SND Bacteria
One Bacterium — Simultaneous Nitrification-Denitrification
Our proprietary SND bacteria perform simultaneous nitrification and denitrification in a single aerobic process, eliminating the need for complex multi-stage treatment systems. Over 10 years of R&D has produced a stable, highly effective biological solution for aquaculture water treatment.
The Problem with Traditional Nitrogen Removal
Conventional aquaculture water treatment relies on multi-stage biological processes — separate aerobic tanks for nitrification and anaerobic tanks for denitrification. This approach is expensive, space-consuming, energy-intensive, and inherently unstable. pH swings, nitrite accumulation, and system crashes are common, leading to catastrophic fish losses costing $50K-$100K per incident.
Freshwater SND microbial consortia
Saltwater SND microbial consortia
SND AquaMats test base — Guangzhou, China
SND container deployment — Yangcheng Lake, China
How SND Bacteria Work
SND (Simultaneous Nitrification-Denitrification) bacteria are specially cultivated microorganisms that perform both nitrification and denitrification within a single aerobic environment. This breakthrough eliminates the need for separate treatment stages.
Toxic Ammonia
NH₃ / NH₄⁺
Direct Oxidation
SND bacteria oxidize ammonia directly
Shortened Nitrification
Bypasses harmful nitrite buildup
Aerobic Denitrification
Works with O₂ — no anaerobic tank needed
Clean Output
N₂ gas + stable pH + safe water
Toxic Ammonia
NH₃ / NH₄⁺
Direct Oxidation
SND bacteria oxidize ammonia directly
Shortened Nitrification
Bypasses harmful nitrite buildup
Aerobic Denitrification
Works with O₂ — no anaerobic tank needed
Clean Output
N₂ gas + stable pH + safe water
Toxic Ammonia
NH₃ / NH₄⁺
Direct Oxidation
SND bacteria oxidize ammonia directly
Shortened Nitrification
Bypasses harmful nitrite buildup
Aerobic Denitrification
Works with O₂ — no anaerobic tank needed
Clean Output
N₂ gas + stable pH + safe water
Single-Stage Process
Traditional systems need 2-3 separate tanks for nitrification and denitrification. SND bacteria do it all in one aerobic reactor — cutting costs, space, and complexity.
Direct Ammonia Oxidation
SND bacteria directly oxidize toxic ammonia (NH3/NH4+) into harmless nitrogen gas, bypassing traditional intermediate steps that produce harmful nitrite.
Shortened Nitrification
In the same aerobic reactor, ammonia is converted through a shortened nitrification pathway, significantly reducing the accumulation of toxic intermediates.
Aerobic Denitrification
Unlike conventional bacteria that require anaerobic conditions for denitrification, SND bacteria perform this step in the presence of oxygen, simplifying system design.
Stable pH Maintenance
The simultaneous process naturally balances acid and alkaline reactions, maintaining stable pH without chemical intervention — a key factor in fish health.
See SND Technology in Action
Applications
Recirculating Aquaculture Systems (RAS)
Integrate SND bacteria into RAS biofilters for continuous, zero-discharge water treatment with minimal footprint.
Open Pond Culture
Apply SND bacterial treatment to traditional open-pond systems to reduce water exchange and eliminate antibiotic dependence.
Container-Based Aquaculture
Compact SND systems designed for modular container farms, enabling high-density culture in urban and remote locations.
Integration with the WaterDoctor Ecosystem
Functional bacteria, such as SND, is the biological core of the WaterDoctor system, working in concert with our other three technologies.
