and

Department of Civil Engineering

Sequestered soil contamination refers to soil contamination that has migrated deep into soil particles over a long period of time. It is difficult to remediate this type of contamination because it is not found on the soil particle surface where it could easily be mobilized. It is found deep within the soil aggregate where it is sheltered from aggressive surface treatments and "immobilized" by diffusive mass transport resistance. In some soils sequestered contamination represents a significant fraction of the total mass burden.

Electrokinetic (EK) enhanced treatment methods appear to offer the possibility of accelerating the remediation of sequestered soil contamination. They also may offer interesting possibilities for rapidly measuring sequestered mass burdens. When a DC field is imposed across the soil, it can induce an electromobility of ionic species that accelerates mass transport rates far above diffusional mass transport. Some experimental work has been done on EK-accelerated remediation, but most of this has used soils that were recently contaminated so they probably did not contain sequestered mass fractions.

The research discussed in this presentation is designed to evaluate the use of EK-acceleration in combination with ion-selective membranes as a method of quantifying both the sequestered mass burden of soils and the electromobility constants necessary for designing an Electrokinetic remediation process. To accomplish this, "old contamination soils" contaminated with several heavy metals are being identified and harvested for the Brownfields of the greater Cleveland Area.