ISNA®
Integrated Short-cut Nitrification and Anammox process
Process introduction:
ISNA ® It is an upgraded technology for integrated short-range nitrification anaerobic ammonia oxidation process and biological denitrification of wastewater.
Anaerobic ammonia oxidation is carried out by anaerobic bacteria. These bacteria can form shortcuts in the nitrogen cycle by oxidizing nitrite and ammonia to nitrogen.
The reaction of this bacterium is as follows:
AOB:NH4++2HCO3-+ 1.5 O2→ NO2-+ 3H2O + 2CO2
Anammox:NH4++ 1.32 NO2-+ 0.066HCO3-+ 0.13H+→ 1.02N2+ 0.26NO3-+ 2.03H2O + 生物量
Due to the fact that the short-range nitrification reaction only converts half of NH4+into NO2-, the oxygen and alkali consumption are reduced by 58% and 50% respectively compared to traditional nitrification processes. In addition, the anaerobic ammonia oxidation process is an autotrophic process. Anaerobic ammonia oxidizing bacteria use nitrite as an oxidant to oxidize ammonia to nitrogen or use ammonia as an electron donor to reduce nitrite to nitrogen, without the need for additional carbon sources. The anaerobic ammonia oxidation process produces less sludge and can save 85% of sludge disposal costs.
Technical features:
1. Short range nitrification and anaerobic ammonia oxidation reactions are carried out simultaneously in the same tank, saving time, space, and cost;
2. Adopting fully mixed flow and accurately controlling the concentration of NO2- and NH4+in the system;
3. Unique sludge separation system ensures the separation of particles and flocs from sludge.
Performance indicators:
The influent NH4+- N>100mg/L, with a maximum of 3000mg/L; Volume nitrogen load 5-15kg/(m3 · d) Total nitrogen removal rate>80%, ammonia nitrogen removal rate>95%
Application scope:
Biological treatment of low C/N and high ammonia wastewater in industries such as photovoltaic energy, sludge digestion, landfill, food processing, petrochemicals, pharmaceutical chemicals, metal smelting, and animal husbandry.