The Effect of pH and Current Density on Electrocoagulation Process for Degradation of Chromium (VI) in Plating Industrial Wastewater

Abstract

The heavy metal of chromium is one of the most common pollutants of the plating industrial wastewater. Cr (VI) is one of toxic metal that cause serious threat to human health and the environment due to its cumulative effects and non-degradability. Among the technologies for removing these pollutants, electrocoagulation can be considered as an effective method. This method has some advantages such as fewer amounts of produced sludge and high efficiency in removal of pollutants. This research intended to study effect initial pH and current density on the degree of Cr (VI) removal from wastewater of plating industry by using the electrocoagulation method. The process is done at pH values of (3-9) at current density of 0.42, 0.63, 0.83, 1.04, and 1.25 mA/cm2. Synthetic chromium wastewater was prepared at the initial concentration of 50 mg L-1 during 30 minutes of electrocoagulation process. After electrocoagulation treatment, concentration of Cr (VI) analysed by UV-Vis spectrophotometer. The result revealed that the best removal was achieved at pH 7 and current density of 1.25mA/cm2.