The enhancement of completely autotrophic nitrogen removal over nitrite (CANON) by N 2 H 4 addition

Effect of trace hydrazine addition on the functional bacterial community of a sequencing batch reactor performing completely autotrophic nitrogen removal over nitrite

“…It has been reported that the addition of trace N 2 H 4 can strengthen ANAMMOX (Yao et al, 2013) but also exhibits a certain inhibiting impact on the activity of the AOB and NOB (Tomlinson et al, 1966;Yao et al, 2013). In the CANON system without the addition of N 2 H 4 , the relative abundance percentage of the bacteria in (Mobarry et al, 1996) AnAOB Amx368 CCTTTCGGGCATTGCGAA All ANAMMOX organisms (Schmid et al, 2003) the phylum Actinobacteria (Servin et al, 2008) that contained most of the heterotrophs was 1.9%, and the relative abundance percentage of the bacteria in the phylum Nitrosospira, to which NOB belong, was 2.15%; the relative abundance percentages of bacteria in the phylum Proteobacteria, to which AOB belong, and the phylum Planctomycetes, to which AnAOB belong, were 33.75% and 3.40%, respectively (Fig.…”

“…(NH 4 ) 2 SO 4 and NaHCO 3 were used to prepare synthetic wastewater. The concentration of NaHCO 3 was 1.5 g/L, and 1.25 mL trace element solution (Yao et al, 2013) was added in 1 L synthetic wastewater. The solids retention time and the hydraulic retention time were 20 days and 11.8 h, respectively.…”

“…Hydrazine (N 2 H 4 ) is a strong reducing agent with biological toxicity. However, despite partial inhibition on aerobic ammonia oxidation, adding trace N 2 H 4 to the CANON reactor could improve the nitrogen removal performance by effectively strengthening ANAMMOX and significantly inhibiting the oxidization of nitrite, and consequently reduce the generation of nitrate (Yao et al, 2013). In order to provide microbiological evidence for the possible strengthening mechanism mentioned above and microscopic theoretical supports for the optimization of CANON system, based on the functional gene of the AOB, the a-subunit of ammonia monooxygenase (amoA), and the functional gene of the AnAOB, the a-subunit of hydrazine synthase (hzsA), the following work were accomplished in this paper: (1) the community structures of functional bacteria (AOB and AnAOB) in the CANON system were qualitatively analyzed; (2) the AOB and AnAOB were quantitatively determined through qPCR before and after the addition of trace N 2 H 4 ; (3) the superficial morphology of the granular sludge in the CANON system with long-term addition of trace N 2 H 4 was detected by using scanning electron microscope (SEM) and spatial distribution patterns of the AOB and AnAOB in the granular sludge were revealed via using FISH technique.…”

Biological Removal of Ammonia from Municipal Landfill Leachate (Kozodrza, Poland) at Limited Oxygen Access and Presence of Kaldnes Media

“…This may suggest that unbalanced ammonia nitrogen losses are related to DO concentration. Elimination of ammonia nitrogen in the systems based on the activated sludge maintained under anaerobic-aerobic conditions can be linked with the ability of Nitrosomonas genus bacteria, to produce nitrogen oxides and molecular nitrogen [Stűven et al 1992 Yao et al [2013] informed that plantomycete-like Anammox bacteria bioactivity could be enhanced by increasing the concentration of N 2 H 4 , the compound which seems to be one of the main intermediate products of the reaction, according to the possible metabolic pathways. It has been found that ammonia nitrogen removal from leachates can proceed according to the 0-order reaction.…”

Startup and Performance Stability of a Nitritation-Anammox Reactor Using Granular Sludge

“…Because the doubling time of AOB is more than 10 times that of AAOB, the HRT was extended from 6 to 24 h, and 4 mg/L N 2 H 4 was added as an intermediate product for stimulating the AAOB growth. These actions led to enhanced anammox [25] and rapid AAOB enrichment.…”