Fed batch approach for stable generation of power from dairy wastewater using microbial fuel cell and its kinetic study

Abstract

An attempt was taken for a stable generation of power from dairy wastewater using single chamber microbial fuel cell (SCMFC), and Escherichia coli-K-12 was used as a biological catalyst. The experiments were carried out initially at batch operation with simulated dairy wastewater (SDW) for 72 hr, followed by two steps feeding strategies. The two successive feedings were carried out by concentrated SDW at 72 hr, followed by various chemical oxygen demand (COD) containing real dairy wastewater (RDW) at 120 hr, and pH was initially adjusted to 9 before feeding. The maximum open-circuit voltage (OCV) of 654 mV was found after 123 hr of fed-batch operation in the presence of 1000 mg COD/L of RDW. The COD removal efficiency was found to be 95.45%, and coulombic efficiency was 67.53% during fed-batch operation. Kinetic parameters were computed through nonlinear regression analysis of experimental data obtained from fed-batch study. The performance study of SCMFC was carried out based on polarization behavior and cell potentials. It was evident from results that the maximum power and current density were found to be 1.05 W/m2 and 8.01 A/m2, respectively in the presence of 1000 mg COD/L of RDW. The performance of SCMFC in the presence of RDW suggests that SCMFC is a promising alternative for power generation along with treatment of wastewater.