Performance optimization of a batch scale electrocoagulation process using stainless steel mesh (304) cathode for the separation of oil-in-water emulsion

Abstract

Electrocoagulation (EC) as a favorable treatment technique has been used for the elimination of oil from oil-in-water emulsions. However, how to reduce the energy consumption of EC technology is still a major challenge, which hinders the industrial scale development of this technique. In the present work, a low-cost and commercially available stainless-steel mesh was proposed as cathode due to its chemical corrosion resistance, high conductivity, good mass transfer as well as heat dissipation performance which can prolong lifespan of electrode material and decrease operational cost. In addition, RSM was employed to evaluate the removal performance of EC with new electrode combination of Al plate-SS mesh (304), and synergistic effects of significant process parameters on COD removal, as well as the interaction between experimental factors. It was found that the peak oil removal efficiency of 90.86% was obtained under the optimum experimental conditions of pH=7.0, applied voltage: 25 V, and working time: 60 min. What's more, main properties of sludge generated in the EC were examined by SEM/EDS and ATR-FTIR spectroscopy methods. Overall, this study provides the necessary leeway for achieving and accelerating the industrial scale application of EC process and its greater performance in the separation of emulsified oil-water mixtures.