Description
Confidential Client Northwest, USA
Summary
Adventus' DARAMEND® technology was selected to
remediate approximately 6,000 tons of soil impacted with pentachlorophenol
(PCP) at a former chemical manufacturing facility located in the
Northwest. Excavated soil was placed in a lined bioremediation cell in a 2
ft layer for treatment.
The Challenge
To reach a remedial goal of less than 50 mg/kg in each soil sampling
zone, containing approximately 175 tons each. The concentration of PCP in
some sampling zones was as high as 2,000 mg/kg initially. This
concentration would be considered by many as acutely toxic to most
microbial populations, rendering the soil non-amenable to standard
bioremediation practices.
The Solution
Following homogenization of the soil undergoing treatment, DARAMEND
was applied using a site-specific aerobic protocol that utilized
indigenous micro organisms. The technology involved the addition of
proprietary organic amendments and site-specific nutrient supplements
designed to optimize the rate of microbial activity in the soil. The soil
moisture content was then maintained at a relatively constant level
(approximately 60% of the soil water holding capacity). The soil was
tilled periodically to maintain an aerobic soil environment. Tilling was
accomplished using a tractor mounted specialized deep rotary tiller with
the capacity to till a depth of 2 ft.
The Result
PCP concentrations were reduced from as high as 2,000 mg/kg in some
sampling zones to less than 30 mg/kg. The mean PCP concentration was
reduced from 359 mg/kg to 16 mg/kg after approximately 8 months of
treatment in 1999. The remedial goal of less than 50 mg/kg was met and
surpassed in all sampling zones.
The Cost
The cost to apply DARAMEND at this site was only $37/ton; however, a
significant portion of the site work was conducted by the site owner.
Companies On This Project
ADVENTUS GROUP
