Effect of MWCNT-modified graphite felts on hexavalent chromium removal in biocathode microbial fuel cells

Wu, Xuezhong; Xiong, Xiaohui; Brunetti, Gianluca; Yong, Xiaoyu; Zhou, Jun; Zhang, Lijuan; Wei, Ping; Jia, Honghua

doi:10.1039/c7ra11696a

Cited by 15 publications

(5 citation statements)

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“…Cr(VI) removal at the sterile control cathode was mainly due to physical adsorption on the graphite felt. On the other hand, for the strain H biocathode, on top of the physical adsorption at the electrode, Cr(VI) removal was also caused by bioadsorption and a minimal contribution from the decay of the endogenous biomass upon Cr(VI) reduction ( Tandukar et al, 2009 ; Wu et al, 2016 , 2017 ). Once the circuits were connected, the Cr(VI) concentrations decreased faster in the two MFCs, and especially in the MFC with the strain H biocathode, indicating that the bioelectrochemical process stimulated Cr(VI) removal in the autotrophic cathode environment.…”

Section: Resultsmentioning

confidence: 99%

“…Previous reports have indicated that Cr(VI) reduction at a biocathode of a MFC is largely due to the bioelectrochemical reaction mediated by the cathodic bacteria ( Tandukar et al, 2009 ; Huang et al, 2010 ; Wu X.-Y. et al, 2015b ; Wu et al, 2016 , 2017 ). CV has been proposed as an effective method of investigating microbial activity in MFCs because the magnitude of redox peaks reveals the electrochemical activity of a biofilm ( Luo et al, 2013 ; You et al, 2018 ).…”

Section: Resultsmentioning

confidence: 99%

“…It can efficiently reduce Cr(VI) to Cr(III) by utilizing electroactive biofilms as biocatalysts in the reductive cathode chamber, and simultaneously harvest electricity during the treatment process ( Tandukar et al, 2009 ; Huang et al, 2010 ). Thus far, several strategies have been applied to enhance the efficiency of the Cr(VI)-reducing biocathode in MFCs, including electrode modification ( Wu et al, 2016 , 2017 ), acclimatization optimization ( Wu X. et al, 2015 ), cathode potential control ( Huang et al, 2011a ), and operating conditions control ( Huang et al, 2011b ). However, the electroactive Cr(VI)-reducing bacteria on the cathode that play the key role in this system have not been well studied.…”

Section: Introductionmentioning

confidence: 99%

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A Facultative Electroactive Chromium(VI)-Reducing Bacterium Aerobically Isolated From a Biocathode Microbial Fuel Cell

Ren

Owens

et al. 2018

Front. Microbiol.

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A facultative electroactive bacterium, designated strain H, was aerobically isolated from the biocathode of a hexavalent chromium (Cr(VI))-reducing microbial fuel cell (MFC). Strain H is Gram-positive and rod shaped (1–3 μm length). 16S rRNA gene analysis suggested that this strain (accession number MH782060) belongs to the genus Bacillus and shows maximum similarity to Bacillus cereus whose electrochemical activity has never previously been reported. Moreover, this strain showed efficient Cr(VI)-reducing ability in both heterotrophic (aerobic LB broth) and autotrophic (anaerobic MFC cathode) environments. Cr(VI) removal reached 50.6 ± 1.8% after 20 h in LB broth supplemented with Cr(VI) (40 mg/L). The strain H biocathode significantly improved the performance of the Cr(VI)-reducing MFC, achieving a maximum power density of 31.80 ± 1.06 mW/m2 and Cr(VI) removal rate of 2.56 ± 0.10 mg/L–h, which were 1.26 and 1.75 times higher than those of the MFC with the sterile control cathode, respectively. This study offers a novel Gram-positive Bacillus sp. strain for Cr(VI) removal in MFCs, and shows a facile aerobic isolation method could be used to screen facultative electroactive bacteria.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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A Facultative Electroactive Chromium(VI)-Reducing Bacterium Aerobically Isolated From a Biocathode Microbial Fuel Cell

Ren

Owens

et al. 2018

Front. Microbiol.

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“…The maximum power density of the modified MFC was 132.1 ± 2.8 mW/m 2 , and the removal rate attained 80.9%, which was 36.5% higher than that of the unmodified control group. Graphite felt biocathodes, modified using acid-pretreated, oxidized multi-walled carbon nanotubes, increased the removal rate of Cr(VI) from 0.97 ± 0.02 mg/(L·h) for the unmodified biocathodes to 2.00 ± 0.10 mg/(L·h) ( Wu et al, 2017 ). Wu et al (2016) constructed a biocathode using an NaX-type zeolite-modified graphite mat, whereby the internal resistance of the modified MFC was 162.30 Ω, compared to 337.01 Ω without modification.…”

Section: Key Factors Affecting the Removal Of Heavy Metals Using Bioc...mentioning

confidence: 99%

Research progress on using biological cathodes in microbial fuel cells for the treatment of wastewater containing heavy metals

Wang,

Zhai,

Long

et al. 2023

Front. Microbiol.

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Various types of electroactive microorganisms can be enriched to form biocathodes that reduce charge-transfer resistance, thereby accelerating electron transfer to heavy metal ions with high redox potentials in microbial fuel cells. Microorganisms acting as biocatalysts on a biocathode can reduce the energy required for heavy metal reduction, thereby enabling the biocathode to achieve a lower reduction onset potential. Thus, when such heavy metals replace oxygen as the electron acceptor, the valence state and morphology of the heavy metals change under the reduction effect of the biocathode, realizing the high-efficiency treatment of heavy metal wastewater. This study reviews the mechanisms, primary influencing factors (e.g., electrode material, initial concentration of heavy metals, pH, and electrode potential), and characteristics of the microbial community of biocathodes and discusses the electron distribution and competition between microbial electrodes and heavy metals (electron acceptors) in biocathodes. Biocathodes reduce the electrochemical overpotential in heavy metal reduction, permitting more electrons to be used. Our study will advance the scientific understanding of the electron transport mechanism of biocathodes and provide theoretical support for the use of biocathodes to purify heavy metal wastewater.

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“…The microbial bio lm electric stimulation can improve the pollutant removal because of microbial metabolism enhancing [11]. In this way, the bio-electrochemical processes have received a lot of attention from researchers in reduction and removal of heavy metals and energy of the system [12,13]. In the MES, the micro-organisms are used to catalyze the oxidation-reduction reaction on the surface of an electrodes.…”

Section: Introductionmentioning

confidence: 99%

Bio-Electroreduction of Chromium (VI) using Immobilized Sulfate Reducing Bacteria on Conductive Microbial Cellulose Biocathode

Loloei

Rezaee

Ghods

2021

Preprint

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The present study evaluated effect of conductive microbial cellulose (MC) biocathode as a carbohyrate biopolymer in hexavalent chromium bio-electroreduction using immobilized sulfate reducing bacteria (SRB). The morphology studies using SEM shows that the biofilm of SRB was formed a good density on the conductive microbial cellulose biocathode. The Brunauer, Emmett and Teller (BET) analysis revealed that the particle-size distribution in the conductive biocathode was 0.9 nm. The kinetic studies shows that the Cr (VI) removal process fallow of pseudo-first-order kinetics with a constant rate was 0.6 h− 1. The energy consumption of the bio-electroreduction system was 2.7×10− 2 kWh/m3. The EDXA spectrum of sediments showed the presence of chromium peak, indicating that Cr (VI) was reduced on the bio-resuction system. The obtained results indicate that proposed bio-electroreduction system using immobilized sulfate reducing bacteria on the conductive microbial cellulose biocathode could be an efficient method for chromium bio-reduction from wastewaters.

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Effect of MWCNT-modified graphite felts on hexavalent chromium removal in biocathode microbial fuel cells

Abstract: Oxidized MWCNT-modified graphite felt significantly improved Cr(vi) removal in biocathode MFCs due to its affinity towards microbes and Cr(vi).

Cited by 15 publications

References 49 publications

A Facultative Electroactive Chromium(VI)-Reducing Bacterium Aerobically Isolated From a Biocathode Microbial Fuel Cell

A Facultative Electroactive Chromium(VI)-Reducing Bacterium Aerobically Isolated From a Biocathode Microbial Fuel Cell

Research progress on using biological cathodes in microbial fuel cells for the treatment of wastewater containing heavy metals

Bio-Electroreduction of Chromium (VI) using Immobilized Sulfate Reducing Bacteria on Conductive Microbial Cellulose Biocathode

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