Investigation of electrochemical color removal from Organized Industrial District (OID) wastewater treatment plants using new generation Sn/Sb/Ni-Ti anodes

In this study, the application of Sn/Sb/Ni-Ti electrodes for the treatment of waste streams were investigated which is promising for ozone production by electrolysis of water because of their stability and high potential for ozone evolution reaction. These series of anodes have a high electrochemical ozone generation potential at ambient conditions (approximately up to 40% current efficiency). But using and testing of these novel anodes for real wastewater are too limited in the literature. Titanium mesh substrate coated with Sn/Sb/Ni-Ti alloy was used as anode immersed in wastewater at room temperature with platinized titanium cathode. These electrodes used for COD and color removal from OID wastewater in Inegol, Bursa, Turkey. Five operational parameters were evaluated for electrochemical COD and color removal processes, such as pH, salt content, applied voltage/current, current efficiency and contact time. Experimental results showed that after 30 min the electrochemical oxidation efficiency of COD and color could reach up to 98% and 99% respectively at pH 8.2 and temperature of 25°C as the optimum conditions. Current density observed as the most effective parameter for COD and color removal efficiencies. The lowest energy consumption was between 10-25 mA cm-2 of current density with only 0.6 kWh gCOD−1, while the highest energy consumption was 100 mA cm-2 of current density with 9.12 kWh gCOD−1 . The optimum current density value has been found as 50 mA cm-2 with 4.05 kWh gCOD−1 . These results were also supported with ANOVA test.