Exploring the use of EK-TAP technology for in situ remediation of groundwater and soil contaminated with oil-field produced wastewater

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Hydraulic fracturing and oil sands extraction are being increasingly used as means of recovering unconventional fossil fuel sources in Canada and around the world. The extraction technologies utilize large volumes of freshwater, and generate wastewater, known as oil-field produced wastewater. The wastewater is comprised of a complex mixture of dissolved organic and inorganic compounds, and is known to possess toxicological effects on aquatic habitats. It is because of its toxicity that there has been a growing concern over the accidental release of the produced wastewater (e.g., via dyke seepage or infiltration at the storage impoundments and tailing ponds, leakage in the injection wells, spill of wastewater-carrying pipelines and trucks) and the contamination of surface water, groundwater, and soil. Therefore, treatment technologies that can mitigate the impact of the produced wastewater will provide great benefits to the oil sands and hydraulic fracturing industries, and protect the environment and public health. The goal of this collaboration is to explore the efficacy of the EK-TAP technology for remediating groundwater and soil contaminated with oil-field produced wastewater. EK-TAP, invented by Geosyntec, utilizes direct current to electrokinetically (EK) enhance the delivery of persulfate into low-permeability subsurface zones, followed by the application of alternating current to thermally activate persulfate (TAP). The activation of persulfate converts the chemical into powerful oxidants (e.g., persulfate and hydroxyl radicals) that can oxidize and remove a wide range of organic contaminants. Laboratory and field experiments will be conducted to examine factors that control the performance of the EKTAP technology, and identify means of making the technology robust and cost-effective for remediating sites contaminated with oil-field produced wastewater.