Improving the performance of the electro-coagulation process through efficient flocculation

Abstract

Abstract This study combines the Electro-Coagulation (EC) process with flocculation to improve the COD removal efficiency of the simulated textile wastewater without a significant increase in energy consumption. The process of flocculation improves the settleability of the flocs generated at the time of EC. A 3D aluminum electrode with perforations was used for both EC and flocculation. During flocculation, the rotating speed of the anode and detention time were taken as the major operating parameters. The operating conditions at the time of EC were kept fixed for all the runs. The maximum COD removal efficiency after EC was observed as 85.14% with a Specific Electrical Energy Consumption (SEEC) of 0.023J/mg. However, this removal efficiency increases to 90.43% when EC is followed by flocculation with a total SEEC (EC + flocculation) of 0.029J/mg. The maximum COD removal efficiency of the filtered sample after flocculating it for 20 min at 1 rpm was comparable with the removal efficiency obtained after providing a 30 min settling after flocculation. Therefore, an additional cost of filtration can be saved. This combined process can be considered as an economical and efficient treatment method to match the stringent discharge standards.