Electrogeneration of inorganic chloramines on boron-doped diamond anodes during electrochemical oxidation of ammonium chloride, urea and synthetic urine matrix.

Ubiquitous presence of chloride in water effluents may result in the unavoidable electrogeneration of active chlorine species when considering the application of electrochemical advanced oxidation processes as water treatment technologies. However, less attention has been drawn to the subsequent generation of other combined chlorine species such as chloramines. In this work, the electrogeneration of chloramines has been assessed in different water matrices containing NHCl 4 , urea or synthetic urine. The yield of chloramines has been followed in-situ by differential electrochemistry mass spectroscopy (DEMS) during electrochemical advanced oxidation process with boron-doped diamond (BDD) anodes. Furthermore, the influence of several variables such as chloride concentration, pH or organics concentration on the different distribution of inorganic monochloramine, dichloramine and trichloramine released as products has been considered. Image 1 • Chloramines followed on-line by differential electrochemical mass spectroscopy. • Inorganic chloramines formed from electrochemical oxidation of urea and urine. • Higher chloride content enhances chlorine evolution and chloramines yield. • Higher O 2 evolution at alkaline pH competitively decreases chloramines formation. • Scavenging effects of competing ionic species in the matrices diminishes chloramines. [ABSTRACT FROM AUTHOR]