United States
                             Environmental Protection
                             Agency
                                 Solid Waste and
                                 Emergency Response
                                 (5102W)
                                 EPA-542-N-94-009
                                 December 1994
                                 Issue No. 10
 SPONGE  TECHNOLOGY  FOR GROUND  WATER
 TREATMENT  OF  METALS
 By Carolyn Esposito, EPA Risk Reduction Engineering Laboratory
 The Dynaphore, Inc Forager™    process streams and acid mine
 Sponge is an open-celled
•cellulose sponge incorporating --
 an amine-containing chelating
 polymer that has selective
 affinity for dissolved heavy
 metals in both cationic and
 anionic states. Through the
 EPA'sSITE(Superfiind
 Innovative Technology
 Evaluation) Program, die ability
 of this technology to remove
 heavy-metals from  contami-
 nated ground water was
 evaluated at the NL Industries,
 Inc. site in Pedricktown, New
 Jersey. The technology effec-
 tively achieved a 97% removal of
 copper and lead from average
 influent concentrations of 917
 micrograms per liter (|Jg/l) and
 578 Hg/1, respectively. There
 was 90% removal of cadmium
 from influent concentrations of
 537|Jg/l. The Forager™
 Sponge can also be utilized to
 remove and concentrate heavy
 metals from a wide variety of
 other contaminated aqueous
 media such as surface water,
 landfill leachate and industrial
 effluents. According to the
 developer, the Sponge can
 scavenge metals in concentration
 levels of parts per million and
 parts per billion from industrial
 discharges, municipal sewage,
 drainage.
— Here's how the Sponge works.
 The Sponge is highly porous,
 thereby promoting high rates of
 absorption of ions. The
 polymer in the Sponge provides
 ligand sites that surround the
 metals to form complexes,
 especially with ions of transition-
 group heavy metals.  The ability
 of the Sponge to preferentially
 bind toxic heavy metals is
 particularly beneficial for the
 treatment of contaminated
 natural waters and has advan-
 tages over conventional ion
 exchange or precipitation
 technologies where valuable ion
 exchange sites or chemicals are
 wasted because they also remove
 cations such as calcium,
 magnesium, aluminum, sodium
 and potassium. The Forager™
 Sponge's low affinity for these
 cations allows these ions, for the
 most part, to pass through the
 system, enabling greater
 absorption of toxic heavy metals.
 The extent of the affinity of the
 polymer for metals is influenced
 by solution parameters such as
 pH, temperature and total ionic
 content. Absorbed ions can be
 removed from the Sponge by
 techniques typically employed
 for regeneration of ion exchange
resins, after which the Sponge
can be reused. Alternatively, the
Sponge can be compacted for
disposal or can be incinerated.
 The Sponge can be used in
columns, fishnet-type enclosures
or rotating drums. For the NL
demonstration, Sponge cubes
were confined in a fishnet taig in
a series of four columns.
Ground water was pumped
through a series of four colunms
at a treatment flow-rate of oiie
gallon per minute or 0.08 bed
volumes per minute. The
columns were situated on a
trailer-mounted unit which
included a water heater to raise
the influent temperature by:
approximately 25 degrees
Fahrenheit to increase reaction
rates. Four columns were
reportedly needed to provide
sufficient path length to meet
the demonstration treatment
goals. Although the developer
had anticipated that replacement
or regeneration of the columns
would not be necessary, some of
the columns became saturated
with cadmium and lead and had
to be regenerated during the
demonstration. The capacity of
the Sponge for copper was much
greater as none of the columns
became saturated with copper.
Although the developer's
treatment claims for copper,
cadmium and lead were achieved,
the treatment claims for chro-
mium were not met, with only
32% removal of chromium as
divalent chrome (initial concen-
trations of 426 |ig/l).
  For more information and/or to get
on the mailing list for the
Innovative Technology Evaluation
Report describing the complete
demonstration, caU Carolyn Esposito
atEPA's Bisk Reduction Engineering
Laboratory in Edison, New Jersey at
908-906-6895.
 THIS MONTH'S CURRENTS CONTAINS NOTES ON ONGO-
 ING RESEARCH AT EPA'S ROBERT S. KERR ENVIRON-
 MENTAL. RESEARCH LABORATORY.

 SPONGE TECHNOLOGY	1	
 PCS DECHL.ORINAT10N	2	
 SURFACTANTS                      3
 RESEARCH                           3
                                          Recyclaiii/Recy elab le
                                                                  Printed with Soy/Canola ink on paper that contains at least 50% recycled fiber

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                                                                                    fi&EteSEi


  NATURAL,  ORGANIC MATTER  SUPPORTS
  REDUCTIVE DECHLORINATION  OF PCE
  By Candida C. West, Robert S. Kerr Environmental Research Laboratory
  Recent research has shown
  that organic matter extracted
  from a soil horizon was able
  to support reductive dechlori-
  nation of tetrachloroethylene
  (PCE).  Ongoing research at
  the site where the soil was
  collected (Sleeping Bear,
 Michigan) had been con-
 cerned with determining the
 rates of natural in situ
 biodegradation of contami-
 nants; and, there was specula-
 tion that the presence of high
 concentrations of indigenous
 dissolved or colloidal organic
 matter might be contributing
 to the biodegradative process.
 Interaction of contaminants
 with indigenous organic
 matter in soil, sediment and
 aquifer solids are important in
 controlling their fate and
 transport.  Organic matter
 plays a major role in sorption
 and potentially serves as a
 biologically available source
 of carbon supporting bio-
 degradative processes.
 Organic carbon concentra-
 tions in the vadose zone are
 generally assumed to decrease
 exponentially from the soil
 surface becoming negligibly
 low to non-existent in the
 saturated zone.  However,
 carbon distribution at the
 Sleeping Bear site is highly
 complex, having buried
 horizons of high organic
 matter and organic films on
aquifer solids.
  The primary objective of
 the study highlighted here
was to determine if leachable
 organic matter in the vadose
 zone might provide primary
 organic carbon for reductive
 biodegradation of PCE. The
 secondary objective was to
 examine if TCE saturated
 water, i.e., simulating
 rainwater percolating through
 TCE residual, enhanced
 eidlerthe-extraction-ox———
 bioavailability of the organic
 matter.
   Organic carbon from the
 Sleeping Bear site was
 extracted from a high organic
 carbon spodic horizon in the
 vadose zone by using two
 extractants: (1) distilled
 water alone, and (2) distilled
 water saturated with approxi-
 mately 1000 parts per million
 (ppm)TCE. The soil to
 solution ratio was 1:2.6 grams
 per gram (g/g); and, the
 solution pH for the distilled
 water/soil and the distilled
 water with TCE/soil was 7.6
 and 7.47, respectively. After
 overnight extraction, remain-
 ing TCE was removed from  r
 the TCE/water soil extracts
 by purging with N2 gas prior
 to dissolved organic carbon
 (DOC) analysis and micro-
 cosm construction. The
 concentrations of dissolved
 organic carbon in the water
 extract and the TCE-
saturated water extract were
 16 and 20 milligrams per liter
 (mg/1), respectively. The
higher efficiency of carbon
extraction using TCE
saturated distilled water was
reproduced in a second
  extraction experiment;
  however, the mechanism for
  this additional extraction is
  not clear.  It has been
  observed that the TCE
  saturated solution extracts
  more colloidal material.
  Different volumes (0,10, 50,
  100 milliliters) of the TCE/
—waterand~water-onljrsoil—-•—
  extracts were added to
  replicate microcosms contain-
  ing subsurface core material.
  All microcosms were spiked
  with 5 ppm PCE.
  Chloroethene concentrations
  were monitored by purge
  and trap GC analysis of
  subsamples at various time
  points.
   The microcosms were
  monitored over time to
  determine the utilization
  (dechlorination) of PCE.
  Results of the microcosm
  experiments showed the loss
  of PCE and the production
  of daughter products over
  time for both extracts when
..present insufficientconcen- „...
  trations indicating that the
  extracts provide a metaboliz-
  able electron donor capable
  of supporting microbial
  cpnsortia responsible  for
  reductive dechlorination of
  PCE. However, we do not
 yet know either the specific
 identity of these compounds
 or the mechanism of extrac-
 tion.
   Potentially any organic
 substance capable of being
 catabolized  under anaerobic
 conditions should be able to
  support or "drive" reductive
  dechlorination. First, the
  complete degradation of lafge
  or complex compounds
  usually requires the activity of
  different types of microorgan-
  isms. Second, under anaero-
  bic conditions the oxidation
  of organic compounds is
  -linkcdTrcrthc-rcdtitetiorrof* - -
  electron acceptors other than
  oxygen. Previous research
  suggests that, in the subsur-   ,
  face,  reductive dechlorination
  may be only a minor factor
  (less than 0.1%) for the
  reduction generated during
  the anaerobic oxidation
  reactions.
    Further research activities
  are needed to identify the
  specific components of the
  soil organic matter being
  mobilized by water and
  solvent/water mixtures,
  including simple aromatic
  compounds and organic
  acids. Attempts will be made
  to enrich dechlorination
^^.^
  such as ferulic acid, vanillic
  acid and guaiacylglycerol.
   For more information, call
  Candida WestofEPA's
 Robert S.Kerr Environmental
 Research Laboratory at 405-
 436-8551.  Also, for a fuller
 discussion of this research,
 see: Lyon, William G.,
 Candida C. West, Michelle
 L. Osborn and Guy Sewell,
 "Microbial Utilization of
 Vadose Zone Organic
 Carbon for Reductive

        (continued on page 4)

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  SURFACTANT  CONSORTIUM AND  PUBLICATIONS
  The Robert S. Kerr Environ-
  mental Research Laboratory has
  organized a Consortium for
  Surfactant-Based In Situ Aquifer
  Remediation Technologies
  (Consortium) and will publish
  proceedings of the meetings.
  The Consortium is described
  below, together with informa-
  tion on ordering not only
  Consortium Proceedings but
  also information on a recent
  eraluatib'n'bfcationic'surfac-' ~"
 tants.
 Consortium for Surfactants
   A meeting of representatives
 from 11 universities, the
 Department of Energy, the
 Department of Defense and
 the U.S. Geological Survey
 and several private industries,
 including surfactant technol-
 ogy users and surfactant
 manufacturers was held in
 Norman, Oklahoma at the
     University of Oklahoma on
     November 30,1994. The
     Consortium was organized by
     Robert S. Kerr Environmen-
     tal Research Laboratory
     (RSKERL) personnel for the
     purpose of providing a central
     organization for the evalua-
     tion and implementation of
     surfactant-based innovative
     technologies for in situ
     aquifer remediation. A total
     of45*parti"cipantswere  —--•.--
     present for the Consortium
     which included a breakout
     into five discussion groups
     related to surfactant use:
     surfactant chemistry/compat-
     ibility, hydrogeology.,
     microbiology, regulatory.
     issues and implementation.
     The consensus of the group
     was that this organization
     would be useful for sharing
     information on developments
     in research on demonstra-
  tions of surfactants, to     '
  provide peer review of work:
  plans and manuscripts on
  in situ surfactant use, to
  provide education on the use
  and implications of surfac- •
  tants in the subsurface and to
  develop protocols for imple-
  mentation of surfactant-
  based subsurface remediation.
  The Consortium is planning
  to hold regular annual
  meetings and to publish the
  Proceedings of the meetings,!
   To get on the mailing list  '
 for a copy of the November
  1994 "Proceeding of the
  Consortium for Surfactant-
 Based In Situ Aquifer
 Remediation Technologies,"
 send a fax to Dr. Candida
  West at RSKERL at 405-436-
 8703 who will send you your \
 copy of the Proceedings after
 they are printed.
 RESEARCH
 The EPA's RobertS. Kerr
 Environmental Research'
 Laboratory (RSKERL) has
 some important research in
 progress relating to ground
 water remedktion. What
 follows is a brief description of
 some of these efforts.

 Surfactants.
  Working under two coopera-
 tive agreements with the
University of Oklahoma,
Dr. Candida West of RSKERL
is involved with research
directed at the surfactant
IN  PROGRESS
    enhanced remediation of
    subsurface material cdhtanii-"
    nated with dense non-aqueous
    phase liquids (DNAPLs). The
    primary emphasis of the
    research is to show the
    efficiency of recovery of the
    surfactant solution.  The first
    effort, conducted by Dr. David
    Sabatini, is designed to develop
    an environmentally acceptable
    system for enhancing pump-
    and-treat systems. The
    approach involves measuring
    the efficiency and effectiveness
    of specific classes of surfactant
systems for solubilizing and
mobilizing residual and    '  ;
free-phase DNAPLs. Studies
are being carried out to test
chosen systems for ionic matrix
sensitivities, biodegradability,
solid phase interactions
and transport properties.
Dr. Robert Knox will utilize the
findings of the first phase of
the investigation to design and
conduct a small-scale field study
ofsurfactant-enhanced
contaminant removal and
surfactant recovery using a
recirculating well system at the
  Cationic Surfactants
    The RSKERL has pub-
  lished an Environmental
  Research Brief on "The Use
  of Cationic Surfactants to
  Modify Aquifer Materials to
  Reduce the Mobility of
  Hydrophonic Organic
  Compounds," by John C.
  Westall, Julia Wagner and
  Hua Chen of Oregon State
  University and Bruce J.
  Brownawell of the Waste
  Management Institute,
  Marine Sciences Research
  Center at SUNY.
   A copy of the Environmental
  Research Brief (Document No.
  EPA/600/S-94/002) can be
  ordered from CERIat
  513-569-7562.
 U. S. Coast Guard Station in
 Traverse City, Michigan.

 Ske Characterization.
  An essential part of any aquifer
 remedktion project is a site
 characterization that provides
 information necessary to select,
 design, operate and evaluate an
 appropriate remedial technol-
 ogy.  Carl Enfield at RSKERL is
 working with Captain Jeffrey
 Stinson under an Interagency
Agreement to thoroughly
 characterize a site at Tyndall Air
 Force Base using ground
        (continued on page 4)

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Rtseard) continuedfiom page 3
penetrating radar and other
seismic techniques, cone
penetrometer investigations and
fiber optic spectroscopy. The
goal of the project is to deter-
mine the feasibility of using
selected technologies to enhance
the performance of a pump-
and-treat system. A second site,
selected from nine Department
of Defense test facilities, will also
be included in this investigation.

Cosolvent-Enhanosd
Remediation.
  LynnWoodofRSKERLis
conducting a research project
under a Cooperative Agreement
with the University of Florida to
evaluate the feasibility of using
miscible organic cosolvents such
as alcohols to remediate
subsurface environments
contaminated by nonaqueous
phase liquid (NAPL)
hydrophobicorganic chemicals.
The project, entitled "Field-
                    Evaluation of Cosolvent
                    Enhanced In-Situ
                    Remediation," is being carried
                    out as a pilot-scale field study at
                    Hill Air Force Base in Utah
                    using sheet piling cells to provide
                    hydraulic containment

                    Chromate and TCE
                    Treatment
                     A RSKERL research team has
                    evaluated the use of elemental
                    iron as a surface treatment
                    alternative for chromate and
                    trichloroethylene (TCE)
                    extracted from contaminated
                    ground water at the U.S. Coast
                    Guard,Support Center at. _„ ._;-
                    Elizabeth City, North Carolina.
                    The field test involved the use of
                    two 55-gallon drums packed
                    with two different types of
                    elemental iron mixed with
                    aquifer material from the site.
                    Influent concentrations of
                    8 milligrams per liter (mg/I)
                    chromate, 717 micrograms per
                    liter (pg/T) TCE, 194 |Jg/l c-DCE
 and 51 Mg/1 vinyl chloride were
 used. Effluent chromate
 concentrations were below
 detection (0.005 mg/1) using
 flow rates ranging from 0.5
 to 4.0 liters per minute.
 Reductions in the concentra-
 tions of organic compounds
 ranged from 14 to 99 percent
 depending upon the flow rate.
 An array of these large "col-
 umns" is proposed as a means
 of intercepting the leading edges
 of overlapping plumes of
chromate and TCE at the site.
Potential long-term plans are to
install a permeable reactive wall
at the site composed of
elemental kon to passively
remediate both the chromate
and TCE ground water
contamination.
  GROUND WATER
CURRENTS is monitoring the
progress of these research efforts.
We will provide additional
finding of this research as they
become available.
 PCE continued from page 2
 Dechlorination of PCE,"
_suh.n?!9~d toJOURNAL_OF
    :. : ONMENTAL
 ,::^NCE 6-HEALTH;
 Wilson J. T., D. H. Kampbell
 and J. Armstrong, "Natural
 Bioreclamation of
 Alkylbenzenes (BTEX) From
 a Gasoline Spill in Ground-
 water," in R. E. Hinchee and
 B. C. Alleman, eds.,
 PROCEEDINGS OF THE
 SECOND INTERNATIONAL
 SYMPOSIUM ON IN SITU
 BIORECLAMATION,  .
 April 5-8, 1993, San Diego,
 CA; West, C. C., W. G. Lyon,
 D. L. Ross and L K.
 Pennington, "Investigation of
 the Vertical Distribution and
 Morphology of Indigenous
 Organic Matter at the Sleeping i
 Bear Site, Michigan, "ENVI-
 RONMENTAL GEOLOGY
 (in press).
                                      MAIl-ING LIST/ORDER  ttNFO
To Ortfaf additional wpie* of Own* ttfeferOmrafe or to teftvdufef on the psnaaaeat
                      *ribn«te« (NCEPf) at 5 \ WHWCT5, sr«w** mull «v***> NCEP), P.O.
                       Please refer to the doeumenr number «f*-tfee cover of *e issue ff avafeWe,
                                                                                              , Onctoo*.

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