Related Experiment Video
Updated: Jun 15, 2026
08:13
A Novel Bioreactor for High Density Cultivation of Diverse Microbial Communities
Published on: December 25, 2015
Autotrophic nitrogen removal discovered in suspended nitritation system
YongTao Lv1, Lei Wang, Ting Sun
1School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, 13 Yanta Road, Xi'an 710055, China.
Chemosphere
|March 2, 2010
Summary
This study optimized nitrogen removal from wastewater using a sequencing batch reactor. Lowering dissolved oxygen and increasing hydraulic retention time achieved 80% total nitrogen removal, driven by nitritation and Anammox processes.
Area of Science:
- Environmental Science
- Microbiology
- Wastewater Treatment
Background:
- Ammonium-rich wastewater treatment often faces challenges with nitrogen removal efficiency.
- Conventional methods may not be sufficient for high ammonium concentrations.
- Anaerobic ammonium oxidation bacteria (AnAOB) play a key role in nitrogen cycling.
Purpose of the Study:
- To investigate nitrogen removal efficiency in a lab-scale sequencing batch reactor (SBR) treating ammonium-rich synthetic wastewater.
- To determine the impact of operational parameter adjustments (dissolved oxygen, hydraulic retention time) on nitrogen removal.
- To elucidate the microbial communities and processes involved in nitrogen removal.
Main Methods:
- Operation of a lab-scale sequencing batch reactor (SBR) in batch mode.
- Adjustment of dissolved oxygen concentration and hydraulic retention time.
- Monitoring of nitrogen species (ammonium, nitrite, nitrate) and pH.
- Fluorescence in situ hybridization (FISH) for microbial community analysis.
Main Results:
- A minor nitrogen loss of approximately 9% was observed initially without AnAOB seeding.
- After optimizing conditions (lower DO, longer HRT), 80% total nitrogen removal efficiency and a capacity of 0.49 kg N m(-3) d(-1) were achieved.
- Microbial analysis revealed dominance of Nitrosomonas, with presence of AnAOB and Nitrospira spp.
- A low nitrate production ratio (0.10+/-0.02) indicated efficient nitrogen removal.
Conclusions:
- Nitritation, Anammox, and autotrophic denitrification were identified as the primary nitrogen removal mechanisms.
- The co-action of nitrite-oxidizing bacteria and AnAOB contributed to nitrate production.
- Optimized SBR operation can effectively treat ammonium-rich wastewater by promoting key microbial processes.
More Related Videos
08:05Measurement of the Potential Rates of Dissimilatory Nitrate Reduction to Ammonium Based on 14NH4+/15NH4+ Analyses via Sequential Conversion to N2O
Published on: October 7, 2020
07:14Automated, High-resolution Mobile Collection System for the Nitrogen Isotopic Analysis of NOx
Published on: December 20, 2016
Related Concept Videos
01:26Microbes and the Nitrogen Cycle
The nitrogen cycle is a complex biogeochemical process critical to maintaining the balance of nitrogenous compounds in ecosystems. This cycle involves multiple microbial-mediated transformations through which nitrogen changes oxidation states, supporting essential ecological functions and contributing to plant and microbial growth.Nitrogen Fixation and AmmonificationNitrogen fixation initiates the cycle by converting inert atmospheric nitrogen (N₂) into bioavailable ammonia (NH₃), a process...
01:22Inorganic Nitrogen Assimilation
Nitrogen is an essential element in biological systems, forming a crucial component of proteins, nucleic acids, and other cellular constituents. Many bacteria and archaea acquire nitrogen in the form of nitrate (NO₃⁻) or ammonia (NH₃), which are then assimilated into biomolecules through specific enzymatic pathways.Assimilatory Nitrate ReductionWhen nitrate enters the cell, it undergoes a two-step reduction process known as assimilatory nitrate reduction. Initially, the enzyme nitrate reductase...
01:20Overview of Nitrogen Metabolism
Nitrogen is a very important element for life because it is a major constituent of proteins and nucleic acids. It is a macronutrient, and in nature, it is recycled from organic compounds and stored in the form of ammonia, ammonium ions, nitrate, nitrite, or nitrogen gas by many metabolic processes. Many of these metabolic processes are carried out only by prokaryotes.
The largest pool of nitrogen available in the terrestrial ecosystem is gaseous nitrogen (N2) from the air, but this nitrogen...
The largest pool of nitrogen available in the terrestrial ecosystem is gaseous nitrogen (N2) from the air, but this nitrogen...
01:15Metabolism of Chemolithotrophs
Chemolithotrophs are microorganisms that obtain energy by oxidizing inorganic molecules such as hydrogen gas (H₂), ammonia (NH₃), reduced sulfur compounds (H₂S, S²⁻), and ferrous iron (Fe²⁺). Unlike heterotrophic organisms that rely on organic carbon, chemolithotrophs transfer electrons from these inorganic donors to the electron transport chain (ETC), generating a proton motive force (PMF) that drives ATP synthesis through oxidative phosphorylation. However, because inorganic electron donors...
01:30Microbial Wastewater Treatment
Microbial communities in aquatic ecosystems play a key role in the natural breakdown of contaminants introduced through domestic and industrial effluents. Acting as biological catalysts, these microbes change and mineralize a wide range of organic and inorganic pollutants under different redox conditions.In oxygen-rich surface waters, aerobic heterotrophs lead organic matter breakdown, using oxygen as the terminal electron acceptor to efficiently oxidize substrates to carbon dioxide and water.
01:49The Nitrogen Cycle
Nitrogen atoms, present in all proteins and DNA, are recycled between abiotic and biotic components of the ecosystem. However, the primary form of nitrogen on Earth is nitrogen gas, which cannot be used by most animals and plants. Thus, nitrogen gas must first be converted into a usable form by nitrogen-fixing bacteria before it can be cycled through other living organisms. The use of nitrogen-containing fertilizers and animal waste products in human agriculture has greatly influenced the...