KDO Experiments at NYC DEP's Full-Scale Demonstration Facility

KDO, the half-saturation coefficient for dissolved oxygen (DO) which determines how quickly nitrification (ammonia and nitrite oxidation) progresses as a function of DO concentration, was determined in a full-scale experiment conducted at the New York City (NYC) Department of Environmental Protection's (DEP's) Full-Scale Demonstration Facility, Battery E at the Wards Island Wastewater Treatment Plant (WWTP). Results from the full-scale testing and bench scale tests using biomass from Battery E indicate that the KDO may be as high as 1.5 mg DO/L.These findings could have a significant impact on process operations by requiring plants to operate at a greater minimum DO concentration to ensure optimal nitrification, particularly in the winter months and during times of nitrification recovery, impacting both the performance and economics of treatment.