Performance of Electrocoagulation Process with Copper Electrodes for Tannery Wastewater Treatment

The effluents from the tanning industry pose challenges due to the complex and difficult-to-manage wastewater generation process. Usually, the main issue in tannery wastewater is the high levels of chemical oxygen demand (COD), chlorides (Cl), and chromium (Cr), which have a negative impact on human health and the environment. Since the conventional biological treatment methods are not effective for treating tannery wastewater, the main aim of this study was to assess the performance of the electrocoagulation process (EC) in treating tannery wastewater by copper electrodes. The study was conducted through an investigation of stirring speeds (low (60 rpm), medium (780 rpm), high (1500 rpm)), current densities (4, 8, 12, and 16 mA/cm2), and reactor volume capacities (0.5, 1, 1.5 L) over an examination period of 60 min. The EC process has proven its high efficiency in removing pollutants. The results showed the best removal efficiencies, where the removal rates of COD, Cl, and Cr reached 92.3%, 96.5%, and more than 99%, respectively, at the following optimum parameters: stirring speed of 60 rpm, current density of 4 mA/cm2, and reactor volume of 1 L. Corrosion of the Cu electrodes was observed via scanning electron microscope (SEM) imagery, and the generated sludge was analyzed via Fourier transform infrared (FTIR) spectroscopy.