Influence of cell design and electrode materials on the decolouration of dyeing effluents

Abstract

Electrochemical techniques are applied in different textile processes, including wastewater treatment, as they are clean and generally operate at room temperature. In the current work, doped SnO2 electrodes (Ti/SnO2-Sb-Pt) were prepared. They were used as anodes in two electrochemical cells (simple batch mode and batch recirculation mode) to achieve the removal of two reactive azo dyes (Remazol Black 133B and Procion Yellow H-EXL) in synthetic dyeing effluents. With these electrodes, both cells exhibit similar decolouration rates. In addition, the doped SnO2 electrodes are compared with Ti/Pt electrodes in order to establish the influence of electrode material. They were applied to the treatment of four synthetic effluents containing one of the following reactive azo dyes: Remazol Black 133B, Procion Yellow H-EXL, Procion Crimson H-EXL and Procion Navy H-EXL. It was stated that the decolouration is faster with Ti/Pt anodes than with the doped SnO2 ones, but these last electrodes generate lower amount of chloroform during the electrolysis