Advanced oxidation processes emerged as highly promising water treatment technologies for the abatement of organic pollutants in waters. The treatment of N-containing aromatic pollutants such as amines and nitro-derivatives is of great relevance due to their carcinogenicity. However, one of the major questions is the possible release of NOx species from the oxidation of these pollutants by (OH)-O-center dot. The evolution of these hazardous NOx during the water treatments by (OH)-O-center dot has been suggested to explain the loss of nitrogen during the mass balances, but unfortunately this hypothesis has not been demonstrated experimentally. In this work, the release of NOx has been ascertained and the overall current efficiency of conversion of N-containing pollutants to CO2 and NOx was estimated semi-quantitatively using differential electrochemistry mass spectroscopy (DEMS) during electrochemical advanced oxidation process with boron-doped diamond (BDD) anodes. Moreover, the relationship between the distributions of N-volatile species with the nitrogenized functional group of each pollutant has been highlighted. (C) 2017 Elsevier B.V. All rights reserved.