Effect of solubility on enhanced electrokinetic extraction of metals

Conference · Wed Dec 31 04:00:00 EST 1997

OSTI ID:567840

Alshawabkeh, A N ^[1]; Puppala, S K ^[2]; Acar, Y B; Gale, R J ^[3]; Bricka, M ^[4]

---

1. Northeastern Univ., Boston, MA (United States)
2. Electrokinetics Inc., Baton Rouge, LA (United States)
3. Louisiana State Univ., Baton Rouge, LA (United States)
4. Waterways Experiment Station, Vicksburg, MS (United States)

This paper presents the results of a study investigating the effect of solubility on enhanced electrokinetic extraction of a mixture of metals from contaminated soils. Clayey soil samples retrieved from a contaminated Army Ammunition site were used. Chemical analysis of the soil showed the following concentrations: calcium 19,670 mg/kg, iron 11,840 mg/kg, copper 10,940 mg/kg, chromium 9,930 mg/kg, zinc 6,330 mg/kg, and lead 1,990 mg/kg. Two unenhanced and two enhanced bench-scale tests were conducted. The enhancement approach comprised introduction of a weak acid at the catholyte to neutralize the water reduction electrolysis reaction. This procedure is expected to prevent formation of an alkaline catholyte and consequently prevent formation of metal hydroxide precipitates in the soil. Current density applied in these tests was 0.5 A/m{sup 2}. The tests were processed for 1,876 hours and 3,774 hours. The results showed that metal solubility greatly affect transport and extraction efficiency. Different removal rates were achieved in these tests for different metals. Metals with higher initial concentration, less sorption affinities, higher solubilities, higher ionic mobilities are transported and extracted faster than other metals.

• OSTI ID: 567840
• Report Number(s): CONF-971032--
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
58 GEOSCIENCES
CONTAMINATION
ELECTRODYNAMICS
ENVIRONMENTAL ENGINEERING
METALS
MILITARY FACILITIES
REMEDIAL ACTION
SOILS
SOLUBILITY