Discover how Anammox technology provides a cost-effective, sustainable solution for high-concentration nitrogen in wastewater, saving energy and reducing chemical use.
Why Anammox Technology Is Needed in Wastewater Treatment
Recently, the shift has been toward co-digestion using anaerobic digestion to produce biogas, instead of landfilling or incinerating organic waste like sludge. When organic waste decomposes, it releases methane, a greenhouse gas that is 28 times more potent than CO₂ over a 100-year period. This has spurred efforts to reduce methane emissions and combat climate change.
In addition to environmental benefits, biogas can be converted into valuable energy sources such as electricity, LNG, hydrogen, methanol, or sustainable aviation fuel (SAF), creating significant economic gains.
However, during anaerobic digestion, carbon from organic waste is transformed into biogas, but nitrogen remains largely unchanged, ending up in the digestate—a material rich in high-concentration ammonium nitrogen. While this digestate can be used as fertilizer on agricultural land, urban areas that process sewage sludge and food waste require costly treatment to prevent nitrogen from contaminating groundwater.
Conventional nitrogen removal (nitrification–denitrification) requires large amounts of methanol and energy-intensive aeration. Often, the costs of these chemicals and energy exceed the revenue generated from biogas, hindering biogas production efforts.
This is where Anammox technology comes in: it dramatically reduces the cost of nitrogen removal—saving about 67% on electricity and 100% on external chemicals. By making co-digestion more economically viable, it also contributes to climate change mitigation. It’s a revolutionary wastewater treatment method that benefits both the environment and businesses.
Types of Anammox Technology: Single Reactor vs. Two-Stage
Anammox systems typically involve two types:
(1) Single Reactor
A single-reactor system combines aerobic ammonium-oxidizing bacteria (AOB) and anaerobic Anammox bacteria in one unit to save space. However, this design forces two groups with fundamentally opposite growth requirements—oxygen for AOB and oxygen-free conditions for Anammox—to coexist in the same environment. This creates operational challenges and makes the system highly prone to failure.
(2) Two-Stage System
A two-stage system uses separate reactors: one for AOB to carry out partial nitritation, and another for Anammox bacteria to consume the resulting nitrite and ammonium. This separation allows each group of microorganisms to thrive under their optimal conditions, ensuring stability and safety.
Most suppliers favor single-reactor systems to minimize space, but is this truly the best solution?
Why BKT Developed the 2-Stage AMX System
BKT(known globally as Tomorrow Water) is the only company to commercialize the 2-Stage Anammox process. Here’s why this method stands out:
(1) Robust and Stable Operation
Co-digestion processes various organic wastes together, which brings fluctuations in anaerobic digester operations. Digestate characteristics can vary depending on organic content or alkalinity, yet single-reactor technology struggles to accommodate these changes. Because oxygen cannot be arbitrarily adjusted in a single tank that requires both aerobic and anaerobic conditions, high organic loads often cause poor conversion to biogas and carry over into influent water, raising the C:N ratio.
(2) Faster Nitrogen Removal & Smaller Footprint
Maintaining optimal conditions for both AOB and Anammox bacteria in a single reactor is extremely challenging. BKT’s two-stage system controls oxygen levels separately for each group, ensuring stability and efficiency. This enables higher nitrogen-loading rates, faster treatment times, and a smaller plant footprint compared to single-reactor systems.
(3) Exceptional Strain and Versatile Applications
BKT’s Anammox bacteria, Brocadia sinica, was supplied by Professor Okabe of Hokkaido University in Japan. By selecting the fastest-growing strains that can withstand load fluctuations, BKT ensures reliable and efficient performance.
While most single-reactor Anammox solutions are limited to sidestream municipal wastewater, BKT’s innovative 2-Stage AMX can be adapted for industrial and high-strength wastewater, offering greater flexibility and efficiency.
Applications include:
- Industrial wastewater, such as semiconductor effluents, where high nitrogen loads must be treated efficiently
- Landfill leachate management to prevent groundwater contamination
- Livestock wastewater treatment to reduce environmental impact
If you’re interested in a cost-effective, reliable, and environmentally friendly solution for high-concentration nitrogen removal, BKT’s 2-Stage Anammox (AMX) technology is a smart choice.
Learn more about BKT’s 2-Stage AMX technology and how it can transform your wastewater treatment system.
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