Demonstration of Glycerol Fed Separate Centrate Treatment Process


  • Sarah Dailey and Paul Pitt - Hazen and Sawyer
  • Robert Sharp - Manhattan College
  • Melissa Motyl - CH2MHILL
  • Allen Deur and Keith Beckmann - NYCDEP

The glycerol AT-3 demonstration took place at the ACEC award-winning 26th Ward WWTP, where the AT-3 process was originally developed.

The New York City Department of Environmental Protection (NYCDEP) began a full-scale demonstration of glycerol addition to the AT-3 Separate Centrate Treatment (SCT) process at the 26th Ward biological nitrogen removal plant. The purpose of the demonstration study was to optimize the glycerol-driven SCT process, and determine its impact on whole plant performance, including glycerol kinetics, glycerol dosing optimization, bioaugmentation of nitrifiers in the main plant, maintenance of main plant nitrification under cold weather operations, optimization of caustic addition, and overall TN removal. Glycerol-based carbon sources have gained a lot of attention from the wastewater industry because they are a sustainable alternative (waste product of biodiesel production), do not pose health and safety risks like methanol and ethanol, do not have kinetic limitations in cold weather, and have proven to be effective at pilot and full-scale. For these reasons NYCDEP chose glycerol as their main supplemental carbon source as part of BNR upgrades to six of their 14 WWTPs.

The full paper will describe in detail the optimization and performance of the glycerol fed AT-3 process, including its impacts on main-plant performance, its role in bioaugmentation of nitrifiers in the main plant and maintenance of main plant nitrification under cold weather operations and upset conditions, and the potential contributions of simultaneous nitrification/denitrification (SND) and nitrous stripping in overall nitrogen removal.

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