Holistic Aeration Optimization Saves Big Money from 1 MGD to 270 MGD

As wastewater agencies drive to reduce operational costs and improve sustainability, the aeration process quickly stands out as a top priority for improvement as it generally consumes the majority of energy in a wastewater treatment facility (Figure 1). Upgrades to aeration processes can produce returns on investment greater than 50% annually, while greatly improving a treatment plant’s carbon footprint.The aeration process is the single largest consumer of energy (and associated greenhouse gas emissions) in wastewater treatment plants. Many of these systems were designed and installed decades ago when energy was less expensive and concerns about greenhouse gases and sustainability were nonexistent. As a result, these systems are typically wasteful and are reaching the end of their useful lives. Times have changed. Budgetary pressures and the drive for sustainability are forcing many agencies to scrutinize and optimize their aeration processes.There are several methods to reduce aeration energy consumption including replacing diffusers and blowers with new high efficiency models as well as implementing automated process control systems to actively monitor ammonia (NH4) concentration and control dissolved oxygen (DO) in the treatment system to ensure the plant uses only the energy required for treatment and no more. Additionally, process changes can be made to allow for denitrification which utilizes nitrate present in the treated wastewater in lieu of oxygen, further saving aeration energy.This paper discusses small and large scale case studies that utilized a holistic approach to optimize the efficiency of aeration including a combination of efficient blowers, air diffuser systems and process control to achieve substantial energy savings.