Engineered carbon-depleted zone in Anaerobic/Aerobic/Anoxic process as a key in-situ anammox incubation hub for mainstream municipal wastewater treatment

Competitive nitrite consumption by heterotrophic organisms and the carbon sensitivity of anammox bacteria limit mainstream anammox performance. This study demonstrates that deliberately established carbon-depleted zones within anaerobic/aerobic/anoxic (AOA) processes served as in-situ anammox incubation hubs by regulating endogenous and exogenous carbon metabolism, achieving 92.3% nitrogen removal with 59.4% via anammox and effluent total inorganic nitrogen of 5.1 mg/L at C/N 3.2.