Investigation of the effect of current density and PH on oil and grease removal from leather industry wastewaters by electrocoagulation method

In this study, the effects of pH and current density on the removal of high concentrations of oil and grease in leather industry wastewater by the electrocoagulation method were investigated. Two different types of electrodes were used in the study. Studies with aluminum electrodes have shown that these electrodes are more effective than iron electrodes in removing oil and grease. In addition, aluminum electrodes are affected more by the system pH than iron electrodes. Studies have shown that higher oil and grease removal efficiencies are obtained below pH 4 for both electrodes. While the oil and grease removal efficiency with Al electrodes is 95% at pH 2, this value decreases to 83% at pH 6. In Fe electrodes, while the removal efficiency is 87.83% at pH 2, it decreases to 83% at pH 6. The effect of current density on oil and grease removal was examined and it was observed that the removal efficiency remained constant above a certain current density in aluminum electrodes. While the efficiency of Al electrodes is 83.31% at 0.6 mA cm-2 current density, this value has increased to about 98% at 1.2, 1.8, and 2.4 mA cm-2 current densities. In Fe electrodes, the oil and grease removal efficiency is 82.66% at 0.6 mA cm-2 current density, while it is 90% at 1.2 and 1.8 mA cm-2 current densities and 98% at 2.4 mA cm-2. These results show that the electrocoagulation process removes the oil and grease in wastewater at a high rate. This shows that this process can also be used as pre-treatment before the biological treatment of industrial wastewater with high oil and grease content. Copyright 2021, Yıldız Technical University.