Gravity settling of planktonic bacteria to anodes enhances current production of microbial fuel cells

Li, Tian; Zhou, Lean; Qian, Yawei; Wan, Lili; Du, Qing; Li, Nan; Wang, Xin

doi:10.1016/j.apenergy.2017.04.078

Cited by 42 publications

(10 citation statements)

References 38 publications

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“…Li et al demonstrated that the gravity effect being applied to the MFC not only facilitated easy attachment of microbes on the electrode, but also increased the biofilm thickness. Thus, the startup time was shorter than the control by 12%, and the maximum current density reached 8.41 ± 0.13 A/m 2 , which was 29% higher than without the gravitational effect [18]. He et al indicated that if the fiber diameter of anode fiber was lesser than the bacteria size, the thickness of biofilm will be less, which may result in less current density due to the fact that the fibers will form small pores and hinder the bacterial penetration [19].…”

Section: Introductionmentioning

confidence: 85%

Effect of Wall Boundary Layer Thickness on Power Performance of a Recirculation Microbial Fuel Cell

2018

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Abstract:Hydrodynamic boundary layer is a significant phenomenon occurring in a flow through a bluff body, and this includes the flow motion and mass transfer. Thus, it could affect the biofilm formation and the mass transfer of substrates in microbial fuel cells (MFCs). Therefore, understanding the role of hydrodynamic boundary layer thicknesses in MFCs is truly important. In this study, three hydrodynamic boundary layers of thickness 1.6, 4.1, and 5 cm were applied to the recirculation mode membrane-less MFC to investigate the electricity production performance. The results showed that the thin hydrodynamic boundary could enhance the voltage output of MFC due to the strong shear rate effect. Thus, a maximum voltage of 21 mV was obtained in the MFC with a hydrodynamic boundary layer thickness of 1.6 cm, and this voltage output obtained was 15 times higher than that of MFC with 5 cm hydrodynamic boundary layer thickness. Moreover, the charge transfer resistance of anode decreased with decreasing hydrodynamic boundary layer thickness. The charge transfer resistance of MFC with hydrodynamic boundary layer of thickness 1.6 cm was 39 Ω, which was 0.79 times lesser than that of MFC with 5 cm thickness. These observations would be useful for enhancing the performance of recirculation mode MFCs.

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Section: Introductionmentioning

confidence: 85%

Effect of Wall Boundary Layer Thickness on Power Performance of a Recirculation Microbial Fuel Cell

2018

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“…Additionally, enhanced substance diffusion [either the substrate or metabolic end products (H + )] can increase the biomass, viability and performance of the anode biofilm. It has been shown that using a highly concentrated phosphate-buffered saline (PBS) solution as the anode electrolyte or increasing the pH of the anode electrolyte from a weak acid (pH = 6–7) to alkalinity (pH = 7–9) to mitigate proton accumulation in the anode biofilm or adjusting the gravity settling of planktonic bacteria and bioanode can increase the biomass, viability and current generation of anode biofilms ( Liu et al, 2005 ; Cheng and Logan, 2007 ; Patil et al, 2011 ; Dhar et al, 2017 ; Li et al, 2017 ). In previous studies, we found that aerobically enriched anode biofilms with sufficient substance diffusion in the inner layer had a thicker inner layer and a higher current generation.…”

Section: Introductionmentioning

confidence: 99%

Shear Stress Affects Biofilm Structure and Consequently Current Generation of Bioanode in Microbial Electrochemical Systems (MESs)

Yang

Cheng

et al. 2019

Front. Microbiol.

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Shear stress is an important factor that affects the formation and structure of anode biofilms, which are strongly related to the extracellular electron transfer phenomena and bioelectric performance of bioanodes. Here, we show that using nitrogen sparging to induce shear stress during anode biofilm formation increases the linear sweep voltammetry peak current density of the mature anode biofilm from 2.37 ± 0.15 to 4.05 ± 0.25 A/m2. Electrochemical impedance spectroscopy results revealed that the shear-stress-enriched anode biofilm had a low charge transfer resistance of 46.34 Ω compared to that of the unperturbed enriched anode biofilm (72.2 Ω). Confocal laser scanning microscopy observations showed that the shear-stress-enriched biofilms were entirely viable, whereas the unperturbed enriched anode biofilm consisted of a live outer layer covering a dead inner-core layer. Based on biomass and community analyses, the shear-stress-enriched biofilm had four times the biofilm density (136.0 vs. 27.50 μg DNA/cm3) and twice the relative abundance of Geobacteraceae (over 80 vs. 40%) in comparison with those of the unperturbed enriched anode biofilm. These results show that applying high shear stress during anode biofilm enrichment can result in an entirely viable and dense biofilm with a high relative abundance of exoelectrogens and, consequently, better performance.

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“…Three-electrode single-chamber BESs were assembled as previously described ( Li et al., 2017 ) to provide a stable redox environment at the anodes. The reactor was framed by a cylindrical chamber (5 cm in length and 5 cm in diameter) with an effective volume of 100 mL, which was tightly sealed with a polytetrafluoroethylene cover to maintain the anaerobic environment.…”

Section: Methodsmentioning

confidence: 99%

Synthesis of silver nanoparticles using living electroactive biofilm protected by polydopamine

et al. 2021

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Summary The biosynthesis of metal nanoparticles from precious metals has been of wide concern. Their antibacterial activity is a main bottleneck restricting the bacterial activity and reduction performance. Here, bio-electrochemical systems were used to harvest electroactive biofilms (EABs), where bacteria were naturally protected by extracellular polymeric substances to keep activity. The biofilm was further encapsulated with polydopamine (PDA) as additional shield. Silver nanoparticles (AgNPs) were biosynthesized on EABs, whose electroactivity could be fully recovered after Ag + reduction. The PDA increased bacterial viability by 90%–105%, confirmed as an effective protection against antibacterial activity of Ag + /AgNPs. The biosynthetic process changed the component and function of the microbial community, shifting from bacterial Fe reduction to archaeal methanogenesis. These results demonstrated that the electrochemical acclimation of EABs and encapsulation with PDA were effective protective measures during the biosynthesis of AgNPs. These approaches have a bright future in the green synthesis of nanomaterials, biotoxic wastewater treatment, and sustainable bio-catalysis.

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Gravity settling of planktonic bacteria to anodes enhances current production of microbial fuel cells

Cited by 42 publications

References 38 publications

Effect of Wall Boundary Layer Thickness on Power Performance of a Recirculation Microbial Fuel Cell

Effect of Wall Boundary Layer Thickness on Power Performance of a Recirculation Microbial Fuel Cell

Shear Stress Affects Biofilm Structure and Consequently Current Generation of Bioanode in Microbial Electrochemical Systems (MESs)

Synthesis of silver nanoparticles using living electroactive biofilm protected by polydopamine

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