Related Experiment Video
Updated: Jul 6, 2026
08:13
A Novel Bioreactor for High Density Cultivation of Diverse Microbial Communities
Published on: December 25, 2015
17.0K
Exploring Aeration Strategies for Enhanced Simultaneous Nitrification and Denitrification in Membrane Aerated
Maryam Ghasemi1, Sheng Chang2, Sivabal Sivaloganathan3
1Department of Applied Mathematics, University of Waterloo, Waterloo, ON, N2L 3G1, Canada. m23ghase@uwaterloo.ca.
Bulletin of Mathematical Biology
|August 7, 2024
Summary
Periodic aeration strategies can enhance simultaneous nitrification-denitrification in membrane aerated biofilm reactors (MABRs). Optimizing off-phase oxygen concentration and duration is key for efficient wastewater treatment.
Area of Science:
- Environmental Engineering
- Biotechnology
- Water Treatment
Background:
- Simultaneous nitrification-denitrification (SND) is crucial for efficient wastewater treatment.
- Denitrification rates often lag behind nitrification rates in conventional systems.
- Membrane aerated biofilm reactors (MABRs) offer potential for improved nitrogen removal.
Purpose of the Study:
- To investigate the influence of different aeration strategies on SND processes in MABRs.
- To identify key factors controlling denitrification under periodic and intermittent aeration.
- To optimize MABR performance for enhanced nitrogen removal.
Main Methods:
- Utilized a two-dimensional deterministic multi-scale computational model.
- Simulated periodic and intermittent aeration scenarios.
- Analyzed the impact of oxygen concentration, off-phase duration, and initial inoculation.
Main Results:
- Oxygen concentration during the off-phase and off-interval duration significantly impact denitrification.
- Complete oxygen discontinuation inhibits anaerobic bacteria and impedes denitrification.
- Extended off-intervals enhance denitrification, while periodic aeration can prolong MABR operational cycles due to lower biofilm growth.
Conclusions:
- Periodic and intermittent aeration strategies are effective for enhancing SND in MABRs.
- Careful control of off-phase parameters is essential for optimizing nitrogen removal.
- Findings provide insights for the design and operation of MABRs in wastewater treatment.
Related Concept Videos
01:25Microbial Mats
Microbial communities forming biofilms and mats represent complex, spatially structured ecosystems where metabolic processes are stratified according to light, oxygen, and nutrient gradients. Biofilms are initial colonization stages, only a few millimeters thick, while mature microbial mats can reach centimeter-scale thickness and display intricate vertical organization. Their structural and functional heterogeneity allows microorganisms to occupy distinct ecological niches within a few...
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...
01:30Microbial 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.
01:29Bioreactor Design and Operational System
Bioreactors are engineered vessels designed to cultivate microorganisms under controlled conditions for industrial bioprocessing. They maintain sterility and allow precise regulation of pH, temperature, oxygen, and nutrient levels to optimize microbial growth and metabolite production. Bioreactors range from small laboratory units of 1 liter to industrial systems holding up to 500,000 liters, though only about 75% of their volume is actively used for fermentation. The remaining headspace...
01:28Bioreactor Controls-I
Maintaining optimal conditions within fermenters is essential for maximizing microbial productivity and ensuring process efficiency. This lesson focuses on key parameters—temperature, foam, pH, carbon dioxide, oxygen, and pressure—and their precise measurement and control strategies in fermentation systems.Temperature ControlTemperature regulation is critical due to the exothermic nature of many fermentation processes. In small laboratory fermenters, temperature is commonly monitored using...
01:18Bioreactor Controls-II
In aerobic fermentations, oxygen is vital for microbial growth and metabolite production. Since air comprises only about 20% oxygen and the gas is poorly soluble in water—just 9 ppm at 20°C—supplying sufficient oxygen becomes a critical challenge, especially in high-demand processes like yeast growth or citric acid production. Even a fully saturated broth may offer only a few seconds of oxygen availability.To address this, sterile or scrubbed air is introduced into the fermentor via a sparger...