3
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                       /A newsletter about soil, sediment, and ground-water characterization and remediation technologies
                       Issue 11
                                                                                           March 2004
          AOP Treats Dioxane-Contaminated Ground Water
                                                                                Contents
The San Gabriel Basin Water Quality
Authority is working with private industry
to examine options for removing 1,4-dioxane
in ground water undergoing chlorinated
solvent removal at two former industrial sites
in Southern California. Apump and treatment
system employing liquid-phase granular
activated carbon (LGAC) has operated at one
of the sites, in South El Monte, since 1995
to remove chlorinated solvents. The system
was found ineffective at removing 1,4-
dioxane, which was discovered in 1999 at
concentrations reaching 20 ug/L. Apilot-scale
advanced oxidation process (AOP) using ex-
situ injection of ozone and hydrogen peroxide
was implemented for one month in 2001 to
address the 1,4-dioxane.

The AOP is a continuous, in-line process
operating at feed  water pressure with a flow
of 10-1,000 gpm. The 10-gpm AOP mobile
unit used during  the pilot contains a solid-
state ozone generator producing ozone at a
pressure of 40-50 psig. The unit also houses
a hydrogen peroxide delivery system that uses
a continuous  reactor to  inject hydrogen
peroxide initially at a single point, followed
by ozone at  multiple points along the flow
path. Earlier testing showed mat multiple
small-scale injections, rather than a single
large-scale  event, increased the process
effectiveness  and minimized byproduct
formation.

The continuous reactor initially contained 18
individual reactors, each with three separate
sections for injection, mixing, and chemical
reaction (Figure  1), and sampling ports at
the point of effluent. Depending on the rate
of flow, residence time  within each of the
                          individual reactors was 3-10 seconds. Ozone
                          and hydrogen peroxide initially were applied
                          at rates of  9.4 ppm  and  14.2 ppm,
                          respectively. Approximately 0.7 moles of
                          peroxide solution were injected into the
                          influent for each mole of ozone applied within
                          the reactor. Subsequent system optimization
                          reduced the ozone and hydrogen peroxide
                          application rates to 3.1 ppm and 6.9 ppm,
                          respectively,  and reduced the  number of
                          required reactors to 3.

                          Treatment resulted in a decrease of the 1,4-
                          dioxane concentration to a level below the
                          State of California drinking water standard
                          (3 ug/L) and a 98% decrease in most other
                          chlorinated solvents. Based on the pilot's
                          success, a full-scale AOP was  constructed
                          in 2002 and has operated for the  past year as
                          a continuous pre-treatment step.  The system
                          comprises three ozone injectors with eight
                          static mixers operating at a capacity of 500
                          gpm.

                          Early  monitoring results of the full-scale
                          operation demonstrate the same removal rates
                          for 1,4-dioxane and chlorinated solvents as
                          those observed during the pilot project. Data
                          indicate that addition of the AOP system is
                          increasing the life of the LGAC, which is
                          now replaced semi-annually rather than
                          quarterly. As a result of 1,4-dioxane removal,
                          effluent from the LGAC system now can be
                          reinjected into ground water approximately
                          1-2  miles upgradient of a nearby drinking
                          water well field to serve as a barrier.

                          Similar success was demonstrated in a pilot
                          AOP system operated in the City of Industry.

                                            [continued  on page 2]
AOP Treats Dioxane-
Contaminated  Ground
Water
page 1
ETV Program Verifies
Performance of Ground-
Water Sampling Devices   page 2

ESTCP Evaluates
Bimetallic Nanoscale
Particles in Treating
CVOCs                  page 3

NRMRL Evaluates
Microbial Responses
to Ground-Water
Remediation
Technologies            page 5
   On-line Resources
 As a new feature of Technology
 News and Trends, we will
 highlight one of the many on-line
 resources available through
 CLU-IN,  our primary information
 network. In this issue we feature
 EPA REACH IT (http^//
 www.epareachit.org). where
 environmental professionals can
 search, view,  download, and
 print information about innovative
 remediation and characterization
 technologies.  REACH IT
 currently contains  information on
 435 technology vendors, 680
 technologies, and 2,013
 applications at Superfund sites.
                                                                                                   Recycled/Recyclable
                                                                                                   Printed with Soy/Car»la Ink or paper that
                                                                                                   contains at least 50% recycled fiber

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continued from page 1]
At this location,  1,4-dioxane was
detected in extraction wells that feed
an  air  stripper  used  to remove
chlorinated solvents. Concentrations of
1,4-dioxane were found to decrease
consistently from 610 to 4 ppb during
AOP pre-treatment. Researchers believe that
a further  reduction  in 1,4-dioxane
concentrations would have been achieved
with higher ozone dosage. A full-scale
system with a 70-gpm capacity has been
installed at this site for use as a pre-
treatment step prior to air stripping.
                      03/02
                             I nj ecti on
                             Manifold
  I nf I uent Water
                                                        Effluent Water
Due to the recent discovery of 1,4-dioxane
in ground water throughout California, the
Santa Clara  Valley  Water  District
anticipates continued need for 1,4-dioxane
monitoring.

Contributed by Reid Bowman, Ph.D.,
Applied Process Technology, Inc. (805-
649-5796 or rbowman@aptwater.com)
and Tom Mohr, Santa Clara Valley
Water District  (408-265-2607 or
tmohr@valley\vater. org)
                                                                          Figure 1. AOP injections occurred in a
                                                                          series of individual reactors, each of
                                                                          which allowed mixing and reaction
                                                                          with contaminated sround water.
            ETV Program Verifies Performance of Ground-Water Sampling Devices
The EPA-sponsored Environmental
Technology Verification (ETV) program
has established several testing centers
over the past  10 years to verify new
technologies  for  a   variety   of
environmental applications. One of these
centers—the Advanced Monitoring
Systems Center (AMS)—recently tested
eight ground-water sampling devices:
six devices (including bladder pumps,
grab samplers, passive sampling devices,
and a  down-well  sampling module)
suitable for deployment in conventional,
2-inch diameter and larger wells and two
devices deployable in 1-inch or smaller
diameter wells installed by direct-push
methods.

As  one  of  several   third-party,
independent testing organizations within
AMS,  Sandia National Laboratories
designed and conducted the tests in
cooperation  with the  technology
vendors. Tests were performed  under
well-controlled conditions in a test facility
and under less experimental control at
contaminated ground-water sites.
Controlled testing was conducted at a 100-
foot standpipe at the U.S. Geological
Survey's Hydro logical Instrumentation
Facility at the NASA Stennis Space Center,
MS. The standpipe is housed in a former
Saturn V rocket hangar with multiple
access platforms along the length of the
standpipe. Large mixing tanks and a water
supply at the top of the pipe allow
contaminant-spiked solutions to be
prepared and dispersed into the standpipe.
Ground-water sampling devices were
deployed in the pipe from the top in the
same manner they would be deployed in
an onsite monitoring well. The 5-inch
diameter, stainless-steel standpipe was
equipped with multiple  external access
ports along its length to allow collection
of co-located reference samples at the same
time that vendors collected samples from
inside the pipe.

Field testing of the conventional larger-scale
devices was conducted in a ground-water
monitoring well field at the NASA Stennis
site.  Ground water in this  region is
contaminated with a variety of volatile
organic compounds (VOCs)—predominately
chlorinated solvents—resulting from
former machine shop  operations and
solvent disposal. VOC concentrations in
ground water at the test area ranged from
single digit parts per billion levels to tens
of parts per million.

Field testing for the smaller direct-push
well devices was conducted at Tyndall Air
Force  Base,  FL.  Several areas of
contaminated ground water exist at the
site as a result of past disposal of solvents
used in aircraft maintenance. With its
existing network of 1 -inch diameter, direct-
push wells, Tyndall AFB is one of several
military installations involved in long-term
comparison of conventionally installed
wells   and  direct-push  wells  at
contaminated sites. VOC concentrations
in ground water at the test area ranged
from single digit parts per billion to
hundreds of parts per billion.

Performance of the following ground-
water sampling devices was verified in
cooperation with vendors:

               [continued on page 3]

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  Figure 2. Pooled test results for
  conventional-well samplers were
  compiled from six target VOCs at low
  (20 \lg/L) and high (200 \lg/L)
  concentrations and standpipe sampling
  depths of 17, 35, 53, and 91 feet. Not
  all samplers were deployed at all
  sampling depths.
[continued from page 2]

 > Multiprobe 100 (Burge Environmen-
   tal, Inc.)
 > SampleEase SP15T36 (Clean Envi-
   ronmental Equipment)
 > Micro-Flo 57400 (GeoLog, Inc.)
 > Gore-Sorber Water Quality Monitor
   (W.L. Gore and Associates)
 > Kabis Sampler I/II (Sibak Industries)
 > Well Wizard Dedicated Sampling Sys-
   tem T120M/T1250 (QED Environ-
   mental Systems, Inc.)
 > Mechanical Bladder Pump MB470
   (Geoprobe  Systems, Inc.), and
 > Pneumatic Bladder Pump GW1400
   (Geoprobe  Systems, Inc.).


Sampler Type
Multiprobe 100
SampleEase
Micro-Flo
Gore-Sorber
Kabis Sampler
Well Wizard
Precision
(Percent Relative Standard Deviation)
Median (Range)
Technology
9.4 (3.0-21.1)
11.7 (5.1 -24.2)
8.5 (2.7-26.7)
14 (2-28)
10.7 (2.9-25.8)
7.7 (3.9-19.7)
Reference
8.6 (2.0-17.4)
10.7 (4.1 -15.2)
4.7 (1.6-30.8)
N/A [see report]
8.7 (4.1 -17.6)
8.2 (1.1 -30.7)
Relative Accuracy*
(Percent Difference)
Median (Range)
-5 (-30-15)
-5 (-16-31)
-1 (-21 -27)
N/A [see report]
-3 (-39-18)
1 (-17-20)
* relative to co-located and simultaneous standpipe reference samples
Each device was used to collect 100 or more
standpipe and ground-water samples and all
vendor samples were matched with
reference samples.  Performance was
determined  for  sampler  precision,
comparability with a reference, versatility,
and logistical requirements. Typical precision
and relative accuracy performance data for
standpipe VOCs are summarized in Figures
2 and 3.

Sampler Type
Mechanical Bladder Pump
Pneumatic Bladder Pump
Precision
(Percent Relative Standard Deviation)
Median (Range)
Technology
1.2 (0.2-3.4)
1.3 (0.3-2.8)
Reference
1.4 (0.0-2.5)
1.6 (0.4-2.6)
Relative Accuracy*
(Percent Difference)
Median (Range)
-2.5 (-5.0- 0.3)
-2.3 (-5.6 - 0.9)
* relative to co-located and simultaneous standpipe reference samples
  In general, test results revealed that all
  tested sampling devices are suitable for
  use in various ground-water sampling
  applications.    The    published
  performance verification data for each
  device can be used to optimize the
  choice of a sampler in a particular field
  application. A complete performance
  report on each of these ground-water
  sampling devices is available on the
  ETV website (http://www.epa.gov/etv).

  Contributed by Wayne Einfeld,
  Sandia National Laboratories (505-
  845-8314 or w ein fel&sandia. sov)
                                                                            Figure 3. Pooled test results for
                                                                            narrow-bore well samplers were
                                                                            compiled from four target VOCs at
                                                                            intermediate (-80 /Jg/L) concentra-
                                                                            tions and standpipe sampling at
                                                                            depths of 17 and 35 feet.
               ESTOP Evaluates Bimetallic Nanoscale Particles in Treating CVOCs
Under the Environmental Security
Technology  Certification  Program
(ESTCP), the  U.S. Department  of
Defense (DOD)  is evaluating the use of
bimetallic nanoscale iron (BNI) particles
in establishing a permeable, in-situ,
reactive zone for treating chlorinated volatile
organic compounds (CVOCs) in ground
water. When compared to conventional
iron-based permeable reactive barriers
employing granularparticles, nanoscale (less
than a micron in size) metallic iron provides
more available surface area per unit of
iron mass. Preliminary results  of the
ESTCP study indicate that the increased
surface  area allows higher levels of

               [continued on page 4]

-------
[continued from page 3] conversion of contaminants into non-toxic

reactivity with
gas.
contaminants, while


generating lower iron mass loadings. DOD Using BNI produced through two types of
anticipates that the use of nanoscale colloid manufacturing techniques,
particles will enable iron to be injected laboratory studies were conducted in soil
beneath ground-surface structures, columns packed with soil and treated with
where surface access is otherwise limited ground-water samples taken from
a site at
by existing land uses, or at depths at which Vandenberg Air Force Base, CA, which
trenching is impractical, with minimal serves as the primary pilot location for this
ground surface disruption. project. Samples were collected several
hundred yards from a missile launch pad
The use of BNI colloids for in-situ , • , , i, . • 1 1 ,1
drainage channel where trichloroethene
remediationbuilds on the use of nanoscale ^^T-,, ,- , • ,
11 -j i u- uu u (TCE) was found in ground water at a
ironcolloidsalone,whichhavebeenused concentration of 2 5 /L The TCE
by others in both bench- and field-scale , , .. . . , ~ ,. ,, .,
degradation product as- 1 .2-dichloroethene
applications. During this project, analytical (DCE) ^ wag identffied but at lower
results showed that the addition of an
concentrations.
incomplete coating (0.03% w/w) of
palladium as a hydrogenation catalyst to The "aqueous precipitation" technique used
the surface of nanoscale iron particles to manufacture nanoscale iron particles
increased the CVOC dechlorination rate involves reduction of a solution of ferric
from a kinetic value of 0.002 L/mVg to chloride using sodium boro hydride. In
values of IL/mVg or more. Data indicated contrast, the "ball milling" technique
that the increased surface area provided involves reduction of larger, typically
by nanoscale iron, combined with the micron-size, iron powder granules to
increased reaction rate caused by the nanoscale size through an attrition process
addition of hydrogenation catalyst, using a suitably sized ball mill. Over three
achieved a 100-150% higher treatment years, this project supported enhancements
rate than those estimated to be achieved to the ball milling process that have lowered
by granular iron filings. The addition of the cost of manufacturing nanoscale iron
palladium also enabled more complete to $5/lb (Figure 4).

10000 -

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7/5 100
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1997 1998 1999 2000 2001 2002 2003 2004



Years

— Precipitated — Ball Milled



To date, laboratory testing has resulted in
the creation of a "library" of kinetic
treatment rates indexed by the types of
nanoscale iron being tested. The kinetic
rate constants normalized for the surface
area of iron have ranged from 0.05 L/m2/
g to 0.4 L/m2/g. Colloids ranging in size
from 200 to thousands of nanometers
were tested in the laboratory to determine
the optimal size for field application.
Results demonstrated that colloids in the
range of 200-600 nanometers achieved
optimal mobility and a sufficient reactivity
rate for in-situ CVOC dechlorination.
Colloids of smaller size were subject to
adsorptive interfacial forces in the geologic
matrix, while larger ones were adversely
affected by gravitational settling.
This project has resulted in a cost-effective
BNI production process mat can be up-
scaled to yield nanoscale iron in large
quantities (several tons) for full-scale
remediation. As it continues, this project
will focus on: (1) understanding and
manipulating technical factors that
improve the reactive life of BNI once it is
deployed in-situ; and (2) demonstrating
BNI applicability for remediation of
CVOCs present as dense, nonaqueous
phase liquid (DNAPL) in laboratory soil
columns. Updated information on this
ongoing ESTCP project is available at
http://www.estcp.org.
Contributed by David Liles, ARCADIS
(919-544-4535 or dliles&arcadis-
us.com) and Andrea Leeson DOD/
SERDP (703-696-2118 or
Andrea.Leeson&osd.mil)




Figure 4: Field application of
nanoscale iron particles for
remediation of contaminated ground
water is no longer significantly
limited by colloid manufacturing
costs.
I 1

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     NRMRL Evaluates Microbial Responses to Ground-Water Remediation Technologies
The   U.S.  EPA  National  Risk
Management Research Laboratory
(NRMRL)   recently   completed
independent evaluation of the microbial
responses to technology demonstrations
that were conducted over the past several
years at Cape Canaveral Air Station, FL.
The Interagency DNAPL Consortium had
conducted    side-by-side    field
demonstrations of three technologies for
treating trichloroethene existing  as
DNAPL: permanganate-based, in-situ,
chemical oxidation (ISCO), six-phase
heating (SPH), and steam injection (SI).
[Performance summaries are available in
the March 2003 Technology  News and
Trends and July 2001 Ground Water
Currents at http://www.clu-in.org]. The
recent  NRMRL  evaluation  was
conducted in  part to address concerns
that   aggressive   source   control
technologies such as those demonstrated
at Cape Canaveral might sterilize the
subsurface, thus hampering  the use  of
natural or enhanced  bioattenuation
processes as remedial finishing steps.
Aggressive technologies  typically
remediate a substantial portion of DNAPL
but do not achieve regulatory clean-up
levels. Results of the study indicate that
sterilization did not occur. Biomass levels
following  application  of  all three
technologies returned  to  near  pre-
treatment levels.

NRMRL's study focused on the analysis
of phospholipid ester-linked  fatty acids
(PLFA)  profiles,  which  provide
information on the phy logenic identity and
physiological  status of microbes.
Individual fatty acids are known to differ
in chemical composition that depends  on
microbial  type  and  environmental
conditions. These differences  allow fatty
acids to be used as biomarkers providing
a quantitative  insight into three primary
attributes of microbial communities: viable
biomass, community structure, and
metabolic activity.
During the three-year NRMRL evaluation,
PLFA distribution and content were
determined from 266  core  samples
extracted aseptically at depths of 6-44 feet.
Samples were collected at a site control
with no DNAPL contamination and in the
areas  where  each   of  the  three
demonstrations occurred (Figure 5).

Comprehensive spatial and temporal
screening  data  suggested that  the
technology applications did not significantly
alter the site's microbial community
structure. PLFA distribution at the  site
control suggested that the microbial
community structures were  atypical. In
particular, the biomass gradient did not
decrease with increasing depth. The high
level of biomass variation identified at each
depth, however, was consistent  with the
extensive heterogeneity of biota expected
in subsurface environments.  Analysis of
fatty acid structural groups indicated that
short  saturates constituted  the largest
group and that the number of long saturates
was significantly higher than usual. These
findings contrasted with other studies
indicating that monosaturated PLFAusually
are the  most abundant in  subsurface
conditions, while long saturates constitute
a fewer percent of the total fatty acids.

PLFA distribution for each of the three
demonstration areas also indicated a high
variation in biomass at each sampling event
and depth. ISCO was the only technology
found to stimulate microbial abundance; a
significant initial increase in biomass was
observed following completion of the ISCO
demonstration. This behavior is consistent
with findings from other permanganate-
based chemical oxidation applications.
Biomass   and  the  proportion   of
monounsaturates returned to normal levels
shortly after chemical injections  ceased.

In general,  no significant change in the
microbial community composition was
observed in the SPH or SI treatment areas
at Cape Canaveral. Microbial communities
recovered to near initial conditions by the
second sampling event performed for both
the SPH and SI demonstrations.

Limiting factors for this evaluation may
include the selection of fatty  acid
structural groups that may have  been
insufficiently  sensitive to  subtle
differences in microbial populations, or
the use of samples with very low biomass
and corresponding patterns of PFLA.
Although the PLFA tests suggest that the
indigenous microbial population recovered
after treatments, further investigations are
required to demonstrate conclusively that

                [continued on page 6]
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                       Technology
                    News and Trends
       Solid Waste and
       Emergency  Response
       (5102G)
                    EPA 542-N-04-002
                    March 2004
                    Issue No. 11
      United States
      Environmental Protection Agency
      National Service Center for Environmental Publications
      P.O. Box 42419
      Cincinnati, OH 45242
                        First Class Mail
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                        Permit No. G-35
     Official Business
     Penalty for Private Use $300
       [continued from page 5]
       the population can be used as a finishing
       step. Details on the general approach used
       for sampling and analysis during  this
study will  be  available  in a  2004
environmental research brief available at
http://www.epa.gov/ORD/NRMRL/Pubs/
index.html.
                            Contributed by Ann Azadpour-Keeley,
                            NRMRL (580-436-8890 or
                            keeley.ann&gpa.gov)
          Figure 5. A total of 266
          core samples were
          analysis in the three
          demonstration areas and
         from site control locations
          at Cape Canaveral Air
          Station.
             MBC-019
                 MBf120 ,'
           MB-30S
         MBC-009i
         TB&//vtsti
mto»f  ,-'SS§/
     f   / £LMB-10a l       t
       MB-30SMB-20S/      •
;v;
 ,MBC-01Q
                                              A Test Core
                                                  Sw-P/iase Heaf/ng (SPHj: MS 01 - MS 05
                                                  InStu Chemical Oxidation (/SCO): MB 06 - MB 10
                                                  Steam Injection (SI): MB 16-MB 20
                                                Control Core
                                                  Plot Controls: MBC-01 - MBC-14 &MB-16- MB-20
                                                  Site Controls: A-E. -date

                                                       Core Sampling Code:
                                                            MB-210
                                                      A  /  l\
                                                    Test Cote    /   Core Location
                                                       2"°'Post-demonstration
                                                        Monitoring Event
                                                                                                 Test Plot Boundaries
                                                                                                0      25       50
                                                                                                 I	i	i
                                                                                                       FEET
                                                                                                                           July 2003
                                                                              .,
                                                                  Xchemical^:
                                                                    Oxidation
                                                                         °
     EPA is publishing this newsletter as a means of disseminating useful information regarding innovative and alternative treatment techniques and
6    technologies. The Agency does not endorse specific technology vendors.

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