Investigation of Electrocoagulation/Electroflotation Process Efficiency with Aluminum-Graphite felt Electrodes in Removal of E.coli and S. typhimurium from Drinking Water

Abstract

Introduction: Electrocoagulation is an electrochemical method for the treatment of water. The present study aimed to investigate the removal of E. coli and S. typhimurium bacteria from drinking water by using Electrocoagulation (EC) - Electroflotation (EF) with Aluminum- Graphite felt electrodes parallel with the monopole mode. Materials & Methods: Independent variables included different concentrations of E.coli and S. typhimurium bacteria (104, 105 and 106 CFU/mL), reaction time (5, 10, 15 and 20 min), initial pH (7, 8 and 9), inter-electrode distance (1, 2 and 3 cm), current density (0.83, 1.67 and 2.5 mA/cm2) to determine the optimum conditions. Results: The results showed that under optimum conditions the increase in pH from 7 to 9 significantly decreased removal efficiency of bacterial strains of E.coli and S. typhimurium from 100% to 83% and from 100% to 90%, respectively. For the initial concentration of 105 CFU/mL, optimum conditions were obtained 2.5 mA/cm2 for current density, 20 min for reaction time and 2 cm for inter-electrode distance. Conclusion: According to the results, efficiency of E.coli and S. typhimurium removal was 100% under optimum conditions. Thus EC/EF process can be used for the removal of pathogenic bacteria from drinking water.