Aeration Tank Odor Eliminated Through Pure-Oxygen Injection Into a Jet-Aeration System

A meat-processing wastewater pretreatment facility produced an odor linked to insufficient dissolved oxygen (DO) levels in the first of three aeration tanks. Hydrogen peroxide had been used for the odor, but there were concerns about the cost and effectiveness. The addition of new aeration equipment was constrained by the structural cover of the aeration tank.Praxair proposed and demonstrated that odor could be eliminated through restoration of aerobic conditions in the first aeration tank. The shortfall in the required oxygen transfer rate (OTR) could be met through injection of pure oxygen into the recirculating water line of the jet aeration system of the first aeration tank. During the demonstration, it was shown that DO levels above 0.5 mg/L could be maintained approximately half of the day, and the sulfide odor was eliminated. The pure-oxygen solution was found to be much more effective and less expensive than the peroxide application.