Continuous Bioelectricity Generation from Phenol‐Contaminated Water by Mediator‐Less Microbial Fuel Cells: A Comparative Study between Air‐Cathode and Bio‐Cathode Systems

Abstract

Abstract Due to metabolic activity of bacteria, microbial fuel cells (MFCs) can directly generate electricity by converting chemical energy of a biodegradable substrate to electrical energy. Simultaneous production of clean energy and wastewater treatment can be accomplished in these systems. In this study, phenol (100 ‐ 1,000 ppm) as a toxic model of wastewater pollutant compounds was used as the sole source of carbon and energy for growth of bacteria and concomitant power generation in a dual‐chamber MFC. Experiments were conducted in two lab‐scale systems including an air‐cathode and a bio‐cathode MFC operating in continuous mode. Anode and bio‐cathode chambers were inoculated with aerobic activated sludge from an industrial wastewater treatment plant. The highest output power was obtained at a phenol concentration of 700 ppm in both air‐cathode (25 mW m −2 ) and bio‐cathode (5 mW m −2 ) MFCs without using any co‐substrate for the first time confirming the higher performance of the air‐cathode electrode in oxygen reduction reaction. Phenol removal efficiency for an influent concentration of 700 ,ppm with an HRT of 125 min was 59.0% and 71.8% in bio‐cathode and air‐cathode MFCs, respectively. Cyclic voltammetry results confirmed involvement of both soluble and membrane‐bound mediator components in electrochemical activity of anodic biofilm.

Key findings

• ▸The highest output power was obtained at a phenol concentration of 700 ppm in both air-cathode and bio-cathode MFCs.
• ▸Phenol removal efficiency was achieved for an influent concentration of 700 ppm without using a co-substrate.
• ▸The air-cathode electrode showed higher performance in oxygen reduction reaction compared to the bio-cathode electrode.

Keywords

Identifiers

DOI

10.1002/fuce.201800027

Journal

Fuel Cells

Year

2018