Current distribution and experimental behaviour of a bipolar rector for drinking water disinfection.

E. R. HENQUÍN; M.E.H. BERGMANN; J.M. BISANG

Fortaleza

Congreso; XX Congreso de la Sociedad Iberoamericana de Electroquímica. (SIBAE 2012).; 2012

Modern reactors for electrochemical drinking water disinfestation are made by a bipolar stack of parallel-plate electrodes with a small interelectrode gap. The reactor used in this work was built with six bipolar electrodes RuO2/IrO2 on Ti. Plastic plates were optionally arranged in the inlet and outlet to the electrodes to produce entrance or exit regions. The Laplace equation was numerically solved for the solution phase including the electrolyte outside the intereletrode gap. The calculation performed without entrance and exit region show that the current distribution is pronounced at the thickness of the electrodes and at the electrode edges, the leakage current was lower than 2%. The presence of plastic plates increase the current distribution and diminishes the leakage current to 0,1%. The reactor was tested analysing the on-line production of sodium hypochlorite from drinking water. In a typical experiment, performed at 10,31 A with volumetric flow rate of 3 dm3 min-1, the hypochlorite concentration was 25.03 mg dm-3. The applied potential difference was 128 V, current efficiency 4.34%, 16ºC temperature. it can be concluded that the tested reactor is well-designed device and it represents a promising reactor for the electrochemical disinfection of drinking water.