Investigation electrocoagulation process by using iron and stainless steel electrodes for baker's yeast wastewater treatment

Baker's yeast wastewater is one of the types of food industry wastewaters that contain high organic pollution and color. In this study, the electrocoagulation process using iron and stainless steel electrodes were investigated as an efficient method for supplementary treatment of Baker's yeast wastewater. In this experimental study of laboratory pilot, the effects of operating parameters such as current density (i.e. 80,100, 120 and 140 A/m2), time (i.e. 15, 30, 45 and 60 min) and electrode material types (i.e. iron and stainless steel) on the removal efficiency of COD (chemical oxygen demand), turbidity and color from Baker's yeast wastewater were investigated and the optimum operation conditions were determined for each of these parameters by using Taguchi statistical method. Based on the results, the removal efficiency of COD, turbidity and color increased with increasing of current density and operation time and the efficiency of stainless steel electrodes were more than iron electrodes. The optimal operation conditions of electrocoagulation process for supplementary baker's yeast wastewater treatment were: the current density of 120 A/m2, with retention time of 45 min and the use of stainless steel electrodes. The results showed that in these conditions the removal efficiency of COD, turbidity and color were 54.84, 44.98 and 40.26% and the corrosion rate of electrodes and the electrical energy consumed were 0.086 g/lit and 3.226 Watt/lit, respectively. Considering environmental and economical priorities, this process can be suggested as a supplementary treatment process for wastewaters with high organic pollution and color.