Electrocoagulation for Cyanide Removal from Industrial Waste Solutions: an Innovative Cell Design and Optimization Using Response Surface Methodology

This study investigates the application of electrocoagulation for the removal of cyanide from industrial waste solutions, utilizing a novel cell design and optimization via Response surface methodology. The electrocoagulation cell consists of two aluminum electrodes with a unique geometry that offers built-in cooling and uniform interelectrode gap. The Response surface methodology was employed to optimize the process parameters, including current density, initial cyanide concentration, pH, and sodium chloride concentration. The experimental results demonstrated a high efficiency of cyanide removal, reaching up to 98% within 120 min. The energy consumption was found to range between 2.5 and 24 kW∙h/m3 of solution. The sludge produced from the process was characterized using FTIR, TEM, and EDX, revealing the presence of amorphous aluminum oxyhydroxides and small, agglomerated particles. The statistical analysis of the data using ANOVA confirmed the significance of the reduced quadratic model, with an F-value of 735.94 and a P-value of 0.0001. The optimization of the process resulted in the identification of the optimal conditions for maximum cyanide removal: time = 116 min; initial cyanide concentration = 175 mg/L; pH = 10; NaCl conc. = 2.2 g/L; and current density = 11.15 mA/cm2. This study provides valuable insights into the efficient removal of cyanide from industrial waste solutions using electrocoagulation, offering a promising approach for environmental protection and industrial waste management.