“…In fact, aerobic guilds tend to prefer smaller aggregates ( e.g. flocs) with less diffusion limitations than biofilms (Corbala-Robles et al., 2015, Vlaeminck et al., 2010, Volcke et al., 2010, Winkler et al., 2012). In the H-MBBR, about 35% of AOB and 25% of NOB grew in suspension (as estimated by multiplying the qFISH relative abundances and the TSS of the biofilm and flocs, Table 2).…”
Section: Discussionmentioning
confidence: 99%
“…thick biofilms) and the aerobic AOB and NOB guilds tend to preferentially populate smaller aggregates ( e.g. flocs) with less diffusion limitations (Corbala-Robles et al., 2015, Vlaeminck et al., 2010, Volcke et al., 2010, Winkler et al., 2012). The coexistence of biofilm and flocs has been shown to improve the PN/A performance and the NOB suppression at high temperatures (>25 °C), both on digester supernatant (Veuillet et al., 2014) and pre-treated MWW (Malovanyy et al., 2015).…”
The implementation of autotrophic anaerobic ammonium oxidation processes for the removal of nitrogen from municipal wastewater (known as “mainstream anammox”) bears the potential to bring wastewater treatment plants close to energy autarky. The aim of the present work was to assess the long-term stability of partial nitritation/anammox (PN/A) processes operating at low temperatures and their reliability in meeting nitrogen concentrations in the range of typical discharge limits below 2 mgNH4-N·normalL−1 and 10 mgNtot·L−1. Two main 12-L sequencing batch reactors were operated in parallel for PN/A on aerobically pre-treated municipal wastewater (21 ± 5 mgNH4-N·normalL−1 and residual 69 ± 19 mgCODtot·L−1) for more than one year, including over 5 months at 15 °C. The two systems consisted of a moving bed biofilm reactor (MBBR) and a hybrid MBBR (H-MBBR) with flocculent biomass. Operation at limiting oxygen concentrations (0.15–0.18 mgnormalO2·normalL−1) allowed stable suppression of the activity of nitrite-oxidizing bacteria at 15 °C with a production of nitrate over ammonium consumed as low as 16% in the MBBR. Promising nitrogen removal rates of 20–40 mgN·L−1·d−1 were maintained at hydraulic retention times of 14 h. Stable ammonium and total nitrogen removal efficiencies over 90% and 70% respectively were achieved. Both reactors reached average concentrations of total nitrogen below 10 mgN·L−1 in their effluents, even down to 6 mgN·L−1 for the MBBR, with an ammonium concentration of 2 mgN·L−1 (set as operational threshold to stop aeration). Furthermore, the two PN/A systems performed almost identically with respect to the biological removal of organic micropollutants and, importantly, to a similar extent as conventional treatments. A sudden temperature drop to 11 °C resulted in significant suppression of anammox activity, although this was rapidly recovered after the temperature was increased back to 15 °C. Analyses of 16S rRNA gene-targeted amplicon sequencing revealed that the anammox guild of the bacterial communities of the two systems was composed of the genus “Candidatus Brocadia”. The potential of PN/A systems to compete with conventional treatments for biological nutrients removal both in terms of removal rates and overall effluent quality was proven.
“…In fact, aerobic guilds tend to prefer smaller aggregates ( e.g. flocs) with less diffusion limitations than biofilms (Corbala-Robles et al., 2015, Vlaeminck et al., 2010, Volcke et al., 2010, Winkler et al., 2012). In the H-MBBR, about 35% of AOB and 25% of NOB grew in suspension (as estimated by multiplying the qFISH relative abundances and the TSS of the biofilm and flocs, Table 2).…”
Section: Discussionmentioning
confidence: 99%
“…thick biofilms) and the aerobic AOB and NOB guilds tend to preferentially populate smaller aggregates ( e.g. flocs) with less diffusion limitations (Corbala-Robles et al., 2015, Vlaeminck et al., 2010, Volcke et al., 2010, Winkler et al., 2012). The coexistence of biofilm and flocs has been shown to improve the PN/A performance and the NOB suppression at high temperatures (>25 °C), both on digester supernatant (Veuillet et al., 2014) and pre-treated MWW (Malovanyy et al., 2015).…”
The implementation of autotrophic anaerobic ammonium oxidation processes for the removal of nitrogen from municipal wastewater (known as “mainstream anammox”) bears the potential to bring wastewater treatment plants close to energy autarky. The aim of the present work was to assess the long-term stability of partial nitritation/anammox (PN/A) processes operating at low temperatures and their reliability in meeting nitrogen concentrations in the range of typical discharge limits below 2 mgNH4-N·normalL−1 and 10 mgNtot·L−1. Two main 12-L sequencing batch reactors were operated in parallel for PN/A on aerobically pre-treated municipal wastewater (21 ± 5 mgNH4-N·normalL−1 and residual 69 ± 19 mgCODtot·L−1) for more than one year, including over 5 months at 15 °C. The two systems consisted of a moving bed biofilm reactor (MBBR) and a hybrid MBBR (H-MBBR) with flocculent biomass. Operation at limiting oxygen concentrations (0.15–0.18 mgnormalO2·normalL−1) allowed stable suppression of the activity of nitrite-oxidizing bacteria at 15 °C with a production of nitrate over ammonium consumed as low as 16% in the MBBR. Promising nitrogen removal rates of 20–40 mgN·L−1·d−1 were maintained at hydraulic retention times of 14 h. Stable ammonium and total nitrogen removal efficiencies over 90% and 70% respectively were achieved. Both reactors reached average concentrations of total nitrogen below 10 mgN·L−1 in their effluents, even down to 6 mgN·L−1 for the MBBR, with an ammonium concentration of 2 mgN·L−1 (set as operational threshold to stop aeration). Furthermore, the two PN/A systems performed almost identically with respect to the biological removal of organic micropollutants and, importantly, to a similar extent as conventional treatments. A sudden temperature drop to 11 °C resulted in significant suppression of anammox activity, although this was rapidly recovered after the temperature was increased back to 15 °C. Analyses of 16S rRNA gene-targeted amplicon sequencing revealed that the anammox guild of the bacterial communities of the two systems was composed of the genus “Candidatus Brocadia”. The potential of PN/A systems to compete with conventional treatments for biological nutrients removal both in terms of removal rates and overall effluent quality was proven.
“…S1). AOB tend to locate on the surface of the biofim, while the anammox bacteria and denitrifiers tend to grow in the inner part (Volcke et al 2010;Winkler et al 2012). The average influent NH 4 ?…”
The simultaneous partial nitrification, anammox and denitrification (SNAD) process for treating domestic wastewater was investigated in a sequencing batch reactor (SBR). The SBR was operated with air flow rate of 500 L h at 30 °C. Domestic wastewater was used as influent and Kaldnes rings were used as biomass carriers. In the beginning, long aeration condition was implemented to cultivate nitrification biofilm. Afterwards, intermittent aerobic condition was conducted during the cycle operation. The influent organic matter loading rate was improved by reducing the aeration and mixing times. Consequently, when the SNAD biofilm reactor was fed with the organic matter loading rate of 0.77 (kg COD m d), the bio-bubbles appeared in the reactor and the total inorganic nitrogen (TIN) removal efficiency decreased. After the organic matter loading rate decreased to 0.67 (kg COD m d), the reactor showed excellent nitrogen removal performance. The TIN removal efficiency varied between 80 and 90 %, and the average TIN removal loading rate was 0.22 (kg TIN m d). Additionally, the scanning electron microscope (SEM) observation confirmed that the anammox bacteria located in the inner part of the carriers. Finally, the microbial community analysis of 16S rRNA gene cloning revealed that the anammox bacteria on the carriers consisted of three main genuses: Candidatus Brocadia sp., Candidatus Brocadia caroliniensis and Candidatus Brocadia fulgida.
“…Brocadia fulgida and Ca. Anammoxoglobus propionicus, are capable of performing dissimilatory nitrate reduction to ammonium (DNRA) with nitrite as an intermediate, and volatile fatty acids (VFA) as electron donors (organotrophic activity) (Kartal et al, 2007a(Kartal et al, , 2007bWinkler et al, 2012b). In the anammox-driven DNRA pathway, VFA are oxidized to CO 2 via acetyl-CoA (Russ et al, 2012) instead of assimilating into biomass (Kartal et al, 2007b), and thus a low level of biomass is maintained.…”
Section: Principles Of Nitritation-anammox Processmentioning
confidence: 99%
“…Anammox bacteria naturally form aggregates (i.e., biofilm) whereas both AOB and NOB tend to form smaller aggregates (i.e., flocs) with less diffusion limitation (Corbala´-Robles et al, 2016;Vlaeminck et al, 2010;Volcke et al, 2010;Winkler et al, 2012b). The coexistence of biofilm and flocs has been shown to improve reactor performance and NOB suppression at temperatures .25 8C when treating pretreated mainstream wastewater (Malovanyy et al, 2015a).…”
Section: Research Status Of Mainstream Nitritation-anammoxmentioning
The nitritation-anammox process is an efficient and cost-effective approach for biological nitrogen removal, but its application in treating mainstream wastewater remains a great challenge. Mainstream nitritation-anammox processes could create opportunities for achieving energy self-sufficient, or energy-generating water resource recovery facilities. Significant advancements have been achieved via pilot- and full-scale trials to overcome the major obstacles under mainstream conditions, such as repression of nitrite-oxidizing bacteria, limiting the overgrowth of denitrifiers, and effective selection and retention of ammonia-oxidizing bacteria and anammox bacteria. This review paper intends to provide a detailed update of research progress on mainstream nitritation-anammox processes, discuss metabolic interactions, and examine major challenges and possible solutions towards the future development.
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