&EPA
                                   United States
                                   Environmental Protection
                                   Agency
                 EPA/540/MR-93/503
                 February 1993
                                   SUPERFUND  INNOVATIVE
                                   TECHNOLOGY EVALUATION
                                   Demonstration  Bulletin
                           BESCORP Soil Washing System Alaskan
                                       Battery Enterprises Site

                              Brice Environmental Services Corporation
Technology Description: The BESCORP Soil Washing Sys-
tem is an aqueous volume reduction system that utilizes trommel
agitation, high-pressure washing, sizing, and  density separation
to remove lead, lead compounds, and battery casing chips from
soil contaminated by broken lead batteries.

The basic concept is to first liberate the lead/lead compounds from the
larger soil particles by slurry agitation and .spray rinsing and to then
separate, by gravity, these heavy particles (greater than 6 sp. gr.) from
the soil (sp. gr. 2.5). In a similar manner, the process segregates the
casing chips (less dense than soil) by gravity.

The remediation objective was to dean the gravel and sand fractions
to the USEPA cleanup levels for the Alaskan  Battery Enterprises
(ABE) Site: less than 1,000 mg/kg total lead and less than 5 mg/L
Toxicity Characteristic Leaching Procedure (TCLP) lead.

A mobile 20 ton/hr unit performed this SITE Demonstration. The
system flowsheet, illustrated in Rgure 1, receives contaminated soil
(minus 2 W in diameter) in a hopper/conveyor that feeds the revolving
trommel wash unit. Material ranging from minus 2 W to plus 1/4" (the
gravel fraction) passes from a drum screen in the trommel to a casing
chip separator that removes, by gravity, both battery casing chips and
coarsQ metallic lead.

Material minus 14" passes through the drum screen into the first of two
counter-flow separation chambers. Additional casing chips (minus 1/4"
to plus 10 mesh), recovered from the chamber by sizing and density
separation, accumulate in a chip pile. The balance of the minus 1/4"
slurry1 flows to the second separator which recovers the minus !4" to
plus 150 mesh soil (the sand fraction). This sand passes over another
density separator for metallic lead fines removal and then through a
dewatering spiral classifier. A unique advantage of using the separa-
tion chambers is the small amount (less than 1%) of minus 150 mesh
fines left in the sand fraction.

The suspended and highly contaminated fine soil fraction (minus 150
mesh) overflows the separatbn chambers; the system mixes it with a
                                                      Recycle Water
-2 
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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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