United States
Environmental Protection
Agency
Solid Waste and
Emergency Response
(SKEW)
EPA-542-N-94-005
June 1994
v°/EPA Ground Water Currents
Developments in innovative ground water treatment
LOW-LEVEL URANIUM REMOVED
FROM GROUND WATER
By Annette Gatchett, Risk Reduction Engineering Laboratory
's SITE (Superfund
Innovative Technology
Evaluation) Program
evaluation of the Colloid
Polishing Filter Method
(CPFM) has demonstrated
that CPFM is effective in
removing low levels of
uranium from contaminated
ground water at the
Department of Energy's
Rocky Flats Plant in Golden,
Colorado. Additionally, the
developer of the technology,
Filter Flow Technology, Inc.
(FFT), has stated that the
CPFM system has effectively
removed trace concentrations
of colloidal, complexed,
chelated and ionic heavy
metals and nontritium
radionuclides from surface
and ground water,
wastewater, and secondary
wastewater generated from
soil washing. The CPFM is a
transportable, trailer mounted
system.
At the heart of the
technology is the sorption
unit which consists of four
horizontal polypropylene
filter plates that house three
colloid filter packs that
remove contaminants by
sorption, chemical mech-
anisms, adsorption and
physical filtration. Each filter
pack contains a proprietary,
inorganic, insoluble, oxide-
based, filter bed material in
particle and bead form
Operationally, the filter packs
are pneumatically pressure
sealed between each set of
plates.
The system can process
contaminated waters
continuously at 5 to 100-
gallons per minute. At Rocky
Flats approximately 10,000
gallons of ground water
containing about 100
picoCuries per liter (pCi/L)
of uranium was processed at
5 gallons per minute. The
contaminated water may be
pretreated if necessary to
adjust the chemical oxidation
state and acidity (pH) in
mixing tanks. Total
suspended solids (TSS) are
removed in a small, parallel
plate separator or mini-
clarifier and bag filters to
prolong colloid filter pack
life. Sludge from the mini-
clarifier is pumped through a
small filter press; and, the
filtered water is returned to
the mini-clarifier. Effluent
from the bag is routed to the
colloid filter units and evenly
dispersed throughout the
filter packs which remove the
contaminants. Water from
the filter packs is collected
and directed to a final pH
adjustment tank. If
necessary, effluent from the
colloid filter units is treated
with acid in this tank prior to
discharge to reduce the pH to
between 8.0 and 8.3.
Once treatment is
complete, air blow-down is
used to dewater the filter bed;
then the hydraulic pressure
on the support plates is
released, the plates separated
and the filter packs removed.
Spent filter media is then
mixed with solids from the
mini-clarifier and bag filters
and stabilized to meet EPA
land disposal restrictions.
The developer has stated that,
alternatively, the filter media
can be regenerated and reused.
The SITE evaluation focused
on the ability of the CPFM
system to remove uranium
from ground water. For the
first three test runs, removal
efficiencies for uranium and
gross alpha were approximately
75%. Run 4, which pretreated
the effluent with sodium
sulfide, achieved removal
efficiencies of 95% for uranium
and 96% for gross alpha.
Prior to the SITE demon-
stration, preliminary bench-
scale studies using Rocky Flats
feed water spiked with
uranium, radium, plutonium
and americium had shown
greater than 99% removal rates.
Initial influent pCi/L con-
centrations had
(See Uranium, Page 4)
This Month in Currents
THIS MONTH'S CURRENTS FEATURES REMOVAL
TECHNOLOGIES FOR HEAVY METALS AND
RADIONUCUIDES .
SORPTION
ION-EXCHANGE
MEMBRANE
NEW FOR THE BOOKSHELF
Recycled/Recyclable • Printed with Vegetable Oil Based Inks on 100% Recycled Paper (50% Postconsumer)
-------
SITE SEARCH
PROMISING ION-EXCHANGE TECHNOLOGY
SEEKS SITE FOR DEMONSTRATION
By Naomi Barkley, Risk Reduction Engineering Laboratory
J. ilot-scale studies through immobilized in a silica
EPA's Superfund Innovative polymer. It is a hard ma-
Technology Evaluation
(SITE) Emerging Technolo-
gies Program and through a
Department of Energy
(DOE) effort have confirmed
that the AlgaSORB®
technology represents an
advancement of the ion-
exchange "state of the art".
EPA's Emerging Technology
Program tested AlgaSORB®
in an onsite, pilot-scale
demonstration on mercury-
contaminated ground water
at a hazardous waste site in
Oakland, California.
Additionally, ground waters
contaminated with heavy
metal ions were treated from
three different DOE sites:
Savannah River, Hanford and
Oak Ridge Y-12 Plant. Based
on the good results from these
two evaluations, the EPA
SITE program would like to
evaluate AlgaSORB® in a
full-scale demonstration. The
technology developer, Bio-
Recovery Systems, Inc., needs
a sponsor and a site for the
demonstration. Could it be
your site?
AlgaSORB®, is a biological
sorption process designed to
remove heavy metal ions
from aqueous solutions. The
system functions as a bio-
logical ion-exchange resin to
bind both metallic cations
and metallic oxoanions.
AlgaSORB is composed of a
non-living algal bio-mass
terial where the algal cells
are protected from decom-
position by other micro-
organisms. The material can
be packed into columns
(similar to commercial ion
exchange resins) which, when
pressurized, exhibit good flow
characteristics. The tech-
nology is based on the natural
affinity of algae cell walls for
heavy metal ions and thus
functions well for removing
heavy metals from ground
waters that contain high
levels of dissolved solids and/
or organic contaminants.
Dilute solutions containing
heavy metals are passed
through columns where
metal ions are absorbed by
the AlgaSORB® resins and
anions such as chlorides or
sulfates are only weakly
bound or not bound at all.
Compared to traditional ion
exchange resins, an advantage
of the immobilized algal
biomass resins is that they are
capable of producing effluent
metal ion concentrations in
the low parts per billion
(ppb) range, even in the
presence of high concentra-
tions of salts such as calcium
or magnesium.
Each contaminated
ground water has unique
contaminating metals, metal
concentrations, ionic
composition and treatability
target goals. Treatability
studies form the basis for
choosing the optimum
adsorbent and flow rates to
meet effluent quality
standards and to minimize
operating costs. The algal
biomass resins can be "tailor-
made" for specific site
conditions, including type of
metal. Different species of
algae can be immobilized on
silica gel heads to produce
adsorbents which vary in their
metal ion binding capability.
The high selectivity of the
resins for a particular metal
allows for high capacity and
thus opportunities for
recovery of removed con-
stituents due to the very high
pollutant concentrations.
Once saturated by the resins,
the metal ions can be stripped
from the resin biomass in
highly concentrated form by
using acids, bases or other
suitable reagents. This
solution may require ad-
ditional treatment to further
concentrate the metals for
recycling or disposal.
The EPA Emerging
Technology pilot demon-
stration and the DOE
treatability studies addressed
the issues of optimum flow
rates, binding capacities and
the efficiency of the stripping
agents. During the EPA's
three-week demonstration,
588 bed volumes (235 liters),
containing mercury con-
centrations varying from 330
to 1,000 ppb were passed
through the test apparatus.
The demonstration was
continued until the effluent
mercury exceeded the
discharge limit of 10
micrograms per liter (ug/L)
At least 534 bed volumes
(214L) were successfully
treated prior to column
breakthrough. Data
confirmed previous tests that
AlgaSORB® 624 was capable
of removing the majority of
the mercury and that
AlgaSORB® 640 was further
capable of polishing effluent
from AlgaSORB® 624 below
permitted discharge limits to
7.7 ppb.
The objective of the DOE
treatability studies at
Hanford, Oak Ridge and
Savannah River was to
establish treatment proto-
cols and to optimize an
AlgaSORB /ion exchange
technology system to remove
and recover toxic metal ions
from these contaminated
ground waters. Because the
chemical nature of the
ground waters from each site
was unique, different metal
ion adsorbents (which
included different algae
species as well as certain
specialty ion exchange resins),
different operational
parameters and different
stripping protocols were
developed for treatment of
each contaminated ground
(See Site Research, Page 3)
Ground Water Currents
-------
NORTH OF THE BORDER
PERVAPORATION MEMBRANE
By Lisa Keller, Environment Canada
./he Zenon pervaporation
membrane process removes
REMOVES VOCS
volatile organic compounds
(VOCs) from contaminated
ground water, wastewater and
leachate. Pervaporation has
advantages over conventional
technologies such as activated
carbon or air stripping
because it allows for
contaminant recovery.
Pervaporation can be applied
when VOCs in ground water
exceed 10 parts per million
(ppm). Environment
Canada's Development and
Demonstration of Site
Remediation Technology
(DESRT) program sponsored
a four-month pilot scale study
of the system at a pumping
station in southern Ontario,
where ground water had
become contaminated with
BTEX compounds (benzene,
toluene, ethylbenzene and
xylenes). The pervaporation
removal efficiency for the
BTEX compounds was
98.2% based on average
concentrations obtained with
hourly sampling over an
eight-hour period.
In the pervaporation
system, organic-contaminated
water flows into a pervapora-
tion module containing a
dense, organophilic mem-
brane. The contaminated
water is pumped across one
side of the membrane, while
the opposite side of the
membrane is exposed to a
vacuum. Organics are
adsorbed to the membrane
and diffuse through to the
other side where they are
drawn off by a vacuum
(typically 29" Hg). Treated
water which is depleted of
organics by the pervaporation
module exits the Zenon
system for reuse or discharge.
Organics passing through the
membrane, now called
permeate, are condensed and
flow to a permeate collection
tank where gravity separation
of water and organics occurs.
The concentrated organics
are pumped from the collec-
tion tank to storage, while
collected water is returned to
the pervaporation system for
further treatment. The
vacuum is vented to a con-
denser to eliminate VOC
releases to the air. The
permeate contains high
concentrations of organic
compounds which often
separate into an aqueous and
organic phase, making the
organic fraction potentially
recoverable.
During the DESRT study,
ground water from the well
with the highest concentra-
tions of BTEX compounds
was routed to the pervapora-
tion system. Initial untreated
VOC concentrations and
concentrations in treated
water were: benzene, 480
micro-grams per liter ug/L)
untreated to 9 ug/L in treated
water; toluene 340 ug/L to 6
ug/L; ethylbenzene, 120 ug/L
L to 2 ug/L and total xy-
lenes, 690 ug/L to 12 ug/L.
System performance was
verified by the U.S. EPA
during eight hours of sampl-
ing and monitoring. No
detectable BTEX com-
pounds were measured in the
air vent from the vacuum
pump. Higher removal
efficiencies of treated water
could be achieved by
increasing residence time in
the system.
Design and construction
of a full-scale pervaporation
unit by Zenon is currently
underway. An EPA SITE
(Superfund Innovative Tech-
nology Evaluation) demon-
stration of the unit has
tentatively been scheduled for
the summer of 1994 in San
Diego, California.
For more information, call
Lisa Keller of Environment
Canada at 819-953-0962. A
report of the study should be
available by the end of 1994.
(Site Research cont. from page 2)
water. The bench scale
treatability studies consisted
of four segments. First,
several adsorbents were
screened and tested for
effectiveness and selectivity
in recovery of target metal
ion(s). Then, protocols to
strip target metal ions from
the adsorbents were de-
veloped. Column studies to
optimize flow rates for target
metal ion binding and
stripping were conducted
next. The final task involved
column studies to verify
adsorbent recyclability. In
general, these experiments
were designed to investigate
treatment options rather than
to optimize engineering
applications which would
require on-site testing.
The specialty ion exchange/
AlgaSORB® resins tested in
these studies show promise
for selectively removing
chromium, mercury and
uranium from contaminated
ground waters at all three
DOE sites. The data show
that effluents which satisfy
the allowable metal ion limits
are possible and most likely
achievable. At Hanford,
concentrations in ground
water from several wells of
200 ppb uranium, 323 ppb
chromium and 300 ppb
chromium, dropped to 10
ppb, 50 ppb and 40 ppb,
respectively, after treatment.
At Oak Ridge, 2000 bed
volumes of ground water
containing 30 ppb mercury,
dropped to 2 ppb after
treatment. At Savannah
River, ground water con-
taining approximately 4 ppb
mercury was spiked to
(See Site Research, Page 4)
Ground Water Currents
-------
NEW FOR THE BOOK SHELF
GROUNDWATER SAMPLING
INFORMATION AVAILABLE
Get ready to order your copy
of the Proceedings from
EPA's Ground Water
Sampling Work Shop that
was held late last Fall in
Dallas, Texas. The Work
Shop provided a valuable
forum for the presentation
and discussion of recent
research findings on ground
water sampling. Participants
included: representatives of
universities and private
industry; environmental
consultants; and scientists and
other innovative technology
personnel from the U.S. EPA,
U.S. Geological Survey, U.S.
Department of Energy and
several State environmental
agencies.
The Proceedings will be in
published form by early Fall
1994. To get on the mailing
list, send a FAX to EPA's
Robert S. Kerr Environ-
mental Research Laboratory
at 405-436-8503.
(Uranium cont. from page I)
been approximately: 98 for
total uranium; 56 for uran-
ium-234; 35 for uranium-238;
7 for plutonium-239; and 22
for americium-241. Other
removal rates and their initial
approximate initial concent-
rations were: 86% of 166 pCi/
L gross alpha; 54% of 124 pCi/
L gross beta; and 46% of 13
pCi/L radium-226.
For more information, call
Annette Gatchett at EPA's Risk
Reduction Engineering
Laboratory at 513-569-7697.
Key findings from the demon-
stration, including complete
analytical results and economic
analysis, will be issued in a
Capsule Report, an Innovative
Technology Evaluation Report
and a videotape, all of which
will be available by the Fall of
1994.
(Site Research cont. from page 3)
contain 10 ppb mercury,
which dropped to less than 2
ppb following treatment. At
Hanford and Savannah River,
recycling experiments show
no diminution in perfor-
mance. However, at Oak
Ridge, there was some
diminished activity of the
adsorbent by the third cycle.
For more information, or if
your site may be a candidate
for a full-scale SITE
demonstration, call Naomi
Barkley at EPA's Risk
Reduction Engineering
Laboratory at 513-569-7854
or Michael Hosea at Bio-
Recovery Systems, Inc. in Las
Cruces, New Mexico at 800-
697-3190.
To order additional copies of Ground Water Currents, or to be included on the permanent mailing list, send a fax request to the National
Center for Environmental Publications and Information (NCEPI) at 513-891-6685. or send a mail request to NCEPI. 11029 Kenwood Road,
Building 5, Cincinnati, OH 45242-0419. Please refer to the document number on the cover of the issue if available.
Ground Water Currents welcomes readers' comments and contributions. Address correspondence to:
Managing Editor, Ground Water Currents (5102W). U.S. Environmental Protection Agency,
401 M Street S.W.. Washington, DC 20460
United States
Environmental Protection Agency
National Center for Environmental
Publications and Information
P.O. Box 42419
Cincinnati, OH 45242-0419
Offical Business
Penalty for Private Use $300
EPA-542-N-94-005
-------
he U.S. EPA Environmental Technology Initiative (ETI)
was announced by President Clinton in his State of the
Union address on February 17, 1993. By promoting the
development, commercialization and use of environmental
technology, ETI will improve environmental quality while
fostering the creation of new jobs and businesses. ETI is
funded at $36 million in Fiscal Year 1994 (October, 1993-September,
1994) and a proposed $80 million in FY95. EPA's
Innovative Technology Council (ITC) coordinates
ETI activities Agency-wide. The Council is working
closely with a broad network of interested parties
including other federal agencies, the environmental
technology industry, non-profit groups, universities,
state and local governments, and others.
"Environmental technologies" include
technologies, goods, and services whose developement
is triggered primarily by environmental improvement
objectives. These include: products and services to
monitor and assess pollutant releases and exposure
levels; innovative technologies which prevent pollution,
control air and water pollution levels, safely manage
waste and remediate contaminated soil and groundwater; and, manage
environmenta data
The FY94 Program Plan describes 73 projects including: seven
projects involving the metal fabrication industry aimed at reducing
emissions and compliance costs for electroplaters and metal finishers;
partnerships with other federal agencies to demonstrate pollution
control, monitoring, and prevention technologies in Mexico, South
America, Asia, Central and Eastern Europe; and, the Clean Car
Technology Demonstration Program where EPA, the Department of
Energy and domestic auto manufacturers will demonstrate ways to
improve car and truck fuel economy and lower carbon dioxide
emissions. The EPA Technology Innovation Strategy is a blueprint for
the Agency's future efforts to create incentives for the development
and use of innovative technologies in federal and state environmental
regulations, to reduce trade barriers to technology innovation strategy,
and improve the competitivness of the
environmental technology industry in domestic
and international markets.
EPA is now in the process of soliciting FY 1995
project proposals. In the first solicitation, EPA is
seeking environmental technology proposals from
federalagencies, stategovernments (including state
colleges that are departments of state agencies), and
tribal governments (including Alaska Native
Villages). The second solicitation will seek proposals
from non-profit groups, universities and their
partners. The third solicitation will be awarded to
Phase 3, Small Business Innovation Research (SBIR)
projects. Candidate projects must have already
completed Phases 1 and 2 of the SBIR process.
Copies of the EPA Environmental Technology Initiative: FY 1994
Program Plan (S/N 055-00000465-O), the EPA Technology
Innovation Strategy (S/N 055-000-00466-8), and the EPA
Environmental Technology Initiative: Program Solicitation Package
for FY 1995 (S/N 055-000-00476-5) are available through the GPO
Order Desk. Please contact the Order Desk at (202) 512-1800.
*7442
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copes of the EPA Environmental Technology Initiative: FY 1995 Program Solicitation Package,
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copies of fhe EPA Environmental Technology Initiative: FY 1994 Program Plan,
S/N 055-000-00465-0 for ":-3.00 each !:3,75 foreign)
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