Simultaneous Removal of Cadmium and Copper in Aqueous Solution by Electrocoagulation: Influence of pH and Electric Current Density

Abstract

Efficient removal of heavy metals from wastewater is crucial due to their harmful effects on health and the environment. Electrocoagulation is an alternative treatment technique that applies electric current to metallic electrodes, forming coagulants and precipitating contaminants. This study evaluated the efficiency of electrocoagulation in removing copper (Cu) and cadmium (Cd) from aqueous solutions. An experimental study was conducted to assess the simultaneous and independent removal of each metal. Electrodes based on 1050 aluminum alloy were used, and different pH values (2.6, 5, and 7) and electric current densities (1, 2, and 3 mA/cm²) were evaluated. The treatments were carried out for 40 min at room temperature (25 ± 1 °C). Atomic absorption spectroscopy technique was employed for monitoring and quantification of both metals. The results showed the complete removal of Cd in mixture and almost complete removal of Cu (>99 %) when used independently. The removal efficiency increased with pH and electric current density, and it was found that removal was more efficient under neutral or slightly alkaline pH conditions. The findings of this study can be useful for the implementation of this technology in the industry for the treatment of wastewater contaminated with both metals.