Alexandria Renew Enterprises has begun operating a system to help clean wastewater that is expected to save up to 25 percent on energy and chemicals compared to conventional wastewater cleaning processes.

The technology uses Anammox microbes, also known as red bugs. AlexRenew — which operates a wastewater reclamation facility in Alexandria, Virginia, and processes about 13 billion gallons of wastewater every year — is the first in the US to design a full-scale sidestream deammonification system, and its system is only one of a few anammox deammonification systems in operation nationally.

Anammox exists in the natural environment and is safe for use in the wastewater treatment process. The application is used in Europe and Asia with excellent results. AlexRenew conducted a pilot program in the US in 2008 with DC Water, CH2M, New York Department of Environmental Protection, and others.

The use of anammox bacteria will also reduce the number of trucks delivering chemicals to the water resource recovery center located near historic Old Town Alexandria.

The sidestream anammox operation is part of AlexRenew’s State-of-the-Art Nitrogen Upgrade Program (SANUP) and is a key component of the Centrate Pre-treatment Facility (CPT). Using huge centrifuges, ammonia-rich wastewater is extracted from solids and placed in the CPT, where the anammox and other microbes go to work converting ammonia in dirty water into nitrogen gas that is safely released back into the atmosphere.

The next steps in the use of anammox will be to learn more and optimize the process, and then begin testing for mainstream operations, which AlexRenews says could lead to even greater cost savings.

Truong Duy