Bioremediation Using DARAMEND for
Treatment of POPs in Soils and Sediments
POPs - WASTES APPLICABILITY (REFS. 1,6, AND 10):
DARAMEND® is a bioremediation technology that has been used to treat soils and sediments
containing low concentrations of pesticides such as toxaphene and DDT as well as other contaminants.
POPs Treated:
Other Contaminants Treated:
Toxaphene and DDT
ODD, DDE, RDX, HMX, DNT, and TNT
TECHNOLOGY DESCRIPTION (REFS. 4,5 AND 10):
OVERVIEW
DARAMEND® is an amendment-enhanced
bioremediation technology for the treatment of
POPs that involves the creation of sequential
anoxic and oxic conditions. The treatment
process involves the following:
1. Addition of solid phase DARAMEND®
organic soil amendment of specific
particle size distribution and nutrient
profile, zero valent iron, and water to
produce anoxic conditions.
2. Periodic tilling of the soil to promote oxic
conditions.
3. Repetition of the anoxic-oxic cycle until
the desired cleanup goals are achieved.
DARAMEND® particle colonization as
viewed throuqh an electron-microscope
The addition of DARAMEND organic
amendment, zero valent iron, and water stimulates the biological depletion of oxygen generating strong
reducing (anoxic) conditions within the soil matrix. The diffusion of replacement oxygen into the soil
matrix is prevented by near saturation of the soil pores with water. The depletion of oxygen creates a
very low redox potential, which promotes dechlorination of organochlorine compounds. A cover may
be used to control the moisture content, increase the temperature of the soil matrix and eliminate run-
on/run off. The soil matrix consisting of contaminated soil and the amendments is left undisturbed for
the duration of the anoxic phase of treatment cycle (typically 1- 2 weeks).
In the oxic phase of each cycle, periodic tilling of the soil increases diffusion of oxygen to microsites
and distribution of irrigation water in the soil. The dechlorination products formed during the anoxic
degradation process are subsequently removed trough aerobic (oxic) biodegradation processes,
initiated by the passive air drying and tilling of the soil to promote aerobic conditions.
Addition of DARAMEND® and the anoxic-
oxic cycle continues until the desired
cleanup goals are achieved. The
frequency of irrigation is determined by
weekly monitoring of soil moisture
conditions. Soil moisture is maintained
within a specific range below its water
holding capacity. Maintenance of soil
moisture content within a specified range
facilitates rapid growth of an active
microbial population and prevents the
generation of leachate. The amount of
DARAMEND® added in the second and
subsequent treatment cycles is generally
less than the amount added during the first
cycle.
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Bioremediation Using DARAMEND for
Treatment of POPs in Soils and Sediments
DARAMEND technology can be implemented using land farming practices either ex situ or in situ. In
both cases, the treatment layer is 2 feet (ft) deep, the typical depth reached by tilling equipment.
However, the technology can be implementation in 2-ft sequential lifts. In the ex situ process, the
contaminated soil is excavated and sometimes mechanically screened in order to remove debris that
may interfere with the distribution of the organic amendment. The screened soil is transported to the
treatment unit, which is typically an earthen or concrete cell lined with a high-density polyethylene liner.
In situ, the soil may be screened to a depth of 2-ft using equipment such as subsurface combs and
agricultural rock pickers.
STATUS AND AVAILABILITY (REF. 1):
DARAMEND® is a proprietary technology and is available only through one vendor - Adventus
Remediation Technologies (ART), Mississauga, Ontario, Canada. In the U.S., the technology is
provided by ART'S sister company, Adventus Americas Inc., Bloomingdale, IL. The technology has
been used for the treatment of POPs (toxaphene and DDT) since 2001. Table 1 lists performance data
for DARAMEND® technology application at selected sites. Through 2005, DARAMEND® has been
implemented at two POPs contaminated sites.
Table 1: Performance Data of DARAMEND at Selected Sites
Site Name
Scale
Quantity
Treated
(tons)
No. of
treatment
cycles
Duration
of each
cycle
Cost
per
ton*
Performance
Contaminant
Untreated
Concen-
tration
(mg/kg)
Treated
Concen-
tration
(mg/kg)
POPs Contaminated Sites
T.H. Agricultural &
Nutrition (THAN)
Superfund Site,
Montgomery,
Alabama
W.R. Grace,
Charleston, South
Carolina
Full
Pilot
4,500
250
15
8
10 days
1 month
$55
$95
Toxaphene
DDT
DDE
ODD
Toxaphene
DDT
See Table 2 for
performance data
239
89.7
5.1
16.5
Non-POPs Contaminated Sites
Naval Weapons
Station, Yorkt own,
Virginia
Iowa Army
Ammunition Plant,
Burlington, Iowa
Confidential Site,
Northwest U.S.A.
(applied in multiple
2-ft lifts)
Full
Full
Full
4,800
8,000
6,000
12
5
Aerobic
treatment
7-10
days
7-10
days
N/A
$90
$150
$37
TNT
RDX
DNT
RDX
HMX
TNT
PCP
PCP
15,359
1,090
1,002
1 ,530,
1,112,
95.8
359
760
14
1.6
13
16.2
84.5
8
8
31
Source: Ref. 1
* Treatment costs are as reported by vendor. The vendor did not specify what was included in this cost.
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Bioremediation Using DARAMEND for
Treatment of POPs in Soils and Sediments
DESIGN (REF. 5):
The major design factor for the implementation of this technology is the amount and type of soil
amendments required for bioremediation. This is dependent on site conditions and the physical
(textural variation, percent organic matter, and moisture content) and chemical (soil pH, macro and
micronutrients, metals, concentration and nature of contaminants of concern) properties of the target
soil. The duration of the treatment cycle is based on soil chemistry, concentration of contaminants of
concern and soil temperature. The number of treatment cycles is based on the required cleanup levels
of the contaminant.
THROUGHPUT (REF. 4):
For ex situ treatment, the amount of POPs contaminated soil/sediment that can be treated is
dependent on the available surface area to spread contaminated soil. The technology can also be
applied ex-situ in windrows. For in-situ application, the tillage equipment limits the depth (2-ft) to which
the soil can be remediated. However, the technology can be used in-situ at depth greater than 2-ft
using alternative soil mixing equipment or injection techniques.
WASTES/RESIDUALS (REF. 4):
The primary wastes generated are debris, stone, and construction material that are removed in the
pretreatment process. No leachate is generated if a treatment area cover is used. If no cover is used,
precipitation in the treatment area may generate leachate or storm water run-off.
Sampling and monitoring activities of the treatment pile will generate personal protective equipment
(PPE) and contaminated water from decontamination activities.
MAINTENANCE:
Implementation
the upkeep of tilling, soil moisture control, and other industrial equipment. Because the specific
amendments and application rate of DA
will vary by site and type of soil treated.
Implementation of the DARAMEND® technology to treat POPs requires limited maintenance such as
her
amendments and application rate of DARAMEND® are site and soil-specific, the ongoing maintenance
LIMITATIONS (REFS. 4 AND 9):
DARAMEND® technology may become technically or economically infeasible when treating soils with
excessively high contaminant concentration. The technology has not been used for the treatment of
other POPs such as PCBs, dioxins, orfurans. ART, the developer of the technology, indicated that it
has been only marginally successful in bench scale treatment of PCB-contaminated soil. Bench scale
or pilot scale studies are typically conducted before field application of this technology; the type and
amount of soil amendments required are then based on the results of these studies.
In situ application of this technology using tilling equipment is limited to a depth of 2-ft. However, the
technology can be used in situ at depths greater than 2-ft using alternative soil mixing equipment or
injection techniques. This technology requires that the treatment area be free of surface and
subsurface obstructions that would interfere with the soil tilling. Ex situ application of this technology
requires a large surface area to treat large quantities of the contaminated soil. Implementation of this
technology in 2-ft sequential lifts would increase the total time required to treat the contaminated soil.
The technology can also be applied ex situ in windrows.
Application of this technology requires a source of water (either city, surface, or subsurface).
This technology cannot be applied to sites that are prone to seasonal flooding or have a water table
that fluctuates to within 3-ft of the site surface. These conditions make it difficult to maintain the
appropriate range of soil moisture required for effective bioremediation, and may redistribute
contamination across the site.
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Bioremediation Using DARAMEND for
Treatment of POPs in Soils and Sediments
Volatile organic compound emissions may increase during soil tilling. Other factors that could interfere
with the process would be large amounts of debris in the soil, which would interfere with the
incorporation of organic amendments and reduce the effectiveness of tilling. Presence of other toxic
compounds (heavy metals) may be detrimental to soil microbes. Soils with high humic content may
slow down the cleanup through increased organic adsorption and oxygen demand.
FULL-SCALE TREATMENT EXAMPLES (REF. 3):
Bioremediation of pesticides-impacted soil/sediment, T.H. Agriculture and Nutrition (THAN) Superfund
Site, Montgomery, Alabama.
The THAN site is located on the west side of Montgomery, Alabama, about 2 miles south of the
Alabama River. The site is approximately 16 acres in area. Previous site operations involved the
formulation, packing and distribution of pesticides, herbicides, and other industrial/waste treatment
chemicals. The site was listed on the National Priorities List (NPL) on August 30, 1990. In 1991, EPA
entered into a consent agreement with Elf Atochem North America Inc., the Potentially Responsible
Party (PRP) for the site, to conduct a remedial investigation/feasibility study for the site. The final
Record of Decision (ROD) for the site was signed on September 28, 1998, and bioremediation was
selected as the remedy for treating the contaminated soils and sediments. DARAMEND® was selected
as the bioremediation technology.
The contaminated soil and excavated sediments (approximately 4,500 tons) were treated using
anaerobic/aerobic bioremedi
involved the following steps:
anaerobic/aerobic bioremediation cycle using DARAMEND®. Implementation of the technology
1 . DARAMEND® amendment and powdered iron application and incorporation
2. Determination of water holding capacity (first cycle only)
3. Determination of treatment matrix moisture content
4. Irrigation
5. Measurement of soil redox potential
6. Soil allowed to stand undisturbed for anoxic phase (approximately 7 days)
7. Soil tilled daily to generate oxic condition (approximately 4 days)
8. Steps 1 , and 3 to 7 were repeated for each subsequent cycle. Fifteen treatment cycles were
implemented in some treatment areas on site.
Two agricultural tractors (Model: Massey-Ferguson 394 H) mounted with deep rotary tillers were used
for amendment application and tilling the treatment area. The target soil moisture content at the
beginning of each cycle was approximately 33% (dry wt. basis) or 90% of the soil's water holding
capacity. The optimal pH range (6.6 to 8.5) of the treatment area was maintained by adding hydrated
lime at a rate of 1 ,000 mg/kg during the oxic phase of the third, sixth, and twelfth cycle. Following the
application of each treatment cycle, samples were collected from the treatment area. The treatment
area was divided into 12 sampling zones and one composite sample (composite of four grab samples)
was collected from each zone. The samples were collected from the full 2-ft soil profile of treatment
area. Fifteen treatment cycles were applied to some areas of the site. Table 2 lists the initial and final
concentration of the samples collected from these 12 zones.
Based on the final sampling event DARAMEND® reduced the concentration of all the contaminants of
concern to less than the specified performance standards. The average treatment cost in USD at the
THAN site was $55 per ton. The vendor did not specify what was included in this cost.
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Bioremediation Using DARAMEND for
Treatment of POPs in Soils and Sediments
Table 2: DARAMEND18' performance at the THAN Site
Sampling
Zone
1
2
3
4
5
6
7
8
9
10
11
12
Toxaphene
(29 mg/kg) 1
Initial A
Cone.
(mg/kg)
77
260
340
45
230
90
100
13
330
48
20
720
Final J
Cone.
(mg/kg)
<20
<21
<21
<21
<21
<21
<20
<20
<21
<20
<20
<21
DDT
(94 mg/kg)1
Initial A
Cone.
(mg/kg)
126
227
33.2
55.1
216
13.3
151
9.1
45
44.4
12.6
78
Final J
Cone.
(mg/kg)
10.2
15
4.5
14.7
16.1
2.2
15.3
5.2
5.7
5.7
2.9
6.3
DDD
(94 mg/kg)1
Initial A
Cone.
(mg/kg)
52
133
500
34
93
130
85
44
312
146
46
590
Final J
Cone.
(mg/kg)
26.4
73
89
37
53
59
38
24.3
85
25.5
25.1
87
DDE
(133 mg/kg)1
Initial A
Cone.
(mg/kg)
33
35.3
49
15.8
22.4
17
25.2
6.9
28.2
20.1
6.9
59.6
Final J
Cone.
(mg/kg)
6
8.4
7.8
7.2
6.8
5.7
6.3
2.8
7.2
4.2
3.0
8.6
Notes:
1 . Performance Standard as specified in the Record of Decision, Summary of Remedial
Alternatives Selection, THAN Site.
2. Initial concentration reported from samples collected by responsible party.
3. Final concentration reported from splits samples collected by EPA.
U.S. EPA RPM FOR THAN SITE:
Brian Farrier
EPA Region 4
Telephone: 404-562-8952
Fax: 404-562-8955
Email: farrier.brain(S>,epa.qov
VENDOR CONTACT DETAILS:
David Raymond
Adventus Remediation Technologies, Inc.
1 345 Fewster Drive
Mississauga, Ontario L4W2A5
Telephone: 905-273-5374, Extension 224
Mobile: 416-818-0328
Fax: 905-273-4367
Email: info@adventusremediation.com
Web Site: http://www.adventusremediation.com
PATENT NOTICE:
DARAMEND® is a patented technology with U.S. Patent No. 5,618,427.
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Bioremediation Using DARAMEND for
Treatment of POPs in Soils and Sediments
REFERENCES:
1. Adventus Remediation Technologies, Inc. DARAMEND project summaries. Online Address:
http://www.adventusremediation.com.
2. Adventus Remediation Technologies, Inc. March 2002. Draft Final Report, Ex-Situ
DARAMEND Bioremediation of Soil Containing Organic Explosive Compounds, Iowa Army
Ammunition Plant, Middletown, Iowa.
3. Adventus Remediation Technologies, Inc. November 2003. Final Report, Bioremediation of
Soil and Sediment Containing Chlorinated Organic Pesticides, THAN Superfund Site,
Montgomery, Alabama.
4. EPA. 1996. Site Technology Capsule, GRACE Bioremediation Technologies DARAMEND®
Bioremediation technology. Superfund Innovative Technology Evaluation. EPA/540/R-95/536.
5. EPA. 1997. Site Technology Capsule, GRACE Bioremediation Technologies DARAMEND®
Bioremediation technology. Superfund Innovative Technology Evaluation. EPA/540/R-
95/536a.
6. EPA. 2002. Technology News and Trends, Full-Scale Bioremediation of Organic Explosive
contaminated soil. EPA 542-N-02-003. July.
7. EPA. 2004. TH Agricultural & Nutrition Company Site Information and Source Data. Online
Address: http://www.epareachit.org.
8. EPA. 2004. TH Agricultural & Nutrition Company Site, RODS Abstract information, Superfund
Information Systems. Online Address: http://www.epa.gov/superfund.
9. Farrier, Brian, EPA Region 4. 2004. Telephone Conversation with Younus Burhan, Tetra Tech
EM Inc. August 31 and October 19.
10. Phillips, T., Bell, G., Raymond, D., Shaw, K., and Seech, A. 2001. "DARAMEND® technology
for in situ bioremediation of soil containing organochlorine pesticides."
11. Raymond, David, Adventus Remediation Technologies, Inc. 2004. Telephone Conversation
with Younus Burhan, Tetra Tech EM Inc. August 25.
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