s3£zEPA
United States Environmental Protection Agency
Office of Solid Waste and Emergency Response
Office of Research and Development
Washington, DC 20460
Rock? Flats Field Office
L • * U I | T • * • I < I I • F ¦ i ¦ ( i
PROGRAM FACT SHEET
July 1995
General Environmental Corporation CURE
Electrocoagulation Technology
Rocky Flats Environmental Technology Site
Golden, Colorado
INTRODUCTION
The U.S. Department of Energy (DOE) and the U.S. Environ-
mental Protection Agency (EPA) will demonstrate an innova-
tive technology at DOE's Rocky Flats Environmental Technol-
ogy Site (RFETS) near Golden, Colorado (Figure 1) this
summer. This demonstration is being conducted as part of
EPA's Superfund Innovative Technology Evaluation (SITE)
Program.
The technology to be demonstrated at RFETS is the CURE
electrocoagulation technology developed by General Environ-
mental Corporation of Englewood, Colorado. The demonstra-
tion will evaluate the ability of the CURE technology to
remove radioactive metals (uranium, plutonium, and ameri-
cium) from RFETS Solar Evaporation Pond (SEP) water now
held in storage tanks. This demonstration is a pilot-scale test to
evaluate the technology's potential applicability to cleanup
radioactive metal-contaminated waters and wastes.
EPA's SITE PROGRAM
Each year, EPA solicits proposals from private technology,
developers to demonstrate innovative technologies under the
SITE Program. For each technology selected, EPA does the
following, often with input from state and regional agencies:
¦ Identifies a site with wastes suitable for treatment
¦ Prepares a technology Quality Assurance Project Plan
(QAPP)
¦ Notifies appropriate agencies for intergovernmental and
commun ity reviews
¦ Prepares a fact sheet for the public, proposing the site and
technology match
¦ Prepares the demonstration site
¦ Conducts and audits field sampling and laboratory
analyses
¦ Organizes a Visitors' Day for the public to view the
technology demonstration
¦ Evaluates technology performance
¦ Prepares an Innovative Technology Evaluation Report
summarizing the demonstration results, as well as several
other informational items such as technology bulletins,
demonstration summaries, and a video.
ROCKY FLATS BACKGROUND
RFETS, formerly known as the Rocky Flats Plant, is located in
northern Jefferson County, Colorado, approximately 16 miles
northwest of downtown Denver (Figure 1). The 400-acre plant
site is located within a restricted area of approximately 6,550
acres, which serves as a buffer zone between the plant and
surrounding communities.
Until 1990, plutonium for the manufacture of triggers for
thermonuclear weapons was processed, purified, machined, and
prepared for assembly at the Rocky Flats Plant. As part of the
manufacturing process, wastes were produced containing
plutonium, uranium, and other contaminants.
Much of this process waste was collected in a series of five
evaporation ponds located in the central portion of the RFETS,
inside the protected area (Figure 2). Those liquid process .
wastes contained less than 100,000 picoCuries per liter (pCi/L)
of total long-lived alpha activity, high concentrations of
nitrates, as well as treated acidic wastes, including sanitary
PUBLIC INVOLVEMENT
During this SITE demonstration, the public is invited to
attend a Visitors' Day scheduled for August 22, 1995.
The Visitors' Day will enable the community to become
familiar with the SITE Program, and the CURE technol-
ogy. To attend the Visitors' Day, complete the enclosed
registration form.
-------
sewer sludge, lithium chloride, lithium metal, sodium nitrate,
ferric chloride, sulfuric acid, ammonium persulfates, hydro-
chloric acid, nitric acid, hexavalent chromium, tritium, and
cyanide solutions.
Placement of process waste material in the SEPs stopped in
1986 due to changes in waste treatment operations. In 1994,
the sludge and liquid remaining in the A and B ponds were
removed and placed in storage tanks inside temporary struc-
tures erected on the 750 Pad.
TECHNOLOGY DESCRIPTION
A process flow diagram of the CURE technology is shown in
Figure 3.
The CURE technology is designed to remove contaminants
from groundwater or wastewater, including (1) dissolved ions,
such as metals; (2) suspended colloidal materials, such as
carbon black or bacteria; and (3) emulsified oily materials.
The CURE system uses coagulation, precipitation, and settling
to remove the contaminants from the water. Contaminants are
dissolved or suspended in aqueous solutions as a result of small
electrostatic charges at the surface of the particles. In a
conventional coagulation and precipitation system, a chemical
is added to the contaminated solution. The positively charged
portions of the additive bind with the negatively charged
contaminants in solution, causing them to coagulate and then,
when of sufficient mass, precipitate out of solution. The CURE
system uses an electrical current (electrocoagulation) as the
source of the coagulant rather than a chemical additive.
Direct-current electricity is applied to the cathode-anode
system as the contaminated water passes through the system.
The electricity destabilizes the suspended contaminants. In
addition, the electrolytic process causes cations from the anode
metal (iron or aluminum) to dissolve in the water (Figure 4).
The cations react with the destabilized contaminants and create
metal hydroxides. It is the metal hydroxides that precipitate
out of solution. Much of the precipitate takes the form of very
fine particles commonly referred to as floes.
Contaminated water to be treated by the CURE system passes
through electrocoagulation tubes, which consist of a tube-
shaped anode that concentrically surrounds a tube-shaped
cathode, thereby leaving an annular space between the anode
and the cathode (Figure 4). Contaminated water passes through
the center of the cathode tube, then through the annular space
between the cathode and anode tubes.
After the treated wastewater leaves the electrocoagulation
tubes, it is transferred to a clarifier. In the clarifier, the floes
are separated from the treated water. After settling in the
clarifier, floes are removed in the underflow, and treated water
is removed in the overflow.
If the clarifier underflow is sufficiently low in water, further
dewatering will not be necessary. If further dewatering of the
floes is required, sludge dewatering equipment is integrated
into the transportable treatment unit in the form of a filter press.
TECHNOLOGY DEMONSTRATION
The demonstration of the CURE technology at RFETS is
scheduled to begin on July 31, 1995 and will last approxi-
mately 3 weeks. The CURE pilot scale treatment unit will
treat 8,000 gallons of water during the demonstration at a flow
rate of up to 5 gallons per minute.
The water to be treated during the demonstration will be
pumped from the storage tanks on the 750 Pad and trucked to
the 904 Pad on the southern side of the RFETS industrialized
area (Figure 2). Treated water will be discharged to a second
tanker for final treatment by RFETS. Bench-scale studies of
the CURE system have shown that the technology is capable
of removing nearly 90 percent of the radioactive metal
contaminants from the SEP water.
EPA prepared a detailed demonstration test plan that outlines
the methods and procedures for testing and evaluating the
technology. This demonstration plan has been reviewed by
DOE. In addition, a report summarizing the demonstration
results will be issued by the EPA SITE Program approximately
1 year following completion of the demonstration. The results
of the demonstration will be used to decide whether the CURE
technology may be an effective alternative for cleaning up
similar waste streams across the country. Copies of the report
will be available at no charge from EPA's Center for Environ-
mental Research Information (CERI), 26 West Martin Luther
King Drive, Cincinnati, Ohio 45268 (513) 569-7562.
2
-------
Figure 2: RFETS Facility Map
PROTECTED AREA
COLOEN. coloaaoo
reNCE — ftoo
Figure 3: Process Flow Diagram
Legend
[X] Valve Pump X Sample
Dewatered
Sluge
Port
Flow Direction
Tank
CURE
Electrocoagulation
Tubes
3
-------
ADDITIONAL INFORMATION
Questions or comments about the proposed demon-
stration, or the SITE Program should be directed to:
Annette Gatchett
SITE Project Manager
National Risk Management Research Laboratory
U.S. Environmental Protection Agency
26 West Martin Luther King Dr.
Cincinnati, OH 45268
513-569-7692
Questions about the technology should be directed to:
Carl Dalrymple
General Environmental Corp.
9025 E. Kenyon, Suite 312
Denver, CO 80237
Phone: 303-889-5949
Fax: 303-889-5946
Questions about RFETS should be directed to:
Jill Paukert
Kaiser-Hill Community Relations
Rocky Flats Environmental Technology Site
P.O. Box 464
Golden, CO 80402-0464
303-966-6160
U.S. Environmental Protection Agency
26 West Martin Luther King Drive
Cincinnati, Ohio 45268
Attention: Annette Gatchett
A Printed on Recycled Paper
4
------- |