Proceedings

Following wastewater treatment, dewatering of biosolids at Tres Rios WWTP in Tucson Arizona
results in ≃ 0.5 mgd of effluent with high concentrations of NH4 (1000 ppm). This effluent is returned
to the head works, and the high NH4 concentration results in a need for extra oxygen to be pumped
into the effluent to enhance nitrification. This results in significantly enhanced energy costs (= 30%
total energy costs). Therefore, there is a need to remove the NH4 prior to re-entry into the head works.
This project evaluates an alternative method of removing the NH4 from the effluent – namely
anaerobic oxidation of ammonia or anammox. We are evaluating the efficacy of anammox as an
alternative side stream treatment of effluent, and also determining the influence of anammox on
human pathogenic virus inactivation. Initial studies have shown the incidence of virus in the biosolid
centrate and inactivation during the anammox process.

Keywords
anammox, novel nitrogen removal, planctomycetes