MRS completed a commercial
project involving the successful treatment of soil from 6,000 metering sites
along the natural gas pipeline system in the western United States.
During this 18-month project, MRS� 12-ton
per day mobile unit processed in excess of 6,000 tons of soil containing
100-2,000 ppm of mercury with excellent results. The residual total mercury
in the treated soil was consistently below 2 ppm, TCLP results were below
detection limits, more than 3,500 pounds of metallic mercury were recovered
for sale and recycling, and the project was completed ahead of schedule and
under budget.
|
MERCURY
CONTENT |
TCLP* |
SOIL TYPE |
Untreated (ppm) |
Treated (ppm) |
(mg/kg) |
Sandy |
15,000 |
0.07 |
0.0005 |
Clay |
900 |
0.12 |
0.0008 |
Loam |
255 |
0.05 |
0.0025 |
|
|
EPA Limit......... |
0.2000 |
*Estimated
based upon 100% Leaching |
The process was permitted for operation by
state authorities within four (4) weeks of filing an application and was
exempted from RCRA, air, and solid waste permits due to its low-volume air
flow and the lack of any secondary waste.
Average monthly commercial mercury removal
results:
TOTAL |
RESIDUAL MERCURY |
CONTENT |
Month |
As-Received |
After Treatment** |
TCLP |
1 |
500-2,000 mg/kg |
0.6 mg/kg |
BDL* |
2 |
500-2,000 mg/kg |
0.5 mg/kg |
BDL* |
3 |
500-2,000 mg/kg |
0.6 mg/kg |
BDL* |
4 |
500-2,000 mg/kg |
0.7 mg/kg |
BDL* |
5 |
500-2,000 mg/kg |
0.7 mg/kg |
BDL* |
6 |
500-2,000 mg/kg |
1.1
mg/kg |
BDL* |
7 |
500-2,000 mg/kg |
0.8 mg/kg |
BDL* |
8 |
500-2,000 mg/kg |
0.6 mg/kg |
BDL* |
9 |
500-2,000 mg/kg |
0.7 mg/kg |
BDL* |
10 |
500-2,000 mg/kg |
0.7 mg/kg |
BDL* |
* BDL Below Detection Limits |
** 2.0 mg/kg target specification |
Based upon the low residual total mercury
content in the treated soil, state authorities permitted MRS� client to
utilize the soil as "fill", thereby enabling all material to be
recycled, eliminating the need to landfill, and ending all future liability
relating to this material.
Back
|