Bioremediation Technology for the
Remediation of Persistent Organic
Pollutants (POPs): Toxaphene &
Dichlorodiphenyltrichloroethane
(DDT)
Siti Jariani Mohd Jani
SWS 6262 :
Soil Contamination &
Remediation
Outline
Selected
Contaminated
Site :
• Woodbury Chemical
Company Superfund site,
Commerce City, Colorado
Contaminants:
• Toxaphene
• DDT
Remediation
Technology:
• Applied
• Recommended
Contaminated Site History
1950 • Pesticide formulation facility
1971
• Fire destroyed the main building
1965 • Soil, debris, bags of water soaked pesticides were dumped
1976
1983
1986
1992
• First site sampling by Health Department
• Superfund National Priorities List (NPL)
• Starts of remediation works in May
• Completion of remediation works
• Removal from NPL (no further operation activities &
maintenance are needed)
1993
Site Information
Site details
Size
Wells: downgradient
(West- Northwest) of
Woodbury site,
between South Platte
and the conyaminated
site
Population /
Residential area
•Woodbury Chemical Company Superfund
Site, Commerce City, Colorado
•Total area: 15 hectares
•30 industrial or residential wells
•11: Groudwater from bedrock aquifer
•19: Surface aquifer (downgradient well,
DGW)
•The nearest DGW 0.5 miles away the South
Platte
•municipal drinking water
•Water for irrigation
•Within 1 mile: 3000
•0.3 mile: Mobile home park
Site Information (cont.)
Groundwater
•Unconfined
aquifer
conditions
in
the
alluvium
and
semi-confined
aquifer
conditions in the underlying bedrock
•Depth: 30 feet.
•Water table: 20-27 feet below the ground
surface.
•water flow: to the west and northwest,
towards the South Platte River.
Surface water
•Runoff off-site via 3 major drainage
channels on the site drain to the north and
west.
•Discharges into a drainage ditch that runs
along the northern boundary of the site in a
westerly direction for about 3,000 feet
before emptying into a retention pond.
Evaporation and infiltration lead to water
loss from the pond.
•Major waterways: To the South Platte River
EPA Superfund Record of Decision, 1985
(EPA/ROD/R08-85/003)
Contaminated Site
Contaminated land size
Major source of
contaminants
•2.2 acre of disposed rubble and debris
•Disposable site: flat (550 ft long X 175 ft
wide)
•Disposable rubble and debris piles: 4 ft
height
•Toxaphene
•DDT
Types of media treated &
quantity
•Rubble & debris piles: 250 cubic yards
•Soils: 5470 cubic yards
Remediation Technology
•Excavation
•Incineration
Remediation plan
•To achieve cleanup concentration value of 3
ppm for total pesticides = 5kg of total
pesticides remaining in the 2.2 acre site
EPA Superfund Record of Decision, 1985
(EPA/ROD/R08-85/003)
Contamination at each Medium
Medium/characteristic
Descriptions
Soil:
MW3: toxaphene (12ppm) – Upper 10 feet
Pesticide
contamination
discovered at different
depth from soil boring of
installed monitor well
RSO-8: total pesticide level of 35.12 ppm (60% is
toxaphene) – 10 feet
Sediments
In 1984 & 1985: on and off-site in sample of drainage
ditch sediments.
Groundwater
July 1984: total pollutants concentration of 0.06-0.2
ug/L – in 2 of 5 monitored wells.
RSO-10: total pesticide level of 4 ppm at 10-30 feet
(toxephene the only contaminants to exceed 1 ppm)
November 1984: No concentration of pollutants was
found.
Surface water
1979: DDT, highest concentrations at 25.3 ug/L
EPA Superfund Record of Decision, 1985
(EPA/ROD/R08-85/003)
Contaminants
POPs
Toxaphene
DDT
Chemical
Structure
Characteristic  Insecticide
Persistent in the environment
and can be transported in the
environment over very long
distances.
T1/2: 100days -12 years
Toxicity
Maximum
clean up level
(MCL)
Insecticide: kill weeds and
vector-borne
diseases
like
typhus and malaria
Persistency
leads
to
bioaccumulate
and
biomagnification
effect
on
organisms in the environment.
T1/2: 2-15 years
Probable
human
carcinogen possibly carcinogen to humans
(USEPA
(USEPA
Drinking water: 0.003mg/L
Drinking water: 0.007mg/L
Maximum contaminant level Maximum contaminant level
goal: 0
goal: 0.007mg/L
ASTDR, 2010
Applied Technology
Excavation
Incineration
Removal of 250 cubic yards (cy) to EPA Ex-situ
incineration
at
EPA
permitted
permitted incineration facilities.
facilities: The excavated materials burned in a
> 100 ppm total pesticides.
furnace designed for burning hazardous
materials in a combustion chamber at high
temperatures
1) Excavated using backhoes and excavator 1) Large rocks and debris and excess water
track hoes.
was removed.
2) Loaded into trucks. Total of 2500 loaded 2) The materials are then placed in the
truck.
combustion chamber
3) Sent for incineration
3) heated to an extremely high temperature
4) The soil was covered with tarps
for a specified period of time.
5) Excavation is complete when test results
show that the remaining soil around the
hole meets established cleanup levels.
Excavated area filled with clean soil.
After an excavation was filled in, the area was covered with landscaped
How long?
Start in May 1986 and remediation completed in 1992
Total Cost : $2,471,000
EPA Superfund Record of Decision, 1985 (EPA/ROD/R08-85/003)
Advantages
• Can treat most contaminants and address large volumes of
contaminated material
• Hazardous Waste MGM facilities that is well established and
reliable
• A fast clean up method
Disadvantages
• Potential environmental and health effects: Combustion of
POPs
• Dioxins and furan: human carcinogens and can leads to
serious human health problem
(USEPA)
Applicable Technology
Remediation Technology
Description
Thermal desorption
clean up soil that is contaminated with VOCs and SVOCs at depths shallow enough to reach through
excavation. Faster and provide better cleanup than other methods, particularly at sites that have high
concentrations of contaminants. Thermal desorption is being used or has been selected for use at over
70 Superfund sites across the country.
Thermal chemical
degradation : Gas phase
Chemical reduction
(GPCR)
GPCR is a thermal-chemical degradation technology that combines high temperature and hydrogen gas
to treat POPs. Based on available information, the technology has treated DDT, HCB, PCBs and dioxin
in contaminated soil, sediments, and liquids. Due to the high temperature requirement of this
technology, GPCR could potentially treat other POPs.
Physical-chemical
treatment
Physical-chemical treatment includes soil vapor extraction, solidification/stabilization, soil flushing,
chemical oxidation, and electrokinetic separation.
Bioremediation
Using natural microorganism (such as bacteria, Fungi, biopolymers) and plants (phytoremediation) to
degrade hazardous organic contaminants or convert hazardous inorganic contaminants to
environmentally less toxic or nontoxic compounds of safe levels in soils, subsurface materials, water,
sludges, and residues.
Phytoremediation
Uses plants to clean up contaminated environments. Can clean up many types of contaminants
including metals, pesticides, explosives, and oil. However, they work best where contaminant levels are
low because high concentrations may limit plant growth and take too long to clean up. Plants also help
prevent wind, rain, and groundwater flow from carrying contaminants away from the site to
surrounding areas or deeper underground.
USEPA
Recommended Technology
Anaerobic Bioremediation using Blood Meal
• Soil
(Allen et. al., 2002 and EPA, 2007)
Phytoremediation using Aquatic Plants
• Surface water
(Iowa State University)
Soil : Anaerobic Bioremediation of
Toxaphene using Blood Meal
What is it?
• Biostimulation of native anaerobic with amendment
• Developed by US EPA’s Environmental Response
Team (ERT)
• Successfully implemented in several sites
• Full scale cleanup cost: $130 - $271 per cubic yards
(EPA, 2007)
Materials & Methods
Biological Amendment
• Blood Meal: dried & powdered animal blood (nutrient)
• Phosphates: added to the contaminated soil as pH buffer
Dosages of Blood Meal & Phosphates
• 1% by weight of contaminated soil
• 1% by weight of starch (to establish rapid anaerobic
conditions
• Standard recipe (pH 6.7): Equal proportion of monobasic
& dibasic phosphates salts (1:1)
• Low phosphate/starch recipe: Monobasic:dibasic (1:3)
Soil – amendment mixture
Mix contaminated soil with water
Method: Blending in a dump truck, mechanical
mixing in a pit or mixing in pug mill
Transferred to a lined cell
Add water to produce slurry
To maintain anaerobic condition, up to a foot of water is recommended above the settled solid
Covered lined cell with a plastic sheet
Isolate the cell from the environment
Incubated for several month
Sampling
Procedures
Performance Data
Sites Site
Name
Treated
soil (cy)
Cell
dimensions
(ft)
Initial
contaminants
concentration
(mg/kg)
Final
concentration
(mg/kg)
Period
(Days)
Percent
Reduction
(%)
Cost
(USD)
total/
per (cy)
Navajo Vats Chapter
Laahty
Family Dip
Vat
253
Henry O Dip
Vat
23
73:30:4
1)
2)
75:35:5
65:30:5
29
4
31
86
$75,000/
$296
23
8
68
67
65,000/
$98
272
87-98
$793,000/
$226
Gila River Indian Community
(Cell 1)
875
178:43:7
59
(Cell 2)
875
178:43:7
31
(Cell 3)
875
178:43:7
29
(Cell 4)
875
178:43:7
211
total
3500
Sources: Allen et al., 2002 and US EPA, 2007.
Notes: cy = cubic yard
mg/kg = Milligram per kilogram
2-4
Maintenance Measures
• Maintenance of water level: Periodic addition of water to
treatment cells.
• Maintenance of treatment cells from leaks
• Maintaining cover integrity
• Gas build-up monitoring
• Odours monitoring
• Monitoring remedial progress by soil sampling
Waste/Residuals
• Low chlorinated chlorobornane congeners
• Chloride ions
• Gaseos waste: CO2, methane, hydrogen sulphide
Surface water: Phytoremediation
of DDT using aquatic plants
What is it?
• Phytoremediation is an innovative technology that uses plants to
get rid of contaminants from soil, groundwater, air, sediments, and
surface.
• Comprised of several different techniques that utilize vegetation,
its related enzymes, and other complex processes. Collectively,
these processes are able to isolate, destroy, transport, and remove
organic and inorganic pollutants from contaminated media.
• Study done by Iowa State University (Metalochlor & Atrazine)
• Reduced in the concentration of contaminants
Remediation Plant

Ceratophyllum demersum
(coontail, hornwort)

Elodea canadensis
(American elodea,
Canadian pondweed)

Lemna minor
(common duckweed)
Performance Data: Concentration
of pollutants remain after 16days
Pollutants
Ceratophyllum
demersum
Elodea
canadensis
Lemna minor
Metolochlor
1.44 %
4.06%
22.7%
Atrazine
41.3%
63.2%
85%
Sources: Rice et al.,
Iowa State University
Limitations
Anaerobic bioremediation (blood meal)
• Temperature. Not to extremely cold climates. Best operation
periods: Spring and summer.
• Bench scale test: to determine applicability at a given site, and to
estimate duration of treatment.
• Minimal duration for treatment: Five weeks
• Treated low-strength waste contaminated with toxaphene (EPA,
2007)
Phytoremediation (Aquatic Plants)
• Pilot test: select the most effective species of aquatic plant that
can remediate the contaminants. (EPA, 2008)
• Plants that absorb contaminants from the water do not
biodegrading them to non-toxic compounds and commute them to
their stems or leaves could potentially harm herbivores (Frazar,
2000).
Conclusions

Incineration: Effective but high risk to human health

Bioremediation & Phytoremediation has been seen as
an innovative alternative with great potential that
should be explored and developed (Frazar,2000)

Despite its limitations;
 minimal exposure of contaminants to human
 environmentally safe
 cheap
Thank You
Q&A Session