New Insight into Partial Denitrification (PD)-based Anammox Process and Potential Engineering Application: A Review

Recently reported partial denitrification (PD, NO3--N → NO2--N) has attracted extensive attention as a novel promising alternative for anaerobic ammonium oxidation (anammox)-based process. Flexible and stable nitrite (NO2--N) supply via PD provides substantial electron acceptors for sustainable and economic anammox wastewater treatment with simple control and minimal cost. However, our understanding of researches on PD-based anammox processes applied in biological wastewater treatment is still limited. Given obviously advantages for PD-based anammox (PDA) coupling process held and countless researches have been developed, the major objective of this study was to review the latest advances of which, key influencing factors, principled characteristics and economical analyses. Comprehensive knowledge of PDA engineering application prospects were also helpful to deepen our understanding of its practices, i.e., advanced nitrogen removal from tertiary municipal sewage, post-anammox treatment of nitrogen-rich wastewater and simultaneous nitrogen removal from domestic and nitrate (NO3--N) contained wastewater. Ultimately, future researches trend of PDA was prospected to enlarge its application into full-scale wastewater treatment. In summary, PD-based anammox process held obvious advantages in actual wastewater treatment through efficiently ammonia and nitrate removal, providing a new insight into retrofitting current wastewater treatment plants. Additionally, more attention should be paid to exploring the complicated metabolic network of different types of bacteria in the PD and anammox integration system.