S.EPA
United States
Environmental Protection
Agency
EPA/540/MR-93/510
April 1993
SUPEFtFUND INNOVATIVE
TECHNOLOGY EVALUATION
Demonstration Bulletin
Biogenesis?"1 Soil Washing Technology
Biogenesis™
Technology Description: The BioGenesisSM soil washing tech-
nology was developed by BipGenesis Enterprises, Inc. to remove
organic compounds from soil. The technology uses a proprietary
solution (BioGenesisSM cleaner) to transfer organic compounds
from the soil matrix to a liquid phase. BioGenesis claims that this
treatment process can be used onsrte; generates treated air;
generates treatable water; and soil suitable for onsite backfill.
Because the BioGenesisSM cleaner, a complex blend of surfac-
tants, is rapidly degraded by soil microbes, the cleaner and
contaminant-rich wastewater generated during the process can
be biodegraded in a bioreactor. Moreover, residual BioGenesisSM
solution on the soil particles stimulates the biodegradation of soil
contaminants not removed by the washing process.
A schematic diagram of the BioGenesisSM treatment system is
shown in Figure 1. The BioGenesis8" treatment unit used for the
Superfund Innovative Technology Evaluation (SITE) technology
demonstration at a Refinery site included the soil washing unit
fitted with an oil skimmer, a baffle filter, and an air compressor.
Support equipment, such as an American Petroleum Institute
(API) oil-water separator, oil coalescer, holding tanks, and
bioreactor, was not used during the Refinery site demonstration.
The water used for soil washing was supplied by the Refinery
and was not recycled. Steam was used by the Refinery to raise
the temperature of the washwater to 60°C prior to its introduction
into the wash unit. Wastewater from the soil wash unit was
pumped to the Refinerys wastewater treatment system, which is
equipped with oil-water separators.
During the treatment process, the BioGenesisSM system pumps
approximately 1,000 gal of water into the wash unit and loads it
with as much as 20 yd3 of soil. After the wash unit is loaded,
three mechanical shakers on each side of the wash unit are used
to agitate the soil and water mixture. Next, additional water
(about 1,500 gal) and approximately 8 gal of BioGenesisSM cleaner
are pumped into the wash unit. The resulting slurry is agitated by
the shaker and a series of aerators that are in the bottom of the
wash unit. After the slurry is sufficiently mixed, additional water
(approximately 500 gal) is added to raise the fluid level, allowing
floating oil product to flow out of screened ports on the side of the
unit. Once the floating product is removed, the soil is agitated
again.
When agitation is complete, the fluid level is raised again and
floating oil product is removed from the system. Valves in the
bottom of the wash unit are then opened, and contaminated
wastewater is drained from the wash unit. Because no bioreactor
was used as part of the demonstration at the Refinery site, the
contsiminated wastewater was pumped to the Refinerys waste-
water treatment system. Refinery personnel were responsible for
Filter
Unit
Effluent from
Wash Unit
^. To Wastewater
Treatment Plani
Treated Soil
Make-Up Water
Figure 1. Biogenesis™ soil washing process.
Printed on Recycled Paper
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the disposal or recycling of treated waters and recovered oil. The
BfoGenesisSM soil washing technology was tested at a site in
Santa Maria, California prior to the demonstration at the Refinery
site to determine optimum process parameters such as, mixing
time, number of washes, and BioGenesisSM cleaner dose. Results
from the Santa Maria site indicated that the amount of contamina-
tion removed from soils can be increased by repeated washing.
Therefore, once the wash unit was drained, the process of adding
water and BfoGenesisSM cleaner and agitating the soil was re-
peated. Treated soil was then removed from the washing unit,
drained of wastewater, and placed in a holding area for sampling.
Waste Applicability: BfoGenesis claims the following for the
BioGenesis8** process:
* The process is capable of extracting volatile and nonvolatile
hydrocarbons, including petroleum hydrocarbons, chlorinated
hydrocarbons, pesticides, polychlorinated biphenyls (PCB), and
potycyclicaromatichydrocarbons(PAH)from most soils, includ-
ing clays.
• The process can treat soils and sludge contaminated with
petroleum hydrocarbons at levels up to 50% oil.
* The prototype transportable wash unit and support equipment
can treat 25 to 35 tons of soil per hour. Succeeding production
units will treat up to 70 ton/ hr.
• For heavy crude oil contamination in cold climates, the proto-
type unit removes 70% to 85% of the hydrocarbon contamina-
tion with washing. For lighter contaminants such as gasoline or
diesel, and depending upon contaminant concentration, the
process deans from 85% to 98% with washing alone.
• Residual contaminants in soil and wastewater are further re-
moved by biodegradation.
Demonstration Results: The BfoGenesisSM soil washing tech-
nology was demonstrated at the Refinery site in a series of three
runs over a 2-day period in November 1992. The Refinery con-
tracted BfoGsnesis3" to treat approximately 2,000 yd3 (3,800 tons)
of soil that was contaminated with petroleum hydrocarbons (heavy
crude oil). Analytical results from a sample collected from the
untreated soil prior to the demonstration revealed total recover-
able petroleum hydrocarbon (TRPH) concentration of 30,800
ppm, and trace levels of benzene, toluene, ethylbenzene, and
xylene (BTEX). Because TRPH was detected at relatively high
concentrations, it was selected as the contaminant group of
concern for the demonstration.
EPA collected samples from treated and untreated soil, water,
and wastewater. EPA collected two buckets of treated soil and
kept the buckets at a temperature of 20°C. EPA collected samples
on the 14th, 40th, 60th, and 90th day following the field demon-
stration to determine the effect of biodegradation on TRPH con-
centrations. Additional samples will be collected on the 120th
and 180th day. Process operating data were collected during the
demonstration to document process operating conditions.
The analytical data from all the samples are not yet available.
Key findings of the SITE demonstration, including sample analyti-
cal results, will be discussed in the SITE technology capsule and
the innovative technology evaluation report. During the SITE
demonstration at the Refinery, the following preliminary findings
were noted:
• Soil washing and biodegradationwith BioGenesisSM removed
about 85% of the TRPH-related contaminants in the soil.
• The treatment systems performance was reproducible at con-
stant operating conditions.
• At the end of 90 days, TRPH concentrations have decreased
an additional 50% compared to washing alone. Sampling to
determine extent of biodegradation will continue.
• BioGenesis indicated that the prototype equipment operated
within design parameters. New production equipment is ex-
pected to streamline overall operating efficiency.
For Further information:
Annette Gatchett
U.S. EPA Risk Reduction Engineering Laboratory
26 West Martin Luther King Drive
Cincinnati, OH 45268
(513) 569-7697 (FAX: 569-7620)
•U.S. Government Printing Office: 1993 — 750-071/80013
United States
Environmental Protection Agency
Center for Environmental Research Information
Cincinnati, OH 45268
Official Business
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PERMIT No. G-35
EPA/540/MR-93/510
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