Efficacy of Electrolytic Generation and Transport of Oxygen for Soil Remediation

The availability of dissolved oxygen is one of the essential variables governing intrinsic aerobic biodegradation rate in soil and groundwater. Long-term addition of oxygen to subsurface systems presents an engineering problem because of the limited solubility of oxygen in water, the heterogeneity of soil, the preferential flow paths, and the limited hydraulic conductivity of fine-grained soils. A possible method for increasing dissolved oxygen levels at contaminated sites is by electrolysis. In this study, direct current of few Amp/m² is used to generate and inject dissolved oxygen into a low permeability soil by electro-osmosis. Oxygen build-up rate across 40 cm compacted clay was measured at 0.6 mg/L.day. The electroosmotic injection rates of oxygenated water in low permeability clay can be on the order of one cm/day. The rate is dependent on the current density. The results show that electrolytic generation/transport of oxygen is a simple, efficient, and economical method that has potential enhancement of intrinsic aerobic degradation of contaminants.