United States
                    Environmental Protection
                    Agency
Municipal Environmental Research  ^
Laboratory                     -
Cincinnati OH 45268             "^
                    Research and Development
EPA-600/S2-84-013 Mar. 1984
&ER&          Project  Summary
                    Determination  of  Dioxin  Levels
                    in  Carbon  Reactivation  Process
                    Effluent  Streams
                    J. E. Howes, Jr., F. L DeRoos, D. Aichele, D.F. Kohler, M.E. Larson, and B.W.
                    Lykins, Jr.
                     A preliminary study  was made  to
                    evaluate the potential formation and
                    persistence of tetrachlorodibenzo-p-
                    dioxins (TCDDs) and tetrachlorodibenzo
                    furans (TCDFs) in effluent streams  of
                    the fluidized bed system used at the
                    Cincinnati, Ohio Waterworks for thermal
                    reactivation of granular activated
                    carbon (GAC). The study resulted from
                    concern about possible releases  of
                    adsorbed organic compounds or their
                    reaction products into the environment
                    during reactivation of the GAC used for
                    treating municipal drinking water.
                     Four tests were performed to sample
                    the effluent streams of the reactivator
                    system and the spent carbon feedstock
                    during reactivation of a batch of GAC
                    used to treat Cincinnati municipal
                    drinking water. During one test, the
                    natural  gas supply to the reactivation
                    system was sampled for polychlorinated
                    biphenyls (PCBs). The effluent stream
                    and spent carbon feed samples were
                    analyzed to determine (1) 2,3.7,8-
                    TCDD and 2,3,7,8-TCDF concentra-
                    tions, (2) total TCDD and TCDF con-
                    centrations,  and (3) the TCDD and
                    TCDF isomeric composition (i.e., the
                    number and, when possible, the identity
                    of isomers in the samples).
                     This Project Summary was developed
                    by EPA's Municipal Environmental
                    Research Laboratory, Cincinnati. OH,
                    to announce key findings of the research
                    project  that is fully documented in a
                    separate report of the same title (see
                    Project Report ordering information at
                    back).

                    Introduction
                     Activated carbon has  been used for
                    many years to  remove taste and odor
components from drinking water. Recent
studies have focused on activated carbon
treatment to remove potentially hazardous
trace organics from municipal  drinking
water supplies. In  this regard, the
Cincinnati Waterworks conducted a
study of water treatment with granular
activated carbon (GAC). After exhaustion,
this carbon was thermally reactivated in a
fluidized-bed furnace and reused in the
water treatment process. During carbon
reactivation, organic compounds could be
released into effluent streams that enter
the environment. Thus the total evaluation
of the  net gains achieved by water
treatment with GAC included an examina-
tion of the potential for causing exposure
to the  public from the reactivation
process effluents.
  This  program was  undertaken to
determine whether tetrachlorodibenzo-
p-dioxins (TCDDs) and tetrachlorodibenzo
furans  (TCDFs) were in any  effluent
streams from the Cincinnati Waterworks
reactivator unit during a carbon reactiva-
tion cycle. The study also evaluated the
possible presence of TCDDs and TCDFs in
the spent carbon feedstock and PCBs in
the natural gas supply used to fire
the carbon reactivator system. The data
generated will be used to evaluate any
possible environmental and health
hazards associated -with effluents from
reactivation of carbon used in municipal
water treatment.

Procedures
  Four tests were performed to measure
TCDD and TCDF levels in the  effluent
streams and the spent carbon feedstock
of the Cincinnati Waterworks carbon
reactivation system (shown schematically
in Figure 1). The tests were conducted

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 Spent Carbon
 Storage Tank
         Spent
         Carbon
         Feed
  Reactivated
   Carbon
 Storage Tank
                                                                                                        Exhaust
                                                                                                         Stack
                                                                                                              
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(XAD-2) sample from one test. The total
TCDD concentrations found in the stack
emissions (particulate material and gase-
ous emissions) ranged from 0.06 to 0.3
nanograms per dry, standard cubic meter
(ng/dscm), and emission factors ranged
from 0.49 to 1.11 ng total TCDDs/kg of
spent carbon feed. TCDDs were detected
in the  dryer  off-gas cyclone catch
samples from all four tests and in the
scrubber liquid samples from  two of the
four tests. The total TCDD concentrations
found in the cyclone catch ranged from
0.20 to 4.14 ng/g. TCDDs at concentra-
tions of 0.12 and 0.21 ng/L werefound in
the scrubber water from two tests.
  Effluent streams in which TCDFs were
detected were the stack emission and the
dryer off-gas cyclone catch. TCDFs were
not detected in any  scrubber water,
quench water, or spent carbon  feed
samples from the four tests. TCDFs were
detected in  stack particulate samples
from three tests and in the vapor phase
(XAD-2) samples from two tests. The total
TCDF concentrations found in the stack
emissions  (particulate material and
gaseous emissions) ranged from 0.08 to
0.51 ng/dscm,  and emission factors
ranged from  0.28 to  1.88 ng total
TCDFs/kg of spent carbon feed. TCDFs
were detected in the dryer off-gas cyclone
catch from all four tests at concentrations
ranging from  0.48 to  3.33 ng  total
TCDFs/g.
  The principal TCDD  isomers found in
the samples were 1,3,6,8-TCDD, 1,3,7,
8-TCDD, 1,3,7,9-TCDD, and 2,3,7,8-
TCDD.  Some samples contained other
unidentified TCDD  isomers, but  they
were present at very low levels relative to
the isomers listed above. When present,
2,3,7,8-TCDF was identified; but other
TCDF isomers could not be specifically
identified because of lack of suitable
reference standards.
  PCBs at a concentration of  2.6 micro-
grams per standard cubic meter (/ug/scm)
were found in the natural gas supply used
to fire  the  reactivation unit during the
tests. The principal PCBs detected in the
natural gas were tri- and tetrachlorobi-
phenyls.
  Reactivated carbon and spent carbon
samples obtained during the test program
and a sample of virgin carbon  of the type
being reactivated were analyzed for total
organic halogens (TOX). The TOX levels
found in the samples were as follows:
    Virgin carbon 	  None detected
    Spent carbon 	 657 mg/kg
    Reactivated carbon	55 mg/kg
  The  full report was submitted  in
fulfillment of Contract No. 68-02-3487 by
Battelle Columbus Laboratories under
the sponsorship of the U.S. Environmental
Protection Agency.
   J. E. Howes, Jr.. F. L DeRoos, D. Aichele, D. F. Kohler, and M. E, Larson are with
     Battelle-Columbus Laboratories, Columbus, OH 43201.
   Ben W. Lykins, Jr. is the EPA Project Officer (see below).
   The complete report, entitled "Determination ofDioxin Levels in Carbon Reactiva-
     tion Process Effluent Streams," (Order No. PB 84-137 710; Cost: $14.50.
     subject to change) will be available only from:
          National Technical Information Service
          5285 Port Royal Road
          Springfield, VA 22161
          Telephone: 703-487-4650
   The EPA Project Officer can be contacted at:
          Municipal Environmental Research Laboratory
          U.S. Environmental Protection Agency
          Cincinnati,  OH 45268
                                     U.S. GOVERNMENT PRINTING OFFICE; 1984 — 759-015/7602

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