Meet Anammox


Meet Anammox

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AlexRenew has implemented the first full-scale mainstream deammonification facility in North America. The process promotes short-cut nitrogen removal by Anammox bacteria, also known as red bugs. The red bugs remove nitrogen from wastewater to improve the quality of treated water AlexRenew releases into the Potomac River and Chesapeake Bay.



Our mainstream deammonification hydrocyclones enrich our red anammox microbes so they can clean our water efficiently.

Why Red Bugs?
Compared to conventional wastewater cleaning processes, the red bugs are expected to save energy by using 60 percent less oxygen. The process also is expected to reduce supplemental carbon use by more than 40 percent, reducing the number of trucks delivering chemicals to AlexRenew and decreasing greenhouse gas emissions.

Anammox bacteria are naturally occurring and safe to use in the wastewater treatment process. These bacteria take a shortcut when converting ammonia in dirty water into nitrogen gas, which is safely released back into the atmosphere. 

Building a Blueprint
AlexRenew began operating our Centrate Pretreatment Facility in May 2015 with impressive results. In this sidestream deammonification facility, Anammox bacteria clean nitrogen-rich water that we remove from our solids using large spinning centrifuges. This water, called centrate, holds as much as 25% of all nitrogen in the dirty water at AlexRenew. The Centrate Pretreatment Facility can treat 276,000 gallons of centrate per day, removing 85% of the total nitrogen from this waste stream.

In the last few years, laboratory and field-scale Anammox demonstration studies have increased significantly. There are only a handful of full-scale mainstream deammonification facilities currently in operation, primarily in Europe, but none are subject to the same strict nitrogen discharge limits as AlexRenew. Implementation of mainstream deammonification at AlexRenew is a milestone in the development of this technology that provides a blueprint for other facilities to follow.

Part of our Nitrogen Upgrade
Mainstream and sidestream deammonification work in conjunction with our Nutrient Management Facility as part of AlexRenew’s State-of-the-Art Nitrogen Upgrade Program. The Nutrient Management Facility stores wastewater to balance the amount of nitrogen that goes into AlexRenew’s biological treatment process, where mainstream deammonification takes place. Together these upgrades will reduce the total nitrogen AlexRenew discharges to the Chesapeake Bay by an additional 20 percent annually.