Non-Steady State Oxygen Transfer Testing of New High Purity Oxygen Dissolution and Mixing Device for Activated Sludge Aeration

Air Products and Chemicals, Inc. (APCI) and Aqua-Aerobic Systems, Inc. (AAS) have jointly developed an oxygen injection and mixing system, OxyMixTM, for the activated sludge wastewater treatment process. The OxyMixTM concept utilizes a high-speed, direct-drive floating mixer fed with high purity oxygen to provide all the necessary aeration and mixing for an activated sludge basin. Clean water oxygen transfer efficiency is measured as high as 74% for the 10-hp and 60% for the 40-hp OxyMixTM device. Although the final system design has not been optimized the initial test results indicate that the OxyMixTM concept is capable of producing higher oxygen dissolution rates than conventional technologies presently applied in the industry. The effects of oxygen flow rate and water depth on the efficiency of the device are discussed. Computational fluid dynamics (CFD) were used to model the mixing and investigate the possible effects of water depth on the aeration process.