Combination of cascade and feed-forward constrained control for stable partial nitritation with biomass retention

A novel and efficient way of removing nitrogen from wastewater poor in biodegradable organic carbon, is the combination of partial nitritation and anoxic ammonium oxidation (anammox), as in the one-stage oxygen-limited autotrophic nitrification/denitrification (OLAND) process. Since anoxic ammonium-oxidizing bacteria grow very slowly, maximum biomass retention in the reactor is required. In this study, a lab-scale sequencing batch reactor (SBR) was used to develop granular, rapidly settling biomass. With SBR cycles of one hour and a minimum biomass settling velocity of 0.7 m/h, OLAND granules were formed in 1.5 months and the nitrogen removal rate increased from 50 to 450 mg N L−1 d−1 in 2 months. The granules had a mean diameter of 1.8 mm and their aerobic and anoxic ammonium-oxidizing activities were well equilibrated to perform the OLAND reaction. Fluorescent in-situ hybridization (FISH) demonstrated the presence of both β-proteobacterial aerobic ammonium oxidizers and planctomycetes (among which anoxic ammonium oxidizers) in the granules. The presented results show the applicability of rapidly settling granular biomass for one-stage partial nitritation and anammox.

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Stability and control of a partial nitritation reactor with biomass retention

Chemical Engineering Research and Design ◽

10.1016/j.cherd.2019.02.017 ◽

2019 ◽

Vol 144 ◽

pp. 318-333 ◽

Cited By ~ 1

Author(s):

Martín Jamilis ◽

Fabricio Garelli ◽

Hernán De Battista ◽

Eveline I.P. Volcke

Keyword(s):

Partial Nitritation ◽

Stability And Control ◽

Biomass Retention ◽

And Control

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Operating conditions analysis for a partial nitritation process with biomass retention.

IFAC-PapersOnLine ◽

10.1016/j.ifacol.2019.06.135 ◽

2019 ◽

Vol 52 (1) ◽

pp. 643-648

Author(s):

Martín Jamilis ◽

Fabricio Garelli ◽

Hernán De Battista ◽

Eveline I.P. Volcke

Keyword(s):

Operating Conditions ◽

Partial Nitritation ◽

Biomass Retention

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Comparative performance of air-lift partial nitritation processes with attached growth and suspended growth without biomass retention

Environmental Technology ◽

10.1080/09593330.2013.868037 ◽

2014 ◽

Vol 35 (11) ◽

pp. 1328-1337 ◽

Cited By ~ 5

Author(s):

Jeongdong Choi ◽

Youngho Ahn

Keyword(s):

Comparative Performance ◽

Partial Nitritation ◽

Attached Growth ◽

Suspended Growth ◽

Biomass Retention ◽

Air Lift

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Nitrogen removal from sludge reject water by a two-stage oxygen-limited autotrophic nitrification denitrification process

Water Science & Technology ◽

10.2166/wst.2004.0737 ◽

2004 ◽

Vol 49 (5-6) ◽

pp. 57-64 ◽

Cited By ~ 40

Author(s):

S. Wyffels ◽

P. Boeckx ◽

K. Pynaert ◽

D. Zhang ◽

O. Van Cleemput ◽

...

Keyword(s):

Nitrogen Removal ◽

Anaerobic Ammonium Oxidation ◽

Nitrite Accumulation ◽

Autotrophic Denitrification ◽

Ammonium Oxidation ◽

Partial Nitritation ◽

Reject Water ◽

Biomass Retention ◽

Volumetric Loading ◽

Denitrification Process

Nitrogen removal from sludge reject water was obtained by oxygen-limited partial nitritation resulting in nitrite accumulation in a first stage, followed by autotrophic denitrification of nitrite with ammonium as electron donor (similar to anaerobic ammonium oxidation) in a second stage. Two membrane-assisted bioreactors (MBRs) were used in series to operate with high sludge ages and subsequent high volumetric loading rates, achieving 1.45 kg N m-3 day-1 for the partial nitritation MBR and 1.1 kg N m-3 day-1 for the anaerobic ammonium oxidation MBR. Biomass retention in the nitritation stage ensured flexibility towards loading rate and operating temperature. Nitrite oxidisers were out-competed at low oxygen and high free ammonia concentration. Biomass retention in the second MBR prevented wash-out of the slowly growing bacteria. Nitrite and ammonium were converted to dinitrogen gas in a reaction ratio of 1.05, thereby maintaining nitrite limitation to assure process stability. The anoxic consortium catalysing the autotrophic denitrification process consisted of Nitrosomonas-like aerobic ammonium oxidizers and anaerobic ammonium oxidizing bacteria closely related to Kuenenia stuttgartiensis. The overall removal efficiency of the combined process was 82% of the incoming ammonium according to a total nitrogen removal rate of 0.55 kg N m-3 day-1, without adding extra carbon source.

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