Use of an Electromagnetic Field Generator for Enhanced Oxygenation of Aquatic Systems, Understanding Mechanisms of Effect and the Associated Ecosystem Benefits

Dissolved oxygen is a key parameter for characterizing the quality of natural and wastewaters, so keeping its concentration at optimal levels is crucial for maintenance and support of aquatic life. High biochemical oxygen demand (BOD) and sediment oxygen demand (SOD) can cause low DO levels, and this may require the use of artificial aeration. This research field tested an innovative aeration technology in two aquatic environments, the EOS-2000 in stormwater ponds for two years, and a related technology, the EMF-1000, in sewage lagoons for one year. Investigations centered on how the technology functioned to increase atmospheric gas exchange to the water and its effects on key water quality parameters in both environments. Some physical properties of water were examined in response to the EOS-2000 treatment. A predictive model, configured within WASP (Water Quality Analysis Simulation Programme), assessed some water quality responses based on increased O2 levels in the respective aquatic environments. Treatment of water using the EOS device decreased surface tension and viscosity of water, and results suggest an effect of treatment on enthalpy of water. First-order gas transfer rates (K600) varied between the treated and control ponds, but a more than twofold increase in K600 was recorded for the treated pond. The device showed positive impacts for TOC, chlorophyll a, and sediment deposition, among other effects. Phosphorous, in both the treated and control ponds, was removed at appreciable rates during both years. Retention/export efficiencies for nutrients for both ponds were lower in the second year when there was no treatment. Simulations done with WASP showed higher predicted means for DO for the treated pond compared to the control. Small differences were observed between treated and control for cBOD, chlorophyll a, TKN, and phosphorus. The EMF-1000 showed potential for increasing DO and reducing NH3, phosphorus, and chlorophyll a in sewage lagoons. The predicted patterns fitted reasonably well with the field values for certain parameters but were variable for others in the ponds and lagoons.