For more information, contact: 
Carrie W. Capuco
Director of Communications 

Understanding the Impacts of Low-Energy and Low-Carbon Nitrogen Removal Technologies on Bio-P and Nutrient Recovery Processes (NTRY13R16)

(Alexandria, VA) - Past WE&RF research identified the benefit of low-energy, low-carbon nitrogen removal processes and the impact that struvite harvesting can have on phosphorus recovery from municipal water resource recovery facilities (WRRFs). WE&RF has awarded a contract to Northwestern University to study design and operational impacts of incorporating enhanced biological phosphorus removal (Bio-P) or other phosphorus recovery techniques with a low-energy, low-carbon nitrogen removal process at WRRFs. Recent advancements in technology are transforming biological N removal through increased efficiency and increased energy recovery. Combining these processes and technologies is a necessary step towards sustainable wastewater treatment, especially when integration can facilitate phosphorus recovery.

The goal of the research is to develop a multi-pronged approach to facilitate low energy N and P removal and recovery using Bio-P as a central theme. The project will follow three complementary research tracks:

  • Track 1 focuses on the understanding of mechanisms that allow for selection of denitrifying polyphosphate accumulating organisms (DPAOs) in plants using shortcut nitrogen removal processes integrated with Bio-P removal.

  • Track 2 emphasizes the need to understand mechanisms that allow for efficient carbon diversion and P removal using short solids retention rate (SRT) high-rate activated sludge prior to a second-stage shortcut nitrogen removal process.

  • Track 3 focuses on determining economic and technical feasibility of recovering P directly from sludge digestate from full-scale facilities which practice a combination of Bio-P and chemical precipitation.

The primary expected outcome is to have successful full-scale implementation of energy-efficient N removal with Bio-P in WRRFs that have stringent N and P criteria. 

For more information, contact Christine Radke at


The Water Environment & Reuse Foundation (WE&RF) is a 501c3 charitable corporation seeking to identify, support, and disseminate research that enhances the quality and reliability of water for natural systems and communities with an integrated approach to resource recovery and reuse; while facilitating interaction among practitioners, educators, researchers, decision makers, and the public.