Strategy of nitrate removal in anaerobic ammonia oxidation-dependent processes

The anaerobic ammonium oxidation (anammox), a microbial process that is considered as a low-cost and high efficient wastewater treatment, has received extensive attention with an attractive application prospect. The anammox process reduces nitrite (NO2−) to nitrogen gas (N2) with ammonium (NH4+) as the electron donor. However, some nitrate (NO3−) equivalent to 11% of total nitrogen (TN) is generated in this process, which limits the development of anammox. To overcome this problem, many efforts have been made in this regard, mainly combining with other biological treatment methods (denitrification, denitrifying anaerobic methane oxidation, etc.), introducing the substance into anammox process, etc. Herein, we summarized a detailed review of previous researches on the removal of NO3− in the anammox-dependent processes. It is hoped that this review could serve as valuable guidance in future research and practical applications of anammox. [Display omitted] •Anammox-dependent process is systematically summarized.•Anammox-dependent process is efficient to remove nitrate.•Anammox-dependent process may be a solution for wastewater treatment.