Electrocatalytic properties of Ti-supported Pt for decolorizing and removing dye from synthetic textile wastewaters

As an innovative alternative, the electrochemical processes for treating wastewater containing dyes have been recently proposed. In this work, the treatment of synthetic wastewaters containing Methylene Blue (MB), as model dye, by anodic oxidation using Ti/Pt anodes was investigated. Galvanostatic electrolyses of MB synthetic wastewaters have led to the complete decolorization removal at different operating conditions (current density, agitation rate and temperature). The influence of these parameters was investigated in order to find the best conditions for TOC and COD concentration removal, which remained into the Brazilian law regulations. According to the experimental results obtained, the electrochemical oxidation process is suitable for removing COD and decolorizing wastewaters containing MB dye, due to the electrocatalytic properties of Ti/Pt anode. Energy requirements for removing color during galvanostatic electrolyses of MB synthetic solutions depends mainly on the applied current density, temperature and agitation rate; for example, it passes from 7.95 kWh at 10 mA cm−2 to 33.60 kWh at 50 mA cm−2 per volume of treated effluent removed (m−3); from 18.78 kWh m−3 at 25 °C to 10.29 kWh m−3 at 60 °C and from 21.74 kWh m−3 at 300 rpm to 12.60 kWh m−3 at 620 rpm, respectively. Based on the results obtained, the electrochemical process can be a feasible alternative as a pre-treatment or treatment for decolorizing wastewaters containing dyes.