Electrocoagulation process using aluminum electrodes for treatment of baker's yeast industry wastewater

Abstract

Background and Aims: Severe contamination with organic compounds and very high color is characteristic of yeast industry wastewater. Discharging this wastewater into the environment has adverse effects on the environment. The present study was conducted to determine the efficiency of the electrocoagulation (EC) using aluminum electrodes for the removal of color, turbidity, and chemical oxygen demand (COD) from the baker's yeast industry wastewater. Materials and Methods: In this experimental study, the effect of current densities (60, 80, 100, and 120 A/m2) and reaction times (15, 30, 45, and 60 min) using aluminum electrode was investigated on removal efficiencies of COD, color, and turbidity. The pilot consisted of a reactor with a useful volume of 2.5 l of epoxy glass, a direct current power supply, and aluminum electrodes of 8 cm × 8 cm in diameter. Results: The highest removal efficiencies were obtained to be 83% for COD, 93% for color, and 96% for turbidity at density of 80 A/m2 and 45-min contact time (pH = 7). Under these conditions, the power and electrode consumption was 16.89 kWh and 94.3 g/m3, respectively, and the treatment cost of wastewater was estimated to be 1.5 $ per each cubic meter. Conclusion: The results showed that EC process using aluminum electrode is an appropriate and effective method for removing color, turbidity, and COD from baking industry wastewater.