Taguchi optimized electrocoagulation technology: A sustainable approach to oil-water separation in large scale applications

Abstract

Electrocoagulation (EC) method used for eliminating oil from oily wastewater, though it encounters challenges such as high operational costs and electrode passivation. The novelty of this research is its development of a cost-effective and highly efficient EC process, specifically optimized for sunflower oil wastewater. The effectiveness of EC in reducing turbidity was evaluated through experimental analysis. The Taguchi methodology was employed to optimize critical process parameters: pH, operating voltage, EC duration, electrode spacing, and sodium chloride concentration. The Optimal conditions identified were pH 6, 30 V, 80 minutes of EC duration, 5 cm electrode spacing, and 0.2 g/L NaCl, achieving an impressive oil removal rate of 94.46 %, along with high energy efficiency. Characterization of the electrodes using UV spectroscopy, SEM, and EDX under these optimal conditions further supported the findings. The study also examined the operating cost (OC) associated with the EC process using aluminium electrodes. Energy consumption ranged from 0.96 kWh/m³ to 22.61 kWh/m³ , while aluminium electrode consumption varied between 0.06 kgAl/m³ and 0.275 kgAl/m³ . The OC fluctuated from 0.252 to 4.654 USD per 1000 litres of oil wastewater treatment across nine orthogonal array experiments. This research contributes to advancing sustainable EC technology for separating emulsified oil-water mixtures, aligning with circular economy principles for responsible industrial wastewater management.