(562c) Electrokinetic Treatment of Mercury Contaminated Soil at the Mercury Refining Company Superfund Site

Since 1955 the Mercury Refining Company (MERECO) conducted operations to reclaim metallic mercury (Hg) from off-specification metallic Hg, Hg batteries and other Hg bearing waste. The Hg was reclaimed using retort furnaces at the faculty. Unfortunately, as a result of the activities at the MERECO Hg was released and has contaminated the soil at the site. In 2003 the USEPA conduced a remedial investigation study and found Hg as deep as 60 feet at the site and in concentration in excess of 10,000 mg/kg.

Due to the fact that the site is small and mostly covered by buildings and/or pavement electrokinetic (EK) treatment of the soil may offer the most cost effective solution for site remediation. Unfortunately, preliminary screening test indicate that elemental mercury (as expected) was not mobilized via EK treatment. As a result, amendments were screened to determine if the elemental Hg could be transformed to divalent mercury and removed using EK. A total of 10 reagents were screened using a series of batch test to determine effective concentrations and amendments. A total of 4 reagents were selected for EK laboratory EK testing. Currently a total of 8 cells (4 amendments in duplicate) are being ran at a current density of 1.5 milliamps/square centimeter. The paper will present the result of the batch and EK cell studies describing the effectiveness of the treatment method.