Nitrite accumulation in continuous-flow partial autotrophic denitrification reactor using sulfide as electron donor.
Chunshuang Liu1, Wenfei Li1, Xuechen Li1
1College of Chemical Engineering, China University of Petroleum, Qingdao 266580, China.
Bioresource Technology
|July 20, 2017
Summary
This study shows how to accumulate nitrite from wastewater using specific bacteria. The accumulated nitrite can be used for anaerobic ammonia oxidation, offering a new wastewater treatment method.
Area of Science:
- Environmental microbiology
- Wastewater treatment technologies
- Biogeochemical cycles
Background:
- Nitrate and sulfide are common pollutants in industrial wastewater.
- Nitrite accumulation can be a key intermediate in wastewater treatment processes.
- Upflow anaerobic sludge blanket (UASB) reactors are effective for wastewater treatment.
Purpose of the Study:
- To investigate nitrite accumulation in a continuous-flow UASB reactor treating nitrate and sulfide-laden wastewater.
- To identify key functional microbial strains involved in the process.
- To evaluate the potential of accumulated nitrite for subsequent anaerobic ammonia oxidation.
Main Methods:
- Utilized a continuous-flow upflow anaerobic sludge blanket reactor.
- Controlled sulfide/nitrate-nitrogen ratios and loading rates.
- Analyzed elemental sulfur and nitrite accumulation rates.
- Identified dominant microbial communities using molecular techniques.
Main Results:
- Optimal conditions (sulfide/nitrate-nitrogen ratio 1:0.76, loading rates 1.2kg-Sm-3d-1 and 0.4kg-Nm-3d-1) led to peak elemental sulfur and nitrite accumulation of 90% and 70%, respectively.
- Identified Acrobacter, Azoarcus, and Thauera as key functional strains.
- Demonstrated the feasibility of accumulating nitrite as a feedstock.
Conclusions:
- Nitrite accumulation is achievable in UASB reactors under specific conditions.
- The accumulated nitrite shows promise as a feedstock for anaerobic ammonia oxidation.
- An integrated process combining partial autotrophic denitrification, anaerobic ammonia oxidation, and aeration is proposed for comprehensive wastewater treatment.
More Related Videos
Related Concept Videos
01:15Metabolism of Chemolithotrophs
986
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.
986
01:30Anoxygenic Photosynthesis
1.5K
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...
1.5K
01:22Inorganic Nitrogen Assimilation
651
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...
651
01:20Sulfur Assimilation
429
Sulfur is an essential element in biological systems, contributing to synthesizing key biomolecules, including amino acids such as cysteine and methionine, and cofactors such as coenzyme A and biotin. Microorganisms primarily assimilate sulfur as sulfate (SO₄²⁻) from the environment, which must undergo a series of biochemical transformations before it can be incorporated into cellular components. As sulfate is highly oxidized, it must undergo assimilatory sulfate reduction to...
429
01:28Carbon-dioxide Fixation
768
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...
768