Modeling and Comparison of Electrolytic Aeration and ORC ® Aeration of Anoxic Groundwater in a Simulated Laboratory Aquifer

Abstract

This study investigated the electrolytic method of aerating anoxic groundwater, where the goal for aeration is to enhance in situ bioremediation by indigenous microbes. Experiments in a simulated aquifer were performed to study the electrolytic cell as an oxygen generating source, and its performance was compared to oxygen release compound (ORC^®) with respect to aerating the anoxic aquifer. Two different flow rates and concentrations of a dissolved oxygen (DO) scavenger were tested. Sodium sulfite was used to simulate the presence of DO scavengers such as Fe²⁺. Electrolytic aeration is possible at a current of 100 mA, and is competitive with ORC^® aeration. A higher flow rate resulted in lower dissolved DO levels in the simulated aquifer, and lower sulfite levels increased the DO levels. A mathematical model was developed to simulate the movement and dispersion of DO down-gradient of the oxygen delivery well. The model results confirmed that the two aeration technologies are comparable. The use of the model in determining the zone of influence of an electrolytic well for oxygenating an anoxic aquifer is demonstrated for a hypothetical scenario.