Enhanced nitrogen removal of the simultaneous partial nitrification, anammox and denitrification (SNAD) biofilm reactor for treating mainstream wastewater under low dissolved oxygen (DO) concentration

Enhanced nitrite accumulation under mainstream conditions by a combination of free ammonia-based sludge treatment and low dissolved oxygen: reactor performance and microbiome analysis

“…Low DO (<1.0 mg L À1 ) with intermittent aeration has been used to repress or eliminate NOB under mainstream conditions. [6][7][8] However, compared with Nitrobacter, Nitrospira with higher affinities for nitrite and DO was enriched under long-term low DO, and NOB would outcompete AOB, which brought about the failure of mainstream partial nitritation. [9][10][11] These contradicting results in published research indicate that the regime of NOB guilds under long-term low DO needed to be further checked and claried.…”

Anammox and partial denitrification coupling: a review

“…122 The advantage of this process is that the anammox activity and denitrication activity are positively related, and the synergistic metabolism can greatly improve the TN removal rate. [134][135][136] Because the screening of the type of sludge is largely determined by the coupling process, the screening of functional anammox and denitrifying bacteria is oen performed by adding screening factors (such as pH, T and salt) to the sewage during process operation and commissioning. 31 Because of the large difference in demand for sludge-dominant bacteria for sewage treatment performance goals, sludge must be domesticated and cultivated.…”

Integrated A-B processes for municipal wastewater treatment

“…NOB repression, microbial competition, retention of anammox bacteria, etc. The low DO strategy has been widely adopted to repress NOB activity (Laureni et al, 2016;Zheng et al, 2019); however, unsuccessful NOB repression has been widely reported, which might be because of the variations in oxygen affinities among different NOB genera (Regmi et al, 2014;Strous et al, 1999). Moreover, it has been found that DO at low concentrations may inhibit AOB activity as well and eventually result in nitrite limitation for anammox bacteria (Lotti et al, 2015).…”