenzene as PICs from the combustion of dichlorobenzene has been shown to occur in a laboratory study [8]. Seven of the eight incinerators tested by MRI used chlorinated methanes, tri- and tetrachlorinated ethanes and ethenes as waste feed POHCs [1]. The only incinerator that did not use these compounds as waste feed POHCs was the American Cyanamid facility. The DREs measured at the American Cyanamid facility were typically greater than 99.999% to greater than 99.99999% [2]. Table 3 shows some of the possible PIC formation routes that probably occurred at the incinerators tested by MRI. Many of the PIC formation reactions shown in Table 3 have been identi®ed in laboratory and full scale incinerator testing [4,7±9]. In mathematical terms, the DREs calculated during the MRI study were actually based on the following model: DRE
POHC inÿPOHC out POHC formed as PIC POHC in
When the POHC formed as a PIC is small compared to the POHC in, the DRE is not signi®cantly reduced.
J.J. Cudahy/Waste Management 18 (1998) 453±459
455
Fig. 1. Possible PIC formation mechanisms during the MRI testing. Table 2 Example of DRE reduction caused by POHC formation from PICs POHC p-Dichlorobenzene o-Dichlorobenzene m-Dichlorobenzene Monochlorobenzene 1,2,4-Trichlorobenzene
Feed conc. (ppm by weight)
DRE (%)
65,000 50,000 2500 6033 317
99.998 99.997 99.920 99.903 99.330
The results also suggest that the in¯uence of feed concentration is stronger at waste concentrations above 3000 ppm than below, a trend not noted in the ®eld data.'
Based on the results of this test program, the EER study authors stated the following [3]:
It is likely that the PIC to POHC formation mechanism was also a factor in some of the low DREs observed in the EER study. Two of the POHCs used in the EER study were chloroform and 1,1,1-trichloroethane. From the structure of these two compounds, it is obvious that a likely PIC that can be formed from 1,1,1-trichloroethane is chloroform, thus impacting the chloroform DREs. The EER study states that no chloroform DREs are shown in the report because in several cases the quantity of chloroform in the stack gas exceeded the amount of chloroform fed to the spray combustor [3]. The EER report makes the following statement relative to the chloroform:
The results of this study show that DRE is positively correlated with waste concentration in the feed.
The excess chloroform measurements that were noted in both data sets can be attributed to formation
When the POHC formed as a PIC is signi®cant compared to the POHC in, the apparent DRE can be reduced. 2.2. EER study
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J.J. Cudahy/Waste Management 18 (1998) 453±459
Table 3 Possible PIC formation routes at incinerators tested by MRI Incinerator
POHCs with DREs<99.99%
Possible PIC producing POHCs
Ross Incineration Services
Methylene chloride (CH2Cl2)
Carbon tetrachloride (CCl4)
Trade Waste Incineration
Chloroform (CHCl3) Methylene chloride (CH2Cl2) 1,1,1-Trichloroethane (CCl3CH3) Tetrachloroethylene (CCl2CCl2) Chlorobenzene (C6H5Cl)
Carbon tetrachloride (CCl4) Carbon tetrachloride (CCl4) Carbon tetrachloride (CCl4) Carbon tetrachloride (CCl4) Toluene (C6H5CH3)
Upjohn Company
Chlorobenzene (C6H5Cl) Trichlorobenzene (C6H3Cl3) Carbon tetrachloride (CCl4)
Dichlorobenzene (C6H4Cl2) Dichlorobenzene (C6H4Cl2) 1,1,2-Trichloroethylene (CCl2CHCl)
Zapata Industries
Methylene chloride (CH2Cl2)
Carbon tetrachloride (CCl4)
American Cyanamid
None
No common PICs
Benzene (C6H6)
Toluene (C6H5CH3)
Dupont
Chloroform (CHCl3) 1,1,1-Trichloroethane (CCl3CH3)
Carbon tetrachloride (CCl4) Carbon tetrachloride (CCl4)
Plant B
Chloroform (CHC13) 1,1,2-Trichloroethylene (CCl2CHCl) Phenol (C6H5OH)
Carbon tetrachloride (CCl4) Tetrachloroethylene (CCl2CCl2) Toluene (C6H5CH3)
General
Phthalates
Lab contamination?
Mitchell Systems
of chloroform as a PIC during reaction of the other compounds [3].' Two of the other POHCs used in the EER study, toluene and chlorobenzene, are also common PICs that could have impacted low concentration DRE measurements. In addition, incineration of the No. 2 fuel oil combined with the chlorinated organics in the `soup' could also generate PICs such as toluene and chlorobenzene when incinerated. Emission factors published by the EPA in AP-42 indicate that benzene, toluene, ethyl benzene and o-xylene are PICs generated during residual fuel oil combustion [11]. This hypothesis is supported by the fact that the measured low concentration DREs for toluene and chlorobenzene are higher for the n-heptane tests than for the No. 2 fuel oil tests [3]. Of the ®ve POHCs used in the EER study, only acrylonitrile was not a common PIC. The acrylonitrile DRE did not demonstrate a consistent trend with the low DRE-low waste POHC concentration hypothesis. The acrylonitrile DREs were about 96, 60, 99.99 and 94.5% for waste feed concentrations of 30, 300, 3000 and 30,000 ppm by weight [3]. A discussion of the DRE testing at Superfund sites and the EPA's IRF follows. 3. DRE testing at Superfund sites and the IRF To test the hypothesis that DREs of 99.99% could not be achieved at waste feed POHC concentrations below 1000 ppm and that DREs of 99.9999% could not be achieved at waste feed POHC concentrations below
approximately 10,000 ppm, data was obtained from eight tests of mobile incinerators used in the Superfund site remediation program and one test from the EPA's pilot-scale IRF. The DRE data set includes nine tests with 26 test runs and 32 data points for four dierent POHCs regulated under RCRA and polychlorinated biphenyls (PCBs) regulated under the toxic substances control act (TSCA). The test programs occurred at six locations using six dierent incinerators. The waste feed POHC concentrations ranged from 28 to 6652 ppm by weight. This data is summarized in Table 4. As can be seen from Table 4, DREs of greater than 99.99% with waste feed POHC concentrations below 1000 ppm were achieved in 14 of the tests. In 13 of the 14 tests, no POHC was detected in the stack gas so that the DREs are actually greater than the values shown in Table 4. DREs of greater than 99.9999% with waste feed POHC concentrations below 10000 ppm were achieved in 29 of the tests. In 17 of the 29 tests, no POHC was detected in the stack gas so that the DREs are actually greater than the values shown in Table 4. DREs of greater than 99.9999% with waste feed concentrations below 1000 ppm were achieved in 11 of the tests. The DRE data are plotted in Fig. 2. This data clearly indicates that DREs of greater than 99.99% with waste feed POHC concentrations below 1000 ppm and DREs of greater than 99.9999% with waste feed POHC concentrations not only below 10,000 ppm, but also below 100 ppm are achievable. The MRI and EER conclusions and correlations concerning low DREs occurring at low waste feed POHC concentrations are unsupportable as a general rule, based on the newer data. These apparent
J.J. Cudahy/Waste Management 18 (1998) 453±459
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Table 4 DRE and waste feed POHC and PCB concentration data Site Denney Farm
Test date
Location
POHC
Test no.
Waste feed conc. (ppm)
DRE(%)
February, April 1985
Verona, MO
2,3,7,8-TCDD 2,3,7,8-TCIDD 2,3,7,8-TCDD 2,3,7,8-TCDD
1 1 1 1
42 53 28 36
>99.999973 >99.999986 >99.999995 >99.999989
EPA IRF
September 1986
Jeerson, AR
2,3,7,8-TCDD
1
37
>99.999991
Swanson River
September 1986
Kenai Peninsula, AK
PCBs PCBs PCBs PCBs PCBs PCBs
1 1 1 2 2 2
632 615 801 289 608 625
>99.99993 >99.99992 >99.99997 >99.99996 >99.99994 >99.99993
Sikes Disposal Pits (APC no. 1)
April 1992
Crosby, TX
Chlorobenzene Chlorobenzene Chlorobenzene
1 1 1
6336 6667 6652
>99.99999 >99.999989 >99.999989
Sikes Disposal Pits (APC no.2)
April 1992
Crosby, TX
Chlorobenzene Chlorobenzene Chlorobenzene
1 1 1
6336 6667 6652
>99.99999 >99.99999 >99.99999
LaSalle Electric
April 1992
LaSalle, IL
PCBs PCBs PCBs PCBs PCBs PCBs
1 1 1 2 2 2
5728 5824 5878 4302 4480 4452
99.99990 99.999902 9.999908 99.999924 99.999902 99.999939
January 1995
Holbrook, MA
Naphthalene Naphthalene Naphthalene 1,2,4,5-Tetrachlorobenzene 1,2,4,5-Tetrachlorobenzene 1,2,4,5-Tetrachlorobenzene Chlorobenzene Chlorobenzene Chlorobenzene
1 1 1 1 1 1 1 1 1
4083 4042 3830 3977 3967 3769 291 314 327
99.999972 99.999929 99.999953 99.999995 99.999989 99.999989 >99.99977 99.99978 >99.99981
Braird & McGuire
correlations occurred because of the use in these studies of waste feed POHCs at low concentrations which were also generated as PICs from other waste feed POHCs present in the waste feeds at higher concentrations. The Superfund and IRF test programs are described in the following sections. 3.1. Denney Farm site In February and April of 1985, the EPA implemented a test program using the EPA's mobile incineration system (MIS) at the Denney Farm site near Verona, Missouri [12]. The MIS was a 10 MM Btu per h pilot-scale rotary kiln incinerator with a secondary combustion chamber and a wet, rapid quench scrubbing system [12]. During the Denney Farm test program, the EPA's MIS incinerated liquid and soil contaminated with 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD). The POHC used for the DRE tests was 2,3,7,8-TCDD. During one test consisting of four runs,
the 2,3,7,8-TCDD concentration for the combined liquid and soil waste feeds ranged from 28 to 53 ppm [13]. The 2,3,7,8-TCDD DREs ranged from greater than 99.999973% to greater than 99.999995% [14]. No 2,3,7,8-TCDD was detected in the stack gas in any of the four runs. The DRE and waste feed POHC concentration data for the Denney Farm tests are shown in Table 4. 3.2. Incineration research facility In September of 1986, a test program was implemented using the EPA's rotary kiln system (RKS) at the EPA's IRF in Jeerson, AR [15]. The RKS is a 3.5 MM Btu per h pilot-scale rotary kiln incinerator with a secondary combustion chamber and a wet, rapid quench scrubbing system [16]. During the IRF test program, the EPA's RKS incinerated toluene still bottoms waste from trichlorophenol production. The toluene still bottoms were contaminated with 2,3,7,8-TCDD. The
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J.J. Cudahy/Waste Management 18 (1998) 453±459
the stack gas in any of the six runs [17]. No spiking of the soil with PCBs was done for any of the six trial burn runs [19]. The DRE and waste feed POHC concentration data for the Swanson River tests are shown in Table 4. 3.4. Sikes Pits site
Fig. 2. DREs at low POHC concentrations in feed.
POHC used for the DRE tests was 2,3,7,8-TCDD. By analyzing combined extracts from four simultaneous sampling trains, it was possible to measure 2,3,7,8-TCDD stack gas detection limits sucient to demonstrate a DRE value greater than 99.9999%. During this one test run the 2,3,7,8-TCDD waste feed POHC concentration was 37 ppm by weight. The 2,3,7,8-TCDD DRE was greater than 99.999991% [15]. No 2,3,7,8-TCDD was detected in the stack gas in any of the four combined extracts. The DRE and waste feed POHC concentration data for the IRF test are shown in Table 4. 3.3. Swanson River site In September 1988, Ogden Environmental Services implemented a test program using a mobile circulating bed combustor (CBC) incinerator at the Swanson River site on the Alaskan Kenai Peninsula [17]. The CBC is a 10 MM Btu per h full-scale circulating bed ¯uidized bed incinerator with a dry fabric ®lter for air pollution control [17,18]. During the Swanson River test program, the CBC incinerated soil contaminated with PCBs. During three test runs at a CBC feed temperature of about 1600 F, the PCB feed concentrations ranged from 615 to 801 ppm. During three test runs at a CBC temperature of about 1700 F, the PCB feed concentrations ranged from 289 to 625 ppm. The PCB DREs for all six runs ranged from greater than 99.99992% to greater than 99.99997%. No PCBs were detected in
In April of 1992, IT Corporation implemented a test program using a mobile rotary kiln incineration system at the Sikes Disposal Pits site in Crosby, TX. The mobile unit was a single 120 MM Btu per h full-scale rotary kiln incinerator with two parallel and identical secondary combustion chambers and two parallel and identical wet, rapid quench systems, each venting to separate and identical stacks [18,20]. During the Sikes Disposal Pits test program, the rotary kiln system incinerated soil spiked with the POHCs naphthalene and monochlorobenzene. Each of the two stacks was tested independently for POHC emissions. During one test, each stack was tested simultaneously for three runs. The waste feed chlorobenzene concentration ranged from 6336 to 6667 ppm. The chlorobenzene DREs ranged from greater than 99.999989% to greater than 99.999990%. No chlorobenzene was detected in the gas of either stack gas in any of the six runs. The naphthalene DREs, which averaged greater than 99.999% are not used as data in this paper because naphthalene contamination in the sampling train blank reduced the DRE that could be ocially reported. The authors of the reference estimated that without the presence of contamination in the sampling blank, that the naphthalene DREs would have been greater than 99.9999% [20]. The DRE and waste feed POHC concentration data for the Sikes Disposal Pits tests are shown in Table 4. 3.5. LaSalle Electric Utilities site In April 1992, ThermoCor, Inc. implemented a test program using a mobile rotary kiln incineration system at the LaSalle Electric Utilities Superfund site in LaSalle, IL. The mobile unit was a 100 MM Btu per h full-scale rotary kiln incinerator with a secondary combustion chamber and a dry fabric ®lter for air pollution control [18,21]. During the LaSalle Electric test program, the rotary kiln system incinerated soil spiked with polychlorinated biphenyls (PCBs). During three runs at a soil feed rate of about 16 tons of soil per h, the PCB feed concentrations ranged from 5728 to 5878 ppm. During three runs at a soil feed rate of about 22 tons of soil per h, the PCB feed concentrations ranged from 4302 to 4480 ppm. The PCB DREs for all six runs ranged from 99.9999 to 99.999939% [21]. The DRE and waste feed PCB concentration data for the LaSalle Electric tests are shown in Table 4.
J.J. Cudahy/Waste Management 18 (1998) 453±459
3.6. Baird & McGuire site In January 1995, OHM Remediation Services Corporation implemented a test program using a mobile rotary kiln incineration system at the Baird & McGuire Superfund site in Holbrook, MA. The mobile unit was a 80 MM Btu per h full-scale rotary kiln incinerator with a secondary combustion chamber and a wet, rapid quench scrubbing system [18,22]. During the Baird & McGuire test program, the rotary kiln system incinerated soil spiked with naphthalene, 1,2,4,5-tetrachlorobenzene and chlorobenzene POHCs. During one test consisting of three runs, the naphthalene waste feed concentration ranged from 3830 to 4083 ppm. The tetrachlorobenzene waste feed concentration ranged from 3769 to 3977 ppm and the chlorobenzene waste feed concentration ranged from 291 to 327 ppm. The naphthalene DREs ranged from 99.999929 to 99.999972%. The tetrachlorobenzene DREs ranged from 99.999989 to 99.9999950%. The chlorobenzene DREs ranged from greater than 99.99977 to greater than 99.99981% [22]. The DRE and waste feed PCB concentration data for the Baird & McGuire tests are shown in Table 4. 4. Conclusions The Superfund and IRF DRE data discussed in this paper clearly indicates that DREs of 99.99% or greater can be achieved at waste feed POHC concentrations below 1000 ppm and that DREs of 99.9999% or greater can be achieved at waste feed POHC concentrations not only below 10,000 ppm, but also below 100 ppm. In the author's opinion, the MRI and EER conclusions and correlations concerning low DREs occurring at low waste feed POHC concentrations are unsupportable as a general rule, based on the newer data. These apparent correlations occurred because of the use in these studies of waste feed POHCs at low concentrations which were also generated as PICs from other waste feed POHCs present in the waste feeds at higher concentrations. When the POHC formed as a PIC is small compared to the POHC in, the DRE is not signi®cantly reduced. When the POHC formed as a PIC is signi®cant compared to the POHC in, the apparent DRE can be reduced. References [1] Trenholm A, Gorman P, Jungclaus G. Performance evaluation of full-scale hazardous waste incinerators. EPA-600/2-84-181 [®ve vols.] November 1984. [2] Trenholm A, Gorman P, Jungclaus G. Performance evaluation of full-scale hazardous waste incinerators. EPA-600/2-84-181, vol. II, November 1984.
459
[3] Kramlich J, Poncelet E, Charles R, Seeker W, Samuelsen G, Cole, J. Experimental investigation of critical fundamental issues in waste incineration. EPA/600/2-89/048, September 1989. [4] Thurau R. The incomplete combustion of carbon tetrachloride during normal/abnormal hazardous waste incineration. In: Land disposal remedial action, incineration and treatment of hazardous waste. EPA/600/9-88/021, Cincinnati, OH, 1988. p. 444±55. [5] Trenholm A, Gorman P, Jungclaus G. Performance evaluation of full-scale hazardous waste incinerators. EPA-600/2-84-181, Vol. II, November 1984. p. 33. [6] Eicher A. Guide for thermal treatment process trial burns. In: Freeman H, editor. Standard handbook of hazardous waste treatment and disposal. 2nd ed. New York: McGraw±Hill, 1997. p. 8.132±8.175. [7] Taylor P, Dellinger B. Thermal degradation of chloromethane mixtures. Environmental Science and Technology 1998;22(4):438±47. [8] VanDell R, Shado L. Relative rates and partial combustion products from the burning of chlorobenzenes and chlorobenzene mixtures. Chemosphere 1984;13(11):1177±92. [9] Dellinger B, Taylor PH. Hazardous waste incineration Ð assessing the origin and emissions of organic by-products. In: Pershing D, Saro®n A, editors. New York: Wiley and Sons, 1994. p. 31±38. [10] Trenholm A, Gorman P, Jungclaus G. Performance evaluation of full-scale hazardous waste incinerators. EPA-600/2-84-181, vol. IV, November 1984 [appendix E]. [11] Compilation of air pollutant emission factors, AP-42, vol. I, Suppl B, 5th ed. Stationary point and area sources. Research Triangle Park, NC: USEPA, 1997, [chapter 1, section 1.3, table i. 3±8]. [12] Freestone F, et al. Evaluation of on-site incineration for cleanup of dioxin-contaminated materials. In: Land disposal, remedial action, incineration and treatment of hazardous waste. EPA/600/ 9-86/022, Cincinnati, OH, 1986. p. 298±318. [13] Miller R. to Cudahy J, February 3, 1993, personal communication. [14] EPA mobile incinerator safely destroys dioxin. EPA Environmental News, 30 May 1995. [15] Waterland L, et al. Pilot-scale incineration of a dioxin-containing material. Second International Conference on New Frontiers for Hazardous Waste Management. EPA/600/9-87/018F, 27±30 September 1987. p. 375±82. [16] Incineration research facility. EPA/600/M-89/027, November 1989. [17] Ogden Environmental Services, Process demonstration test report for demonstration test of PCB contaminated soils, 14 December 1988. [18] Cudahy J, Troxler W. 1991 thermal treatment remediation industry contractor survey. Journal of Air & Waste Management Association, June 1992 [updated January 1998, unpublished]. [19] Young D, Ives J. Site remediation soils handling, incineration and site closeout challenges and solutions. 85th Annual Meeting of the Air and Waste Management Association, Kansas City, MO, 21±26 June 1992. [20] Jackson K, Dunham M, Westbrook R. Overview of transportable incinerator operations at the Sikes Disposal Pits superfund site. 1993 Incineration Conference, Knoxville, TN, 3±7 May 1993. p. 499±509. [21] ThermoCor, Incorporated and IT Analytical Services. Trial burn report for the LaSalle electric utilities site LaSalle, IL, July 1992. [22] OHM Remediation Services Corporation. Baird & McGuire trial burn report, 6 March 1995.
Low waste feed concentrations and destruction removal eciency James J. Cudahy* Focus Environmental, Inc., Knoxville, TN, USA
Abstract In the early 1980s, the Environmental Protection Agency (EPA) funded research on destruction and removal eciencies (DREs) at eight hazardous waste incinerators. This research appeared to show that DREs of 99.99% could not be achieved at low waste feed principal hazardous organic constituent (POHC) concentrations. During the mid 1980s and 1990s however, testing at Superfund sites has indicated that DREs of 99.9999% or greater can be achieved at low waste feed POHC concentrations. This paper will summarize testing which includes 32 test runs at ®ve Superfund sites and the EPA's incineration research facility. The tests include POHC concentrations from 6552 parts per million down to 28 parts per million at typical DREs of 6±9 s or greater. # 1999 Elsevier Science Ltd. All rights reserved.
1. Introduction In the early 1980s, the Environmental Protection Agency (EPA) funded an extensive research project to perform an evaluation test program at eight hazardous waste incinerators [1]. Table 1 summarizes the design parameters of these eight systems [1]. This test program was implemented by the Midwest Research Institute (MRI) and involved waste feed, ash, scrubber water and stack testing on particulate, HCl, dioxins and furans, other products of incomplete combustion (PICs), metals and carbon monoxide emissions. The test program also involved destruction and removal eciency (DRE) testing for many principle organic hazardous constituents (POHCs) at all eight incinerators. During resource conservation and recovery act (RCRA) DRE testing as de®ned by 40 CFR 264.343(a)(1) and 40 CFR 270.62, one or more POHCs are selected from the Appendix VIII list in 40 CFR 261 and used to calculate POHC DREs for the incinerator being tested. A RCRA incinerator must achieve a DRE of at least 99.99% for each POHC designated in the facility trial burn plan. In the MRI study, the authors developed statistical correlations for both volatile and semi-volatile organics which appeared to show that DREs of 99.99% could not be achieved at waste feed POHC concentrations below 1000 ppm [2]. The MRI volatile organic plot appeared to show that DREs of 99.9999% could not be achieved at waste feed POHC concentrations below approximately 10,000 ppm [2]. * Tel.: +1-423-694-7517; fax: +1-423-531-8854; e-mail: jjcudahy@ focusenv.com
An EPA study performed by Energy and Environmental Research Corporation (EER) and published in 1989, also researched low DREs in relation to low waste feed POHC concentrations [3]. A small 100,000 Btu per hour liquid spray combustor with no secondary combustion and with water-cooled walls surrounding the ¯ame zone was used for the experimental work. The spray combustor waste feed was either No. 2 fuel oil or n-heptane doped with a `soup' of ®ve test compounds. The test `soup' was an equimolar mixture of acrylonitrile, toluene, chlorobenzene, chloroform and 1,1,1-trichloroethane. The test `soup' was added to the No. 2 fuel oil or the n-heptane at various concentrations ranging from 30 parts per million (ppm) to 30% by weight. The spray combustor with the fuel oil `soup' was tested at 120 and 150% excess air, and the n-heptane and `soup' mixture was tested without chloroform at 150% excess air [3]. In the EER study, the authors, based on the MRI study and their research, stated that incineration has diculty meeting the 99.99% DRE permitting requirement when the waste represents less than 1000 ppm of the feed stream [3]. 2. PIC to POHC formation hypothesis Since these two studies were done, testing with mobile incinerators at Superfund sites and at the EPA's incineration research facility (IRF) during the mid 1980s and 1990s has shown that not only are DREs above 99.99% achievable with waste feed POHC concentrations below 1000 ppm but that DREs of 99.9999% or greater
0956-053X/99/$ - see front matter # 1999 Elsevier Science Ltd. All rights reserved PII: S0956 -0 53X(98)00129-9
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Table 1 Design parameters of hazardous waste incinerators tested by MRI Incinerator Ross Incineration Services Trade Waste Incineration Upjohn Company Zapata Industries American Cyanamid Mitchell Systems Dupont Plant B (con®dential)
Location
Type
HWI size (MW Btu/h)
APC
Grafton, OH Sauget, IL LaPorte, TX Butner, NC Willow Island, WV Spruce Pine, NC LaPlace, LA
Rotary kiln Solid hearth Liquid injection Controlled air Liquid injection Solid hearth Rotary kiln and liquid
90 10 6 2 5 10 40
Wet None Wet None None None Wet
can be achieved at waste feed POHC concentrations not only below 10,000 ppm, but also below 100 ppm. The objective of this paper was to evaluate why the MRI and EER data indicated low DREs at low waste POHC concentrations, but the Superfund and IRF test data do not show this. An analysis of the data in Refs. [1] and [3] shows that many of the POHCs used for DRE determinations in these studies are compounds that can form PICs which also happen to be compounds present in the waste feeds as other POHCs. A reasonable hypothesis to explain the MRI and EER low DRE with low waste feed POHC concentration data is that a high concentration waste feed POHC, such as carbon tetrachloride, will form chloroform as a PIC. If chloroform is also present in the waste as a POHC, but at a much lower concentration than the carbon tetrachloride, then the chloroform formed as a PIC is analyzed in the stack gas as if it were the undestroyed chloroform POHC. The sampling methods used for POHC determination in a stack gas can not distinguish between chloroform fed as a POHC or formed as a PIC from another POHC. The additional chloroform generated as a PIC from the carbon tetrachloride can reduce the apparent chloroform DRE relative to what it would have been if only the chloroform POHC in the original waste feed were considered in the DRE equation. This formation of chloroform as a PIC from carbon tetrachloride has been clearly shown to occur in testing at a full scale incinerators [4]. This concept of PICs contributing to the mass emission rate of other POHCs was not well understood in the early 1980s when the MRI study was done, but it is still mentioned in the MRI study as a possible factor in the low DRE±low waste feed concentration correlation [5]. Throughout the mid to late 1980s, as a database of RCRA trial bum test data developed, it became clear that certain chemicals such as chlorinated methanes, triand tetrachlorinated ethanes and ethenes, chlorinated benzenes, and benzene and toluene should not be used as multiple POHCs in a single RCRA trial burn, because of the potential impact of the PICs on the target POHC DRE [6]. Fig. 1 illustrates some of the possible PIC formation mechanisms that probably occurred during the MRI study. The chlorinated methane, chlorinated
benzene and toluene PIC reactions illustrated in Fig. 1 have been shown to occur in laboratory and full scale studies involving the formation of PIC [4,7±9]. The MRI and EER studies are discussed in relation to the PIC to POHC formation hypothesis in the following sections. 2.1. MRI study The MRI report has numerous cases where the target waste feed POHCs generated PICs which are other waste feed POHCs, thereby resulting in the apparent reduction of DREs. A speci®c example of this situation is shown in Table 2. The DRE and waste feed concentration data in Table 2 was taken from Appendix E of Volume IV of the MRI study [10]. The incineration of the high concentration p-dichlorobenzene and o-dichlorobenzene appears to have resulted in the formation of m-dichlorobenzene, monochlorobenzene and 1,2,4-trichlorobenzene as PICs at high enough concentrations to reduce the DREs of the lower concentration compounds. The formation of monochlorobenzene and trichlorobenzene as PICs from the combustion of dichlorobenzene has been shown to occur in a laboratory study [8]. Seven of the eight incinerators tested by MRI used chlorinated methanes, tri- and tetrachlorinated ethanes and ethenes as waste feed POHCs [1]. The only incinerator that did not use these compounds as waste feed POHCs was the American Cyanamid facility. The DREs measured at the American Cyanamid facility were typically greater than 99.999% to greater than 99.99999% [2]. Table 3 shows some of the possible PIC formation routes that probably occurred at the incinerators tested by MRI. Many of the PIC formation reactions shown in Table 3 have been identi®ed in laboratory and full scale incinerator testing [4,7±9]. In mathematical terms, the DREs calculated during the MRI study were actually based on the following model: DRE
POHC inÿPOHC out POHC formed as PIC POHC in
When the POHC formed as a PIC is small compared to the POHC in, the DRE is not signi®cantly reduced.
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455
Fig. 1. Possible PIC formation mechanisms during the MRI testing. Table 2 Example of DRE reduction caused by POHC formation from PICs POHC p-Dichlorobenzene o-Dichlorobenzene m-Dichlorobenzene Monochlorobenzene 1,2,4-Trichlorobenzene
Feed conc. (ppm by weight)
DRE (%)
65,000 50,000 2500 6033 317
99.998 99.997 99.920 99.903 99.330
The results also suggest that the in¯uence of feed concentration is stronger at waste concentrations above 3000 ppm than below, a trend not noted in the ®eld data.'
Based on the results of this test program, the EER study authors stated the following [3]:
It is likely that the PIC to POHC formation mechanism was also a factor in some of the low DREs observed in the EER study. Two of the POHCs used in the EER study were chloroform and 1,1,1-trichloroethane. From the structure of these two compounds, it is obvious that a likely PIC that can be formed from 1,1,1-trichloroethane is chloroform, thus impacting the chloroform DREs. The EER study states that no chloroform DREs are shown in the report because in several cases the quantity of chloroform in the stack gas exceeded the amount of chloroform fed to the spray combustor [3]. The EER report makes the following statement relative to the chloroform:
The results of this study show that DRE is positively correlated with waste concentration in the feed.
The excess chloroform measurements that were noted in both data sets can be attributed to formation
When the POHC formed as a PIC is signi®cant compared to the POHC in, the apparent DRE can be reduced. 2.2. EER study
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Table 3 Possible PIC formation routes at incinerators tested by MRI Incinerator
POHCs with DREs<99.99%
Possible PIC producing POHCs
Ross Incineration Services
Methylene chloride (CH2Cl2)
Carbon tetrachloride (CCl4)
Trade Waste Incineration
Chloroform (CHCl3) Methylene chloride (CH2Cl2) 1,1,1-Trichloroethane (CCl3CH3) Tetrachloroethylene (CCl2CCl2) Chlorobenzene (C6H5Cl)
Carbon tetrachloride (CCl4) Carbon tetrachloride (CCl4) Carbon tetrachloride (CCl4) Carbon tetrachloride (CCl4) Toluene (C6H5CH3)
Upjohn Company
Chlorobenzene (C6H5Cl) Trichlorobenzene (C6H3Cl3) Carbon tetrachloride (CCl4)
Dichlorobenzene (C6H4Cl2) Dichlorobenzene (C6H4Cl2) 1,1,2-Trichloroethylene (CCl2CHCl)
Zapata Industries
Methylene chloride (CH2Cl2)
Carbon tetrachloride (CCl4)
American Cyanamid
None
No common PICs
Benzene (C6H6)
Toluene (C6H5CH3)
Dupont
Chloroform (CHCl3) 1,1,1-Trichloroethane (CCl3CH3)
Carbon tetrachloride (CCl4) Carbon tetrachloride (CCl4)
Plant B
Chloroform (CHC13) 1,1,2-Trichloroethylene (CCl2CHCl) Phenol (C6H5OH)
Carbon tetrachloride (CCl4) Tetrachloroethylene (CCl2CCl2) Toluene (C6H5CH3)
General
Phthalates
Lab contamination?
Mitchell Systems
of chloroform as a PIC during reaction of the other compounds [3].' Two of the other POHCs used in the EER study, toluene and chlorobenzene, are also common PICs that could have impacted low concentration DRE measurements. In addition, incineration of the No. 2 fuel oil combined with the chlorinated organics in the `soup' could also generate PICs such as toluene and chlorobenzene when incinerated. Emission factors published by the EPA in AP-42 indicate that benzene, toluene, ethyl benzene and o-xylene are PICs generated during residual fuel oil combustion [11]. This hypothesis is supported by the fact that the measured low concentration DREs for toluene and chlorobenzene are higher for the n-heptane tests than for the No. 2 fuel oil tests [3]. Of the ®ve POHCs used in the EER study, only acrylonitrile was not a common PIC. The acrylonitrile DRE did not demonstrate a consistent trend with the low DRE-low waste POHC concentration hypothesis. The acrylonitrile DREs were about 96, 60, 99.99 and 94.5% for waste feed concentrations of 30, 300, 3000 and 30,000 ppm by weight [3]. A discussion of the DRE testing at Superfund sites and the EPA's IRF follows. 3. DRE testing at Superfund sites and the IRF To test the hypothesis that DREs of 99.99% could not be achieved at waste feed POHC concentrations below 1000 ppm and that DREs of 99.9999% could not be achieved at waste feed POHC concentrations below
approximately 10,000 ppm, data was obtained from eight tests of mobile incinerators used in the Superfund site remediation program and one test from the EPA's pilot-scale IRF. The DRE data set includes nine tests with 26 test runs and 32 data points for four dierent POHCs regulated under RCRA and polychlorinated biphenyls (PCBs) regulated under the toxic substances control act (TSCA). The test programs occurred at six locations using six dierent incinerators. The waste feed POHC concentrations ranged from 28 to 6652 ppm by weight. This data is summarized in Table 4. As can be seen from Table 4, DREs of greater than 99.99% with waste feed POHC concentrations below 1000 ppm were achieved in 14 of the tests. In 13 of the 14 tests, no POHC was detected in the stack gas so that the DREs are actually greater than the values shown in Table 4. DREs of greater than 99.9999% with waste feed POHC concentrations below 10000 ppm were achieved in 29 of the tests. In 17 of the 29 tests, no POHC was detected in the stack gas so that the DREs are actually greater than the values shown in Table 4. DREs of greater than 99.9999% with waste feed concentrations below 1000 ppm were achieved in 11 of the tests. The DRE data are plotted in Fig. 2. This data clearly indicates that DREs of greater than 99.99% with waste feed POHC concentrations below 1000 ppm and DREs of greater than 99.9999% with waste feed POHC concentrations not only below 10,000 ppm, but also below 100 ppm are achievable. The MRI and EER conclusions and correlations concerning low DREs occurring at low waste feed POHC concentrations are unsupportable as a general rule, based on the newer data. These apparent
J.J. Cudahy/Waste Management 18 (1998) 453±459
457
Table 4 DRE and waste feed POHC and PCB concentration data Site Denney Farm
Test date
Location
POHC
Test no.
Waste feed conc. (ppm)
DRE(%)
February, April 1985
Verona, MO
2,3,7,8-TCDD 2,3,7,8-TCIDD 2,3,7,8-TCDD 2,3,7,8-TCDD
1 1 1 1
42 53 28 36
>99.999973 >99.999986 >99.999995 >99.999989
EPA IRF
September 1986
Jeerson, AR
2,3,7,8-TCDD
1
37
>99.999991
Swanson River
September 1986
Kenai Peninsula, AK
PCBs PCBs PCBs PCBs PCBs PCBs
1 1 1 2 2 2
632 615 801 289 608 625
>99.99993 >99.99992 >99.99997 >99.99996 >99.99994 >99.99993
Sikes Disposal Pits (APC no. 1)
April 1992
Crosby, TX
Chlorobenzene Chlorobenzene Chlorobenzene
1 1 1
6336 6667 6652
>99.99999 >99.999989 >99.999989
Sikes Disposal Pits (APC no.2)
April 1992
Crosby, TX
Chlorobenzene Chlorobenzene Chlorobenzene
1 1 1
6336 6667 6652
>99.99999 >99.99999 >99.99999
LaSalle Electric
April 1992
LaSalle, IL
PCBs PCBs PCBs PCBs PCBs PCBs
1 1 1 2 2 2
5728 5824 5878 4302 4480 4452
99.99990 99.999902 9.999908 99.999924 99.999902 99.999939
January 1995
Holbrook, MA
Naphthalene Naphthalene Naphthalene 1,2,4,5-Tetrachlorobenzene 1,2,4,5-Tetrachlorobenzene 1,2,4,5-Tetrachlorobenzene Chlorobenzene Chlorobenzene Chlorobenzene
1 1 1 1 1 1 1 1 1
4083 4042 3830 3977 3967 3769 291 314 327
99.999972 99.999929 99.999953 99.999995 99.999989 99.999989 >99.99977 99.99978 >99.99981
Braird & McGuire
correlations occurred because of the use in these studies of waste feed POHCs at low concentrations which were also generated as PICs from other waste feed POHCs present in the waste feeds at higher concentrations. The Superfund and IRF test programs are described in the following sections. 3.1. Denney Farm site In February and April of 1985, the EPA implemented a test program using the EPA's mobile incineration system (MIS) at the Denney Farm site near Verona, Missouri [12]. The MIS was a 10 MM Btu per h pilot-scale rotary kiln incinerator with a secondary combustion chamber and a wet, rapid quench scrubbing system [12]. During the Denney Farm test program, the EPA's MIS incinerated liquid and soil contaminated with 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD). The POHC used for the DRE tests was 2,3,7,8-TCDD. During one test consisting of four runs,
the 2,3,7,8-TCDD concentration for the combined liquid and soil waste feeds ranged from 28 to 53 ppm [13]. The 2,3,7,8-TCDD DREs ranged from greater than 99.999973% to greater than 99.999995% [14]. No 2,3,7,8-TCDD was detected in the stack gas in any of the four runs. The DRE and waste feed POHC concentration data for the Denney Farm tests are shown in Table 4. 3.2. Incineration research facility In September of 1986, a test program was implemented using the EPA's rotary kiln system (RKS) at the EPA's IRF in Jeerson, AR [15]. The RKS is a 3.5 MM Btu per h pilot-scale rotary kiln incinerator with a secondary combustion chamber and a wet, rapid quench scrubbing system [16]. During the IRF test program, the EPA's RKS incinerated toluene still bottoms waste from trichlorophenol production. The toluene still bottoms were contaminated with 2,3,7,8-TCDD. The
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the stack gas in any of the six runs [17]. No spiking of the soil with PCBs was done for any of the six trial burn runs [19]. The DRE and waste feed POHC concentration data for the Swanson River tests are shown in Table 4. 3.4. Sikes Pits site
Fig. 2. DREs at low POHC concentrations in feed.
POHC used for the DRE tests was 2,3,7,8-TCDD. By analyzing combined extracts from four simultaneous sampling trains, it was possible to measure 2,3,7,8-TCDD stack gas detection limits sucient to demonstrate a DRE value greater than 99.9999%. During this one test run the 2,3,7,8-TCDD waste feed POHC concentration was 37 ppm by weight. The 2,3,7,8-TCDD DRE was greater than 99.999991% [15]. No 2,3,7,8-TCDD was detected in the stack gas in any of the four combined extracts. The DRE and waste feed POHC concentration data for the IRF test are shown in Table 4. 3.3. Swanson River site In September 1988, Ogden Environmental Services implemented a test program using a mobile circulating bed combustor (CBC) incinerator at the Swanson River site on the Alaskan Kenai Peninsula [17]. The CBC is a 10 MM Btu per h full-scale circulating bed ¯uidized bed incinerator with a dry fabric ®lter for air pollution control [17,18]. During the Swanson River test program, the CBC incinerated soil contaminated with PCBs. During three test runs at a CBC feed temperature of about 1600 F, the PCB feed concentrations ranged from 615 to 801 ppm. During three test runs at a CBC temperature of about 1700 F, the PCB feed concentrations ranged from 289 to 625 ppm. The PCB DREs for all six runs ranged from greater than 99.99992% to greater than 99.99997%. No PCBs were detected in
In April of 1992, IT Corporation implemented a test program using a mobile rotary kiln incineration system at the Sikes Disposal Pits site in Crosby, TX. The mobile unit was a single 120 MM Btu per h full-scale rotary kiln incinerator with two parallel and identical secondary combustion chambers and two parallel and identical wet, rapid quench systems, each venting to separate and identical stacks [18,20]. During the Sikes Disposal Pits test program, the rotary kiln system incinerated soil spiked with the POHCs naphthalene and monochlorobenzene. Each of the two stacks was tested independently for POHC emissions. During one test, each stack was tested simultaneously for three runs. The waste feed chlorobenzene concentration ranged from 6336 to 6667 ppm. The chlorobenzene DREs ranged from greater than 99.999989% to greater than 99.999990%. No chlorobenzene was detected in the gas of either stack gas in any of the six runs. The naphthalene DREs, which averaged greater than 99.999% are not used as data in this paper because naphthalene contamination in the sampling train blank reduced the DRE that could be ocially reported. The authors of the reference estimated that without the presence of contamination in the sampling blank, that the naphthalene DREs would have been greater than 99.9999% [20]. The DRE and waste feed POHC concentration data for the Sikes Disposal Pits tests are shown in Table 4. 3.5. LaSalle Electric Utilities site In April 1992, ThermoCor, Inc. implemented a test program using a mobile rotary kiln incineration system at the LaSalle Electric Utilities Superfund site in LaSalle, IL. The mobile unit was a 100 MM Btu per h full-scale rotary kiln incinerator with a secondary combustion chamber and a dry fabric ®lter for air pollution control [18,21]. During the LaSalle Electric test program, the rotary kiln system incinerated soil spiked with polychlorinated biphenyls (PCBs). During three runs at a soil feed rate of about 16 tons of soil per h, the PCB feed concentrations ranged from 5728 to 5878 ppm. During three runs at a soil feed rate of about 22 tons of soil per h, the PCB feed concentrations ranged from 4302 to 4480 ppm. The PCB DREs for all six runs ranged from 99.9999 to 99.999939% [21]. The DRE and waste feed PCB concentration data for the LaSalle Electric tests are shown in Table 4.
J.J. Cudahy/Waste Management 18 (1998) 453±459
3.6. Baird & McGuire site In January 1995, OHM Remediation Services Corporation implemented a test program using a mobile rotary kiln incineration system at the Baird & McGuire Superfund site in Holbrook, MA. The mobile unit was a 80 MM Btu per h full-scale rotary kiln incinerator with a secondary combustion chamber and a wet, rapid quench scrubbing system [18,22]. During the Baird & McGuire test program, the rotary kiln system incinerated soil spiked with naphthalene, 1,2,4,5-tetrachlorobenzene and chlorobenzene POHCs. During one test consisting of three runs, the naphthalene waste feed concentration ranged from 3830 to 4083 ppm. The tetrachlorobenzene waste feed concentration ranged from 3769 to 3977 ppm and the chlorobenzene waste feed concentration ranged from 291 to 327 ppm. The naphthalene DREs ranged from 99.999929 to 99.999972%. The tetrachlorobenzene DREs ranged from 99.999989 to 99.9999950%. The chlorobenzene DREs ranged from greater than 99.99977 to greater than 99.99981% [22]. The DRE and waste feed PCB concentration data for the Baird & McGuire tests are shown in Table 4. 4. Conclusions The Superfund and IRF DRE data discussed in this paper clearly indicates that DREs of 99.99% or greater can be achieved at waste feed POHC concentrations below 1000 ppm and that DREs of 99.9999% or greater can be achieved at waste feed POHC concentrations not only below 10,000 ppm, but also below 100 ppm. In the author's opinion, the MRI and EER conclusions and correlations concerning low DREs occurring at low waste feed POHC concentrations are unsupportable as a general rule, based on the newer data. These apparent correlations occurred because of the use in these studies of waste feed POHCs at low concentrations which were also generated as PICs from other waste feed POHCs present in the waste feeds at higher concentrations. When the POHC formed as a PIC is small compared to the POHC in, the DRE is not signi®cantly reduced. When the POHC formed as a PIC is signi®cant compared to the POHC in, the apparent DRE can be reduced. References [1] Trenholm A, Gorman P, Jungclaus G. Performance evaluation of full-scale hazardous waste incinerators. EPA-600/2-84-181 [®ve vols.] November 1984. [2] Trenholm A, Gorman P, Jungclaus G. Performance evaluation of full-scale hazardous waste incinerators. EPA-600/2-84-181, vol. II, November 1984.
459
[3] Kramlich J, Poncelet E, Charles R, Seeker W, Samuelsen G, Cole, J. Experimental investigation of critical fundamental issues in waste incineration. EPA/600/2-89/048, September 1989. [4] Thurau R. The incomplete combustion of carbon tetrachloride during normal/abnormal hazardous waste incineration. In: Land disposal remedial action, incineration and treatment of hazardous waste. EPA/600/9-88/021, Cincinnati, OH, 1988. p. 444±55. [5] Trenholm A, Gorman P, Jungclaus G. Performance evaluation of full-scale hazardous waste incinerators. EPA-600/2-84-181, Vol. II, November 1984. p. 33. [6] Eicher A. Guide for thermal treatment process trial burns. In: Freeman H, editor. Standard handbook of hazardous waste treatment and disposal. 2nd ed. New York: McGraw±Hill, 1997. p. 8.132±8.175. [7] Taylor P, Dellinger B. Thermal degradation of chloromethane mixtures. Environmental Science and Technology 1998;22(4):438±47. [8] VanDell R, Shado L. Relative rates and partial combustion products from the burning of chlorobenzenes and chlorobenzene mixtures. Chemosphere 1984;13(11):1177±92. [9] Dellinger B, Taylor PH. Hazardous waste incineration Ð assessing the origin and emissions of organic by-products. In: Pershing D, Saro®n A, editors. New York: Wiley and Sons, 1994. p. 31±38. [10] Trenholm A, Gorman P, Jungclaus G. Performance evaluation of full-scale hazardous waste incinerators. EPA-600/2-84-181, vol. IV, November 1984 [appendix E]. [11] Compilation of air pollutant emission factors, AP-42, vol. I, Suppl B, 5th ed. Stationary point and area sources. Research Triangle Park, NC: USEPA, 1997, [chapter 1, section 1.3, table i. 3±8]. [12] Freestone F, et al. Evaluation of on-site incineration for cleanup of dioxin-contaminated materials. In: Land disposal, remedial action, incineration and treatment of hazardous waste. EPA/600/ 9-86/022, Cincinnati, OH, 1986. p. 298±318. [13] Miller R. to Cudahy J, February 3, 1993, personal communication. [14] EPA mobile incinerator safely destroys dioxin. EPA Environmental News, 30 May 1995. [15] Waterland L, et al. Pilot-scale incineration of a dioxin-containing material. Second International Conference on New Frontiers for Hazardous Waste Management. EPA/600/9-87/018F, 27±30 September 1987. p. 375±82. [16] Incineration research facility. EPA/600/M-89/027, November 1989. [17] Ogden Environmental Services, Process demonstration test report for demonstration test of PCB contaminated soils, 14 December 1988. [18] Cudahy J, Troxler W. 1991 thermal treatment remediation industry contractor survey. Journal of Air & Waste Management Association, June 1992 [updated January 1998, unpublished]. [19] Young D, Ives J. Site remediation soils handling, incineration and site closeout challenges and solutions. 85th Annual Meeting of the Air and Waste Management Association, Kansas City, MO, 21±26 June 1992. [20] Jackson K, Dunham M, Westbrook R. Overview of transportable incinerator operations at the Sikes Disposal Pits superfund site. 1993 Incineration Conference, Knoxville, TN, 3±7 May 1993. p. 499±509. [21] ThermoCor, Incorporated and IT Analytical Services. Trial burn report for the LaSalle electric utilities site LaSalle, IL, July 1992. [22] OHM Remediation Services Corporation. Baird & McGuire trial burn report, 6 March 1995.