Safwat Mahmoud, PhD, PMP

Microbial fuel cells (MFCs) and electrocoagulation cells (ECCs) are two emerging technologies in the treatment of wastewater. The integration between MFCs and ECCs has not been reported yet. This work studied the ability to couple MFCs with an ECC to form an integrated system for wastewater treatment. Two types of wastewater were examined: synthetic wastewater containing a mixture of glucose and soluble starch, and real municipal wastewater. A series of MFCs could provide sufficient energy for the electrocoagulation process. The results showed that the removal efficiencies of COD, TDS, and TSS were 95.4%, 88.4%, and 93.8%, respectively, for synthetic wastewater, while these values were 83.7%, 57.5%, and 85.8%, respectively, for real wastewater. The energy harvested from the MFCs to ECCs when using synthetic wastewater was more than that harvested using real wastewater. The capital cost of the integrated system is high using MFCs and ECCs, but it will significantly reduce the operational cost compared to ECCs.

This work assessed the performance of a single‐chamber microbial fuel cell (MFC) with various substrates. Primary settled domestic wastewaters were used to simulate wastewaters of high biodegradability; while phenol‐based wastewaters and benzene‐based wastewaters were used to simulate wastewaters of low biodegradability. Experiments were performed at initial pH values of 6, 7 and 8. The maximum voltage production, power density and removal of substrate were obtained using primary settled domestic wastewater, whereas the lowest values were obtained using phenol‐based wastewater. The maximum chemical oxygen demand removal efficiency, phenol removal efficiency and benzene removal efficiency were 80.8, 63.3 and 77.8%, respectively. The performance of the MFC was enhanced by increasing the influent pH. The lowest coulombic efficiencies were obtained from phenol‐based wastewater and benzene‐based wastewater, which indicated that electrogenic bacteria were not the primary microorganisms responsible for the biodegradation of low biodegradable wastewater.