Ammonia-oxidizing bacteria in wastewater

Abstract

Ammonia-oxidizing bacteria (AOB) are important for generating nitrite from ammonia in the wastewater. The initial step involved in nitrification is ammonium oxidation resulting in nitrite. This step is carried out by ammonia-oxidizing bacteria. Ammonia-oxidizing bacteria are classified under the class of Proteobacteria, most of which are beta and gamma-proteobacteria. There are several parameters affecting the activity of ammonia-oxidizing bacteria, which are, presence of free ammonia, regulation of the dissolved oxygen concentration, pH, temperature, alkalinity, solid retention time and hydraulic retention time. The effect of these parameters on ammonia-oxidizing bacteria would be discussed in the chapter in detail. Ammonia-oxidizing bacteria are able to degrade micropollutants present in wastewater. The nitrogen constituents present in wastewater are transformed from ammonia to nitrate through nitrification using the ammonia-oxidizing bacteria. In this chapter, the application of ammonia-oxidizing bacteria in the biodegradation of micropollutants is discussed in detail.