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coaguiant/fiocculant This mixture flows to a darifier where it forms a
dense sludge that is discharged to waste storage drums for proper
disposal or further treatment After filtration, the clarified water recycles
(or use In the separation chambers, trommel washer, etc. Make-up
water, fed into th© dean water tank, maintains process water levels.
Waste Applicability: The system can clean gravelly-to-sandy
soils contaminated with lead from batteries. Treatabiltty studies on
representative material are necessary to verify that the process
will meet volume reduction criteria and cleanup goals.
Demonstration Results: This SITE Demonstration took place
at the ABE Site between August 21, 1992 and August 29,1992. It
consisted of three test runs. Two replicate runs processed about
2.4 tons/hr of higher-lead-content soils measuring total lead levels
at 4,211 and 10,374 mg/kg and TCLP lead levels at 72 and 132
mg/L respectively. A third run handled about 4.2 tons/hr of soil
registering tower lead content: 2,276 mg/kg total lead and 50 mg/
L of TCLP lead. The runs averaged about 5 hours in duration and
46 tons in total soil feed processed.
As Indicated above, EPA's goals for the ABE Site cleanup are
toss than 1,000 mg/kg total lead and less than 5 mg/L TCLP lead.
Preliminary data indicate the following results:
Lead Removal from the combined gravel and sand fractions
during the three runs: 61%, 93%, and 85%.
Mstalffo Lead RemovaHmm the contaminated soil produced large
quantities of discrete lead in various sizes (pieces of terminal
posts and internal battery grids). BESCORP tested and modified
the metallic lead removal system during the first two runs. The
processed sand and gravel in Run 3 contained no metallic lead.
Battery Casing Chips Removal from the combined gravel and
sand fractions during the three runs: 94%, 100%, and 80%.
Process Effidencyrose as the Demonstration progressed. Although the
process did not meet the 75% target effidency, performance improved
significantly from 11 % to 32% to 49% during the three runs. BESCORP
projects future efficiencies from 65% to 75%, based on new bench-
scale procedures that retain a treated sand fraction of minus '/>" to plus
80 mesh rather than the minus !4" to plus 150 mesh fraction retained
during the Demonstratbn runs.
Gravel produced by all three runs met TCLP criteria, with aver-
age lead concentrations in the TCLP leachate at 1.0, 0.8, and 0.2
mg/L, respectively. The presence of metallic lead, which broke
through from the casing chip separator, distorted average total
lead concentrations for the first two runs (2,541 and 903 mg/kg
respectively). Process modifications greatly improved metallic
lead removal during the second and third runs. By the third run,
total lead concentration in the treated gravel measured 16 mg/kg.
Sand from all three runs failed both tests: TCLP(42, 40, and 26
mg/L Pb) and total lead (1,819, 1,660, and 1,507 mg/kg). These
failures resulted from improper sizing of the sand. The very fine
sand (minus 80 mesh to plus 150 mesh) was highly contami-
nated. Based on recent bench-scale data, BESCORP claims that
the addition of an attrition scrubber on the minus 1/4" to plus 80
mesh sand fraction can readily clean this fraction to the level
required by EPA. This has not yet been demonstrated by the 20
ton/hr unit.
EPA will publish an Applications Analysis Report and a Technical
Evaluation Report describing the complete Demonstration during
the summer of 1993.
For Further Information:
EPA Project Manager:
Hugh Masters
U.S. EPA Risk Reduction Engineering Laboratory
2890 Woodbridge Ave.
Edison, NJ 08830-3679
Technology Developer Contact:
Craig Jones
BESCORP
3200 Shell St.
Fairbanks, AK 99701
United States
Environmental Protection Agency
Center for Environmental Research Information
Cincinnati, OH 45268
Official Business
Penalty for Private Use
$300
BULK RATE
POSTAGE & FEES PAID
EPA
PERMIT No. G-35
EPA/540/MR-93/503
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