Comment on “Role of Ammonia Oxidation in Organic Micropollutant Transformation during Wastewater Treatment”: Overlooked Evidence to the Contrary

Abstract

In their critical review, (1) Su, Smets, and coauthors extensively summarized studies on the role played by ammonia-oxidizing bacteria (AOB) in organic micropollutant (OMP) transformation using three levels of evidence: molecular, cellular, and community. They also comprehensively covered the abiotic reactions with the N-species formed from nitrification. We agree with the authors that some studies do support the important role played by AOB in the transformation of specific OMPs. However, we find that the authors’ conclusion, “AOB are the main drivers of OMP biotransformation during wastewater treatment processes” (p 2173), does not stand up to proper scientific scrutiny. In the following, we will present our main arguments and provide the overlooked evidence contradicting the authors’ conclusion. (In the following, all page numbers and references to graphical elements refer to Su et al. 2020.