A novel single continuous electrocoagulation process for treatment of licorice processing wastewater: Optimization of operating factors using RSM

The potential application of a novel continuous electrocoagulation (EC) reactor for simultaneous removal of color, chemical oxygen demand (COD), turbidity, and alkalinity from a real licorice processing wastewater was investigated. The individual and interactive effects of four key independent variables (electrolysis time, current density, NaCl concentration, and mixing intensity) was evaluated. The results suggested that color and COD removal enhances with increasing electrolysis time, current density, and mixing intensity and remains practically constant by adding higher concentrations of NaCl. The application of continuous EC process under optimal conditions, such as: electrolysis time (81.8 min), current density (350 A/m2), NaCl concentration (300 mg/L), mixing intensity (45 rpm) allows to achieve these promised removal efficiencies: 90.1 % color, 89.4 % COD, 82 % turbidity, and 73.3 % alkalinity.