Eliena Jonko Birriel

Treatment of hydrocyanic galvanic effluent by electrocoagulation: Optimization of operating parameters using statistical techniques and a coupled polarity inverter

The treatment of hydrocyanic galvanic effluent with Zn, Ni and Cu ions by electrocoagulation (EC) using aluminum electrodes and a polarity inverter was evaluated. 32 experiments were performed and the optimal operating conditions were obtained using statistical analysis: 30 minutes, 5.00 g/L NaCl, 1 cm between electrodes, electrode surface area of 104 cm2/L and current density of 8 mA/cm2. The results for removal with the polarity inverter were: 99.55% total cyanide, 22.49% total nickel, 52.66% total copper and 100% total zinc. After the EC experiments, localized and general corrosion of the aluminum electrodes was evaluated both internally and externally by SEM. Contaminant removal was confirmed by X-Ray powder diffraction (XRD) and Fourier transform infrared (FT-IR) which demonstrated the presence of contaminants in the galvanic sludge generated in the process.