BRICE ENVIRONMENTAL SERVICES CORPORATION

(Soil Washing Process)

TECHNOLOGY DESCRIPTION:

Brice Environmental Services Corporation (BESCORP) has developed a portable aboveground soil washing process that reduces the overall volume of contaminated soil requiring treatment. BESCORP's soil washing process involves site-specific unit operations, the selection of which depend on soil and contaminant characteristics, cleanup standards, cost, and client specifications. The process includes a volume reduction operation, in which oversized soil is cleaned by intensive scrubbing, followed by density, magnetic, and size separations. During volume reduction, contaminants that exist as discrete or attrited particles are partitioned with the soil fines, while the process water is recirculated and treated to remove suspended and dissolved contaminants.

BESCORP's small volume reduction plant, used for demonstration and pilot testing, is contained on one trailer and has a variable process rate from 4 to 20 tons per hour, depending on soil and contaminant characteristics. A full-scale plant (see photograph) has operated successfully since 1993, averaging 15 tons per hour during summer 1994 field activities.

BESCORP Soil Washing Plant

WASTE APPLICABILITY:

The BESCORP soil washing process can treat soils contaminated with radioactive and heavy metals. It can be combined with chemical treatment technologies for complete soil remediation. BESCORP has also built a soil washing plant to remediate hydrocarbon-contaminated soil.

STATUS:

The BESCORP soil washing process was accepted into the SITE Demonstration Program in winter 1991. Under the program, the BESCORP system was demonstrated in late summer 1992 on lead-contaminated soil at the Alaskan Battery Enterprises (ABE) Superfund site in Fairbanks, Alaska. The Demonstration Bulletin (EPA/540/MR-93/503) and the Applications Analysis Report (EPA/540/A5-93/503) are available from EPA.

The BESCORP soil washing process was also linked with a chemical treatment process developed by COGNIS, Inc., to remove heavy metals from contaminated soil at the Twin Cities Army Ammunition Plant (TCAAP) Site F in New Brighton, Minnesota. At Site F, BESCORP and COGNIS, Inc., treated lead, copper, and several other heavy metals to soil cleanup criteria. The technologies treated feed soils containing lead in concentrations from 3,000 to 10,000 parts per million (ppm) to under 300 ppm in a continuous 12- to 15-ton-per-hour process. The full-scale, combined system processed contaminated soil from September 1993 through August 1995.

For further information on the COGNIS, Inc., TERRAMET® chemical treatment process, refer to the profile in the Demonstration Program section (completed projects).

DEMONSTRATION RESULTS:

The demonstration at the ABE site consisted of three test runs using the BESCORP small volume reduction plant, averaging 5 hours in duration; 48 tons of soil were processed. Results from the demonstration include the following:

• Feed soils averaged 4,500 ppm lead, and the processed, separated fines fraction averaged 13,000 ppm lead.
• On-line reliability was 92 percent.
• Lead removal from the combined gravel and sand fractions during the three runs was 61, 93, and 85 percent.
• Large quantities of metallic lead (battery casings) discovered in the excavated soil made it necessary to modify the system by employing density separation equipment. The processed sand and gravel in Run 3 contained no metallic lead.
• Gravel produced by all three runs met toxicity characteristic leaching procedure (TCLP) criteria, with average lead concentrations in the TCLP leachate at 1.0, 0.8, and 0.2 milligram per liter.
• Battery casings removal efficiencies during the three runs were 94, 100, and 90 percent.

Results from the demonstration at TCAAP Site F indicate that the BESCORP process reduced the lead load to the TERRAMET® process by 39 to 63 percent.

FOR FURTHER INFORMATION:

TECHNOLOGY DEVELOPER CONTACT:
Craig Jones
BESCORPL
3200 Shell Street
P.O. Box 73520
Fairbanks, AK 99707
907-452-2512
Fax: 907-452-5018