Superoxygenation: analysis of oxygen transfer design parameters using high-purity oxygen and a pressurized column

There remains significant potential for improvement in oxygen transfer efficiency, which can account for 60% of water and wastewater treatment energy requirements. This research examined superoxygenation, or aerating water under pressure with high-purity oxygen gas. Examined were the effects superoxygenation has on five key aeration design parameters: the mass transfer coefficient (K(L)a), saturation concentration (C-sat*), standard oxygen transfer rate (SOTR), standard aeration efficiency (SAE), and standard oxygen transfer efficiency (SOTE). This research compared values under pressures of 0, 50, 100, 150, and 200 kPa using air and pressure swing adsorption (PSA) generated oxygen. It was found that with increasing pressure for both air and PSA oxygen: K(L)a decreased, C-sat* increased, SOTR and SAE remained constant, and SOTE increased. While comparing air and PSA oxygen, oxygen was found to have a similar K(L)a, larger C-sat*, SOTR, and SOTE, and a lower SAE. It was concluded that superoxygenation is a viable method for increasing oxygen transfer and could potentially reduce oxygenation costs in water treatment processes.