Electrochemical treatment of actual textile indigo dye effluent

Abstract

Electrochemical methods are being used increasingly as an alternative treatment process for the remediation of textile wastewaters. This study focused mainly on the color removal and chemical oxygen demand (COD) reduction of a vat textile dye (Cl Vat Blue 1: indigo) from its most polluted actual effluent by electrochemical oxidation. The process was carded out in a batch-type divided electrolytic cell under constant potential using a Pt cage as anode and Pt foil as cathode. It was shown that complete colour removal was achieved in a very short time (16 mins) at pH 2 by applying a constant electrolysis voltage between the platinum electrodes. The repeated experiments indicated that extending the treatment to 40 minutes caused a considerable percentage of COD reduction (46%), occurring mainly due to indigo oxidation. It is concluded that this electrochemical method can be used effectively as a pre-treatment alternative for reducing COD and colour in industrial textile effluents before conventional treatment.