Rates and products of microbial biotransformation vary between different activated sludge treatment systems. This is at least partly due to differences in microbial community composition and activity, and hence their variable capacity to perform certain biotransformation reactions. Particularly, the presence and activity of nitrifiers has been linked to improved biotransformation of a range of micropollutants.
In this project, we want to further clarify the role of nitrifiers in micropollutant biotransformation. Specifically, we ask what types of biotransformation reactions are catalyzed by nitrifiers, what are the relative roles of nitrifying archaea and bacteria in catalyzing those reactions, and what is the relative importance of heterotrophic microorganisms relative to nitrifying organisms. To address these questions we study the biotransformation extent and products for certain pertinent chemical classes in different inhibition and pure culture experiments.