Nitrification at Low Oxygen Concentration in Biofilm Reactor

Bernet, Nicolas; Peng, Dangcong; Delgenès, Jean-Philippe; Moletta, R.

doi:10.1061/(asce)0733-9372(2001)127:3(266)

Cited by 175 publications

(87 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Nitrification can occur in industrial biofilm reactors down to O 2 concentrations of B30 mM (ref. 23), and isotopic evidence has been interpreted as indicating an onset of nitrification and associated 'oxic' nitrogen cycle processes as early as 2.67 Ga (ref. 24).…”

Section: Resultsmentioning

confidence: 99%

Nitrogen cycle feedbacks as a control on euxinia in the mid-Proterozoic ocean

et al. 2013

View full text Add to dashboard Cite

Geochemical evidence invokes anoxic deep oceans until the terminal Neoproterozoic B0.55 Ma, despite oxygenation of Earth's atmosphere nearly 2 Gyr earlier. Marine sediments from the intervening period suggest predominantly ferruginous (anoxic Fe(II)-rich) waters, interspersed with euxinia (anoxic H 2 S-rich conditions) along productive continental margins. Today, sustained biotic H 2 S production requires NO 3 À depletion because denitrifiers outcompete sulphate reducers. Thus, euxinia is rare, only occurring concurrently with (steady state) organic carbon availability when N 2 -fixers dominate the production in the photic zone.Here we use a simple box model of a generic Proterozoic coastal upwelling zone to show how these feedbacks caused the mid-Proterozoic ocean to exhibit a spatial/temporal separation between two states: photic zone NO 3 À with denitrification in lower anoxic waters, and N 2 -fixation-driven production overlying euxinia. Interchange between these states likely explains the varying H 2 S concentration implied by existing data, which persisted until the Neoproterozoic oxygenation event gave rise to modern marine biogeochemistry.

show abstract

Section: Resultsmentioning

confidence: 99%

Nitrogen cycle feedbacks as a control on euxinia in the mid-Proterozoic ocean

et al. 2013

View full text Add to dashboard Cite

show abstract

“…Oxygen is a necessity for the AAOB to produce NO2 -; however, it is (reversibly) inhibitory to the AnAOB (4). The amount of O2, however, has to be limiting to provide the AAOB with a competitive advantage over the NOB and to ensure continuous NO2 -production in the system (15,21). Biofilm reactors, which display gradients of many diffusible species, may again provide this condition if the bulk oxygen concentration is carefully controlled.…”

Section: Introductionmentioning

confidence: 99%

“…The two sequential reactions can also be obtained in two reactors in series: in an aerated first reactor a partial conversion of NH4 + to NO2 -is performed, while in an anoxic second reactor NH4 + /NO2 -is converted to N2. Several methods to halt aerobic nitrification at the point of NO2 -and provide the influent stream to the second anoxic reactor have been described (14)(15)(16). Although both one-and two-reactor approaches reduce the costs for aeration and electron donor as compared to conventional nitrification-denitrification (17,18), OLAND focuses on single-stage N removal in a biofilm reactor.…”

Section: Introductionmentioning

confidence: 99%

Start-up of Autotrophic Nitrogen Removal Reactors via Sequential Biocatalyst Addition

Pynaert

Smets²,

Beheydt³

et al. 2004

Environ. Sci. Technol.

136

View full text Add to dashboard Cite

A procedure for start-up of oxygen-limited autotrophic nitrification-denitrification (OLAND) in a lab-scale rotating biological contactor (RBC) is presented. In this one-step process, NH 4 + is directly converted to N 2 without the need for an organic carbon source. The approach is based on a sequential addition of two types of easily available biocatalyst to the reactor during start-up: aerobic nitrifying and anaerobic, granular methanogenic sludge. The first is added as a source of aerobic ammonia-oxidizing bacteria (AAOB), the second as a possible source of planctomycetes including anaerobic ammonia-oxidizing bacteria (AnAOB). The initial nitrifying biofilm serves as a matrix for anaerobic cell incorporation. By subsequently imposing oxygen limitation, one can create an optimal environment for autotrophic N removal. In this way, N removal of about 250 mg of N L -1 d -1 was achieved after 100 d treating a synthetic NH 4 + -rich wastewater. By gradually imposing higher loads on the reactor, the N elimination could be increased to about 1.8 g of N L -1 d -1 at 250 d. The resulting microbial community was compared with that of the inocula using general bacterial and AAOB-and planctomycete-specific PCR primers. Subsequently, the RBC reactor was shown to treat a sludge digestor effluent under suboptimal and strongly varying conditions. The RBC biocatalyst was also submitted to complete absence of oxygen in a fixed-film bioreactor (FFBR) and proved able to remove NH 4 + with NO 2 -as electron acceptor (maximal 434 mg of NH 4 + -N (g of VSS) -1 d -1 on day 136). DGGE and real-time PCR analysis demonstrated that the RBC biofilm was dominated by members of the genus Nitrosomonas and close relatives of Kuenenia stuttgartiensis, a known AnAOB. The latter was enriched during FFBR operation, but AAOB were still present and the ratio planctomycetes/ AAOB rRNA gene copies was about 4.3 after 136 d of reactor operation. Whether this relates to an active role of AAOB in the anoxic N removal process remains to be solved.

show abstract

“…Even though SND has been studied by diverse authors, especially in the latest years (Guo et al 2013;Scaglione et al 2013;Zheng et al 2013), the application of this process has shortcomings that hinder achieving an adequate operational robustness: low growth rate of the microorganisms involved in the process, high sensitivity to moderate concentrations of sulfurs, nitrates and nitrites (Bernet et al 2001), high energy costs (Cecen 1996) and availability of organic matter (Guo et al 2009;Martins et al 2003). That is the reason why the search for improvements of the existing processes has led to the proposal of using zeolite as a microbial support and ammonium ion exchanger (Hedström 2001;Ho and Ho 2012;Mace and Mata-Alvarez 2002;Wei et al 2010;Wilderer et al 2000Wilderer et al , 2001.…”

Section: Introductionmentioning

confidence: 99%

Simultaneous nitrification–denitrification of wastewater: effect of zeolite as a support in sequential batch reactor with step-feed strategy

Guerrero

Montalvo

Huiliñir

et al. 2016

Int. J. Environ. Sci. Technol.

View full text Add to dashboard Cite

One of the technologies used for wastewater nitrogen removal consists in simultaneous nitrificationdenitrification. The low microbial growth rate and the low availability of organic material for the denitrification stage make it necessary to study new operational conditions and the use of microbial supports. The aim of this study was to evaluate the operational behavior of a simultaneous nitrification-denitrification process in a sequential batch reactor utilizing zeolite as a biomass support and step-feed strategy. Two reactors of 2 L were used, one with zeolite and another without zeolite, both operated at constant temperature (31°C), varying nitrogen loading rate (NLR) from 0.041 to 0.113 kg total Kjeldahl nitrogen (TKN/m 3 /day). After 209 days, removals higher than 86 and 96 % in nitrogen compounds and organic matter were obtained, respectively. There was not accumulation of nitrate and nitrite in any case; this means that there was a simultaneous nitrification-denitrification in the reactors. The incorporation of zeolite in the system held higher concentration of biomass in the reactor; this led to reduce start-up to 21 days and to improve 11.31 % removal kinetic. The use of a stepfeed strategy prevents events of inhibition by substrate, even duplicating tolerance to higher NLR for the same operation time.

show abstract

Nitrification at Low Oxygen Concentration in Biofilm Reactor

Cited by 175 publications

References 30 publications

Nitrogen cycle feedbacks as a control on euxinia in the mid-Proterozoic ocean

Nitrogen cycle feedbacks as a control on euxinia in the mid-Proterozoic ocean

Start-up of Autotrophic Nitrogen Removal Reactors via Sequential Biocatalyst Addition

Simultaneous nitrification–denitrification of wastewater: effect of zeolite as a support in sequential batch reactor with step-feed strategy

Contact Info

Product

Resources

About