Abstract: Electrochemical generation of active chlorine in diluted and concentrated NaCl solutions was investigated at Ti/PbO₂ anode. The active chlorine yielded by the electrolysis was significantly affected by the concentration of chloride ions, temperature, current density, pH, electrode material, diaphragm. The effects of above mentioned factors are comparatively different in diluted and concentrated NaCl solutions. It was found that the active chlorine produced in the solution was consistently higher at Ti/Ru-Ti-Sn oxide coated titanium anodes than that at Ti/PbO₂ anodes. The results may provide as much information as poss ible for the practical use of electrochemical treatment of industry wastewaters.

Key words: anode, electrochemistry, electrolysis, active chlorine