Anaerobic biofiltrer

Anaerobic biofiltration in aquaculture is a biological treatment process that uses microorganisms in the absence of oxygen (anaerobic conditions) to remove organic waste and certain nitrogen compounds (such as nitrates) from aquaculture water.

Detailed Description:

Operating Principle:

• Unlike aerobic biofiltration (which requires oxygen), anaerobic filtration relies on bacteria that break down organic matter in an oxygen-free environment.

• These bacteria perform fermentation or denitrification reactions.

• Denitrification is especially useful in aquaculture to convert nitrates (NO₃⁻), which accumulate in closed systems, into gaseous nitrogen (N₂), which is harmless and released into the atmosphere.

Required Conditions:

• Low-oxygen environment (confined zones, substrates with low porosity).

• Presence of organic carbon (often added in the form of sugar or methanol) to support the growth of denitrifying bacteria.

• Temperature, pH, and other parameters must be controlled to optimize bacterial performance.

Benefits for Aquaculture:

• Reduction of nitrates, improving water quality and fish health.

• Lower sludge production compared to aerobic systems.

• Can operate in low-energy environments (no need for aeration).

Drawbacks / Challenges:

• Slower process compared to aerobic filtration.

• Possible production of foul-smelling gases (e.g., H₂S).

• Requires careful monitoring to avoid imbalances (pH, accumulation of by-products).