STUDIES ON REMOVAL OF CYANIDE FROM AQUEOUS ENVIRONMENTS USING ALUMINUM ELECTRODES

One of the most toxic compounds, cyanide, threatens human health and can enter the environment in different forms. Owing to its high ability to remove various contaminants from aqueous environments, the electrocoagulation process (ECP) is now considered an effective process. The aim of this study was to determine magnesium oxide nanoparticles (MgO) as a coagulant aid in ECP on the removal of cyanide from aqueous environments using aluminum electrodes. In this study, a reaction chamber was used with 4 aluminum electrodes (with dimensions 2x20x250 mm and volume 1 L) equipped with an electricity generating device to remove cyanide. The effects of pH, current density, initial cyanide concentration in the reactor inlet, and different doses of MgO nanoparticles as a coagulant aid were studied in this process. Results showed that process efficiency under pH=5, current density=15 mA/cm2, initial concentration=100 mg/L and time=40 min was equal to 80%. Moreover, as the coagulant aid increased, process efficiency also increased. At optimum levels of MgO coagulant aid (0.1 mg/L in ECP) and reaction time=45 min, cyanide removal efficiency was equal to 90%. Results from kinetic studies showed that cyanide removal is most consistent with the second-order model (higher R2). According to results of this study, ECP is a suitable process for removing cyanide-toxic contaminants. Moreover, MgO nanoparticles act as suitable coagulant aids in ECP along with aluminum electrodes, increasing process efficiency and subsequently enhancing cyanide removal from aqueous environments.