Biological Nutrient Removal 2017

Expert Symposium

Hosted by the Water Research Foundation in June 2017, this regional workshop covered the latest developments in the field of biological nutrient removal (BNR). The presentation was given by James L. Barnard, Ph.D., of Black & Veatch.

Workshop attendees from across the Front Range of Colorado heard from Dr. James L. Barnard, who has worked in the field of BNR for decades and has consulted on the design of water reclamation plants around the world. The videos posted below provide a helpful introduction to BNR and also cover recent innovations in this area.

*There are 10 videos included in the playlist below. Click on the button in the top left corner of the video player (next to "1/10") to access the workshop videos.




In this video, Dr. Barnard sets the stage for biological nutrient removal. Increased populations around the world have led to amplified nutrient levels in wastewater and agricultural runoff. This can lead to many problems, including but not limited to cyanobacteria, algal blooms, and fish kills. These drivers increase the challenge of keeping our receiving waters healthy.


Activated Sludge

This segment covers activated sludge and BNR basics, including hydraulic retention time, solids retention time, nitrification, and denitrification.


Biological Phosphorus Removal - Part 1

Dr. Barnard describes the drawbacks of chemical phosphorus removal and introduces the concept of biological phosphorus removal. The evolution of biological phosphorus removal strategies is explained.'


Biological Phosphorus Removal - Part 2

Depending on climate, the extent of fermentation within collection systems varies. Many treatment plants have experimented with in-plant fermentation strategies. Dr. Barnard explains that phosphorus removal can be enhanced under deeper anaerobic conditions, with Tetrasphaera also taking up phosphorus.


Membrane Bioreactors (MBRs)

A recent innovation in the world of BNR is using membrane bioreactors. MBRs integrate membranes into the activated sludge process, which can produce a much higher effluent quality.


Phosphorus Recovery

Phosphorus is a finite resource and recovering it is very important. Dr. Barnard explains complete phosphorus recovery through the WASSTRIP method as well as struvite precipitation technology alternatives.


Granular Activated Sludge

In normal activated sludge operations, “fluffy” flocs are formed. The granular activated sludge process, however, forms granulated flocs, which settle faster and can enhance phosphorus removal.



Anammox bacteria can take ammonia and nitrite and turn them into nitrogen gas. This process saves energy and has a smaller footprint.


Biological Treatment of Emerging Contaminants

Biological treatment takes up many of the carcinogens, personal care products, and pharmaceuticals commonly found in wastewater. Solids retention time is a key operating parameter for the degradation of these compounds.