Electrocoagulation of Corrugated Box Industrial Effluents and Optimization by Response Surface Methodology

The electrocoagulation method using stainless steel anodes was applied to a corrugated cardboard box manufacturing plant's wastewater with high COD content. The effects of current density, processing time and stirring speed on response functions were studied using the Response Surface Methodology (RSM). The removal efficiency of chemical oxygen demand (COD) and energy consumption were selected as response functions. The Central Composite Design (CCD) was chosen to explain the single and combined effects of independent variables on response functions. The COD concentration of the real industrial wastewater used in the experiments was 9130 mg L^-1. The maximum COD removal efficiency of 91.6% is obtained with 19.78 Wh g^-1 energy consumption. Current density and treatment time were effective parameters for both COD removal and energy consumption. Optimization for maximum COD removal with minimum energy consumption showed 80.9% of COD removal with 6.7 Wh g^-1 of energy consumption at 15 mA cm^-2, 700 rpm, and 28 min treatment time. The variables are optimized with a few experiments using the response surface method.