Oxygen transfer efficiency measurements in mixed liquor using off-gas techniques

It has been reported that approximately 1.75 million hp of aeration equipment is currently in place on the North American continent, in both municipal and in dustrial treatment facilities.1 These facilities are being operated at a power cost exceeding $0.6 billion per year. Evidence suggests that the overall oxygen transfer effi ciency for this equipment is low and the cost of power could be reduced by as much as 50% by improved design and operation.1 Although there are many reasons for imperfect application of oxygen transfer devices in wastewater, one basic cause has been the unavailability of, or failure to use, optimal methods for the measure ment of oxygen transfer.