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Confidential Client
Ontario, Canada
Project
Treatment of Soil Impacted by Chlorinated
Pesticides
Summary
This project was the second of three pilot scale
projects within a research and development
program designed to validate certain
DARAMEND® applications on chlorinated
pesticide impacted soil.
The Challenge
Treatment of 250 tons of soil impacted by
chlorinated pesticides including Metolachlor,
Atrizine, and Dinoseb. Metolachor was of
particular interest since it is one of the most
common herbicides used during corn production in
North America. Although Metolachlor is known to
be photodegradable at normal field application
rates, its persistence in subsurface soils,
particularly when an accidental release results
in relatively high concentrations in soil, has
become an environmental issue at numerous
manufacturing and warehousing facilities
throughout North America.
The Solution
A treatment cell was divided into three separate
areas which included a 230-ton main treatment
cell and two 10-ton treatment cells. One
contained heavily impacted soil, and the other
contained soil similar to the main treatment area
for use as an untreated control.
The principal contaminant driving remediation was
Metolachlor, which had an initial concentration
of 67mg/kg, 170mg/kg, and 37mg/kg in the main
treatment cell, the heavily impacted treatment
cell, and the control cell, respectively.
The Result
Following treatment the mean concentration of
Metolachlor was reduced to <1mg/kg in the main
treatment cell and 11mg/kg in the heavily
impacted treatment cell. Concentration remained
unchanged in the control cell.
The Cost
The estimated treatment cost for the full scale
application of DARAMEND® bioremediation at
this site, which would have involved the
treatment of <1,000 tons of similarly
contaminated material, was approximately
US$112/ton. Costs associated with full scale
treatment at this site are slightly higher than
most due primarily to the small volume of
material requiring treatment.
The Timeline
The demonstration was successfully completed
following approximately 10 months of active
treatment in 1996 and 1997.
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