Exploring new anode materials to improve operational stability and cost-effectiveness of MFC-based biosensors for BOD analysis of wastewater

Water pollution has increasingly been recognised as a global issue, as it poses a serious threat to both human and environmental health. As a result, the analysis of the concentration of organic contaminants in wastewater has become a growing priority for contamination prevention and treatment. Biochemical oxygen demand (BOD) is one of the key parameters for assessing organic pollutants concentration and the most conventional and well-known approach to measure it is a bioassay methodology called BOD5 test, which requires 5 days to be completed, making impossible to collect data in real time and requiring specialized personnel. In this context, microbial fuel cells (MFCs) have been proposed as real time biosensors in which microorganisms are used as catalyst to oxidise biodegradable organic pollutants in wastewater to generate electricity. The electrical output of MFCs has been demonstrated to be correlated to the amount of organic contaminants in wastewater, making it suitable as a biosensor with the added benefit of being self-sustaining. However, the practical application of MFC-based biosensors has run across substantial challenges, including instability over time, mainly due anode biofouling and degradation, and expensive material and production costs. The goal of my research is to develop a cost-effective and operationally stable MFC-based biosensor for applications in water quality monitoring. The study will be focused on enhancing anode performance by selecting innovative materials, which should be more porous and biocompatible than typical carbonaceous electrodes currently used in MFCs. Chemically and thermally functionalized activated carbon fabric and titanium foam obtained by electrochemical anodization have been selected on the basis of their good electrical conductivity, porosity, surface charge, hydrophilicity and cost. They will be tested as anode materials in MFC-based biosensors to establish their performance over an extended period of time, and comparing them with traditional carbon cloth anodes.