Impact of Ammonia-Based Aeration Control (ABAC) on energy consumption

Abstract

An Ammonia-Based Aeration Control (ABAC) system is installed in the primary aeration basins of a regional wastewater treatment facility. The energy consumption of the system of air blowers, measured in kilowatts per hour by an existing meter, is analyzed for seven months after the installation of the ABAC system and compared to system performance prior to commissioning of the ABAC system. Processed data, including volume flow rate, ammonia loading, and treatment equipment efficiency, are evaluated for periods before and after the ABAC system installation. Ammonia mass loading and air transfer ratio in the aeration basins are determined to be the leading factors affecting the performance of the ABAC system and thus impacting the metered energy consumption. The metered energy consumption data are normalized by the two calculated ratios, which reflect the change in ammonia loading and air transfer ratio. The normalized and metered energy consumption data are compared, and the results show a reduction in energy consumption since the installation of the ABAC system. A yearly savings of approximately 9 ± 1% in energy costs is estimated with the installation of the ABAC system. The savings in energy consumption calculated as well as the improvements in nitrification efficiency confirm the benefit of an ABAC system in reducing operation costs and enhancing process control.