Dataset Information

Nitrifying granules cultivation in a sequencing batch reactor at a low organics-to-total nitrogen ratio in wastewater.

ABSTRACT: It is possible to cultivate aerobic granular sludge at a low organic loading rate and organics-to-total nitrogen (COD/N) ratio in wastewater in the reactor with typical geometry (height/diameter?=?2.1, superficial air velocity?=?6 mm/s). The noted nitrification efficiency was very high (99%). At the highest applied ammonia load (0.3?±?0.002 mg NH (4) (+) -N g total suspended solids (TSS)(-1) day(-1), COD/N?=?1), the dominating oxidized form of nitrogen was nitrite. Despite a constant aeration in the reactor, denitrification occurred in the structure of granules. Applied molecular techniques allowed the changes in the ammonia-oxidizing bacteria (AOB) community in granular sludge to be tracked. The major factor influencing AOB number and species composition was ammonia load. At the ammonia load of 0.3?±?0.002 mg NH (4) (+) -N g TSS(-1) day(-1), a highly diverse AOB community covering bacteria belonging to both the Nitrosospira and Nitrosomonas genera accounted for ca. 40% of the total bacteria in the biomass.

SUBMITTER: Cydzik-Kwiatkowska A

PROVIDER: S-EPMC3131513 | biostudies-literature | 2011 May

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Nitrifying granules cultivation in a sequencing batch reactor at a low organics-to-total nitrogen ratio in wastewater.

Cydzik-Kwiatkowska A A Wojnowska-Baryła I I

Folia microbiologica 20110527 3

It is possible to cultivate aerobic granular sludge at a low organic loading rate and organics-to-total nitrogen (COD/N) ratio in wastewater in the reactor with typical geometry (height/diameter = 2.1, superficial air velocity = 6 mm/s). The noted nitrification efficiency was very high (99%). At the highest applied ammonia load (0.3 ± 0.002 mg NH (4) (+) -N g total suspended solids (TSS)(-1) day(-1), COD/N = 1), the dominating oxidized form of nitrogen was nitrite. Despite a constant aeration in ...[more]

PMID: 21618047

Similar Datasets

Project description:Elevated nitrogen removal efficiencies from ammonium-rich wastewaters have been demonstrated by several applications, that combine nitritation and anammox processes. Denitrification will occur simultaneously when organic carbon is also present. In this study, the activity of aerobic ammonia oxidizing, anammox and denitrifying bacteria in a full scale sequencing batch reactor, treating digester supernatants, was studied by means of batch-assays. AOB and anammox activities were maximum at pH of 8.0 and 7.8-8.0, respectively. Short term effect of nitrite on anammox activity was studied, showing nitrite up to 42 mg/L did not result in inhibition. Both denitrification via nitrate and nitrite were measured. To reduce nitrite-oxidizing activity, high NH3-N (1.9-10 mg NH3-N/L) and low nitrite (3-8 mg TNN/L) are required conditions during the whole SBR cycle. Molecular analysis showed the nitritation-anammox sludge harbored a high microbial diversity, where each microorganism has a specific role. Using ammonia monooxygenase ?-subunit (amoA) gene as a marker, our analyses suggested different macro- and micro-environments in the reactor strongly affect the AOB community, allowing the development of different AOB species, such as N. europaea/eutropha and N. oligotropha groups, which improve the stability of nitritation process. A specific PCR primer set, used to target the 16S rRNA gene of anammox bacteria, confirmed the presence of the "Ca. Brocadia fulgida" type, able to grow in presence of organic matter and to tolerate high nitrite concentrations. The diversity of denitrifiers was assessed by using dissimilatory nitrite reductase (nirS) gene-based analyses, who showed denitifiers were related to different betaproteobacterial genera, such as Thauera, Pseudomonas, Dechloromonas and Aromatoleum, able to assist in forming microbial aggregates. Concerning possible secondary processes, no n-damo bacteria were found while NOB from the genus Nitrobacter was detected.

Project description:Ammonia-oxidizing bacteria (AOB), which oxidize ammonia to nitrite in the first step of nitrification, play an important role in biological wastewater treatment systems. Nitrosomonas mobilis is an important and dominant AOB in various wastewater treatment systems. However, the detailed physiological and genomic properties of N. mobilis have not been thoroughly investigated because of limited success isolating pure cultures. This study investigated the key physiological characteristics of N. mobilis Ms1, which was previously isolated into pure culture from the nitrifying granules of wastewater treatment bioreactor. The pure culture of N. mobilis Ms1 was cultivated in liquid mineral medium with 30 mg-N L-1 (2.14 mM) of ammonium at room temperature under dark conditions. The optimum growth of N. mobilis Ms1 occurred at 27°C and pH 8, with a maximum growth rate of 0.05-0.07 h-1, which corresponded to a generation time of 10-14 h. The half saturation constant for ammonium uptake rate and the maximum ammonium uptake rate of N. mobilis Ms1 were 30.70 ± 0.51 ?M NH4+ and 0.01 ± 0.002 pmol NH4+ cells-1 h-1, respectively. N. mobilis Ms1 had higher ammonia oxidation activity than N. europaea in this study. The oxygen uptake activity kinetics of N. mobilis Ms1 were Km(O2) = 21.74 ± 4.01 ?M O2 and V max(O2) = 0.06 ± 0.02 pmol O2 cells-1 h-1. Ms1 grew well at ammonium and NaCl concentrations of up to 100 and 500 mM, respectively. The nitrite tolerance of N. mobilis Ms1 was extremely high (up to 300 mM) compared to AOB previously isolated from activated sludge and wastewater treatment plants. The average nucleotide identity between the genomes of N. mobilis Ms1 and other Nitrosomonas species indicated that N. mobilis Ms1 was distantly related to other Nitrosomonas species. The organization of the genes encoding protein inventory involved in ammonia oxidation and nitrifier denitrification processes were different from other Nitrosomonas species. The current study provides a needed physiological and genomic characterization of N. mobilis-like bacteria and a better understanding of their ecophysiological properties, enabling comparison of these bacteria with other AOB in wastewater treatment systems and natural ecosystems.

Dataset Information

Nitrifying granules cultivation in a sequencing batch reactor at a low organics-to-total nitrogen ratio in wastewater.

Publications

Nitrifying granules cultivation in a sequencing batch reactor at a low organics-to-total nitrogen ratio in wastewater.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets