Low Permeability Zone Remediation via Oxidant Delivered by Electrokinetics and Activated by Electrical Resistance Heating: Proof of Concept

This study proposes and proves (in concept) a novel approach of combining electroldnetic (EK)-assisted delivery of an oxidant, persulfate (PS), and low temperature electrical resistivity heating (ERH), to activate PS, to achieve remediation of contaminated, low permeability soil. This Unique combination is able to overcome existing challenges in remediating low permeability materials, particularly associated with delivering remediants. A further benefit of the approach is the use of the same electrodes for both EK and ERH phases. Experiments were conducted in a laboratory-scale sand tank packed with silt and aqueous tetrachloroethene (PCE) and bracketed on each side by an electrode. EK first delivered unactivated PS throughout the silt. ERH then generated: and sustained the target temperature to activate the: PS As a result, PCE concentrations decreased to below detection limit in the silt in a few weeks. Moreover, it was found that activating PS at similar to 36 degrees C eliminated more PCE than activating it at >41 degrees C. It is expected this results from the reactive SO4 center dot- radical being generated more slowly, which ensures more complete reaction with the contaminant. The novel, application of EK-assisted PS delivery followed by low temperature ERH appears to be a viable strategy for low permeability contaminated soil remediation.