Effect of Sodium Dodecyl Sulfate (SDS) and Tween 80 on Cell Viability in an Air-Cathode Microbial Fuel Cell
Committee membersAmy, Gary L.
Permanent link to this recordhttp://hdl.handle.net/10754/209396
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AbstractMicrobial fuel cells (MFCs) generate current via electrochemical reactions produced by bacteria attached to the anode that oxidize organic matter. Due to their high volume use in household products, some concentration of surfactant will reach wastewater treatment plants. The average surfactant concentration in wastewater ranges from 10 to 20 mg L-1, and up to 300 mg L-1, for domestic and industrial wastewaters, respectively. This study aimed to demonstrate the feasibility of enhancing power production by adding Tween 80 and SDS surfactants to air-cathode MFCs, and their effect in cell viability at the anodic biofilm. In order to analyze the effect of anionic and nonionic surfactants in MFCs performance, eight MFCs were spiked with two types of surfactants, the anionic surfactant sodium dodecyl sulfate (SDS) and the nonionic surfactant Tween® 80 at two different concentrations 10 and 100 mg L-1. Cell viability at the anodic biofilms was examined using the LIVE/DEAD BacLight viability assay and images were visualized with a confocal laser scanning microscope. The electrochemical results demonstrate that, for an air-cathode MFC operating on 1 g L-1 acetate in a fed-batch mode, reactors where SDS was added show a lower overall performance, maximum PD of 544 mW m-2, CE of 12.3%, Rint of 322 Ω (10 mg L-1) and maximum PD of 265 mW m-2, CE of 9.4%, Rint of 758 Ω (100 mg L-1). Reactors where Tween 80 was added show quite stable performance, maximum PD of 623 mW m-2, CE of 15.4%, Rint of 216 Ω (10 mg L-1) and maximum PD of 591 mW m-2, CE of 10.8%, Rint of 279 Ω (100 mg L-1), compared with reactors operating at only acetate as a substrate, maximum PD of 574 mW m-2. Confocal microscopy images confirm this observation and biofilm viability appeared severely compromised in SDS reactors, especially at high concentrations. This study has opened up a whole new research area in determining which types of surfactants are toxic to the anodic biofilm and to further investigate the scale-up feasibility of this technology for wastewater treatment.