10.1021/acs.est.6b06339.s001 Soumya Pandit Soumya Pandit Sneha Shanbhag Sneha Shanbhag Meagan Mauter Meagan Mauter Yoram Oren Yoram Oren Moshe Herzberg Moshe Herzberg Influence of Electric Fields on Biofouling of Carbonaceous Electrodes American Chemical Society 2017 electrode surface properties magnitude biofilm formation ROS reactive oxygen species carbonaceous capacitive deionization electrodes Carbonaceous Electrodes Biofouling two-electrode flow cell Pseudomonas aeruginosa biofilm redox CA potential stress PA 2017-07-25 00:00:00 Journal contribution https://acs.figshare.com/articles/journal_contribution/Influence_of_Electric_Fields_on_Biofouling_of_Carbonaceous_Electrodes/5301769 Biofouling commonly occurs on carbonaceous capacitive deionization electrodes in the process of treating natural waters. Although previous work reported the effect of electric fields on bacterial mortality for a variety of medical and engineered applications, the effect of electrode surface properties and the magnitude and polarity of applied electric fields on biofilm development has not been comprehensively investigated. This paper studies the formation of a Pseudomonas aeruginosa biofilm on a Papyex graphite (PA) and a carbon aerogel (CA) in the presence and the absence of an electric field. The experiments were conducted using a two-electrode flow cell with a voltage window of ±0.9 V. The CA was less susceptible to biofilm formation compared to the PA due to its lower surface roughness, lower hydrophobicity, and significant antimicrobial properties. For both positive and negative applied potentials, we observed an inverse relationship between biofilm formation and the magnitude of the applied potential. The effect is particularly strong for the CA electrodes and may be a result of cumulative effects between material toxicity and the stress experienced by cells at high applied potentials. Under the applied potentials for both electrodes, high production of endogenous reactive oxygen species (ROS) was indicative of bacterial stress. For both electrodes, the elevated specific ROS activity was lowest for the open circuit potential condition, elevated when cathodically and anodically polarized, and highest for the ±0.9 V cases. These high applied potentials are believed to affect the redox potential across the cell membrane and disrupt redox homeostasis, thereby inhibiting bacterial growth.