Slurry Reactor Biotreatment of Explosives-Contaminated Soils at Joliet Army Ammunition Plant, Joliet, Illinois

Site Name:

Joliet Army Ammunition Plant

Location:

Joliet, Illinois

Period of
Operation:

July 1994 to August 1995

Cleanup
Type:

Field demonstration

Technology:
Slurry-Phase Bioremediation
- Field bioslurry system included a soil screening operation, four 420-gallon bioslurry reactor tanks (variable speed drive mixer with double impeller); two slurry dewatering beds; and tanks for water storage
- Bioslurry demonstration was performed in the reactors (350-380 gals/reactor), with addition of molasses, pH adjustment (to >6), and aerobic-anoxic operating cycles
- Four reactors were operated: (1) a control with no molasses; (2) a 20% weekly replacement; (3) a 10% weekly replacement; and (4) a 5% daily replacement
- All reactors were operated with a 10-16% W/W soil slurry in a sequencing batch mode
- Soil was screened to 40 mesh (0.0165 inch) prior to placement in the reactors

Cleanup Authority:
CERCLA
- Final ROD scheduled for June 2001

Technical Contacts:
J.F. Manning, Jr., R. Boopathy,
and E.R. Breyfogle
Argonne National Laboratory
Environmental Research Division
Bioremediation Group
9700 South Cass Avenue
Argonne, IL 60439-4843

Mark Hampton
U.S. Army Environmental Center
SFIM-AEC-ETD
Aberdeen Proving Ground, MD 21010-5401
(410) 436-6852
mark.hampton@aec.apgea.army.mil
Site Contact:
Not identified

EPA Remedial Project Manager:
Diana Mally
U.S. EPA Region 5
77 W. Jackson Blvd.
Chicago, IL 60604
(312) 886-7275
E-mail: mally.diana@epa.gov

Contaminants:
Explosives
- Excavated soils had concentrations of TNT - 1,000 - 6,226 mg/kg; DNT - ND - 360 mg/kg; TNB - 48 - 360 mg/kg; RDX - ND - 310 mg/kg; and HMX - ND - 215 mg/kg

Waste Source:
Process water from munitions washout

Type/Quantity of Media Treated:
Soil

Purpose/Significance of Application:
Use of bioslurry technology for treatment on explosives wastes

Regulatory Requirements/Cleanup Goals:
- Determine effectiveness and cost of bioslurry systems for degrading explosives in soil
- Evaluate a field-scale system for mechanical integrity and ability to enrich a microbial consortium, and to analyze system performance over an extended operating period
- A target goal of 20 mg/kg for TNT was used for the demonstration, since a cleanup goal had not yet been established

Results:
- Removed more than 99% of explosives
- The 20% weekly replacement reactor (soil retention time of 5 weeks), when operated at >25°C, degraded TNT to <50 mg/kg and 4A26DNT to <100 mg/kg, and RDX and TNB to <10 mg/kg; the report does not indicate if this reactor met the target goal for TNT
- The 10% weekly replacement reactor (soil retention time of 10 weeks), when operated at >25°C, degraded TNT to <20 mg/kg and 4A26DNT to <10 mg/kg, and RDX and TNB to <10 mg/kg
- The 5% daily replacement reactor (soil retention time of 5 weeks) had performance similar to that of the 20% weekly replacement reactor, and removed TNT to <20 mg/kg
- The control reactor (no molasses addition) showed no explosives removed from the soil

Cost Factors:
- Projected costs for full-scale implementation of the slurry-phase biotreatment system was $290-350/yd3

Description:
Joliet Army Ammunition Plant was constructed in Will County, Illinois, approximately 17 miles south of Joliet, in the early 1940's. JAAP contains two major functional areas - a manufacturing area for production of constituent chemicals and explosive materials, covering 14 square miles, and a load- assemble-package (LAP) area for munitions filling and assembly lines, storage magazines, and demilitarization, covering 27 square miles. In April 1989, the LAP area was added to the NPL. Soil for a field demonstration of bioslurry technology was obtained from Group 61, Site L1 of the LAP Area, a ridge-and-furrow area that received pink water from washout of munitions.

The field demonstration showed that bioslurry technology could reduce concentrations of TNT and other explosives in soil. The important process parameters are the need for an organic co-substrate (molasses), operation of the reactors in an aerobic-anoxic sequence, and temperature. In warmer temperatures (>25°C), operation of the system at >=20% weekly replacement will achieve removal of explosives. Colder temperatures did not destroy the microbial activity, but did slow the metabolic rate. In particular, degradation of TNT continued with the accumulation of 4A26DNT. The reactors were operated successfully at lower replacement rates (<=10% weekly) in colder weather. The treated soil (bioslurry) can be applied directly to land and will not affect plant growth.