Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Microbes and the Nitrogen Cycle01:26

Microbes 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...
Overview of Nitrogen Metabolism01:20

Overview 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...
Metabolism of Chemolithotrophs01:15

Metabolism 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...
Microbes and the Carbon Cycle01:24

Microbes and the Carbon Cycle

The carbon cycle is a fundamental Earth process involving the transfer of carbon among the biosphere, lithosphere, atmosphere, and hydrosphere. It plays a critical role in regulating the planet’s climate and supporting life by cycling carbon through various chemical forms and reservoirs. Carbon primarily circulates as carbon dioxide (CO₂), representing its oxidized form, while reduced forms such as methane (CH₄) and organic compounds also play essential roles.Microbial activity is central to...
Carbon-dioxide Fixation01:28

Carbon-dioxide Fixation

Carbon dioxide fixation in prokaryotes enables the assimilation of inorganic carbon into organic molecules, supporting biosynthetic pathways, sustaining ecosystems, and contributing to the global carbon cycle. It also has industrial applications in carbon capture and bioproduct synthesis. Autotrophic organisms rely on this process to utilize CO₂ as a carbon source in diverse environments.The Calvin CycleThe Calvin cycle is the most widespread carbon fixation mechanism, primarily used by...
Anoxygenic Photosynthesis01:30

Anoxygenic Photosynthesis

Anoxygenic photosynthesis is a phototrophic process that captures light energy to drive carbon fixation without producing molecular oxygen. Unlike oxygenic photosynthesis, which utilizes water as an electron donor and releases oxygen, anoxygenic phototrophs use alternative electron donors such as hydrogen sulfide (H₂S), elemental sulfur (S⁰), or thiosulfate (S₂O₃²⁻). This process is carried out by diverse groups of bacteria, including purple bacteria, green sulfur bacteria, heliobacteria, and...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Application of the activated sludge model for nitrogen to elevated nitrogen conditions.

Water environment research : a research publication of the Water Environment Federation·2008
Same author

The effect of cyclic aerobic-anoxic conditions on biodegradation of benzoate.

Water environment research : a research publication of the Water Environment Federation·2006
Same author

Effects of oxygen on biodegradation of benzoate and 3-chlorobenzoate in a denitrifying chemostat.

Water research·2004
Same author

Relative efficacy of intrinsic and extant parameters for modeling biodegradation of synthetic organic compounds in activated sludge: dynamic systems.

Water environment research : a research publication of the Water Environment Federation·2004
Same author

Effects of oxygen on anoxic biodegradation of benzoate during continuous culture.

Water environment research : a research publication of the Water Environment Federation·2003
Same author

Relative efficacy of intrinsic and extant parameters for modeling biodegradation of synthetic organic compounds in activated sludge: steady-state systems.

Water environment research : a research publication of the Water Environment Federation·2003

Related Experiment Video

Updated: Jun 27, 2026

Estimating Sediment Denitrification Rates Using Cores and N2O Microsensors
07:59

Estimating Sediment Denitrification Rates Using Cores and N2O Microsensors

Published on: December 6, 2018

An updated process model for carbon oxidation, nitrification, and denitrification.

William C Hiatt1, C P Leslie Grady

  • 1SCH2M Hill Inc., Spartanburg, South Carolina, USA.

Water Environment Research : a Research Publication of the Water Environment Federation
|November 26, 2008
PubMed
Summary

A new Activated Sludge Model for Nitrogen (ASMN) improves upon existing models by accurately simulating nitrification and denitrification processes, including key intermediates and emissions, for enhanced wastewater treatment. This model offers comparable results to ASM#1 for essential parameters.

More Related Videos

Measurement of the Potential Rates of Dissimilatory Nitrate Reduction to Ammonium Based on 14NH4+/15NH4+ Analyses via Sequential Conversion to N2O
08:05

Measurement 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

Single-throughput Complementary High-resolution Analytical Techniques for Characterizing Complex Natural Organic Matter Mixtures
09:38

Single-throughput Complementary High-resolution Analytical Techniques for Characterizing Complex Natural Organic Matter Mixtures

Published on: January 7, 2019

Related Experiment Videos

Last Updated: Jun 27, 2026

Estimating Sediment Denitrification Rates Using Cores and N2O Microsensors
07:59

Estimating Sediment Denitrification Rates Using Cores and N2O Microsensors

Published on: December 6, 2018

Measurement of the Potential Rates of Dissimilatory Nitrate Reduction to Ammonium Based on 14NH4+/15NH4+ Analyses via Sequential Conversion to N2O
08:05

Measurement 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

Single-throughput Complementary High-resolution Analytical Techniques for Characterizing Complex Natural Organic Matter Mixtures
09:38

Single-throughput Complementary High-resolution Analytical Techniques for Characterizing Complex Natural Organic Matter Mixtures

Published on: January 7, 2019

Area of Science:

  • Environmental Engineering
  • Environmental Microbiology
  • Wastewater Treatment Technology

Background:

  • Existing activated sludge models like ASM#1 and ASM#3 inadequately represent nitrification and denitrification.
  • Limitations include poor description of ammonia oxidation inhibition, nitrite accumulation, and gaseous emissions (nitric oxide, nitrous oxide).

Purpose of the Study:

  • To introduce a novel, comprehensive activated sludge model named ASMN.
  • ASMN aims to accurately simulate nitrogen transformations in wastewater treatment processes.

Main Methods:

  • ASMN models two nitrifying populations: ammonia-oxidizing bacteria and nitrite-oxidizing bacteria.
  • It utilizes free ammonia and free nitrous acid as specific substrates.
  • ASMN incorporates a four-step denitrification process with reaction-specific parameters.

Main Results:

  • Simulations using ASMN were conducted for three activated sludge configurations.
  • Steady-state and dynamic municipal-type influent conditions were evaluated.
  • ASMN results for ammonia, nitrate, soluble substrate, and biomass concentrations were comparable to ASM#1.

Conclusions:

  • The ASMN provides a more robust framework for modeling nitrogen removal in activated sludge systems.
  • It addresses critical limitations of previous models concerning nitrification and denitrification pathways.
  • The model's accuracy is validated by its comparable performance to established models under various conditions.