United States
                   Environmental Protection
                   Agency
Water Engineering
Research Laboratory
Cincinnati OH 45268
                    Research and Development
EPA/600/S2-87/006 Apr. 1987
oEPA         Project Summary
                   Alternative  Disinfectants  and
                   Granular  Activated  Carbon
                   Effects  on  Trace  Organic
                   Contaminants

                   Wayne E. Koffskey and Benjamin W. Lykins, Jr.
                     A study was conducted to evaluate
                    the effects of alternative disinfectants
                    on drinking water quality at Jefferson
                    Parish, Louisiana, and the  ability of
                    granular activated carbon (GAC) to re-
                    move disinfection byproducts and
                    specific organic compounds. Bacterio-
                    logical information was collected on
                    the influent and  effluent of  sand and
                    GAC columns.
                     Four parallel pilot-column process
                    streams were dosed with a different
                    disinfectant (ozone, chlorine dioxide,
                    monochloramine, and chlorine) and
                    compared  with  a fifth pilot-column
                    stream that was  not disinfected. After
                    30 minutes of disinfectant contact time,
                    the water in each process stream was
                    passed through parallel sand, GAC, and
                    duplicate GAC filters, each with 20 min-
                    utes of empty bed contact time (EBCT).
                    Samples collected from each process
                    stream were analyzed for total organic
                    carbon (TOC), total  organic  halide
                    (TOX), 10 volatile organics, 65 solvent-
                    extractable hydrocarbons, 26  chlori-
                    nated hydrocarbon insecticides, hetero-
                    trophic plate count (HPC),  total
                    coliforms, and dissolved oxygen. To
                    simulate distribution  conditions, ali-
                    quots of each column effluent were
                    dosed with monochloramine and free
                    chlorine and analyzed  for TOX and 10
                    volatile organics after storage for
                    5 days at river water temperature.
                     The process train that yielded the
                    least dissolved organic contaminants
                    was predisinfection with ozone fol-
                    lowed by GAC filtration and postdisin-
                    fection with monochloramine.
  This Project Summary was devel-
oped by EPA's Water Engineering Re-
search 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
  The Mississippi River along with its
tributaries drains nearly two-thirds of
the continental United States and sup-
plies a source of drinking water to many
cities located along its banks, including
Jefferson Parish. The waters of the Mis-
sissippi River and its tributaries also re-
ceive vast quantities  of industrial and
municipal wastes as well as agricultural
run-off that create various levels (ng/L)
of trace organic contamination. In addi-
tion, significantly higher levels (mj/L) of
organic contamination form when chlo-
rine is used in disinfection. Therefore, a
research project, funded jointly by the
U.S. Environmental Protection Agency
(EPA)  and Jefferson  Parish, was ini-
tiated to determine the effect of apply-
ing various disinfectants (ozone, chlo-
rine dioxide, monochloramine, and
chlorine) to clarified and filtered water
followed by GAC adsorption.

Pilot-Column Plant
  At the raw water intake of Jefferson
Parish (located on the east bank above
the mouth of the Mississippi River), raw
water is pumped to four separate treat-
ment plants. Nondisinfected clarified
water was applied to  the pilot-column

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plant by the Permutit III plant (Figure 1).
  Raw river water was clarified with di-
allyldimethylammonium chloride and/
or dimethylamine type cationic poly-
mers  and fluoridated with fluosilicic
acid before entering  the  pilot-column
system.  The clarified water was then fil-
tered through one of two pressure sand
filters and divided into five process
streams.
  Each disinfected process stream con-
sisted of a 30-minute disinfectant con-
tact chamber followed by parallel filtra-
tion through a sand column,  a  GAC
column, and a duplicate GAC column.
The duplicate column was used to de-
termine variability  between GAC
columns  within the same process
stream.  The configuration of the non-
disinfected process stream was identi-
cal to that of the disinfected process
streams except that the disinfectant
contact  chamber was eliminated.
  All  materials used to construct the
pilot-column system (pumps, pressure
sand filters, plumbing, contact cham-
bers, and columns) were composed of
stainless steel, teflon, or  glass. Plastic
flow totalizers were installed at the end
of each  process stream, but all samples
were taken upstream. Each pilot column
was constructed from  6-in.  ID x 10-ft
glass pipe with 150 Ib/in.2 stainless steel
flange ends and a teflon/stainless steel
screen underdrain. The pilot columns
  were charged with 6.8 ft of either sand
  or GAC media  to  obtain a 20-minute
  EBCT with a flow of 0.5 gpm.
    Each disinfectant contact chamber
  was constructed  from 12.75-in. OD
  (0.18-in. wall) stainless steel pipe with
  stainless  steel blind flanged or capped
  ends. The chlorine  dioxide, monochlor-
  amine, and chlorine contact chambers
  were 10 ft in height in order to produce
  30 minutes of disinfectant contact time
  with a flow of 2 gpm. The ozone contact
  chamber was 11  ft in  height and de-
  signed for countercurrent operation
  with the water entering at the top of the
  contact chamber  and  the  ozone gas
  stream entering on the bottom.  The
  water and ozone gas influent lines were
  oriented  such  that the influent water
  would be in contact with the ozone gas
  stream for 30 minutes. Ozone gas exit-
  ing the contact chamber was reduced
  by passage through a heated pelletized
  nickel oxide column to prevent conden-
  sation.
    Ozone  was generated from com-
  pressed dry air using  an  electrically
  powered  ozone  generator with a maxi-
  mum output capacity of 0.25 Ib/day.
  Chlorine  dioxide was generated using
  two solutions, one containing sodium
  chlorite and sodium hypochlorite  and
  the other containing sulfuric acid.
  Adding a  50% excess of sulfuric acid ad-
  justed the pH of the final solution to 4.
                            i— Cationic Polymer

                                 Fluosilicic Acid
          Mississippi River
          Mile 105.4 AMP
                    Chloramines


                        Filtration
            Regenerative
Permutit III      Turbine
 Clarifier       Pumps
ted -
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Cont
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Chlorine -*l
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                                                         Pressure Sand Filters
                                                          Legend

                                                           cm- GAC
                                                              1- Sand
                             to Waste

 Figure 1.    Pilot-column system flow schematic

                                  2
These two solutions were pumped tc
gether and received in-line mixing in
small generating tower constructed c
teflon shavings and glass. All  compc
nents that came into contact with chic
rine dioxide  were made of teflon o
glass. This method generated a 96°/
yield of chlorine dioxide. Chlorine ga
was fed to both the monochloramim
and chlorine process streams usini
teflon eductors. Ammonia was added ii
the form of an ammonium hydroxidi
solution by pumping  into the chlo
ramine  process  stream ahead of  thi
chlorine eductor.

Disinfectant Effectiveness
  After 30 minutes, ozone residuals av
eraged 0.5 mg/L as O3 and  chlorine
dioxide 0.5 mg/L as CI02. The  average
30-minute  residual for chlorite was
slightly higher than that of  chlorine
dioxide at 0.6 mg/L as CI02. Essentiallv
all of the chlorite resulted from the re
duction  of chlorine dioxide during  the
30-minute contact period. This  was  de-
termined by data generated from the
chlorine dioxide demand analyses per-
formed in a batch mode using deionized
carbon filtered water and nondisin-
fected pilot-column influent water. The
average concentrations of chlorine
dioxide  constituents in deionized car-
bon filtered water were 1.6 mg/L CI02,
0.0 mg/L CIO2, 0.2 mg/L CI2, 0.1  mg/L
NH2CI, and 0.1 mg/L NHCI2. Those resid-
uals observed after 30 minutes of con-
tact time with the influent water of the
pilot  column were 0.7 mg/L CIO2,
0.6 mg/L CIO2, 0.1  mg/L CI2, 0.2  mg/L
NH2CI, and 0.1 mg/L NHCI2. An  average
chlorine dioxide demand of 0.9 mg/L as
CIO2 was seen with 0.6 mg/L or 67% re-
duced to chlorite.
  Thirty-minute monochloramine resid-
ual averaged  2.1 mg/L as NH2CI or 1.4
mg/L  as CI2.  A dichloramine residual
was also observed averaging 0.4 mg/L
as NHCI2. The average 30-minute chlo-
rine residual  for the chlorine  process
stream was 1.0 mg/L as CI2 with  an aver-
age monochlorine residual of 0.2 mg/L
as NH2CI and an average dichloramine
residual of 0.3 mg/L as NHCI2. The pres-
ence of 0.1 to 0.2 mg/L of naturally  oc-
curring  ammonia nitrogen produced
chloramines.
  After 30 minutes of disinfectant con-
tact time, ozone exhibited the highest
level of disinfection followed by chlo-
rine dioxide and chlorine whereas
monochloramine was somewhat less
effective.  Chlorine dioxide, chlorine,
and monochloramine became equallv

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effective after filtration through the
sand columns. As  ozonated  water
passed through the sand column, the
geometric mean for the HPC rose from 8
to 4594 CFU/mL,  indicating  a biologi-
cally activated sand column. Whereas
the geometric means for the HPC in-
creased across the sand columns for all
of the disinfected process streams, it de-
creased for the nondisinfected process
stream. Because each disinfectant be-
came ineffective in the first  portion  of
each GAC column, the geometric mean
of the HPC in the effluent of each disin-
fected GAC column increased to  a level
similar to that observed for the nondis-
infected  influent water of  the pilot-
column system. Most of the colonies
picked from the  heterotrophic  plates
were gram positive. Of the gram nega-
tive  bacteria identified, Pseudomonas,
Alcaligenes, Moraxella, and Acineto-
bacter calcoaceticas were  observed
most frequently. Some positive col-
iforms were observed, especially at the
beginning of the study.
Organic Products
  TOC and TOX surrogates were evalu-
ated during  this study. After  30-minute
disinfection  contact time, average TOC
concentrations were 3.3, 3.0, 3.3, 3.4,
and 3.3 mg/L for nondisinfected,  ozone,
chlorine dioxide, monochloramine, and
chlorine,  respectively. After sand filtra-
tion, the ozone stream  showed a 0.5
mg/L concentration reduction. The TOC
concentrations of the other streams
were comparable to  their influent val-
ues. GAC effluent concentrations  at
steady state (180  days) were 2.7 mg/L
TOC for all  disinfection  streams exept
ozone (2.2 mg/L).
  Average instantaneous TOX concen-
trations  after  30-minute disinfectant
contact time were 25, 15, 85, 117, and
263  ng/L for  nondisinfected, ozone,
chlorine dioxide, monochloramine, and
chlorine,  respectively. TOX byproducts
were formed after disinfectant addition
except for the  ozonated stream,  where
an average 10 (xg/L reduction  was seen.
Instantaneous TOX concentrations  in
the sand column  effluents were com-
parable to their respective  influents.
GAC effluent instantaneous  TOX con-
centrations were influenced by the
amount applied to the columns. Higher
influent produced higher effluent con-
centrations.
  Flame ionization detection  and elec-
tron  capture chromatograms provided
an overall indication of the effect of
using various disinfectants. Compared
to nondisinfected  water, chlorination
produced the most peaks followed by
chloramination, chlorine dioxide, and
ozone. (Figures 2 and 3).
  For the volatile organics detected (tri-
halomethanes,  1,2-dichloroethane,
dichloromethane, trichloroethylene,
1,1,2-trichloroethane, and carbon tetra-
chloride), only the trihalomethanes
were affected by disinfection. Average
trihalomethane concentrations after 30
minutes of contact time were 1,  1, 1,4,
and 34 g/L for nondisinfected,  ozone,
chlorine dioxide, monochloramine, and
chlorine, respectively. GAC removed
the trihalomethanes formed by  chlori-
nation  for about 60 days until  break-
through and for about 80 days for those
formed by chloramination.
  The nonvolatile organics identified in
the pilot system influent consisted of 28
chlorinated hydrocarbons, 16 alkylben-
zenes, 8 alkanes,  7  phthalates,
6 chlorobenzenes, 3  nitrobenzenes,
2 alkylaldehydes,  tributylphosphate,
triphenylmethane,  4-nonylphenol, and
d-fenchone.
                                     The herbicide atrazine and the insecti-
                                   cide alachlor were present in the influ-
                                   ent to the pilot system throughout the
                                   study. Influent atrazine concentrations
                                   ranged from 23 to 249 ng/L with an aver-
                                   age of 80 ng/L.  The influent atrazine
                                   concentration was not affected by chlo-
                                   rine dioxide,  chloramine, or chlorine
                                   disinfection. Compared with the nondis-
                                   infected influent, however, ozonation
                                   removed  an  average of 83% of the
                                   atrazine. Alachlor levels in the nondisin-
                                   fected influent  of the  pilot column
                                   ranged from 13 to 593 ng/L with an aver-
                                   age of 127 ng/L. Alachlor was also unaf-
                                   fected by chlorine dioxide, chloramine,
                                   or chlorine disinfection, but its concen-
                                   tration was reduced an average of 84%
                                   by ozonation.
                                     Other chlorinated hydrocarbon insec-
                                   ticides (CHIs) were evaluated as a total
                                   sum of all the individual CHIs monitored
                                   during the study except atrazine and
                                   alachlor. The total CHI concentration in
                                   the nondisinfected influent ranged from
                                   18 to 88 ng/L with an annual average of
                                   36 ng/L. The concentration of these sub-
  Nondis-
  infected
                      -JUUU-
  Chlorine
  Dioxide
                                 JLJ,
                                        jJLl
                                                                   I
                                                                  JUX
  Chlorine
                                                              -I	1	1	3
Figure 2.   Flame ionization GC profiles after idsinfeciton (runday 87).
 Ozone

Chlorine
         dULJL
   Mono-
  chloramine
   Chlorine
Figure 3.    Electron capture GC profiles after disinfection frunday 87).

                                      3

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  stances was unchanged after disinfec-
  tion except for ozonation,  which pro-
  duced an average total CHI reduction of
  57%.
    The total alkylbenzene concentration
  in the nondisinfected influent ranged
  from 59 to  10,300 ng/L with an average
  of 590 ng/L. Thirty minutes of disinfec-
  tant contact time with chlorine dioxide,
  chloramine, and free chlorine produced
  an  increase in the total  alkylbenzene
  concentration  of 11%, 14%, and  100%,
  respectively.  Treatment with ozone,
  however,  reduced the total alkylben-
  zene  concentration by 52%. The total
  alkane concentration  in the nondisin-
  fected influent averaged 50 ng/L with a
  range of 10 to 150 ng/L. Ozonation re-
  duced the  concentratio'n  of the total
  alkanes by an average of 35%. Addition
  of the other disinfectants  had  no effect
  on the total alkane concentration.
    The total phthalate concentrations  in
  the nondisinfected influent ranged from
  70 to 470 ng/L with an average  of 180
  ng/L. Ozonation produced  an average
  total phthalate reduction of 1 1 %. No sig-
  nificant changes in total phthalate levels
  occurred  for  the  other disinfectants.
  Total chlorobenzene concentrations  in
  the nondisinfected influent ranged from
  4 to  304 ng/L with an average  of 100
  ng/L. Nitrobenzene concentrations
  ranged from a minimum of 0.1 ng/L for
  2-nitrotoluene to 260 |o.g/L for 2,4-
  dinitrotoluene. Ozonation  produced an
  average of 68% concentration reduction
  for total chlorobenzene and 61% for
  total nitrobenzene. Conversely,  chlori-
  nation resulted in a 75% increase  in total
  chlorobenzene and a 43% increase  in
  total nitrobenzene.
     Two  alkylaldehydes, octanal and
  nonanal, were quantified. The total con-
       the nondisinfected influent ranged from
       below detection (<0.1 ng/L) to 37  ng/L
       with  an average of 14.4 ng/L. An aver-
       age uniform increase in the total alkyl-
       aldehyde of 144% was observed in the
       ozonation system, whereas a relatively
       nonuniform increase of  56%  occurred
       for the chlorine system relative to the
       nondisinfected influent. No significant
       changes  in the concentration  of total
       chlorobenzene, total nitrobenzene, and
       the alkylaldehydes were noted for the
       other disinfectants.
         Sand filtration had some effect on the
       total alkylbenzenes, total phthalates,
       total chlorobenzenes, and total alkyl-
       aldehydes, with lower concentrations in
       the effluent as compared to the influent.
       On the average, GAC removed me cnio-
       rinated hydrocarbons 90% to 97%, total
       alkylbenzenes 40% to 45%, total alkanes
       44%  to 52%, total chlorobenzenes  93%
       to 96%, and total nitrobenzenes 81% to
92% for the 1-year operational period
The removal of total phthalates by GAC
averaged  44% to 50% for about 25C
days before the ozonated stream brokt
through.
  Ozone appears to be the disinfectan
of choice because lower concentration:
of organics were detected during it:
use. More research is needed, however
to understand what happens to the or
ganics after ozonation. Are these organ
ics  oxidized  and  destroyed;  are the^
converted  to other organics that are
more biodegradable; are  they more
water soluble and not extractable, mak
ing  them difficult to detect?
  The full report was submitted in par
tial  fulfillment of Cooperative Agree
ment No. C8806925 by Jefferson Parish
Louisiana,  Department of Public Utili
ties, under the sponsorship of U.S. Envi
ronmental Protection Agency.
          Wayne E. Koffskey is with the Parish Department of Public Utilities, Jefferson.
           LA  70121- the EPA author Benjamin W. Lykins. Jr., (also the EPA Project
           Officer,  see below) is  with the  Water Engineering Research Laboratory,
           Cincinnati, OH 45268.
          The complete report, entitled "Alternative Disinfectants and Granular Activated
           Carbon Effects on Trace Organic Contaminants," (Order No, PB 87-146 700/
           AS; Cost: $24.95, 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:
                 Water Engineering Research Laboratory
                 U.S. Environmental Protection Agency
                 Cincinnati, OH 45268
           t u  iicae twu
                          i launmi rl.
United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
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EPA/600/S2-87/006
                                0169064
                                                          It    60604

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