Utilizing Automatic Dissolved Oxygen and Internal Recycle Set-Point Control at Abington WWTP in Southeastern Pennsylvania

As permit requirements for effluent quality at wastewater treatment plants continue to become more stringent, intelligent control systems are needed to ensure optimal performance of the secondary treatment process. Such a control system was installed at Abington Wastewater Treatment Plant in southeastern Pennsylvania in 2005. Since that time, the control system has been optimizing dissolved oxygen set-points based on real-time loading with the goal of minimizing aeration requirements and maximizing process reliability. In 2009, after a plant upgrade, internal recycle optimization was added to the system. The benefits of this system have been a 5.5% reduction in aeration requirements, consistently meeting effluent ammonia goals, and optimal use of the anoxic volume for denitrification.