Performance Evaluation of Electrocoagulation with Hybrid Electrodes in the Decolourisation of Methyl Orange Dye

Abstract

The study evaluated the influence of electrode characteristics in electrocoagulation (EC) of textile dye wastewater. Methyl orange, an azo dye, has been utilized for the study to represent textile dye. The performance of stainless steel and aluminium electrodes under different electrode configurations was studied keeping other parameters like temperature, interelectrode distance, depth of immersion, current and voltage, volume of the sample and pH as constants. Perforated electrodes of anodes arranged as concentric circles within the cathode were adopted for the study. Under the various configurations of aluminium (Al) and stainless steel (SS) electrodes as anode and cathode, Al-SS-SS-Al showed the maximum colour removal efficiency (CRE) of 98%. But the froth generated and material degradation on using aluminium electrodes have resulted in selecting SS-SS-SS-SS (95% of CRE) as the optimized geometric arrangement which generated comparatively less greasy sludge (by volume) and material consumption. Considering the ease of handling the sludge, efficiency and economy, the combination of stainless steel was identified to be the optimum configuration. The reaction time was optimized to 30 min for maximum CRE. Energy consumption for EC process using perforated stainless steel electrodes under given operating condition was estimated to be 5KWh/m3. The amount of metal dissolved and deposited with time passage for the same was estimated using theoretical equations as per Faraday’s law as 0.107 g of M cm−2.