This technology is a method for selective conversion of nitrate to nitrite during denitrification of wastewater.
Current methods for biological nutrient removal during wastewater treatment consist of nitrification followed by denitrification involving an aerated process that is costly and inefficient. A potentially more cost-effective approach involves converting nitrate to nitrite prior nitrite conversion to nitrogen gas by combining denitrifying and anaerobic ammonium oxidation (anammox) bacteria in one bioreactor. However, this approach relies on toxic sulphides, is difficult to control, and is inefficient in continuously operated systems where anammox bacteria is outcompeted. Therefore, currently no methods exist to adequately control denitratation as a method to remove nitrogen from sewage.
This technology provides a method for incomplete denitrification using an individual bioreactor with bacteria. The denitrification reaction is controlled in a biological reactor that includes denitrifying bacteria with conditions that favor denitratation of nitrate to nitrite. The nitrite effluent from the incomplete denitrification process can then be fed to an anammox reactor to efficiently and cost-effectively reduce nitrite to harmless nitrogen gas. As a result, this process is more environmentally friendly and allows for better control of individual steps in the overall process. Furthermore, the sequential use of the bioreactors adds operational flexibility and allows detailed optimization to maximize nitrogen removal and to reduce aeration requirements, making this an improved method for treating wastewater.
This technology has been validated with denitrifying bacteria and glycerol as the carbon and electron source.
IR CU16314
Licensing Contact: Satish Rao