Electrochemistry of the chlorine-water system

The electrochemical production of disinfectant solutions containing active chlorine is usually carried out within cells, whose anode and cathode chambers are separated by a dividing wall (an ion-selective diaphragm or a membrane). The latter separator is generally present in order to avoid the cathodic reduction of active species synthesized at the anode; however, dealing with aqueous solutions containing small amounts (a few grams per liter) of chloride ions, a reasonable synthesis of active chlorine can be obtained also in undivided cells, i.e. in the absence of a diaphragm or a membrane. In these cases, the species synthesized at the anode can be effectively consumed or partly reduced at the cathode, and the reaction products depend on the chosen electrochemical parameters (current density, temperature, anode material). The present communication will focus on data obtained through 3-hours electrolyses at different conditions, carried out on aqueous solutions containing 5 g/l of KCl; a speciation of chlorinated species were performed every 30 minutes, by means of titrations and ion chromatography