2023 Volume 79 Issue 25 Article ID: 23-25024
In this study, the actual nitrous oxide (N2O) emissions in four different wastewater treatment systems were investigated at an actual wastewater treatment plant with a small nitrogen influent load and nitrification acceleration operation. As a result, it was estimated that the N2O emissions of the treatment plant were about 75 % smaller than those calculated using the current official N2O emission factor. In the all systems, it was estimated that most of the N2O generated was produced as a byproduct of ammonia nitrification in the aerobic tank. In addition, it was found that N2O was also generated as a byproduct of the denitrification reaction that proceeds during sludge sedimentation in the final sedimentation tank and during sludge return. Based on these findings, it is necessary to review the N2O emission factor and develop an operation method to reduce N2O emissions.
