Anaerobic Bioremediation Using Blood Meal for
Treatment of Toxaphene in Soil and Sediment
POPS-WASTES APPLICABILITY (REFS. 1 AND 5):
Anaerobic Bioremediation Using Blood Meal was able to rapidly degrade toxaphene in soil to achieve
cleanup goals in bench- and pilot-scale tests. Bench-scale tests have indicated that the technology is
also effective in treating dichlorodiphenyltrichloroethane (DDT). Full-scale implementations have
successfully treated several toxaphene-contaminated sites. The quantity of soil treated at these sites
ranged from 250 to 8,000 cubic yards. This technology does not typically achieve greater than 90
percent contaminant reduction.
POPs Treated: Toxaphene and DDT
Other Contaminants Treated: None
Application: Ex-situ
TECHNOLOGY DESCRIPTION (REFS. 1 AND 5):
OVERVIEW
This technology uses biostimulation to accelerate the degradation of toxaphene in soil or sediment. It
involves the addition of biological amendments, including blood meal (nutrient) and phosphates (pH
buffer), to stimulate native anaerobic microorganisms. Blood meal is a black powdery fertilizer made
from animal blood. The typical dosage of blood meal and sodium phosphate is one percent by weight
of contaminated soil. This is sometimes augmented with one percent by weight of starch to rapidly
establish anaerobic conditions. The standard recipe uses monobasic and dibasic phosphate salts in
equal proportions (monobasic:dibasic-1:1) to maintain soil pH around 6.7. The low phosphate/starch
recipe uses three times more dibasic than monobasic phosphates (monobasic:dibasic - 1:3) and
maintains soil pH around 7.8.
The soil to be treated is mixed with amendments and water. Mixing methods including blending in a
dump truck, mechanical mixing in a pit, and mixing in a pug mill have been used to produce
homogeneous soil-amendment mixtures. The mixture is transferred to a cell with a plastic liner, and
excess water is added to provide up to a foot of cover above the settled solids. The water provides a
barrier that minimizes the transfer of atmospheric oxygen to microorganisms in the slurry, which helps
maintain anaerobic conditions. The lined cell is covered with a plastic sheet to isolate the cell from the
environment, and the slurry is incubated for several months. The slurry may be sampled periodically to
measure treatment progress. Once treatment goals have been met, the cell is drained. The slurry is
usually left in place, but it may be dried and used as fill material on site. The slurry also serve as a
source of acclimated microorganisms for use at another toxaphene-contaminated site.
Anaerobic degradation of toxaphene usually results in the production of intermediates such as less
chlorinated congeners of toxaphene. Further degradation of intermediates results in the production of
carbon dioxide, methane, water, inorganic chlorides, and cell mass.
STATUS AND AVAILABILITY (REFS. 2 AND 6):
The technology has been implemented at full scale to treat toxaphene-contaminated sites. Four such
sites are:
(1) The Laahty Family Dip Vat (LDV) site (253 cubic yards in one cell)
(2) The Henry O Dip Vat (HDV) site (660 cubic yards in two cells)
(3) The Gila River Indian Community (GRIG 1) site (3,500 cubic yards in four cells)
(4) The GRIG 2 site (8,000 cubic yards in five cells)
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Anaerobic Bioremediation Using Blood Meal for
Treatment of Toxaphene in Soil and Sediment
EPA's Environmental Response Team (ERT) is the developer of the technology. The technology is
unlicensed and is available through the ERT. The biological amendments (blood meal, and monobasic
and dibasic phosphates) are inexpensive and commercially available.
Design (Refs 1, 5):
Factors that need to be considered when designing an anaerobic bioremediation process using blood
meal include:
• The presence of active toxaphene-degrading bacteria
• Soil characteristics
• Volume of soil to be treated
• Concentration of toxaphene in contaminated soil
• Cleanup goal
• Availability of space on site for the construction of treatment cells
• Odor mitigation requirements as determined by surrounding land use and the proximity of
residences
• Need for agreements with landowners and community leaders
• Climate
• Security issues
• Availability of water
THROUGHPUT (REFS. 1 AND 5):
Throughput of a technology that does not operate like a batch processing plant is hard to define.
Remediation involves a series of steps including construction, mix preparation, and treatment.
Treatment is usually the slowest step. Factors that can influence treatment time include, the type of
microbial communities present, amendment dosage, contaminant concentration, treatment goals, and
the presence of inhibitors (such as very cold environments). In general, treatment time can vary from
five weeks to two years.
WASTES/RESIDUALS (REFS 2,3 AND 6):
Products of toxaphene degradation include lower-chlorinated chlorobornane congeners, chloride ions,
cell mass, carbon dioxide, and methane. Chlorobornane congeners have been shown to degrade
completely during treatment. However, treated soil can contain low concentrations (below cleanup
goals) of unutilized toxaphene and lower-chlorinated chlorobornane congeners.
Gaseous wastes produced can include methane and hydrogen sulfide. Therefore, odor concerns
should be considered. If treatment cells are not left in place at the end of remediation, solid wastes can
include debris from the demolition of treatment cells and associated temporary facilities. Debris
potentially contaminated with toxaphene will require testing to determine its hazardous nature in
compliance with local, State, and Federal requirements prior to disposal.
MAINTENANCE (REFS. 2 AND 6):
• Periodic addition of water to treatment cells to maintain water level
• Maintaining treatment cells to prevent leaks
• Maintaining cover integrity
• Monitoring for gas buildup
• Monitoring for fugitive odors
• Soil sampling to monitor remedial progress
LIMITATIONS (REFS. 2 AND 6):
• The anaerobic process is affected by temperature. Spring and summer are the best periods
for operation. This technology cannot be used in extremely cold climates.
• This technology requires a bench scale test to determine applicability at a given site, and to
estimate treatment duration.
• At a minimum, five weeks are required for treatment.
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Anaerobic Bioremediation Using Blood Meal for
Treatment of Toxaphene in Soil and Sediment
This technology typically does not achieve greater than 90 percent contaminant destruction.
Blood meal accelerates the rate of reductive dechlorination of toxaphene, but does not affect
the extent of dechlorination.
Unfavorable soil chemistry can inhibit the process. Unfavorable soil chemistry may result from
the presence of bioavailable heavy metals including mercury, arsenic, and chromium; solvents;
and pesticides (including toxaphene).
Level C personal protective equipment is required when working with blood meal.
FULL-SCALE TREATMENT EXAMPLES (REFS. 1,2,5 AND 6):
Anaerobic bioremediation using blood meal and phosphate amendments has been implemented at a
full scale at twenty two (22) Dip Vat sites in the Navajo Nation. Other sites where this technology has
been applied at a full scale to remediate toxaphene-contaminated soil include:
(1) The Ojo Caliente Dip Vat site
(2) The Laahty Family Dip Vat site
(3) The Henry O Dip Vat site
(4) The Acoma Reservation at Sky City
(5) The Gila River Indian Community (GRIG 1) crop duster site
(6) The GRIG 2 crop duster site
The resources used for this fact sheet contain performance data on nine applications of this
technology. Performance data for each of these sites is presented in Table 1 at the end of this fact
sheet. Three of these sites are discussed below in greater detail. The unit cost of implementation at
these sites in USD ranged from $98 to $296 per cubic yard.
Laahty Family Dip Vat (LDV) site
The LDV site is located in The Zuni Nation, New Mexico. Soil at the site was contaminated with
toxaphene at an average concentration of 29 milligrams per kilogram (mg/kg). A total of 253 cubic
yards (cy) of soil was excavated and stockpiled on site. A cell with dimensions, 73 feet (ft) by 30 ft by 4
ft (deep) was constructed and lined with a plastic liner. Contaminated soil was placed in a concrete
mixer and mixed with biological amendments and water. Blood meal and monobasic phosphate were
added, each at a dosage rate of 10 grams per kilogram (g/kg) of contaminated soil. Dibasic phosphate
salts were also added at a dosage rate of 3.3 g/kg soil. The nutrient-amended soil slurry was then
placed in the lined cell. Water was added to provide one foot of cover above the solids in the cell. The
cell was then covered with a plastic sheet and incubated. Samples were collected periodically to
monitor progress. The toxaphene concentration decreased in the anaerobic cell from an initial
concentration of 29 mg/kg to 4 mg/kg in 31 days. This corresponded to an overall reduction of 86
percent. The post-treatment concentrations were below the 17 mg/kg action level established for the
site. In 2004, the total cost of treatment in USD was $75,000. Consequently, the unit cost of treatment
at this site was $296 per cubic yard.
Henry O Dip Vat (HDV) Site
The HDV site is located in The Zuni Nation, New Mexico. Approximately 660 cy of soil at this site was
contaminated with toxaphene at an average concentration of 23 mg/kg. Two cells were constructed for
soil treatment:
• The north cell (Cell 1) was 75 ft by 35 ft by 5 ft (deep).
• The south cell (Cell 2) was 65 ft by 30 ft by 5 ft (deep).
Both cells were lined with plastic liners. Blood meal and sodium phosphate were added to
contaminated soil and placed in a mixing pit using a backhoe. The dosage rate of blood meal was 5
g/kg of contaminated soil, while that of monobasic phosphate was 10 g/kg of contaminated soil.
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Anaerobic Bioremediation Using Blood Meal for
Treatment of Toxaphene in Soil and Sediment
Dibasic phosphate salts were also added at a dosage rate of 3.3 g/kg. Water was added to the soil in
the mixing pit, and the resulting soil slurry was extensively mixed. Once mixed, the soil slurry was
transferred to anaerobic cells 1 and 2. Water was added to provide one foot of additional cover above
the solids in each cell. Each cell was then covered with a plastic sheet and incubated for 61 to 76
days. Samples were collected on day 1 and day 61 from Cell 1 and on day 1 and 76 from Cell 2.
Analysis of the samples indicated that the average toxaphene concentration was reduced from 23
mg/kg to 8 mg/kg. This corresponds to a percent removal of approximately 67 percent removal in 68
days. The post-treatment concentrations were below the 17 mg/kg action level established for the site.
In 2004, the total cost of treatment in USD was $65,000. Consequently, the unit cost of treatment at
this site was$98 per cubic yard.
Gila River Indian Community Site
The Gila River Indian Community (GRIG) site is located in Chandler, Arizona. Approximately 3,500 cy
of toxaphene-contaminated soil required treatment at this site. Four lined cells were constructed with
dimensions of 178 ft by 43 ft by 7 ft (deep). This dosage rate was lower than for other sites to reduce
costs. The dosage rate of blood meal, sodium phosphate, and dibasic phosphates was 5 g/kg of
contaminated soil. Blood meal and phosphates were first mixed in a pit, and then blended with
contaminated soil using a pug mill (100-300 cy/hr throughput). The mixture was then transferred to
cells filled with water to 25 percent capacity. Additional water was then added to the cells to provide
one foot of cover above the solids. Each cell was then covered with a plastic sheet. Samples were
collected from the cells after initial setup and at the end of 3 months, 6 months, and 9 months. The
removal of toxaphene in GRIG site soil took longer than usual due to the reduced amendment dosage
rates. The average toxaphene concentration at the end of 180 days ranged between 4 mg/kg and 5
mg/kg demonstrating 83 to 88 percent toxaphene removal. The samples collected at day 272 showed
residual levels of 2 to 4 mg/kg corresponding to a percent removal between 87 and 98 percent. The
post-treatment concentrations were below the 17 mg/kg action level established for the site. In 2004,
the total cost of treatment in USD was $793,000. Consequently, the unit cost of treatment at this site
was $226 per cubic yard.
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Anaerobic Bioremediation Using Blood Meal for
Treatment of Toxaphene in Soil and Sediment
Table 1
Performance Data for Anaerobic Bioremediation of Toxaphene Using Blood Meal at Selected
Sites
Site Name
Untreated
Concentration
(mg/kg)
Treated
Concentration
(mg/kg)
Period
(Days)
Percent
Reduction
Volume
Treated
(cy)
Navajo Vats Chapter
Nazlini
Whippoorwill
Blue Canyon Road
Jeddito Island
Poverty Tank
Ojo Caliente
Laahty Family Dip
Vat
Henry O Dip Vat
291
40
100
22
33
14
29
23
71
17
17
3
8
4
4
8
108
110
106
76
345
14
31
68
76
58
83
77
76
71
86
67
NA
NA
NA
NA
NA
200
253
660
Gila River Indian Community
Gila River Indian
Community (Cell 1)
Gila River Indian
Community (Cell 2)
Gila River Indian
Community (Cell 3)
Gila River Indian
Community (Cell 4)
59
31
29
211
4
4
2
3
272
272
272
272
94
87
94
98
3,500
Note:
mg/kg: Milligrams per kilogram
NA: Not available
Source: Refs. 1 , 2 and 6
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Anaerobic Bioremediation Using Blood Meal for
Treatment of Toxaphene in Soil and Sediment
U.S. EPA CONTACT:
U.S. EPA Environmental
Response Team
Harry L.Allen III, Ph.D.
Phone: (732)321-6747
Email: allen.harry@epa.gov
LAAHTY FAMILY AND HENRY O DIP
VAT SITES:
Bureau of Indian Affairs
Southwest Region
Zuni Nation
Phone: (505)563-3106
Gila River Indian Community
CONTACT:
GRIG Department of
Environmental Quality
Hazardous Waste Program
Manager
Dan Marsin
Email: hazmat@gilnet.net
Phone: (520)562-2234
PATENT NOTICE:
This technology has not been patented.
REFERENCES:
1. Allen L, Harry and others. 2002. Anaerobic bioremediation of toxaphene-contaminated soil -
a practical solution. 17th WCCS, Symposium No. 42, Paper No. 1509, Thailand. August 14 -
21.
2. Allen L., Harry, EPA Environmental Response Team. 2005. Email to Younus Burhan, Tetra
Tech EM Inc., Regarding Comments from Harry L. Allen on Draft (January 5, 2005) Blood Meal
Fact Sheet. January 25.
3. Allen L., Harry, EPA Environmental Response Team. 2005. Memo to Ellen Rubin, EPA Office
of Superfund Remediation and Technology Innovation. Response to Questions on Toxaphene
Fact Sheet. February 24.
4. U.S. Environmental Protection Agency (EPA). Office of Superfund Remediation and
Technology Innovation. 2004. Cost and Performance Summary Report. The Legacy of the
Navajo Vats Superfund Site, Arizona and New Mexico. October.
5. EPA. 2000. Fact Sheet - Gila River Indian Community Toxaphene Site. October.
6. Rubin, Ellen, EPA Environmental Response Team. 2005. Email to Younus Burhan, Tetra
Tech EM Inc., Regarding Comments from Dr. T. Ferrell Miller on Draft (January 5, 2005) Blood
Meal Fact Sheet. February 7.
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