Electrochemical quartz crystal microbalance to monitor biofilm growth and properties during bioelectrochemical system inoculation and load conditions

BioElectrochemical Systems are an emerging technology of interest. Central to the successful operation of these systems is the development of a biofilm on an electrode surface that facilitates the interaction of microorganisms capable of extra-cellular electron transfer. Porous graphite is typically chosen as the electrode material. However, other materials could contribute to a significant improvement in reactor performance. In order to evaluate these novel materials, a platform methodology is required. In this study, E-QCM-D was evaluated using a gold electrode, a mixed biofilm population and a challenging real influent (fermented solubilised sludge). The results gave real-time feedback on both the acoustic and electrochemical impedance of the working electrode, hence providing information about biofilm thickness, viscoelasticity, kinetics and mass transport. The use of E-QCM-D is novel for this field and has the potential to provide a wealth of new data to help optimise the performance of biofilms in these systems.