v>EPA
United States
Environmental Protection
Agency
INNOVATIVE
TECHNOLOGY EVALUATION
Electrochemical Remediation Technologies (ECRTs)
Technology Deseription:The Electrochemical Remediation
Technologies (ECRTs) process was developed by P2-Soil
Remediation, Inc. P-2 Soil Remediation, Inc. formed a part-
nership with Weiss Associates and ElectroPetroleum, Inc.
to apply the technology to contaminated sites. The ECRTs
process was evaluated for the treatment of marine sedi-
ments contaminated with mercury, PAHs, and phenolic
compounds. The demonstration of the ECRTs was con-
ducted at the Georgia Pacific, Inc. (G-P) Log Pond located
along the Whatcom Waterway in Bellingham Bay, Belling-
ham, Washington.The G-P Log Pond pilot project consisted
of a demonstration of ECRTs, which utilizes a DC/AC cur-
rent passed between an electrode pair (anode and cath-
ode) placed in sediment. Remediation of the sediment was
to be accomplished by either the mineralization of organic
contaminants through the ElectroChemicalGeoOxidation
(ECGO) process, or by use of the Induced Complexation
(1C) process to complex, mobilize, and remove metal con-
taminants plated to the electrodes. The pilot study was
designed to assess and evaluate the ability of the ECRTs
process to reduce concentrations of mercury, polyaro-
matic hydrocarbons (PAHs), and phenolic compounds in a
marine sediment.
The following information has been provided by the tech-
nology developer as descriptions of the ECGO and 1C
processes. The SITE program has not substantiated any
claims made in these descriptions.
ElectroChemicalGeoOxidation—Using a low voltage, low
amperage proprietary coupled DC/AC current, an induced
polarization field is created within the sediment.The sedi-
ment acts as a capacitor, discharging and charging electric-
ity resulting in redox reactions, which cause desorption of
the contaminants from the sediments and mineralization
of the organics in the matrix. Empirical evidence indicates
that reaction rates are inversely proportional to grain size,
such that ECRTs remediate faster in finer-grained materi-
als typically found at contaminated sediment sites. The
sediment-pore water system can be considered an elec-
trochemical cell. In an electrochemical cell, reactions only
occur at the electrodes and comprise anodic oxidation or
cathodic reduction. However, in sediment, in addition to
the local electrode reactions, redox reactions occur simul-
taneously at any and all interfaces within the sediment-
water-contaminant system at the pore scale. The reaction
partners for oxidations and reductions are simultaneously
generated by water hydrolysis.
Empirical ECRTs field remediation data of rapid mineral-
ization of organic contaminants including phenolic com-
pounds and PAHs (and enhanced mobilization rates for
metals) suggest that the secondary current released via
sediment electrical discharges provides the activation and
dissociation energy for the ensuing redox reactions. Ad-
ditionally, it is suspected that trace metals in the sediment
may act as catalysts, reducing the activation energy re-
quired for the redox reactions. The quantification of these
energy releases remains to be completed. Since the redox
reactions are occurring at the pore scale, the ECRTs system
pH is stabilized in the neutral range.
Induced Complexation—Metals remediation is achieved
when redox reactions, created by the same low voltage/
amperage current described above, desorb the contami-
nants from the sediment and create ionic metal complexes
that are mobile. These mobile ions move readily to the
electrodes, are electrically contained by the induced direct
current, and are migrated to the electrodes where they are
chemically deposited. Following treatment, the electrodes
are removed and disposed, or the metals deposited onto
the electrodes are recycled.
For this demonstration project, Weiss Associates, (Em-
eryville, CA) installed, operated, and maintained the ECRTs
pilottest equipment at the Log Pond site. Installation of the
pilot study infrastructure involved placing 9 anode (graph-
ite) and 9 cathode (8 steel and 1 graphite plate) electrodes,
in two rows, into the sediments. Each electrode row (e.g.,
anode sheet electrode line) was approximately 30 feet
long. The distance between the anode and cathode sheet
electrode lines was approximately 30 feet. Electricity was
supplied, in parallel, to each individual electrode plate.
Demonstration Site Description: The G-P Log Pond is a
marine embayment that served as a former log storage
and handling area and receiving water for facility efflu-
ent and stormwater runoff. The ECRTs project area was
designated as an approximately 50-feet (ft) by 50-ft area
within a pre-characterized area of the G-P Log Pond known
to contain elevated concentrations of mercury, phenolics,
and PAHs. However, based on results from a preliminary
survey, mercury was identified as the most ubiquitous and
consistently elevated contaminant relative to Washington
State Sediment Management Standards (SMS) Sediment
Quality Standards (SQS) and Cleanup Screening Levels
(CSL) which are used in Puget Sound to assess contami-
nated sediments underWashington State law.
The actual area for sample collection to evaluate the tech-
nology's effectiveness was a 20-ft by 30-ft zone within the
electrode arrays. With the exception of the Port of Belling-
ham's Shipping Terminal dock on the Whatcom Waterway
adjacent to the test plot, there were no structures within
the project area. The mudline elevations within the test plot
ranged from approximately -4 to -8 feet Mean Lower Low
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Water (MLLW). Log Pond sediments with elevated chemi-
cal concentrations and woody debris measured approxi-
mately 5 to 6 ft thick between underlying native material
and a cap of clean sand from regional maintenance dredg-
ing projects. The area was capped in late 2000 and early
2001 with clean capping material as part of a ModelToxics
Control Act (MTCA) interim cleanup action. Cap thickness
within the sediment treatment demonstration area ranged
from 0.5 to 1 foot in thickness.
Demonstration Results: The SITE demonstration of the
ECRTs system was conducted from August 2002 (Baseline
Survey prior to installation) until March 2003 (Post-Demon-
stration Survey) in cooperation with the Washington State
Department of Ecology (Ecology). The performance of the
ECRTs process was evaluated by collecting sediment cores
from within and adjacent to the electrode array and from
'reference' stations located within the log pond but beyond
the influence of the ECRTs electrical field. Intermediate
monitoring events were conducted in November 2002 and
December 2002 during the active ECRTs demonstration
period. A third monitoring event scheduled for February
2003 was canceled due to system operational concerns.
The primary technical objective of the demonstration was
to determine whether there was a significant trend in the
reduction of sediment mercury concentrations over the pe-
riod of the demonstration. Reference area samples were
collected for comparison to determine whether treatment
differed from natural attenuation. The experimental design
was based upon the presence of a significant mercury re-
duction from the baseline sampling event relative to the
post-treatment sampling event. The primary objective is
not associated with a percent reduction but instead the
primary objective is to determine a statistically significant
negative trend over time. Samples of the cap material and
the underlying native material were used to evaluate po-
tential migration of contaminants.
Sediment samples were collected from ten locations with-
in the test plot, five from the extended zone of influence
(adjacent to the test plot), and five remote reference loca-
tions. Samples were collected on four occasions including
a baseline survey prior to the demonstration, two interme-
diate monitoring events, and the final post-demonstration
event. Six samples were collected from each sediment
core including three separate vertical composite samples
from the contaminated horizon (i.e. top, mid, and bottom
third of material between the cap and native material); one
composite over the length of the contaminated horizon
(i.e. equivalent to compositing the three vertical samples
together); one cap sample; and one native material sam-
ple. Select samples were either submitted for analysis of
mercury, PAHs, phenolic, and sediment conventionals (or-
ganic carbon, total solids, and grain size distribution), or
archived (frozen).
A statistical analysis of the sediment chemistry results
indicate no significant trend in the reduction of sediment
mercury concentrations over the period of the demon-
stration. In addition, there was no trend in the reduction
of PAHs and phenolic compounds. Performance issues
may be partially attributed to system operational prob-
lems encountered during the course of the demonstration.
Electrical readings collected by the technology's sponsor
indicated a steady degradation of system performance
throughout the duration of the demonstration, resulting in
an early shutdown of the system prior to completion of the
planned test period. In addition, when the electrodes were
removed from the test plot, it was evident that the connec-
tions between the electrical supply and anode plates had
completely corroded to the point that a viable contact had
not been maintained. A more detailed discussion of the
technology and results are presented in two companion
SITE documents: theTechnology Capsule and the Innova-
tive Technology Evaluation Report (ITER).
For Further Information:
EPA Project Manager
Randy Parker
U.S. EPA National Risk Management Research Laboratory
26W. Martin Luther King Jr. Dr.
Cincinnati, OH 45268
(513) 569-7271
E-mail: parker.randy@epa.gov
Technology Developer Contact
Kenneth Whittle
Electro-Petroleum, Inc.
996 Old Eagle School Road, Suite 1118
Wayne, PA 19087
Phone: (610) 687-9070
E-mail: Kwhittle@electropetroleum.com
Falk Doering
51, Burghaldenweg, D-70469
Stuttgart, Germany
Phone: 01149-711-859146
E-mail: stqt@ecp-int.com
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