Comparison of sono-direct and sono-alternate current electro-coagulation processes for removal of color and turbidity from domestic wastewater

Background: Nowadays there is a problem related to wastewater handling which is released from different activities. Electrocoagulation has been a dominant treatment method for wastewater treatment. There are different forms of electrocoagulation methods for wastewater treatment. Nevertheless, there was no comparison made for the removal efficiency of the sono-alternate current (SAC), alternate current (AC), sono-direct current (SDC), and direct current (DC) electrocoagulation process. Methods: The efficiency of electrocoagulation method was compared for removal of color and turbidity from Jimma University domestic wastewater. Batch reactor DC/AC electrocoagulation cell was used to determine the removal efficiency. During the comparison, the response surface methodology (RSM) was used to analyze and optimize the data taken from the laboratory. In addition, ANOVA was used to analyze the interaction effects of different parameters. Results: The removal of color and turbidity from domestic wastewater was about 97.53% and 95.28% respectively, using direct current electrocoagulation (DCE). For alternate current electrocoagulation (ACE), the removal of color and turbidity was 98.35% and 96.12%, respectively. The removal of color and turbidity for sono-DCE (SDCE) was obtained to be 98.55% and 98.27%, respectively and for sono-ACE (SACE), the removal of color and turbidity was 99.95% and 99.76%, respectively at the optimum experimental conditions of chemical oxygen demand (COD) 960 g/L, initial wastewater pH of 6.8, the current density of 0.4 A/dm2 , inter-terminal spacing of 1 cm, and the association of electrode of Al-Al. Conclusion: According to the findings of this study, it can be concluded that, the SAC electrocoagulation method is the best and promising technique compared with all other electrocoagulation methods.