Microbial Fuel Cell Presentation

Microbial fuel cell (MFC): A potential system to harness bioelectricity from wastewater

treatment

S Veer RaghavuluS Veer Raghavulu

Bioengineering and Environmental Center (BEEC) Indian Institute of Chemical Technology (IICT)

Hyderabad-500 607, India

IntroductionIntroduction

World wide researching for carbon free power generation and neutral/positive waste water treatment

MFC is a biochemical-catalyzed system which generates electrical energy through the oxidation of biodegradable organic matter in the presence fermentative bacteria.

It is a renewable energy source and is an attractive source.

Advantages Environmentally clean, renew ability, liberates large amount of

energy and easily converted to electricity by fuel cells, only waste product being water.

Dual benefits- generating a clean fuel and reducing waste.

Direct generating of fuel has potential advantages- does not require the separation and purification of the gas.

Currently, research on MFC is growing.

IntroductionIntroduction

Research is going on world wide for carbon free power generation and Research is going on world wide for carbon free power generation and neutral/positive waste water treatmentneutral/positive waste water treatment

Present ScenarioPresent Scenario Possible Possible solutionsolution

Increasing energy Needs Increasing energy Needs Sustainable & Efficient technology for Sustainable & Efficient technology for

production and utilization of energy production and utilization of energy

Depleting fossil reservesDepleting fossil reserves Renewable energy sources Renewable energy sources

Increasing pollution load Increasing pollution load Nonpolluting energy Nonpolluting energy

Microbial Electricity Generation

Components proposed to be involved in the electron transport from cells to the anode in MFC

Some Microbes are be able to produce their own electron mediators enhancing electron transfer

Anodic reactions : CH3COO- + 2OH- → 2CO2 + 5H+ + 8e-Cathodic reaction : O2 + 4e− + 4H+→ 2H2O

MFC consists of two electrodes sandwiched around an electrolyte. Oxygen acts as a final electron accepter generating electricity, water and heat

Electrochemical activity of microorganismsElectrochemical activity of microorganisms

Fuel cell- configurationFuel cell- configuration

Biofilm on the anodeBiofilm on the anode

Fuel for anode bacteriaFuel for anode bacteria

Anodic biocatalystAnodic biocatalyst

Cathode/anode reactionCathode/anode reaction

Proton Exchange MembraneProton Exchange Membrane

It is important to study all these aspects to make MFCIt is important to study all these aspects to make MFC

MFC is a complex systemMFC is a complex system

SCOPE AND OBJECTIVESSCOPE AND OBJECTIVES

To investigate the feasibility of bioelectricity generation To investigate the feasibility of bioelectricity generation eukaryotic and prokaryotic microorganisms as anodic eukaryotic and prokaryotic microorganisms as anodic biocatalysts. biocatalysts.

To optimize physical, chemical and biological parameters. To optimize physical, chemical and biological parameters.

To investigate the influence of various types of proton To investigate the influence of various types of proton exchange membranes (PEM) on the performance of MFC exchange membranes (PEM) on the performance of MFC

To evaluate the potential of MFC as bio-electrochemical To evaluate the potential of MFC as bio-electrochemical treatment system treatment system

To study microbial diversity of anodic chamber in MFC To study microbial diversity of anodic chamber in MFC

To study the effect of bioaugmentation strategy on the To study the effect of bioaugmentation strategy on the process performance of MFCprocess performance of MFC

Scope and Objectives Scope and Objectives Generation of carbon neutral bioelectricity as an alternative energy fuel for Generation of carbon neutral bioelectricity as an alternative energy fuel for

the sustainable environment using wastewater as substratethe sustainable environment using wastewater as substrate………………Green Green and renewable energyand renewable energy

Different organic wastewaters (ranging from domestic to industrial) as Different organic wastewaters (ranging from domestic to industrial) as renewable energy resourcesrenewable energy resources…… …… sustainable developmentsustainable development

Simultaneous wastewater treatmentSimultaneous wastewater treatment… … dual benefitdual benefit

Developing an economically feasible design using low cost materials Developing an economically feasible design using low cost materials (electrodes, PEM, substrate, etc.)(electrodes, PEM, substrate, etc.)

Non-catalyzed electrodes and mediator-less reactorsNon-catalyzed electrodes and mediator-less reactors… … Economic viabilityEconomic viability

Mixed anaerobic consortia as the biocatalystMixed anaerobic consortia as the biocatalyst…. Practical application…. Practical application

Optimization and understanding process parameters during MFC operationOptimization and understanding process parameters during MFC operation Investigation of the anodic redox conditions optimum for electron transfer Analysis of microbial diversity by PCR-DGGEAnalysis of microbial diversity by PCR-DGGE

Schematic Schematic overviewoverview of work of work

AcronymsMFC Microbial fuel cell

PEM Proton exchange membrane

OCV Open circuit voltage

AC Aerated catholyte

FC Ferricynide catholyte

ED Electron discharge

CV Cyclic voltammetry

TDS Total dissolve solvents

DSW Designed synthetic wastewater

CW Chemical wastewater

OLR Organic loading rate

PDB Partially developed biofilm

FDB Fully developed biofilm

DGGE Denaturing gradient gel electrophoresis

Anodic BiocatalystsAnodic Biocatalysts

Characteristics of the wastewaters used as feed

Types of MFC designed and operatedTypes of MFC designed and operated

Single chambered MFCsSingle chambered MFCsDual chambered Dual chambered MFCsMFCs

Bioelectrochemical behavior of by Bioelectrochemical behavior of by Prokaryotic Prokaryotic andand Eukaryotic Eukaryotic

Evaluation of yeast biofuel cell by CV Evaluation of yeast biofuel cell by CV

at different feed pH and OLRat different feed pH and OLREvaluation of prokaryotic biofuel Evaluation of prokaryotic biofuel

cell by CV cell by CV

Cyclic voltammetry profiles generated during stabilized phase of biofuel cell operation at Cyclic voltammetry profiles generated during stabilized phase of biofuel cell operation at variable experimental conditions (0th – black; 16th – blue; 24th – green; 36th – megentha; variable experimental conditions (0th – black; 16th – blue; 24th – green; 36th – megentha; 54th – brown)54th – brown)

Voltage (open circuit) and (b) current generated during the operation of MFC at different feeding Voltage (open circuit) and (b) current generated during the operation of MFC at different feeding pH values and organic loading rates (OLR I, 0.91 kg COD/m3-day; OLR II, 1.43 Kg COD/ m3-day) pH values and organic loading rates (OLR I, 0.91 kg COD/m3-day; OLR II, 1.43 Kg COD/ m3-day) with the function of timewith the function of time

Bioelectricity generation by Bioelectricity generation by Prokaryotic Prokaryotic andand EukaryoticEukaryotic

Open circuit voltage during the operation of MFC Open circuit voltage during the operation of MFC with the function of time (Mixed culture (MFCwith the function of time (Mixed culture (MFCMM); );

Pseudomonas aeruginosaPseudomonas aeruginosa (MFC (MFCPP); ); Escherichia coliEscherichia coli

(MFC(MFCEE) ) Shewanella putrefaciens Shewanella putrefaciens (MFC(MFCSS) and ) and

Aeromonas hydrophilaAeromonas hydrophila (MFC (MFCAA))

Evaluation Evaluation MFC configurationMFC configuration with mixed culture with mixed culture and wastewater and wastewater

Three types of catholytesThree types of catholytesFerricyanide (Double chamber)Ferricyanide (Double chamber)Aerated (Double chamber)Aerated (Double chamber)Open-air cathode (Single chamber)Open-air cathode (Single chamber)

Among these ferricyanide having higher efficiency Among these ferricyanide having higher efficiency with respect to power…. with respect to power…. But not eco-friendly. But not eco-friendly.

Double chamber configuration requires higher reactor Double chamber configuration requires higher reactor volume. volume.

Even though less power generation in single chamber Even though less power generation in single chamber compared to double chamber…..compared to double chamber…..

Economically more feasibleEconomically more feasibleSimilar substrate degradationSimilar substrate degradationAdvantages in up scaling the technologyAdvantages in up scaling the technology

Open circuit voltage and current Open circuit voltage and current variation during MFC operation using variation during MFC operation using ferricyanide and aerated catholytesferricyanide and aerated catholytes

Dual chamber operationDual chamber operation

Single chamber operationSingle chamber operation

Polarization curvePolarization curve

Influence of Influence of anodic pH anodic pH on MFC performanceon MFC performance

Acidophilic pH operation Acidophilic pH operation documented highest current output documented highest current output (5.18 mA (100 Ω); 0.632 V; 3.27 (5.18 mA (100 Ω); 0.632 V; 3.27 mW) with MFCmW) with MFCFCFC ,(4.26 mA; 0.578 ,(4.26 mA; 0.578

V; 2.46 mW) with MFCV; 2.46 mW) with MFCACAC and 339 and 339

mV, 1.66 mA with open air cathode.mV, 1.66 mA with open air cathode.

Alternative materialAlternative material to PEM to PEM

The experiments depict replacing Nafion117 with glass wool and cellulose The experiments depict replacing Nafion117 with glass wool and cellulose material as proton exchange membrane which is cost effective and utilizing material as proton exchange membrane which is cost effective and utilizing wastewater as substrate for wastewater as substrate for in situin situ power generation power generation

Function of various types of proton Function of various types of proton exchange membranes studiedexchange membranes studied

Treatment of Cellulosic material Treatment of Cellulosic material

Plant based cellulosic material prepared and Plant based cellulosic material prepared and used as a PEM in MFCused as a PEM in MFC

OCV during operation of MFC with the function of time and treatmentsOCV during operation of MFC with the function of time and treatments

MFC with 0.75M HMFC with 0.75M H22SOSO44 treated treated

cellulose membrane (CM) as cellulose membrane (CM) as PEM showed maximum OCV PEM showed maximum OCV (334 mV) and current (1.37 mA (334 mV) and current (1.37 mA at 100 Ω)at 100 Ω)

Biofilm growth on anodeBiofilm growth on anode influencing MFC influencing MFC performanceperformance

Influences the direct electron Influences the direct electron transfertransfer

Age of the biofilmAge of the biofilm

Biofilm growth EnvironmentBiofilm growth Environment

Electron discharge and power Electron discharge and power generationgeneration

SEM images of the biofilm developed on anodeSEM images of the biofilm developed on anode

The biofilm formed on the anode was subjected to scanning electron microscopy (SEM). a) PDB and b) FDB on graphite anode

aa bb

Electrochemical influence of bio-augmentation Electrochemical influence of bio-augmentation on MFCon MFC

Pseudomonas auriginosaPseudomonas auriginosa

Aeromonas Aeromonas hydrophilahydrophila

E.coliE.coli

CV of anode generated from MFCCV of anode generated from MFCPP, MFC, MFCM M and MFCand MFCE E fuel cell operations using fuel cell operations using

Ag/AgCl as reference electrode(Block- 0Ag/AgCl as reference electrode(Block- 0thth h ,Pink - 12 h ,Pink - 12th ,th ,Cyan - 24Cyan - 24thth , Blue -36 , Blue -36thth and and Brown - 48Brown - 48thth ) )

Shewanella putrifiecienceShewanella putrifiecience

Before augmentation equal electron discharge (ED) (1.04± 0.16 mA). Higher ED (11.73 mA) Before augmentation equal electron discharge (ED) (1.04± 0.16 mA). Higher ED (11.73 mA) was observed with was observed with S. PutrificiensS. Putrificiens augmented system augmented system followed by followed by P. aeruginosaP. aeruginosa e (8.42 mA), e (8.42 mA), A .hydrophila A .hydrophila (6.32 mA) and (6.32 mA) and E. coliE. coli (3.17 mA) in the CV (3.17 mA) in the CV

Performance of fuel cell with bio-augmentationPerformance of fuel cell with bio-augmentation

Open circuit voltage during the operation of MFCOpen circuit voltage during the operation of MFC

P. aeruginosaP. aeruginosa augmented system yielded higher power output (OCV, 418 mV; 3.87 augmented system yielded higher power output (OCV, 418 mV; 3.87 mA at 100 Ω) followed by mA at 100 Ω) followed by S. putrifiencs S. putrifiencs (OCV, 378 mV; 2.73 mA at 100 Ω) and (OCV, 378 mV; 2.73 mA at 100 Ω) and A. A. hydrophilahydrophila (OCV, 296 mV; 2.26 mA at 100 Ω). (OCV, 296 mV; 2.26 mA at 100 Ω). E.coliE.coli augmented system registered augmented system registered lower power generation (OCV, 216 mV; 1.76 mA at 100 Ω).lower power generation (OCV, 216 mV; 1.76 mA at 100 Ω).

Bioaugmented strains traced by fluorescent Bioaugmented strains traced by fluorescent molecular probingmolecular probing

Survival of augmented strains was traced by FISH technique Survival of augmented strains was traced by FISH technique using cy3 labeled fluorescent probes which was important pre-using cy3 labeled fluorescent probes which was important pre-

requisite for success of bioaugmentationrequisite for success of bioaugmentation

Microbial Diversity analysisMicrobial Diversity analysis

Phylogenetic sequence affiliation and similarity to the closet relative of Phylogenetic sequence affiliation and similarity to the closet relative of amplified 16 rDNA sequence excised from DGGE gels observed dual and amplified 16 rDNA sequence excised from DGGE gels observed dual and single chamber MFCssingle chamber MFCs

DGGE was performed by the PCR amplified product of 16S rDNA at DGGE was performed by the PCR amplified product of 16S rDNA at variable V3 region using universal primers (341F, 517R) for both dual and variable V3 region using universal primers (341F, 517R) for both dual and single chamber MFC.single chamber MFC.

Phylogenetic treePhylogenetic treeSequences were submitted to the Nucleotide Sequence Database to the GeneBank Sequences were submitted to the Nucleotide Sequence Database to the GeneBank public database under the accession numbers from FR670602 to FR670610. public database under the accession numbers from FR670602 to FR670610.

The phylogenetic distribution showed significant diversity in microbial The phylogenetic distribution showed significant diversity in microbial communitycommunity..

Neighbor-joining trees constructed using Neighbor-joining trees constructed using Mega 4.0 from MFCMega 4.0 from MFCDCDC to closely related to closely related

sequences from Gene Banksequences from Gene Bank

Neighbor-joining trees constructed using Neighbor-joining trees constructed using Mega 4.0 from MFCMega 4.0 from MFCSCSC to closely related to closely related

sequences from Gene Banksequences from Gene Bank

MFC function as BMFC function as Bio-electrochemical treatment io-electrochemical treatment systemsystem apart from power generation apart from power generation

Performance of MFC as BETPerformance of MFC as BET

ConclusionsConclusions

• MFC operated with mixed culture was more MFC operated with mixed culture was more effective in power generation, wastewater effective in power generation, wastewater treatment and industrial applicabilitytreatment and industrial applicability

• Performance of MFC influenced byPerformance of MFC influenced by– Reactor configuration (Double and Reactor configuration (Double and

Single chamber)Single chamber)– Operating conditions (pH, Organic Operating conditions (pH, Organic

loading rate, waste composition)loading rate, waste composition)

• Bio-electrochemical treatment was achieved in MFC due to Bio-electrochemical treatment was achieved in MFC due to in situin situ bio- bio-potential of MFCpotential of MFC

• Anodic biofilm development and bioaugmentation strategies were used to Anodic biofilm development and bioaugmentation strategies were used to enhance the electron transfer from bacterial cell to electrodeenhance the electron transfer from bacterial cell to electrode

• The study evaluate the different operational parameters required for The study evaluate the different operational parameters required for optimizing towards scaling up of bioelectricity by MFC optimizing towards scaling up of bioelectricity by MFC

• MFC was opportunistic source for alternative fuel for future generations MFC was opportunistic source for alternative fuel for future generations

Publications from the reported workPublications from the reported work

1. Veer Raghavulu S., Suresh Babu P., Kannaiah Goud R., Srikanth S., Venkata Mohan S. Bioaugmentation of electrochemically active strain to enhance the electron discharge of mixed culture: Process evaluation through

electro-kinetic analysis. Journal of RSC Advances , 2012, 2, 677-688

2. Veer Raghavulu, S., Sarma, PN., Venkata Mohan, S., Bioelectrochemical behavior of Pseudomonas

aeruginosa and Escherichia coli with the function of anaerobic consortia during biofuel cell operation. Journal of Applied Microbiology, 2011. 110, 666–674

3. Venkata Mohan, S., Veer Raghavulu, S., Goud, RK., Sarma, PN. Microbial diversity analysis of

long term operated biofilm configured anaerobic reactor producing hydrogen from wastewater under diverse conditions. International Journal of Hydrogen Energy, 2010. 35, 12208-12215

4. Veer Raghavulu, S., Venkata Mohan, S., Goud, RK., Sarma, PN. Saccharomyces cerviceae as anodic biocatalyst in non-catalyzed aerated biofuel cell: influence of redox condition andsubstrate load on power generation.

Bioresource Technology, 2011. 102, 2751-2757

5. Veer Raghavulu, S., Venkata Mohan, S., Reddy, MV., Sarma, PN. Behavior of single chambered mediatorless microbial fuel cell (MFC) at acidophilic, neutral and alkaline microenvironments during chemical wastewater treatment.

International Journal of Hydrogen Energy. 2009. 34, 7547-7554

6. Veer Raghavulu, S., Venkata Mohan, S., Goud, RK., Sarma, PN. Anodic pH microenvironment

influence on microbial fuel cell (MFC) performance in concurrence with aerated and ferricyanide catholytes. Electrochemical Communications. 2009. 11, 371-375

7. Venkata Mohan, S., Veer Raghavulu, S., Dinakar, P., Sarma, PN. Integrated function of microbial fuel cell (MFC) as bio-electrochemical treatment system associated with bioelectricity generation under higher substrate load.

Biosensors and Bioelectronics. 2009. 24, 2021-2027

8. Venkata Mohan, S., Veer Raghavulu, S., Sarma, PN. Influence of anodic biofilm growth on bioelectricity

production in single chambered mediatorless microbial fuel cell using mixed anaerobic consortia. Biosensors and Bioelectronics. 2009 24, 41-47

9. Venkata Mohan, S., Srikanth, S., Veer Raghavulu, S., Mohanakrishna, G., Kiran Kumar, A., Sarma, PN. Evaluation of the potential of various aquatic eco-systems in harnessing bioelectricity through benthic

fuel cell: Effect of electrode assembly and water characteristics. Bioresource Technology. 2009. 100, 2240–2246

Publications from the reported workPublications from the reported work

10. Venkata Mohan, S., Veer Raghavulu, S.,Sarma, PN. Biochemical evaluation of bioelectricity production process from anaerobic wastewater treatment in a single chambered microbial fuel cell (MFC) employing glass wool

membrane. Biosensors and Bioelectronics. 2008 23, 1326-32.

11. Venkata Mohan, S., Sarvanan, R., Veer Raghavulu, S., Mohankrishna, G., Sarma PN. Bioelectricity production from wastewater treatment in dual chambered microbial fuel cell (MFC) using selectively enriched mixed

microflora: Effect of catholyte. Bioresource Technology.2008. 99(3), 596-603

12. Venkata Mohan, S., Veer Raghavulu, S., Srikanth, S., Sarma, PN. Bioelectricity production by

meditorless microbial fuel cell (MFC) under acidophilic condition using wastewater as substrate: influence of substrate loading rate. Current Science. 2007. 92(12), 1720-1726

Publications from the reported workPublications from the reported work

1. Min-Kyu Ji, Veer Raghavulu S, Hyun-Shik Y,Reda A.I, Jaeyoung C, Wontae Le, Thomas C. Timmes, Inamuddin, Byong-Hun Jeon. Simultaneous nutrient removal and lipid

production from pretreated piggery wastewater by Chlorella vulgaris YSW-04 Applied Microbiology and Biotechnology 2012 (Accepted)

2. Venkata Mohan, S., Veer Raghavulu, S., Mohanakrishna, G., Srikanth, S., Sarma, PN. Optimization and evaluation of fermentative hydrogen production and wastewater treatment processes

using data enveloping analysis (DEA) and Taguchi design of experimental (DOE) methodology. International Journal of Hydrogen Energy. 2009. 34, 216-226

3. Reddy, BS., Reddy, BP., Veer Raghavulu, S., Ramakrishna, S., Venkateswarlu, Y., Diwan, PV. Evaluation of antioxidant and antimicrobial properties of Soymida febrifuga leaf extracts. Phytotherapy Research. 2008 22 (7), 943-947

4. Venkata Mohan, S., Mohanakrishna, G., Veer Raghavulu, S., Sarma, PN. Enhancing biohydrogen production from chemical wastewater treatment in anaerobic sequencing batchbiofilm reactor

(AnSBBR) by bioaugmenting with selectively enriched kanamycin resistant anaerobic mixed consortia. International Journal of Hydrogen Energy. 2007. 32, 3284–3292

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