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

Abstract

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 NHCl₄, 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.

Keywords: Boron-doped diamond anodes (BDD); Chlorine active species; Differential electrochemical mass spectroscopy (DEMS); Electrochemical advanced oxidation; Electrochlorination; Water treatment.