PB84-210848
Development  of  the Volatile Organic
Sampling Train  (VOST)  for Use  in
Determining  Incinerator Efficiency
 (U.S.)  Industrial Environmental  Research Lab.
Research Triangle Park, NC
Jun  84
                        U.S. DEPARTMENT OF COMMERCE
                     National Technical Information Service

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                                                         PB 84-21084 a
                                              EPA-600/D-84-168
                                                    June  1984
 DEVELOPMENT OF THE VOLATILE ORGANIC  SAMPLING TRAIN
(VOST)  FOR USE IN DETERMINING INCINERATOR  EFFICIENCY
                          by
                  Larry D.  Johnson
    Industrial  Environmental  Research Laboratory
          Research Triangle Park, NC 27711
    INDUSTRIAL ENVIRONMENTAL RESEARCH LABORATORY
          OFFICE OF RESEARCH AND DEVELOPMENT
         U.S. ENVIRONMENTAL PROTECTION AGENCY
          RESEARCH TRIANGLE PARK, NC 27711

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TECHNICAL REPORT DATA
(ftcatc reaJ IHU/IICIIUIU on the reverse before completing)
1 REPORT NO.
EPA-600/n-f}4-168
2
4. TITLE AND SUBTITLE
Development of the Volatile Organic Sampl
(VOST) for Use in Determining Incinerate
7. AUTHORIS)
Larry D. Johnson
3. RECIPIENT'S ACCESSION NO.
5 REPORT DATE
ing Train June 1984

>r Efficiency 6- PERFORMING ORGANIZATION CODE
B. PERFORMING ORGANIZATION REPORT NO.
9 PERFORMING OPOANIZATION NAME AND ADDRESS
See Block 12.
12. SPONSORING AGENCY NAME AND ADDRESS
EPA, Office of Research and Development
Industrial Environmental Research Labora
Research Triangle Park, NC 27711
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
NA (Inhouse)
13. TYPE OF REPORT AND PERIOD COVERED
Published Paper; 5/84
14. SPONSORING AGENCY CODE
tory
EPA/600/13
15. SUPPLEMENTARY NOTES Author Johnson's Mail Drop is 62; his phone number is 919/541-
7943.
is. ABSTRACT Thg paper discusses the development, initial evaluation, and field applica-
tion to incinerators of a new sampling train for volatile organic species. The Volatile
Organic Sampling Train (VOST) is a simple portable device, combining Tenax and
Tenax/ char coal cartridges as collection agents. Analysis of the sorption cartridges
includes a further concentration step that permits the measurement of stack concen-
trations as low as 0.1 ng/L. The Resource Conservation and Recovery Act requires
owners or operators of hazardous waste incinerators to demonstrate that the inciner-
ator can achieve adequate destruction efficiency of certain compounds before a per-
mit is issued. Many of the compounds that are commonly of interest are of low mo-
lecular weight and volatile.
17.
KEY WORDS AND DOCUMENT ANALYSIS
1 DESCRIPTORS
Pollution Efficiency
Incinerators Toxicity
Flue Gases
Sampling
Measurement
Organic Compounds
13. DISTRIBUTION STATEMENT
Release to Public
b.lDENTIFIERS/OPEN ENDED TERMS
Pollution Control
Stationary Sources
Volatile Organic Sam-
pling Train (VOST)
Hazardous Waste
19 SECURITY CLASS I'Hia Rtporlj
Unclassified
70 SECURITY CLASS (Tha page)
Unclassified
c. COSATi 1 leltl/Group
13B 14G
06T
21B
14B
07C
21. NO. OF PAGES
17
22. PRICE
EPA Form 2220-1  (9-73|

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                      NOTICE

This document has been reviewed in accordance with
U.S. Environmental Protection Agency policy and
approved for publication.  Mention of trade names
or commercial products does not constitute endorse-
ment or recommendation for use.
                        ii

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                                ABSTRACT
Development of the Volatile Organic Sampling Train (VOST) for Use in



Determining Incinerator Efficiency.








Larry D. Johnson, Industrial Environmental Research Laboratory, U.S.



Environmental Protection Agency, Research Triangle Park, NC 27711








The Resource Conservation and Recovery Act regulations require owners



or operators of hazardous waste incinerators to demonstrate that the



incinerator can achieve adequate destruction efficiency of certain com-



pounds before a permit is issued.  Many of the compounds that are commonly



of interest are low molecular weight, volatile species.







This paper will discuss the development, initial evaluation, and field



application to incinerators of a new sampling train for volatile organic



species.  The train developed, the Volatile Organic Sampling Train (VOST),



is a simple, portable device employing a combination of Tenax and Tenax/



charcoal cartridges as the collection agents.  Analysis of the sorption



cartridges includes a further concentration step which permits the measure-



ment of stack concentrations as low as 0.1 ng/L.








                               Key Words







    stack sampling, volatile organics, hazardous waste, incineration,



    destruction efficiency, measurement methods development





                                    tii

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Introduction




     The development and field application of the volatile organic

sampling train (VOST) has been unusual in the high speed at which it

has progressed, as well as the difficulty of the task it addresses.

The development of the train has generated a high degree of interest

in the industrial and contractor sectors, primarily because of its

application to incinerator trial burns, but also because it fills a

void in the stack sampler's arsenal.




     This paper describes the concepts behind the VOST, several stages

in the development of the train, and a summary of the current status of

the VOST technology.




Background




     Although the need for an improved stack sampling procedure for

volatile organics has existed for years, the situation only became

critical in relation to hazardous waste incineration.  A reference

document designed to assist in planning or review of sampling and analysis
                                                                •
programs for hazardous waste incinerators or related combustors has been

produced by EPA (1).  That document recommends the Modified Method 5

(MM5) train or Source Assessment Sampling System (SASS) for collection of

organics with boiling points greater than 100°C.  The sorbent breakthrough

characteristics associated with lower boiling organics make the use of

these trains inadvisable for quantitative collection of compounds boiling

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below 100°C.  Early drafts of Reference 1 recommended the use of either



plastic sampling bags or glass sample bulbs for collection of these compounds.



These recommendations were based on the assumption that at least 1000 ug/g



off the material was present in the waste feed, and that the destruction




etziciency of interest was 99.99Z.  In early 1982, an urgent need was identi-



fied by EPA R&D engineering programs and the Office of Solid Waste.  A number of




projects had been identified where volatile principal organic hazardous con-



stituents (POHC) were of interest in waste feed at 100 ug/g concentration, and



it was necessary to characterize destruction efficiencies on the order of 99.999Z.



At such low concentrations of POHC in the stack, glass sampling bulbs are



useless, and plastic bags are only effective if combined with a concentration



technique.  Although it is possible to concentrate organics collected in bags



by the use of sorbent tubes or other techniques such as cold trapping, it is



not recommended because of the following reason.  There are drawbacks, difficulties,



and operational pitfalls associated with any sampling technique.  When two techniques



(such as bag sampling of the source and sorbent sampling of the bag) are applied




sequentially, the problems are likely to be compounded.








     Since the need for a new sampling approach was apparent, and time was



an important factor, a meeting of EPA and contractor scientists and engineers



was held in April of 1982 to discuss the problem.  As a result of that meeting,




the basic concepts and train arrangement for the VOST were agreed upon.








Dasic Concepts






     The schematic diagram of the VOST is shown in Figure 1.  The active



elements for collection of volatile organics are the two sorbent cartridges,



although some compounds may also be collected in the condensate under certain

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circumstances.  The first sorbent tube is filled with Tenax porous polymer



as the primary collection agent, while the second tube contains Tenax and




activated charcoal as an extra precaution against breakthrough of the more



volatile materials.  The glass sorbent tubes are 10 cm by 1.6 cm and hold 1.6 g



of Tenax or 1 g of Tenax + 1 g of charcoal.  These tubes were choen because



they were the largest of the commercially available ambient air sampling




tubes and were compatible with existing desorption equipment.  Larger tubes




allow larger sample volume before breakthrough occurs.  Tubes much larger



than those chosen, however, become difficult to heat desorb in an effective



manner, and would require a new desorber design.








     The VOST operates at 1 L/min while the sorbent'tubes are maintained




at 20°C or less during sampling.  It is important that this temperature



be maintained at all times, since higher temperaturs may cause breakthrough



of the more volatile organics.  Six sets of 20 min (also 20 L) samples




are collected over a 2 hr sampling period.  The first set is analyzed as a



"range finder."  If adequate amounts of the material of interest are found,



then the other five sets are also analyzed in an identical manner.  In




some instances only three sets of tubes are analyzed, and the others are



retained temporarily as possible backup samples.  In the event that the first




analysis detects no compound of interest, the remaining five sets are desorbed



and recollected onto one Tenax tube.  Subsequent analysis of that tube gives an



effective detection limit five times as low as the single set analysis.








     The analysis procedure used with the VOST consists of heat desorption



of the Tenax tubes into a small water vessel, followed by EPA Method 624



analysis of the water trap.  EPA Method 624 is a purge and trap procedure

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followed by gas chromatography/mass spectrometry.  The water trap is



included since the Tenax  cartridges are often very wet and cause problems




if desorbed directly into the gas chromatography column.  Several attempts



have been made to improve this part of the procedure, but none have




succeeded as yet.








     For further details concerning operation of the VOST or the associated




analysis system, see References 2, 3, and 4.








Initial Laboratory Studies








     The first laboratory evaluation of the VOST system was assigned to



Midwest Research Institute.  A synthetic gas generation system was constructed



which was capable of producing gas streams fortified with appropriate levels



of test compounds.  The compounds chosen for evaluation were vinyl chloride,



carbon tetrachloride, trichloroethylene, and chlorobenzene.  The concentration




levels tested were 0.1, 10, and 100 ug/L.  A series of 10 test runs were made.



The test matrix included runs at each of the four concentration levels, repli-




cate tests at one level, blanks, and a run where the gas included HC1.  The



HC1 run was included since many incinerator emissions contain this compound.



Three trains sampled the gas manifold system during each run.  The average




results from three trains from the experimental series are summarized in Table 1.



The single pair data was derived from analysis of individual pairs of cartridges,



one Tenax and one Tenax/charcoal.  The combined pairs data results from desorption,



recollection, and subsequent analysis of multiple pairs following the procedure




described earlier.  No combined pairs experiments were carried out at the higher

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concentration levels since that mode of operation was designed for low




concentrations.  The combined pairs data appears to exhibit somewhat less



deviation from the desired results, but most of the recoveries fall within




± 50Z.  It is important to note that the presence of HC1 did not produce



a significant effect in the recovery levels of the organics tested.  Some



of the variability in the carbon tetrachloride results  is believed to be



due to blank variability which was improved for later applications by better




cleaning, storage, and handling procedures.  Vinyl chloride is quite diffi-



cult to handle because of its very low boiling point, and some of the data



presented in Reference 3 indicates breakthrough of the compound at higher



concentration levels.  The major conclusion from the first VOST laboratory



study was that the concept was sound and that the train and subsequent analysis



procedures were capable of producing the data for which they had been



designed.  Further details of the laboratory study are presented in References



3 and 4.








Initial Field Application








     Immediately upon completion of the laboratory study, Midwest Research



Institute was faced with field application of the train as part of an



engineering study for EPA's Industrial Environment Research Laboratory -




Cincinnati in support of the  Office of Solid Waste.  The train was repackaged



into a more compact and rugged arrangement and taken to the field.  Diffi-



culties were encountered on the earliest jobs in this series, primarily



from high blanks and field contamination.  These were soon brought under



control, but certainly made the point that sampling very low concentrations



of volatile organics in contaminated surroundings can be very

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difficult indeed.  Severe contamination was encountered with bag samples




as well, and the conclusion is clear that adequate field blanks are just



as necessary with bag sampling as with VOST.








     D'-rir»R the first series of field tests of the VOST, the equipment was



also operated at two different sampling rates, and two different total




volumes were collected.  The low flow rate operation was designated "Slow



VOST" and collected 5 L of gas at 250 mL/min.  The stack concentrations




obtained by the two methods compared very favorably for carbon tetrachloride,



chloroform, and tetrachloroethylene.  The results for trichloroethylene



were less definitive (4).  Comparability of "Slow VOST" and the original



VOST operating procedure is important because it shows that breakthrough



is generally not occurring and that the equipment may be operated successfully




in more than one mode.








Further Evaluation of the VOST







     The next major project to utilize the VOST was that of emissions



testing for the incinerator ship Vulcanus II.  This project is described



in References 5 and 6.  The VOST used in this project employed the inside-



inside cartridge design, and was constructed for Radian Corporation (formerly



TRW Corporation), Research  Triangle Park (RTF), by Nutech Corp., RTF, NC.  The




inside-inside (I/I) cartridge differs from the inside-outside (I/O) cartridge



in that the ends of the glass tube are drawn down to 4.2 mm (1/4-in.) in order




to accommodate gas chromatography ferrules.  During the heat desorption phase



of the analysis, purge gases travel only through the inside of the I/I cartridge



but flow over as well as through the I/O tube.

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     Prior to application of the VOST to the Vulcanus II project, Radian



Corporation (formerly TRW Corporation) carried out a laboratory evaluation not



unlike that earlier performed by Midwest Research Institute.  A synthetic



gas stream was generated, and sampled by the I/I style VOST.  The data in




Table 2 is derived from the more detailed results given in Reference 5.



It may readily be observed that the precision, and probably the accuracy,



of this data is improved over that given in Table 1.  The two reasons that




seem to best explain the improvement are that much had been learned about control




of contamination and blanks, and that perhaps the I/I design was inherently more




resistant to contamination.








     At any rate, the data in Table 2 strongly supports the conclusion of the



initial laboratory study, that the VOST concept is sound and will perform



as originally intended.








     The first known application of the VOST to sampling highly water soluble



compounds was carried out by EPA's Industrial Environmental Research Laboratory



at RTP.  The VOST was used to sample methyl vinyl ketone and tetrahydrofuran



emissions from a pilot-scale fluidized-bed combustor.  This particular VOST



was of the I/O type and was constructed for EPA by Envirodyne Engineers following



the Midwest Research Institute design.  In theory, highly water 'soluble compounds




are more likely to penetrate the first sorbent cartridge and be found in either



the condensate or the second sorbent cartridge.  It is necessary to perform



spiking and recovery experiments in order to determine whether the compounds



of interest may be analyzed by the purge and trap method.  In the event they



are not, some other method (such as direct injection or high performance liquid




chromatography) will be necessary for analysis of the condensate.

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     In the project described above, the two compounds of interest were both




quantitatively recovered by a slightly modified version of the purge procedure.



Longer purge times were used, but total volume was kept the same in order to




avo?d breaVthrough.  The two compounds were found primarily on the first sorbent



cartridge in spite of their relatively high water solubility.  All equipment



and procedures appeared to work well even though this was the EPA crew's first




experience with it (7).








Current Status








     The VOST is now available commercially, and ownership and field experience



have become more widely spread.  Most of the experience has still been with



respect to the more "popular" incineration related compounds such as those listed



in Tables 1 and 2.  The general consensus from users of the train is that it




works well in the field and yields good results when used with adequate care and



precautions.








     Reference 2 is now available to users of the train and those reviewing



incinerator sampling plans.








     A validation program for VOST is underway and is being managed by EPA's



Environmental Monitoring Systems Laboratory at RTF.  Audit gas cylinders have




been prepared and are available from the same laboratory.  A number of other



VOST related research programs are near completion and should provide additional




insight into the limitations of the train.
                                      8

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Summary








     Laboratory experiments and field experience to date have led to the



following conclusions.




     1.  The VOST concept is sound:  the train performs well in the




         field and yields good results in the hands of careful and experienced




         operators.








     2.  Sampling and analysis of low concentrations of organics in the



         presence of high levels of contamination is very difficult.




         Strong and well planned quality control is essential.








     3.  Both the I/O and I/I designs are capable of producing good results



         if proper precautions are taken.








     4.  Sampling and analysis of water soluble organics may not be as



         difficult as feared, but this area stills needs exploration.








     It appears that the VOST is a generally useful and flexible piece  of



equipment which will be valuable for other sources in addition to incinerators.

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          TABLE 1.  VOST Recovery Efficiencies,  Initial  Studies



                                             Z  Recovery
Expec ted ,
Combined Pairs



Single Pairs





ng/L
0.1
1.0
1.0
1.0*
0.1
1.0
1.0
1.0*
10
100
vinyl
chloride
111
48
146
79
79
63
85
95
142
43
carbon
tetrachloride
176
88
113
110
221
47
55
40
70
108
trichlorethylene
97
108
105
105
79
116
115
95
109
132

104
131
115
96
95
153
105
90
106
101
*Included HC1
                                         10

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          TABLE 2, VOST Recovery Efficiencies, Further Studies
Compound                 Expected Value, ng/L          % Recovery




1, 1 dichlorethane               54                        105



                                 77                         90




chloroform                       69                        147



                                118                         98




1, 2 dichlorethane               77                         95



                                 80                         98




carbon tetrachloride             73                         91



                                 74                         70




trichloroethylene                67                         99



                                 96                         97




1, 1, 2 trichloroethane          66                         78



                                 94                         68



                                 75                        120




tetrachloroethylene             107                        105
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                               REFERENCES
1.   Harris, J.C., Larsen, D.J., Rechsteiner, C.E., and Thrun, R.E.fi
     "Sampling and Analysis Methods for Hazardous Waste Combustion,"
     EPA-600/8-84-002, PB84-155845, February 1984.

2.   Hansen, E. M., "Protocol for the Collection and Analysis of Volatile
     POHCs Using VOST," EPA-600/8-84-007, PB84-170042, March 1984.

3.   Jungclaus, G. A., Gorman, P.G., Vaughn, G., Scheil, G.W., Bergman,
     F.J., Johnson, L.D., and Friedman, D., "Development of a Volatile
     Organic Sampling Train (VOST), " Presented at Ninth Annual Research
     Symposium on Land Disposal, Incineration, and Treatment of Hazardous
     Waste, Ft. Mitchell, KY, May 1983.

4.   Jungclaus, G.A., Gorman, P.G., and Bergman, F.J., "Sampling and Analysis
     of Incineration Effluents with the Volatile Organic Sampling Train (VOST),"
     In Proceedings: National Symposium on Recent Advances in Pollutant
     Monitoring of Ambient Air and Stationary Sources, Raleigh, NC, May 1983,
     EPA-600/9-84-001, January 1984.

5.   Ackerman, D.G., Beimer, R.G., and McGaughey, J.F., "Incineration of
     Volatile Organic Compounds on the M/T VULCANUS II, TRW Inc., Energy
     and Environmental Division, Redondo Beach, CA.  Report to Chemical
     Waste Management, Inc., Oak Brook, IL.  April 1983.

6.   Ackerman, D.G., McGaughey, J.F., Wagoner, D.E., and VanderVelde, G.,
     "Emissions Testing Onboard the Incinerator Ship Vulcanus II Using A
     Volatile Organic Sampling Train, " Presented at Symposium on Organic
     Emissions from Combustion, 187th National Meeting of the American
     Chemical Society, St. Louis, MO. April 1984.

7.   Merrill, R.G., U.S. Environmental Protection Agency, Industrial
     Environmental Research Laboratory, Research Triangle Park, personal
     communication.

                                        12

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             Htottd Probt
 Gloss Woo!
 Porficulafe
 Filter x
   STACK
(or test System)
Isolation Valves
      -Carbon Filter
                    ••Thermocouple
                    Sorbent
                    Cartridge
                Condensote
               Trap Impinger
                  Backup
                  Sorbent
                  Cartridge
                                           Silica Gel
                                                     Vacuum
                                                     Indicator
                                                   (y}
                             ^=r7=p^=
                             \r\=f  T  T
                                                        Pump
                                                     Rofometer
Dry Gat
 Meter
                                 FIGURE I
                               SCHEMATIC OF
                       VOLATILE ORGANIC SAMPLING TRAIN
                                  (VOST)

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