Electrochemical oxidation of a synthetic dye using a BDD anode with a solid polymer electrolyte

•Safranin T dye degraded by anodic oxidation using SPE technology with BDD anode.•Almost complete Safranin T removal (COD approaching 0) was obtained.•Oxidation was under charge-transfer control.•Removal rate depended on applied current and solution conductivity.•Addition of Na2SO4 decreased the removal rate and the energy consumption.

In this study the performance of an electrochemical cell with a solid polymer electrolyte (SPE) has been investigated using Safranin T, a synthetic dye, as a model compound. The cell consists of a Nafion membrane sandwiched between a BDD mesh anode and a Ti/RuO2 mesh cathode operating at constant current. The effects of operating conditions such as applied current, stirring rate and electrolyte conductivity were studied. The experimental results showed that Safranin T was completely removed by reaction with OH radicals generated by water electrolysis and that the oxidation was under charge-transfer control. Furthermore, it was observed that addition of Na2SO4 to the solution decreased the removal rate but also decreased the specific energy required for the process.