Project report on Microbial Fuel Cell

8/15/2019 Project report on Microbial Fuel Cell

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ENERGY RECOVERY FROM SEWAGE SLUDGE USING

MICROBIAL FUEL CELL TECHNOLOGY

A PROJECT REPORT

Submi tted by

ASWINI.K 421612103017

DHINESHKUMAR.V 421612103025

DHIVYA.R 421612103026

HEMANATHAN.T 421612103038

I n partial ful f il lment of the requirement for the award of the degree

of

BACHELOR OF ENGINEERING

IN

CIVIL ENGINEERING

MAILAM ENGINEERING COLLEGE

MAILAM 604 304

ANNA UNIVERSITY: CHENNAI 600 025

APRIL 2016



ANNA UNIVERSITY: CHENNAI 600 025

BONAFIDE CERTIFICATE

Certified that this project report “ENERGY RECOVERY FROM SEWAGE

SLUDGE USING MICROBIAL FUEL CELL TECHNOLOGY” is the

bonafide work of “ASWINI.K, DHIVYA.R, DHINESHKUMAR.V,

HEMANATHAN.T” who carried out the project under my supervision.

SIGNATURE SIGNATURE

Dr. S.SUNDARARAMAN. Dr. S.SUNDARARAMAN.

HEAD OF THE DEPARTMENT SUPERVISOR

Department of Civil Engineering, HEAD OF THE DEPARTMENT

Mailam Engineering College, Department of Civil Engineering,

Mailam. Mailam Engineering College,

Mailam.

Submitted for the main project viva-voce examination held on 12 - 04 - 2016

INTERNAL EXAMINER EXTERNAL EXAMINER



ACKNOWLEDGEMENT

We wish to record our sincere thanks to our Chairman Er.M.DHANASEKARAN,

and Vice Chairman Er. S.V.SUGUMARAN for giving facilities to undertake this

project.

We are grateful to our Principal Dr. S. SENTHIL, for his kind support for the

Design Project.

We are grateful to our Dean Dr. R.RAJAPPAN, for his kind support for the main

Project.

We find no words to express our immense pleasure in thanking especially our Head

of the Department Dr.S.SUNDARARAMAN, M.Tech.,Ph.D. for providing the

foundation and support to carry out this main Projects successfully in all aspects.

We thank our Guide Dr.S.SUNDARARAMAN, M.Tech.,Ph.D.., for his valuable

suggestion and guidance, with patient and pleasure on this great deal of work.

We express our heart full of thanks to our Department staff members for their

valuable guidance through-out in completion of the main Project successfully.

‘Last but not least’ we also express our sincere thanks to our beloved PARENTS

for their moral and financial support for doing this main Project.



ABSTRACT

Energy and waste management are two crisis that world is facing nowadays. A

Microbial fuel cells (MFC) is a collective solution of these two crisis. MFC

converts energy of chemical bond of biodegradable compound into electricity

with the help of microorganisms. MFC technology has very wide range of

applications but very recent researches are more focused on wastewater

treatment and biosensor technology.

There are many types of MFCs are made but among all those 2-chamber H-

type MFC is used in study because it is best for preliminary experimental

purpose. The anoxic anode chamber is connected internally to the cathode

chamber via a proton exchange membrane with the circuit completed by an

external wire.

The project report presents experimental setup construction, setup run

prerequisites and results. In whole project we are aiming to check maximum

generated Voltage, Current and Power and treatability of anaerobic sewage

sludge and review of benefits of MFC technology for wastewater treatment and

simultaneous energy generation. The report presents the study done to

understand various aspects of design and operation of MFC and how it is

implemented to make an experimental setup of MFC as well as feasibility and

benefits of MFC technology for wastewater treatment with electricity

generation.



TABLE OF CONTENTS

CHAPTER TITLE PAGE NO.

NO: ABSTRACT i

LIST OF FIGURES v

LIST OF TABLE vii

LIST OF FLOW CHART viii

1. INTRODUCTION

1.1 GENERAL 1

1.2 ENERGY FROM SEWAGE

TREATMENT PLANTS 1

1.3 SCOPE OF THE PROJECT 5

1.4 OBJECTIVES OF THE PROJECT 6

2. LITERATURE RIVEW

2.1 GENERAL 72.2 MICROBIAL FUEL CELL (MFC) 12

2.3 CLASSIFICATION OF MFC 12

2.4 WORKING PRINCIPLE 20

2.5 ADVANTAGES AND LIMITATIONS 21

2.6 SCOPE FOR FUTURE STUDY 27

3.

MATERIALS AND METHODLOGY

3.1 GENERAL 29

3.2 COMPONENTS OF MFC 29

3.3 EXPERIMENTAL SETUP 31

3.5 MONITORING AND ANALYSIS 34

4. RESULTS AND DISCUSSIONS

4.1 GENERAL 38

iii





LIST OF FIGURES

FIG NO. TITLE PAGE NO.

1.

CEA-MFC design. 12

2.

Double Chamber-MFC design 13

Working of Microbial Fuel Cell 21

3. MFC-1 experimental setup 31

4.

MFC-2 experimental setup day 1 33

5.

MFC-2 experimental setup day 6 33

6.

Voltage generated on Day 1 39

7. Voltage generated on Day 2 40

8.





11.

Maximum Voltage generated fromDay 1- 6. 43

12. Current generated on Day 1 44

13.

Current generated on Day 2 44

14.


15. Current generated on Day 4 45

16.

Current generated on Day 5 4617.


18.

Maximum Current generated from

Day 1- 6. 47

19.

Power generated on Day 1 48

20.


21.


v



22. Power generated on Day 4 49

23.


24.


25.

Maximum power generated from

Day 1- 6. 51

26.

proposed model for AD with MFC 63

vi



LIST OF TABLES

TABLE NO. TITLE PAGE NO.

1.

Types of Substrate and Microbes that can be used in MFC. 19

2.

Characteristics to be determined from the substrate 35

3. Characteristics of sludge sample in MFC-2 38

4. Maximum Voltage generated from day 1-6. 43

5.

Maximum Current from day 1-6 48

6.

Maximum Power generated from Day1- 6 53

7. Initial parameters of anaerobic sludge 55

8. Characteristics of sewage sludge on day 1 56

9.

Characteristics of sewage sludge on day 2 56

10.


11. Characteristics of sewage sludge on day 4 57

12.

Characteristics of sewage sludge on day 5 5813.


Vii



LIST OF FLOWCHART

TABLE NO. TITLE PAGE NO.

1.

Maximum Voltage generated from 43

Day 1- 6.

2. Maximum Current generated from 47

Day 1- 6.

3.

Maximum power generated from 49

Day 1- 6.

Viii



LIST OF SYMBOLS

Sl.no abbreviations words

1 µ Micro

2 0C Degree Centigrade

3 CEA Cloth electrode assembly

4 ETC Electron transport chain

5 TSS Total suspended solids

6 A Ampere

7 BOD Biological oxygen demand

8 C.S.A Cross sectional area

9 cm centimetres

10 COD Chemical oxygen demand

11 KCl Potassium chloride

12 Kg Kilogram

13 L Litre

14 M molarity

15 MFC Microbial fuel cell

16 ml Millilitre

17 NaCl Sodium chloride

18 PEM Proton exchange membrane

19 V Voltage

20 W watt



1

CHAPTER 1

INTRODUCTION

1.1 GENERAL

While the world population is growing, energy and water resources are

becoming limited. An additional challenge associated with population

growth is the increase in wastewater generation and environmental

pollution. While water scarcity and energy demand are continuously

increasing in the world, alternative sources are needed to meet the

requirement of a growing population. Microbial Fuel Cell (MFC) is a

sustainable technology that converts organic matter in wastewater into

electricity, thus it can be a potential alternative source for water and energy.

Although significant studies in MFC research have been accomplished in

the last few years, improvement in power generation and decrease in

material cost are still necessary to bring MFC into Practical application.

The main goal of this work is to contribute in making MFC more applicablein industrial and municipal facilities, and to evaluate its scaling up for real

world application.

1.2 ENERGY FROM SEWAGE TREATMENT PLANTS:

However, wastewater itself is intrinsically rich in energy, estimated to have

an energy content greater than the energy necessary to treat it.

Approximately 66% of this energy is stored in sludge, following treatment

and further developing technologies capable of extracting energy from the

organic material in sludge is key to decreasing external energy demands

and overall treatment costs of wastewater treatment. Energy usage of

wastewater treatment plants (WWTP) can range from 0.4 to 1.4 kWh m-3.

While there are many technologies capable of extracting energy from

sludge to offset this energy demand, anaerobic digestion has seen the most

widespread application [12, 28].Anaerobic digesters are able to convert



2

about 28% of the energy potential of the biodegradable organics in

wastewater to electricity through generation and subsequent combustion of

CH4 biogas, meeting roughly a quarter to almost half the energy needs of

an average WWTP [28]. Though anaerobic digestion is a proven

technology, significant energy reserves are left unrecovered, and effluent

standards are not met necessitating secondary processes such as aeration.

Further developing nascent wastewater technologies with the potential for

increased energy efficiency can greatly decrease wastewater treatment

costs.

Anaerobic digestion (AD) is a well-developed technology to generate

biogas (mainly methane) from organic wastes through a series of microbial

reactions. It has an established performance and is considered as an

effective approach for wastes-to-energy. AD is a well-developed and

practiced technology and AD can handle high strength wastewater at a

loading rate of 10-20 kg COD/ (m3 day) [28]. Biogas is difficult to storeand needs to be treated because of components such as H2S and Conversion

of biogas to electricity requires an additional step and is at an efficiency of

conventional combustion, and The effluent of AD still contains high

organic contents and requires post-treatment and some previous studies and

others’ have f ound that MFCs can improve biodegradation of organics,

even some refractory compounds and MFCs can be diversified with new

functions such as hydrogen production, desalination, and heavy metal

removal.

Microbial fuel cells (MFCs) are a new technology to directly produce

electricity from organic wastes. MFCs are bio-electrochemical reactors in

which bacteria oxidize various organic or inorganic compounds in the

anode chamber and generate proton and electrons that transport to the



3

cathode to reduce oxygen to water. Electron flow from the anode to the

cathode generates an electric current or power if a load is connected

advantages of MFCs include that Direct generation of electricity; no

additional conversion step is require and MFCs can be operated at

temperatures below 20 ºC, and are efficient at low substrate concentration

levels, in terms of both electricity generation and organic removal

Microbial fuel cells (MFCs) are able to the convert the potential energy of

a wide range of organics directly into electricity. Various sludge types were

tested directly in MFCs, including raw sludge, primary sludge, digested

sludge from anaerobic digesters and membrane bioreactors, as well as a

mixture of primary sludge with primary effluent. However, columbic

efficiencies were low and volumetric power densities observed were a

small fraction of what is achievable in MFC systems [32]. Poor

performance can be partly attributed to low concentrations of dissolved

organics and well as inefficient reactor design. In order to improve MFC

power generation from sludge treatment, various sludge pre-treatment procedures have been explored to increase dissolved organic

concentrations, including sonication, sterilization, and basification,

Ozonation, the use of microwaves, and fermentation. Fermentation was not

only highly effective at solubilizing organics, but less energy intensive than

other pre-treatment processes. The power density of a fermented sludge

supernatant/primary effluent solution is much higher than that without the

fermented sludge pre-treatment. However adding phosphate buffer to

fermented sludge solutions doubled or tripled power densities, indicating

that lowering the internal resistance of MFC would be key for further

increasing the power generation from pre-treated sludge. A novel cloth

electrode assembly (CEA) MFC has recently demonstrated high power

while operated in both batch and continuous flow modes.[15] Therefore

this design and its associated community has the potential to generate high





5

1.3 SCOPE OF THE PROJECT

The scope of this project is to take ideas being generated in current research on

microbial fuel cells and apply them to produce a fully functional prototype thatcould potentially be used commercially. This project focuses on engineering

design and optimization of the fuel cells, while meeting specified objectives.

The scope of the project lies within its technology and its applications. In this

project a detailed study and evaluation is done on treatability of wastewater

(anaerobic sludge) with simultaneous electricity production.

1. Microbial Fuel Cell is a promising technology for wastewater

treatment that almost 80% than conventional treatment in removal of

heavy metal.

2. Microbial fuel cell is capability of producing direct electricity from

organic compounds with the help of microorganism.

3. Microbial Fuel Cell can produce Hydrogen as fuel and which is said

to be a future fuel. And these hydrogen will end up on combustion as

water which is even more eco-friendly.

4. Unlike chemical fuel cell, MFC does not require complex systems or

devices in its process of producing energy.

5. Availability of raw material- This technology uses microbes as raw

materials that are abundant.

6. Biosensor- Apart from the mentioned applications, another potential

application of the MFC technology is to use it as a sensor for pollutant

analysis and in situ process monitoring and control.



6

1.4 OBJECTIVES OF THE PROJECT

Because of the complexity of this project it is important to fulfil very basic

objectives like producing electricity and efficiency in reducing COD of

wastewater. Objectives are defined in that manner.

1. To analyse the characteristics of Substrate i.e. Anaerobic sludge chosen

for the present study.

2.

To find the Maximum voltage generated from the chosen substrate (i.e.)Secondary Sewage sludge using Microbial Fuel Cell.

3. To determine the Maximum current generated from Secondary sewage

sludge by Microbial Fuel Cell.

4.

To calculate the Maximum power generated from the produced voltageand current in Microbial Fuel Cell using Secondary Sewage Sludge as

substrate.

5. To study the monitoring parameters such as COD, TSS, VSS removal at

outlet of Microbial Fuel Cell after six days of continuous operation.

6.

To propose a feasible method for anaerobic sludge treatment with more

energy recovery than from conventional anaerobic digester.



7

CHAPTER 2

LITERATURE REVIEW

2.1 GENERAL

In this chapter literature review of this project is carried out from various books,

reference, journals, and from several websites. The brief discussion of the

project is presented below in this project.

2.1.2 Bruce E. Logan, et al, (2010), observed that the Microbial fuel cell

(MFC) research is a rapidly evolving field that lacks established terminology

and methods for the analysis of system performance. This makes it difficult for

researchers to compare devices on an equivalent basis. The construction and

analysis of MFCs requires knowledge of different scientific and engineering

fields, ranging from microbiology and electrochemistry to materials and

environmental engineering. Describing MFC systems therefore involves an

understanding of these different scientific and engineering principles. In this

paper, we provide a review of the different materials and methods used to

construct MFCs, techniques used to analyse system performance, and

recommendations on what information to include in MFC studies and the most

useful ways to present results.

2.1.3 Zhuwei Du, Haoran Li, Tingyue Gu (2011) observes that a microbial

fuel cell (MFC) is a bioreactor that converts chemical energy in the chemical

bonds in organic compounds to electrical energy through catalytic reactions of

microorganisms under anaerobic conditions. It has been known for many years

that it is possible to generate electricity directly by using bacteria to break down

organic substrates. The recent energy crisis has reinvigorated interests in MFCs

among academic researchers as a way to generate electric power or hydrogen

from biomass without a net carbon emission into the ecosystem. MFCs can also

be used in wastewater treatment facilities to break down organic matters. They

have also been studied for applications as biosensors such as sensors for



8

biological oxygen demand monitoring. Power output and Columbic efficiency

are significantly affected by the types of microbe in the anodic chamber of an

MFC, configuration of the MFC and operating conditions. Currently, real-

world applications of MFCs are limited because of their low power density

level of several thousand mW/m2. Efforts are being made to improve the

performance and reduce the construction and operating costs of MFCs.

2.1.4 M.M. Ghangrekar and V.B. Shinde (2011) observes that While treating

sewage, particularly in small capacity treatment plant recovery of methane may

not be attractive, because most of the methane produced in the reactor is lost

through effluent of the reactor. The methane concentration of about 16 mg/L

(equivalent COD 64 mg/L) is expected in the effluent of the reactor due to high

partial pressure of methane gas inside the reactor1. Hence, while treating low

strength wastewater major fraction of the methane gas may be lost through

effluents, reducing the energy recovery. In addition, due to global

environmental concerns and energy insecurity, there is emergent interest to find

out sustainable and clean energy source with minimal or zero use of

hydrocarbons. Electricity can be produced in different types of power plant

systems, batteries or fuel cells. Bacteria can be used to catalyse the conversion

of organic matter into electricity.

2.1.5 Mostafa Rahimnejad, et al, (2011) observes that Microbial fuel cells

(MFCs) are biochemical-catalyzed systems in which electricity is produced by

oxidizing biodegradable organic matters in presence of either bacteria or

enzyme. This system can serve as a device for generating clean energy and,

also wastewater treatment unit. The performance of MFC was analysed by the

measurement of polarization curve and cyclic voltammetry data as well. Closed

circuit voltage was obtained using a 1 kohm resistance. The voltage at steady-

state condition was 440 mV and it was stable for the entire operation time. In a

continuous system, the effect of hydraulic retention time (HRT) on

performance of MFC was examined. The optimum HRT was found to be



9

around 7 h. Maximum produced power and current density at optimum HRT

were 1210 mA m-2 and 283 mWm-2, respectively. As aforementioned, MFCs

can potentially be used for different applications. When used in wastewater

treatment, a large surface area is needed for biofilm to build up on the anode.

A breakthrough is needed in creating inexpensive electrodes that resist fouling.

It is unrealistic to expect that the power density output from an MFC to match

that of conventional chemical fuel cell such as a hydrogen-powered fuel cell.

The fuel in an MFC is often a rather dilute biomass (as in wastewater treatment)

in the anodic chamber that has a limited energy (reflected by its BOD). Another

limitation is the inherent naturally low catalytic rate of the microbes. Even at

their fastest growth rate microbes are relatively slow transformers. Although

Columbic efficiency over 90% has been achieved in some cases, it has little

effect on the crucial problem of low reaction rate.

2.1.6 Katalin Belafi-Bako, et al, (2012) observed that the anaerobic sludge

applied in the anodic cell was pre-treated prior to usage, as it was reported. The

MFC was placed in a thermo stated container, where the liquids in both cells

were possible to circulate and stir. In the cathodic cell air was entered

continuously by a pump to ensure aerobic environment, while N2 was spangled

through the anodic cell to assure the anaerobic conditions. The MFC reactor

was initially inoculated with the pre-treated anaerobic sludge. Then the

microbial consortia started to operate in the cell and they were allowed to adapt

the actual conditions and colonise locally. To follow the processes various

analytical methods: pH, total solid substance (TSS), COD were applied. COD

values of the samples taken from the cells were determined by the potassium

dichromate method, which is based on the following oxidation reaction in

acidic environment as it can be seen remarkable TSS and COD decrease could

be observed during the processes, while electric power was generated

continuously.



10

2.1.7 Zheng Ge, Fei Zhang, Julien Grimaud, Jim Hurst, (2014) observes

that Sewage sludge is a by-product of municipal wastewater treatment and

generated from primary and secondary sedimentation. In municipal wastewater

treatment plants, the treatment and disposal of sewage sludge can comprise up

to 50% of the operation costs .There are several approaches for treating sludge

to reduce solid contents and to stabilize biomass; however, anaerobic digestion

(AD) is generally preferred because of its cost-effectiveness and bioenergy

production. Digested sludge can be further composted for agriculture uses, and

biogas can be converted into electricity and/or heat through combustion and

thus compensate for some energy use in a wastewater treatment plant. Because

of a large amount of organic contents, primary sludge contains about 66% of

the energy content of wastewater, and about 81% of biodegradable organic

energy may be converted to methane. Despite the great energy potential with

biogas production, several issues limit successful methane-to-electricity is

about 33%. Therefore, it is of great interest to explore alternative technologies

for sludge treatment and energy recovery. Electricity can be generated directlyfrom sludge. The amount of current increases when a readily biodegradable

substrate is added, indicating that the current is related to degradation of this

organic (acetate), and that it is microbially mediated. Based on several different

analytical techniques, there is no accumulation of a surface film of Geobacter

or other microorganisms.

2.1.8 Based on Materials and Methodology

Logan et al., (2013) used acetate as their source for power generation, having

concentration of 1g/L. They used pre acclimated bacteria from MFC and cube

shaped single chamber MFC having graphite fiber brush anode. The maximum

current density generated was 0.8 mA/cm2. (12)



11

Catal et al., (2014) used arbitol as one of the substrate for single chamber, air-

cathode microbial fuel cell, producing current density of 0.68 mA/cm2. They

used pre acclimated bacteria from MFC (13)

Dumas et al., (2014) used sodium fumarate and G.sulferreducens for his

stainless steel cathode based MFC and succeeded in producing current density

of 2.05 mA/cm2. (14)

Luo et al. (2008) used phenol of concentration 400mg/ml for his two chamber

and air cathode MFC. He successfully produced current density of 0.1 mA/cm2.

2.1.9 S.K. Dentel et al. (2004) observe that recently it has been shown that

electrical energy can be harvested from marine sediments, simply by

connection of an electrode (anode) in anaerobic marine sediments to an

electrode in the aerobic zone above the sediments. We have now shown that

similar applications are available in sludge treatment. Using a reactor with

graphite foil electrodes in an aerated aerobic and anaerobic sludge zone,

electrical current was generated, and enhanced when an additional organicsubstrate (acetate) was added. Electron microscopy, x-ray diffraction, and PCR

examination of the anode surface showed no surface colonization and no

increase in Geo-bacterrelative to a control, indicating that microbial use of the

anode as an electron acceptor was indirect through the use of redox mediators.

2.1.10 Based on Experiment with complex substrates

Rodrigo et al. (2007) used real urban waste water of concentration of

330mg/ml in two chamber MFC and successfully generated current density of

0.018 mW/cm2. (17)

Oh and Logan (2005) used Food processing waste water for two chamber

MFC, having graphite electrode and generated a current density of 0.05

mW/cm2. (18)



12

2.2 Microbial Fuel Cell (MFC)

A Microbial Fuel Cell or biological fuel cell is a bio-electrochemical system

that drives an electric current with degradation by using microbes. They can be

served for several purposes and their application in energy production and

waste treatment have attracted researchers in recent years thus it’s a promising

technology to address the future energy crisis and waste treatment.

2.3 CLASSIFICATION OF MICROBIAL FUEL CELL

2.3.1 SINGLE CHAMBER

In single chamber MFC, anode and cathode are in the same chamber but on

opposite sides. A higher power density is obtained with single chamber

MFC compared to two chamber system due to a decrease in internal

resistance. Single – chamber MFCs have also the advantage of being less

expensive and simpler than double-chamber MFC [19]. (CEA) MFC is a

single-chamber MFC where anode and cathode are separated by cloth layer

(Figure 1.2). The minimum distance between the two electrodes reduces

internal resistance and consequently, increases power production.

Figure 3.1: Schematic diagram of CEA-MFC design.



13

2.3.2. DOUBLE CHAMBER

In two-chamber MFCs, anode and cathode chambers are separated by a

membrane or salt bridge. The oxidant at the cathode could be ferric cyanide

or permanganate or others [28] Oxygen could be used as well but it is less

efficient and requires energy for air spangling. Two-chamber MFCs are not

much sustainable due to the need of oxidant refilling in the cathode

chamber but though double chamber is one that well suited for studies on

laboratory scales.

Figure 3.2: Schematic diagram of Double Chamber-MFC design

2.3.3 MATERIALS

The need for wider application and increase power output of MFCs has

resulted to the alteration of the essential physical components of MFCs

which includes the anode, cathode and proton exchange membrane. The

following are various materials and components of Microbial Fuel Cell.



14

2.3.4 ANODE CHAMBER

In the Anode chamber, Electricigens which are active bacteria oxidize the

substrate to generate electrons and protons, and transport the electrons to the

anode electrode surface to form biofilm [19, 26]. These electrons travel to the

cathode through the external circuit while the protons travel to the cathode by

diffusing through the electrolyte and exchange membrane. And the electrodes

on anode chamber sometimes remains the same as one on cathode chamber and

some of anodic electrodes are Graphite anodes are the most abundantly used

one and its cost is also low. They are porous metal, therefore graphite anodes

used for MFC are pre-treated with oil or wax to prevent internal pores

deterioration by mechanical & chemical action on anode that cause softening

& swelling, oiling and waxing results in reduced penetration of the electrolyte

and increased mechanical strength [41]. Carbon paper and carbon cloths are

also used, mainly for the lab-scale study of current generations. In this present

study Anode chamber was designed to 500ml volume and the anode electrode

was chosen as carbon cloth electrode. The cathode chamber was maintained

anaerobic and air tight chamber and by which methanogen activity reduces the

results, a head space of 5cm maintained for gaseous collection. And thus only

300 ml of sample is taken for study.

2.3.5 CATHODE CHAMBER

The protons on passing to the cathode chamber forms water by combining

with the electrons and oxygen, with the aid of catalyst. The oxidant at the

cathode could be ferric cyanide or permanganate or others. Oxygen could

be used as well and requires energy for air spangling. And cathode

electrodes are as follows Cathode materials- Cathode are usually made up

of platinum, major concern is the optimization of MFC design in order to

maximize power output and reducing installation and operation costs

simultaneously. The cost of the Platinum catalyst used at the cathode is a



15

major limitation to MFC application and economic viability. On the

Concept of bio-cathodes that would use bacteria instead of Platinum as a

biocatalyst at the cathode. Sometime same anode and cathode materials are

used in the construction of MFC. The electrodes are made from carbon

rods, inert metals can also be used, metals such as copper, iron, zinc,

aluminium etc… Should be avoided as they may give rise to spurious

generation of current from electrochemical dissolution of the metal [18].

Solar energy can serve as an alternative energy source for MFC operation

proposed the concept of a ‘living solar cell’ in which the green alga

Chlamydomonas reinhardtii produces hydrogen photo synthetically which

in turn is oxidized in situ to produce current. In this present study cathode

chamber was designed as similar to anode chamber of 500ml and cathode

electrode of carbon cloth electrode coated with platinum is used where

platinum act as catalyst.

2.3.6 PROTON EXCHANGE MEMBRANE (PEM)

The Proton exchange membrane permits the passage of protons to the

cathode chamber. Nafion-117 a type of PEM developed for optimum

transport of proton generated in the anode chamber to the cathode chamber

due to its selectivity. Nafion-117 is expensive resulting to increase in unit

cost of MFC. The design of a cheaper PEM has been reported to me a major

factor to improve the unit cost of MFC [8]. PEM in some cases is called

CEM based on the fact that it allows for the transfer of other ions like Na+,

K+, NH4 +, Ca2+, and Mg2+ apart from proton. These competitive

transfers has been noted to inhibit proton transport through PEM including

the Nafion-117 And even salt bridge can be used as a proton exchange

membrane. In this present study Nafion-117 is chosen as Proton exchange

membrane and even a salt bridge of agarose and 1MKCl is tested for

economical evaluation of Microbial Fuel Cell.



16

2.3.7 SALT BRIDGE PREPARATION

Salt bridge is made of agar + salt. 100ml of distil water is taken in 250ml beaker

and put on the heating at 80°C, now 0.1g KCl is added as a salt and dissolved.

Provide continuous stirring and add 5 g agar slowly until the viscosity of the

solution rich to solidify. Cotton plugs are placed to the two side opening of the

salt bridge casing pipe and solution is immediately poured. Let it be until the

agar salt bridge is solidified completely. For 2 to 3 hours. Now salt bridge is

ready for operation.

2.3.8 ELECTRODE MATERIALS

Research has shown that the selection of material such as substrate, anode

and cathode electrode for MFC has a major effect on the efficiency of the

MFC [28]. The material affect key parameters of columbic efficiency (CE)

(the ratio of total electrons recovered as current, to maximum possible

electrons if all substrate removal produced current) .The basic properties

of the MFC electrode include biocompatibility, conductivity, non-

corrosive and surface area. Many materials that have found application as

electrode in MFCs include carbon paper, cloth, foam, and felt; graphite

rod, foil, brush and granules, activated carbon, reticulated vitreous carbon,;

metals, aluminium, nickel and stainless steel Carbon felt, platinum,

graphite-ceramic composite, cobalt, ash cement composite [9, 18, 20]. In

this present study anode with carbon cloth electrode and cathode with

carbon cloth electrode coated with platinum where platinum act as a

catalyst were taken for study.

2.3.9 SUBSTRATES

Substrate used for Electricity Generation Substrate is a key factor for

efficient production of electricity from a MFC. Substrate spectrum used

for electricity generation ranges from simple to complex mixture of

organic matter present in wastewater. Although substrate rich in complex



17

organic content helps in growth but simple substrates considered to be

good for immediate productive output. Acetate and Glucose are most

preferred substrate for basic MFC operations and electricity generation.

Ligno cellulosic biomass from agriculture residues are a good source for

electricity production in MFC. Another promising and most preferred

unusual substrate used in MFCs operations for power generation is

Brewery wastewater as it is supplemented with growth promoting organic

matter and devoid of inhibitory substances. Starch processing water can

be used to develop microbial consortium in MFC. Cellulose and Chitin

(from industrial and municipal wastewater), Synthetic or Chemical

wastewater, Dye wastewater and Landfill leachates are some

unconventional substrates used for electricity production via MFCs [23].

And anaerobic sludge from anaerobic digester is taken for the study which

was collected from a Sewage Treatment Plant in Nesapakkam , Tamilnadu

and stored in container at -10 C in order to ensure that no biological activity

to be happen before testing the samples.

2.3.10 MICROORGANISMS IN A MICROBIAL FUEL CELL

Microorganisms in the MFC breakdown organic or and inorganic substrates in

the anode chamber to produce and transfer electrons to an electrode surface,

this biochemical reaction generates proton also which migrate to the cathode

and combine with the electron and mainly oxygen as catholyte, which is

reduced at the cathode surface. This produces electricity and metabolizes the

wastewater which is mainly the MFC fuel, microbes acting as a catalyst on the

anode surface. Brevibacillus sp. found in abundant member of a MFC

community. Power production by Brevibacillus sp. is low unless it is cocultured

with a Pseudomonas sp. or supernatant from a MFC run with the Pseudomonas

sp. is added.



18

The intestinal tract of human and animals have been found to be the major

sources of Salmonella and Escherichia coli in nature [18], which could be shed

in feces. These pathogens may persist for days to weeks to months depending

on the type of pathogen, the medium and the environmental conditions.

Approximately 1% to 3% of all domestic animals are infected with Salmonellae

[12,19]. Furthermore, other nonbacterial pathogens that may be present with

fecal material include protozoa (Cyptosporidium and Giardia) and viruses

(Swine Hepatitis E- virus). The management and disposal of animal wastes

harboring such pathogens can increase the risk of infections and diseases that

threatens human health if these wastes are not properly treated and contained

[20]. Firmicutes and Acidobacteria, Proteobacteria, Saccharomyces cerevisiae,

Hansenula anomala, Shewanella oneidensis, Geothrix fermentans, Rhodoferax

ferrireducens, Proteus vulgaris, Escherichia coli, etc…are some bacteria that

can be used in MFC’s commonly used Microbes in Microbial Fuel Cells

(MFCs) usually mixed culture of microbes is used for anaerobic digestion of

substrate as complex mixed culture permits broad substrate utilization. Butthere are some regular MFCs designs which explore metabolic tendency of

single microbial species to generate electricity. Organic component rich sources

(marine sediment, soil, wastewater, fresh water sediment and activated sludge)

are rich source of microbes that can be used in MFCs catalytic unit [15].

Bacteria used in MFCs with mediator or without mediators have been

extensively studied and reviewed (Table 1). Metal reducing and anodophilic

microorganisms show better opportunities for mediator-less operation of a

MFC.



19

Table 3.1: Types of Substrate and Microbes that can be used in MFC.

Microorganism waste source Aim

Clostridium

acetobutylicum and

Clostridium

thermohydrosulfuricum.

Cellulosic waste Bioelectricity production

Yogurt bacteria and

methylene blue as mediator

Waste carbohydrate

(manure sludge)Bioelectricity production

Pseudomonas putida,

Saccharomyces cerevisiae,

Lactobacillus bulgaricus,

Escherichia coli and

Aspergillus niger

Glucose,

Municipal waste,

Domestic waste

Low Voltage Power

Generation, waste

Treatment

anaerobic mixed consortia Waste water,

Municipal waste,

Industrial waste,

Activated sludge

Bioelectricity production ,

waste Treatment

Mixed population (decay organics)

Industrial waste

Bioelectricity production

Shewanella putre-faciens (starch) Bioelectricity production

and wastewater treatment,

Geobacter sulpfur-reducens (acetate) Bioelectricity production

and waste water treatment

Synechococcus sp. Light as a fuel Bioelectricity production



20

2.4 WORKING PRINCIPLE OF MFC.

MFC explores metabolic potential of microbes for conversion of organic

Substrate into electricity by transferring electrons from cell to circuit. In

anodic chamber, oxidation of substrate in the absence of oxygen by

respiratory bacteria produce electron and proton that are passed onto

Cathode chamber terminal e- acceptor [O2, nitrate or Fe (III)] through

electron transport chain (ETC) [28]. However, in absence of e- acceptor in

a MFC, some microorganisms pass electron onto anode. An efficient

electron shuttle to anode can be achieved either by a spontaneous (direct)

or by means of some electron shuttling mediators. Direct electron transfer

to anode by bacteria requires some physical contact with electrode for

current generation. Line up between bacteria and anode surface involves

outer membrane bound cytochromes or putative conductive pili called

nanowires. Numbers of electron and proton fabricated depends upon

substrate utilized by microbes. Mediator-less MFCs have more commercial

potential as mediators are expensive and are sometimes toxic to

microorganisms. Electrode reactions in a MFC compartments are as

follows:

The reactions occurring at the anode and cathode are the following:

Anode: C6H12O6 + 6H2O 6CO2 +24H

+

+ 24e

-

Cathode: O2 + 4H+ + 4e- 2H2O

If Acetate is used as substrate

Anodic reaction: CH3COO- + H2O → 2CO2+ 2H+ + 8e-

Cathode reaction: O2 +4e- +4H+ → 2H2O



21

If sucrose is used as substrate

Anodic reaction: C12H22O11 + 13H2O → 12CO2 + 48H+ + 48e-

Cathode reaction: O2 + 4e- + 4H- → 2H2O

Fig.3.3 Diagrammatic representation of Working of Microbial Fuel Cell

2.5 ADVANTAGES AND LIMITATIONS

2.5.1 ADVANTAGES:

Wastewater Treatment and Electricity Generation

Due to unique metabolic assets of microbes, variety of microorganisms are

used in MFCs either single species or consortia. Some substrates (sanitary

wastes, food processing wastewater) are exceptionally loaded with organic

matter that itself feed wide range of microbes used in MFCs. MFCs using

certain microbes have a special ability to remove sulphides as required in





23

microbial consortium that can metabolize both an insoluble electron donor

(cellulose) and electron acceptor (electrode) [32]. The pure culture alone

could not produce any electricity from these substrates.

Biosensors

MFCs with replaceable anaerobic consortium could be used as a biosensor

for on-line monitoring of organic matter. Though diverse conventional

methods are used to calculate organic content in term of biological oxygen

demand (BOD) in wastewater, most of them are unsuitable for on-line

monitoring and control of biological wastewater treatment processes. A

linear correlation between Columbic yield of MFC and strength of organic

matter in wastewater makes MFC a possible BOD sensor [32]. Columbic

yield of MFC provides an idea about BOD of liquid stream that proves to

be an accurate method to measure BOD value at quite wide concentration

range of organic matter in waste water.

Generation of Energy Out of Bio-waste/Organic Matter

This feature is certainly the most ‘green’ aspect of microbial fuel cells.

Electricity is being generated in a direct way from bio wastes and organic

matter. This energy can be used for operation of the waste treatment plant, or

sold to the energy market. Furthermore, the generated current can be used to

produce hydrogen gas. Since waste flows are often variable, a temporarystorage of the energy in the form of hydrogen, as a buffer, can be desirable.

Direct Conversion of Substrate Energy to Electricity

As previously reported, in anaerobic processes the yield of high value

electrical energy is only one third of the input energy during the thermal

combustion of the biogas. While recuperation of energy can be obtained by

heat exchange, the overall effective yield still remains of the order of 30%.



24

2.5.2 LIMITATIONS

Low power density

The major limitations to implementation of MFCs for are their power density

is still relatively low and the technology is only in the laboratory phase. Based

on the potential difference, ΔE, between the electron donor and acceptor, a

maximum potential of nearly 1V can be expected in MFCs, which is not much

greater than the 0.7 V that is currently being produced [19]. However, by

linking several MFCs together, the voltage can be increased. Current and power

densities are lower than what is theoretically possible, and system performance

varies considerably. The maximum power density reported in the literature,

3600mW/m2, was observed in a dual-chamber fuel cell treating glucose with

an adapted anaerobic consortium in the anode chamber and a continuously

aerated cathode chamber containing an electrolyte solution that was formulated

to improve oxygen transfer to cathode

High Initial Cost:

A limiting factor to general MFC use is the high cost of materials, such as the

Nafion-117 membrane commonly used in laboratories as a proton permeable

membrane. Attempts are currently underway to produce low cost MFCs

constructed from earthen pots for use in India. By removing the proton

permeable membrane, utilizing locally produced 400 ml earthen pots, stainless

steel mesh cathodes and a graphite plate anode, each MFC unit could be

produced for INR 80. The earthen pot MFCs used sewerage sludge as an initial

inoculum and experiments were conducted using acetate as a carbon source.

While producing low levels of power, these devices could potentially be

incorporated in large numbers into oxidation ponds for the treatment of

concentrated wastewater while generating power. In areas where off grid

applications are required, even low power MFC devices may prove useful.

Current applications are all limited to low power level devices.



25

Up-scaling problems

Scale-up of microbial fuel cells (MFCs) will require a better understanding of

the effects of reactor architecture and operation mode on volumetric power

densities. We compared the performance of a smaller MFC (MFC, 28mL) with

a larger MFC (MFC, 520mL) in fed-batch mode. The SMFC produced

14Wm−3, consistent with previous reports for this reactor with an electrode

spacing of 4 cm. The MFC produced 16Wm−3, resulting from the lower average

electrode spacing (2.6 cm) and the higher anode surface area per volume

(150m2 m−3 vs. 25m2m−3 for the MFC). The effect of the larger anode surface

area on power was shown to be relatively insignificant by adding graphite

granules or using graphite fiber brushes in the MFC anode chamber [18].

Although the granules and graphite brushes increased the surface area. The

maximum power density in the MFC was only increased by 8% and these

results demonstrate that power output. can be maintained during reactor scale-

up; increasing the anode surface area and biofilm formation on the cathode do

not greatly affect reactor performance,1. Several aspects needed for an efficient MFC are hampering up-

scaling.

2.

The influent needs to reach the whole anode matrix sufficiently.

3.

Protons need rapid diffusion towards the membrane.

4. Sufficient electrical contact needs to be established between

bacteria in suspension and the anode.

5.

Sufficient voltage needs to be reached over the MFC to have a

useful power.

6.

Instatement of an aeration device should be avoided.

Activation Losses:

Due to the activation energy needed for an oxidation/reduction reaction,

activation losses (or activation polarization) occur during the transfer of



26

electrons from or to a compound reacting at the electrode surface. This

compound can be present at the bacterial surface, as a mediator in the solution,

or as the final electron acceptor reacting at the cathode. Activation losses often

show a strong increase at low currents and steadily increase when current

density increases. Low activation losses can be achieved by increasing the

electrode surface area, improving electrode catalysis, increasing the operating

temperature, and through the establishment of an enriched biofilm on the

electrode(s).

Ohmic Losses.

The ohmic losses (or ohmic polarization) in an MFC include both the resistance

to the flow of electrons through the electrodes and interconnections, and the

resistance to the flow of ions through the CEM (if present) and the anodic and

cathodic electrolytes. Ohmic losses can be reduced by minimizing the electrode

spacing, using a membrane with a low resistivity, checking thoroughly all

contacts, and (if practical) increasing solution conductivity to the maximumtolerated by the bacteria.

Bacterial Metabolic Losses:

To generate metabolic energy, bacteria transport electrons from a substrate at a

low potential through the electron transport chain to the final electron acceptor

(such as oxygen or nitrate) at a higher potential. In an MFC, the anode is the

final electron acceptorandits potential determines the energy gain for the

bacteria. The higher the difference between the redox potential of the substrate

and the anode potential, the higher the possible metabolic energy gain for the

bacteria, but the lower the maximum attainable MFC voltage. To maximize the

MFC voltage, therefore, the potential of the anode should be kept as low

(negative) as possible. However, if the anode potential becomes too low,



27

electron transport will be inhibitedandfermentation of the substrate (if possible)

may provide greater energy for the microorganisms.

Concentration Losses.

Concentration losses (or concentration polarization) occur when the rate of

mass transport of a species to or from the electrode limits current production.

Concentration losses occur mainly at high current densities due to limited mass

transfer of chemical species by diffusion to the electrode surface. At the anode

concentration losses are caused by either a limited discharge of oxidized

species from the electrode surface or a limited supply of reduced species toward

the electrode. This increases the ratio between the oxidized and the reduced

species at the electrode surface which can produce an increase in the electrode

potential. At the cathode side the reverse may occur, causing a drop in cathode

potential. In poorly mixed systems diffusional gradients may also arise in the

bulk liquid. Mass transport limitations in the bulk fluid can limit the substrate

flux to the biofilm, which is a separate type of concentration loss. By recording polarization curves, the onset of concentration losses can be determined.

2.6 SCOPE FOR FURTHER STUDY

The study and development of MFC is still in initial phase. The fabricated MFC

has produced satisfying amount of voltage, though there is wide scope for

development of MFCs in terms of design and power output as for now the

power density is too low for their use in automobiles, electronic devices,

medical appliances and other industrial applications. Modification in design

components will provide improved results. High quality substrates can be used

in MFC that can provide high power to run electrical appliances. The

microorganisms which supply electrons can be modified genetically to provide

more efficient electron transfer to electrodes. Optimizing the process

parameters involved production of electricity can be increased. It is the matter



28

of proper electrodes, salt bridge, volume of anode chamber and an appropriate

resistance to produce high power. Since the use of catalyzed electrodes have

added most of the cost of fabrication and maintenance, different innovations

like bio cathodes can be applied as a substitute. High quality proton exchange

membranes can effectively increase the ion exchange without hindrance in the

electricity production. Nanoparticles may be incorporated in salt bridge,

cathode chamber or anode chamber which might boost up the output values.

Which might help to find the rate of reactions responsible for maximum and

minimum values of the observed parameters.

The advances in Microbial Fuel Cell may lead to production of secondary fuel

that can drive our fuel crisis and thus on further study can brighten our future

with all prosperity.



29

CHAPTER 3

MATERIALS AND METHODOLOGY

3.1 GENERAL

Microbial Fuel Cell is custom designed to meet the requirements. A Microbial

Fuel Cell or biological fuel cell is a bio-electrochemical system that drives an

electric current with degradation by using microbes. They can be served for

several purposes and their application in energy production and waste treatment

have attracted researchers in recent years thus it’s a promising technology to

address the future energy crisis and waste treatment. The following are the

individual components of MFC designed for evaluation in this present study.

3.2. COMPONENTS OF MFC

3.2.1 Anode Chamber

The anode chamber is the anaerobic chamber which contains an inlet and

outlet provision and the anode chamber is filled with the substrate or

wastewater with microorganism. As a laboratory scale we intended to

design an anode chamber with a volume of 500ml. A head space of 5cm is

taken to control the methanogen activity that might affect the performance.

3.2.2 Cathode Chamber

The cathode chamber is an aerated chamber which is kept open or provided

with external air through air Spangler. External oxygen serves as an

electron acceptor which will readily accept the electrons from anode

chamber and combine with protons to form water. Cathode chamber was

designed as same as anode chamber with a volume of 500 ml with outlet

valves and provisions for aeration.



30

3.2.3 Proton exchange membrane

Proton exchange membrane act as a membrane that transport protons from

anode chamber to cathode chamber. Both the anode and cathode chamber

have contact with the proton exchange membrane. Effective transport of

protons from anode to cathode is to be accomplished so for an effective

working thus a proton exchange membrane Nafion-117 is bought from

Sainergy Fuel Cell India ltd, as to fit the designed the anode and cathode

chamber. And a salt bridge is prepared to construct a natural proton

exchange membrane with agarose and Potassium chloride in a PVC pipe to

investigate the performance and to make membrane economical for

practical application of Microbial Fuel Cell

3.2.4 Anode and Cathode Electrodes

Electrodes have been chosen with immense study on previous literatures.

Greater the surface area of electrodes greater is the results and thus we

decided to choose an electrode with greater surface area and bought carbon

cloth electrode from Sainergy Fuel Cell India ltd, and also Gaphite rod

electrode from Schutz Carbon Electrode pvt ltd in rder study the

performance of both electrodes.

3.2.5 SUBSTRATE:

Sewage sludge was collected from the anaerobic digester in Nesapakkam

sewage treatment plant, Tamilnadu, and The sludge was collected sampling

containers and stored in -10 C such that there is no much of metabolism take

place, before experiments sludge is fermented in the dark at 32 ± 2 ºC after

purging with nitrogen gas for 10 minutes. Samples were collected at 0, 48, 72,

144 hours, centrifuged at 4000 rpm for 20 minutes, filtered, and adjusted to pH

7.0 using NaOH for MFC experiments.



31

3.3 EXPERIMENTAL SETUP

In order to evaluate the performances of MFC. Two experimental set-up was

constructed in which MFC-1 with Graphite rods and Salt Bridge with agarose

and 1MKCl and was constructed to study the possibility of Current generation

and not for evaluation purpose but to propose an economical prototype for

marketing. Another MFC-2 with CEA (Cloth electrode assembly) and PEM

(proton exchange membrane) which is taken for evaluation.

3.3.1 MFC-1

Setup is designed to state the cost-effective basic design, keeping in mind that

the project is the initial efforts to reveal the potential of the MFC technology

for wastewater treatment. Setup is to be constructed in acrylic plastic with the

silicone as sealant.

It was really necessary to gain considerable output even at very first attempt,

volume of MFC is decided to be 500 millilitres each chamber. Dimensions are

determined such that the electrodes and inlet outlet can be positioned. From theliterature survey, solid graphite electrodes are found cheap at the same time

efficient as well.

Fig: 3.3 Photographic view showing MFC-1 experimental setup.



32

Anaerobic chamber has a lid arrangement to completely seal the chamber so

that anaerobic system can be maintained. Lid is having provisions for inlet of

wastewater and electrode wire and sealed with silicone paste after placing feed

pipe and wire. For the removal of wastewater outlet is given at the bottom.

Aerobic chamber is open and have air springer and electrode.

3.3.2 MFC-2 (CEA- MFC)

Setup is designed to state the basic design of a double chamber Microbial Fuel

Cell, keeping in mind that the project is the initial efforts to reveal the potential

of the MFC technology for wastewater treatment. Setup is to be constructed

from inert material avoid inhibition of microbial activity. For that purpose

material of construction in Peli-glass laser cutted with the gaskets and end

plates bolted with bolts and wing nuts.

It was really necessary to gain considerable output even at very first attempt,

volume of MFC is decided to be 500 millilitres each chamber. Dimensions are

determined such that the electrodes and inlet outlet can be positioned. Carbon

cloth electrode at anode and carbon cloth electrode coated with platinum as

catalyst at cathode chamber. Both the anode and cathode chamber are separated

by proton exchange membrane called Nafion-117.

Anaerobic chamber has gasket arrangement to completely seal the chamber so

that anaerobic system can be maintained. Lid is having holes for pouring

wastewater and electrode wire. But sealed with silicone plunge after placing

feed pipe and wire. For the removal of wastewater pneumatic outlet is given at

the bottom of anode and cathode chamber.

Aerobic chamber is open and have air springer and electrode.

The anode and cathode chambers are connected using end plates with gaskets

bolted with wing nuts so as to ensure air tight and from leakages.



33

Fig 3.4 Photographic view showing MFC-2 Experimental setup at day 1

Fig 3.5 Photographic view showing MFC-2 Experimental setup at day 6



34

3.3.3 OPERATING PH AND TEMPERATURE

During the operation pH is maintained at 7.0 ± 0.5. Decrease in pH will

reduce the output voltage. Whole project experimentation is carried out at

room temperature i.e. 25 ± 5 °C.

3.3.4 MAXIMIZING PERFORMANCE

For a maximized performance of MFCs, readily available soluble COD is also

required. This demands solutions for the pre-treatment of the organics to be

used as fuel for bacteria, provided a considerable fraction is not readily

biodegradable. In addition to that, better proton selective membranes, optimum

mass transfer and better cathodes are also needed to overcome factors limiting

MFC performance. Whether to use a membrane or not is now under discussion.

To improve the cathodic performance, some metal oxides combined with

carbon [7, 16,18] or some special materials, such as fullerenes, are proposed as

good candidates for the construction of the cathode.

3.4 MONITORING AND ANALYSIS

3.4.1 MONITORING OF MFCS

The current (I) in the MFC circuit was monitored at 24hr intervals using

multimeter for 6 days continuously with daily feed as 50mg of sample and

added to it .The samples were drawn from the chambers at 0, 48, 72, 144 hours,

centrifuged at 4000 rpm for 20 minutes, filtered, and adjusted to pH 7.0 using

NaOH for MFC experiments [17]. And analysed for the variation of wastewater

characteristics. Analytical procedures followed were those outlined in Standard

Methods for the examination of water and wastewater characteristics (1995).



35

3.4.2 ANALYSIS

Influent and effluent samples were analyzed for chemical oxygen demand

(COD), pH, dissolve oxygen (DO), alkalinity, total dissolved solids (TDS) at

0, 48, 72, 144 hours for biochemical oxygen demand (BOD), Suspended solids

(SS) and Volatile suspended solids (VSS) in the influent and effluent . And the

potential and current and power were measured using a digital multimeter daily.

Table represents the characteristics to be determined in finding treatability of

sewage sludge and procedures are as follows,

Table 3.3: Characteristics to be determined from the substrate

Sr.

No.

Testes to be performed Apparatus

1. COD by open reflux method COD apparatus & Glassware

3. PH PH Paper

4. Volatile suspended Solids With filter paper and oven

5. Total Solids With filter paper and oven

1. CHEMICAL OXYGEN DEMAND (COD)

Most of the organic matters are destroyed when boiled with a mixture

of potassium dichromate and sulphuric acid producing carbon dioxide and

water. A sample is refluxed with a known amount of potassium dichromate insulphuric acid medium and the excess of dichromate is titrate against ferrous

ammonium sulphate. The amount of dichromate consumed is proportional to

the oxygen required to oxidize the oxidizable organic matter [21].

Procedure

Place 0.4g HgSO4 in a reflux tube. Add 20ml or an aliquot sample diluted to

20 ml with distilled water. Mix well, so that chlorides are converted into poorly

ionized mercuric chloride. Add 10ml standard K 2Cr 2O7 solution and then add



36

slowly 30 ml sulphuric acid which already containing silver sulphate. Mix well,

if the colour turns green, take a fresh sample with smaller aliquot. Final

concentration of concentrated H2SO4 should always 18N.

Connect the tubes to condenser and reflux for 2 h at 150oC. Cool and wash

down the condensers with 60ml distilled water. Cool and titrate against

standard ferrous ammonium sulphate using ferroin as indicator. Near the end

point of the titration color changes sharply from green blue to wine red. Reflux

blank simultaneously with the sample under identical conditions.

Calculation

COD, mg/l = (V1-V2)*N*8000 / V0

Where,

V1 = volume of Fe (NH4)2 (SO4)2 required for titration against the blank, in ml;

V2 = volume of Fe (NH4)2(SO4)2 required for titration against the sample, in ml;

N = Normality of Fe (NH4)2(SO4)2;

V0 = volume of sample taken for testing, in ml.

2. Total Suspended Solids (TSS)

Principle:-

A well-mixed sample is filtered through a weighed standard glass-fiber filter

and the residue retained on the filter is dried to a constant weight at 103 to

105°C. The increase in weight of the filter represents the total suspended solids.

If the suspended material clogs the filter and prolongs filtration, it may be

necessary to increase the diameter of the filter or decrease the sample volume.

To obtain an estimate of total suspended solids, calculate the difference

between total dissolved solids and total solids.

Calculation:-



37

Total Suspended Solids, mg/L = (A – B) x 1,000,000/ C

Where: A = final weight of filter + residue in grams

B = final weight of filter in grams

C = mL of sample filtered

3. Volatile Suspended Solids

If VSS is to be determined, carry the TSS blanks and necessary duplicates

through the VSS analysis. To perform VSS, place the TSS filter aluminum pans

(including method blank and duplicate(s)) in a furnace at 550ºC for 15 minutes

using a timer, place them in a desiccator for at least 35 minutes, and weigh

filters individually. Record this weight in a separate logbook for VSS.

Volatile Suspended Solids, mg/L = (A – B) x 1,000,000 / C

Where: A = final weight from TSS analysis

B = final weight of filter after firing

C = mL of sample filtered



38

CHAPTER 4

RESULTS AND DISCUSSION

4.1 GENERAL

The following are the experimental results taken in laboratory on Microbial

Fuel Cell. The microbial fuel cell working for six continuous days is evaluated

are three set of results 1.To determine the initial characteristics of the sewage

sludge sample 2. Evaluating for maximum voltage, maximum current,

maximum generated power and 3. Treatability parameters using Analytical

procedures followed as outlined in Standard Methods for the examination of

water and wastewater characteristics (1995).

4.2 THE INITIAL CHARACTERISTICS OF SUBSTRATE

Sewage sludge was collected from the anaerobic digester in Nesapakkam

sewage treatment plant, Tamilnadu, and the sludge is fermented in the dark at

32 ± 2 ºC after purging with nitrogen gas for 10 minutes. Samples were

collected at 0, 48, 144 hours, centrifuged at 4000 rpm for 20 minutes, filtered,

and adjusted to pH 7.0 using NaOH for MFC experiment and initial analysis of

sludge given as input in Microbial Fuel Cell is tested for several characteristics

and as follows,

Table 4.1: characteristics of sludge sample in MFC-2

SI. No Characteristics MFC-2

1 PH 7

2 Colour Greyish

3 Total Suspended solids (g/L) 6.9 ± 2

4 Volatile Suspended Solids (g/L) 6.1 ± 2

5 COD (g/L)16.7 ± 7

4.3 EVALUATION OF ELECTICITY GENERATION





40

metabolism and thus the voltage increase is gradual and after few hours there

is a decrease in voltage which shows that metabolism by microorganism is not

immediate and it’s a slow process.

2. Amount of voltage generated on day-2

Fig: 4.2 Voltage generated on Day 2

On second day of operation there is gradual increase in voltage which at a point

of stage tends to achieve a peak of 0.52V and all of sudden falls down with

0.4V, this reduction in voltage is may be due to inactivity of microorganism or

inadequate substrate for microorganism. And all of sudden there is a sudden

increment in voltage from 0.45V to 0.52V and thereafter there is a gradual

increase in voltage. A maximum of 0.53V is noted on day-2.

Compared to first day there in a decrease in voltage is seen through there is a

increase for few hours and again they occurs a decrease in voltage which in

turn responsible for more power.






42

On fourth day there is gradual increase in voltage from 0.35V to 0.6v and there

is decrement in voltage which may due to slow in metabolism and hence a 0.1

gm. of glucose is added as a source of carbon and then there is an increment is

noticeable.


Fig: 4.5 Voltage generated on Day 5

On fifth day its noted that there is abrupt increase in voltage and this increase

in voltage shown that the anaerobic microorganism have good growth in the

anaerobic chamber and metabolism is so increasing in turn increases voltage.

There might be an increase in voltage due to complex degradation of COD is

achieved and it is easy to degrade simple organic compounds which will

generate more electrons to flow. And a maximum voltage of 0.80v is recorded.



43


Fig 4.6 Voltage generated on Day 6.

On day-6 there is a gradual decrease in voltage which indicates that there is no

more substrate for metabolism and thus there is a decrease in voltage, when a

substrate is added to it we noted an increase in voltage once again. And a

maximum of about 0.60V is obtained in day-6

TABLE 4.2: Maximum Voltage generated from day 1-6.

DAY MAX.VOLTAGE (V)1 0.458

2 0.524

3 0.533

4 0.67

5 0.804

60.553



44

Fig: 4.7 Maximum Voltage generated from Day 1- 6.

Generated voltage

Voltage generated by anaerobic sludge using double chamber MFC was

recorded at an interval of 1&1/2 Hr per day for the entire time period of 6

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.45

0.50

0.55

0.60

0.65

0.70

0.75

0.80

0.85

1 2 3 4 5 6

DAYS

1 2 3 4 5 6

DAYS



45

days as shown in Fig 4-9. The maximum generated voltage in each of the six

days is depicted in Table 3. It is observed that there was a definitive increase

in the generated voltage from day 1 to day 5 and then a decline in trend is

observed on day 6. The maximum generated voltage at day 5 was 0.804V

and the minimum generated voltage of 0.478 V was observed on day 1. The

voltage measured was open circuit voltage since the external resistance is not

used.

4.3.2 Current generated in an open circuit

1. Amount of current generated on day-1

TIME (HOURS)

Fig 4.8 Current generated on Day 1

0 5 10 15 20 25

0.003

0.004

0.005

0.006

0.007

0.008



46

1.2. Amount of current generated on day-2


TIME (HOURS)

Fig 4.10: Current generated on Day 3

0 5 10 15 20 25

0.000

0.002

0.004

0.006

0.008

0.010



47

On third day of operation there is increase in current and with hour the current

decreases and attains a steady state and this shows that there is steady

production of electrons in anode chamber without an internal resistance.


Fig 4.11 Current generated on Day 4.

On fourth day of operation there is gradual increase in current and with hour

the current decreases and again increase in current is seen which shows that

there is a fluctuation due to pH of the substrate.


0 5 10 15 20 25

0.000

0.002

0.004

0.006

0.008

0.010

TIME (hours)



48

On fifth day of operation there is gradual increase in current and with hour the

current increases which shows that there is a upstream in current generation

due growth of microorganism and degradation of substrate is maximum.

6. Amount of current generated on day -6

TIME (HOURS)

Fig 4.13: Current generated on Day 6

On sixth day of operation there is gradual increase in current and with hour the

current increases which shows that there is a minimum voltage produced and

hence there is an upstream in current generation which is because of low

internal resistance through open circuit.

Table 4.3 Maximum Current from day 1-6.

DAY MAX.CURRENT (µA)

1 0.008

2 0.0076

3 0.0094

4 0.0097

5 0.0105

6 0.0088

0 5 10 15 20 25

0.0055

0.0060

0.0065

0.0070

0.0075

0.0080

0.0085

0.0090



49

0 1 2 3 4 5 6

DAYS

1 2 3 4 5 6

DAYS

Fig 4.14 Maximum Current generated from Day 1- 6

0.0075

0.0080

0.0085

0.0090

0.0095

0.0100

0.0105

0.000

0.002

0.004

0.006

0.008

0.010



50

Generated current

Current generated by anaerobic sludge using double chamber MFC was

recorded at an interval of 1&1/2 hr per day for the entire time period of 6 days

as shown in Fig 11-16. The maximum generated current in each of the six days

is depicted in Table 4. It is observed that there was a definitive increase in the

generated current from day 1 to day 5 and then a decline in trend is observed

on day 6. The maximum generated current at day 5 was 0.0105µA and the

minimum generated current of 0.076 µA was observed on day 1. The current

measured was open circuit voltage since the external resistance is not used.

Hence the voltage generated was due to internal impedance, which seemed to

be very high in the range of mega ohms.

4.3.3 Power generated in an open circuit

1. Amount of power calculated in day-1

TIME (HOURS)

Fig 4.15: Power generated on Day1

On first day of operation the power generation was gradually increasing as fresh

substrate begins to degrade and microorganism are active in their metabolism.

But there is fluctuation in power due to some ohmic loss and concentration loss

0 5 10 15 20 25

0.0004

0.0006

0.0008

0.0010

0.0012

0.0014

0.0016

0.0018

0.0020

0.0022

0.0024

0.0026



51

and since the circuit is open circuit and hence prone to fluctuations due to

voltage drop.

2. Amount of power calculated on day-2




52

On third day of operation there is decrease in power and with hour the power

increases and attains a steady state and this shows that there is steady

production of electrons from substrate.


On the fourth day of operation there are several peaks and several down streaks

were plotted which might be due to change in pH level which affect the growth

of microbes and decrease the organic content by COD removal.




53

On the fifth day of operation there seen an gradual increase in power generation

and at the end of day there is a slight decrease in power generation which might

be due to temperature change that effect the microorganism and increase in pH

level may cause a fluctuation 6. Amount of power calculated on day-6

On the sixth day of power generation shows that there is a fluctuation in power

and not continuous steady power generation is attained as there will no substrate

present for metabolism and thus no power generation is achieved. In order to

confirm that only due to lack of substrate there is low power 0.1 gm. glucose is

added as substrate after which there is an immediate increase in power.

Table 4.4: Maximum Power generated from Day1- 6

DAY MAX. Power (W)

1 0.002422

2 0.003858

3 0.003715

4 0.003715

5 0.008442

6 0.0067



54

1 2 3 4 5 6

Days

1 2 3 4 5 6

DAYS

Fig 4.21 Maximum generated voltage, current, power from day 1- 6.

The maximum generated voltage, current, power is observed to have

similar characteristics from day 1-6. The pattern of their increase and

decrease are also follows the similar trend. On day 5, all the parameters

measured are observed to have maximum value while on day 1 the

minimum values are obtained except in the case of maximum current

which might be due to high impedance of substrate resulted because of

improper mixing of substrate and water.

0.002

0.003

0.004

0.005

0.006

0.007

0.008

0.009

0.000

0.002

0.004

0.006

0.008



55

4.4 TREATABILITY PARAMETERS

The characteristics of the sludge at initial stages were analysed before

feeding into the microbial fuel cell in order to compare the efficiency of

waste treatment via microbial fuel cell. A sample of waste water is collected

daily at end and tested for Chemical Oxygen Demand, Volatile suspended

solids, Total Suspended Solids, and PH by Analytical procedures followed

as outlined in Standard Methods for the examination of water and wastewater

characteristics (1995).

The following are the Analytic test procedures for testing of characteristics

of wastewater.

4.2.1 Initial characteristics of anaerobic sludge

Anaerobic sludge was collected from a sewage treatment plant in Nesapakkam,

Tamilnadu and fermented for microbial growth and analysed for initial

characteristics. The initial parameters are obtained from the time of sludge

collection form the treatment plant on that week of report.

In order to maintain the microbial growth and control the methanogenic gas

samples were stored in refrigerator at 100.

The initial parameters of the sludge are as follows

Table 4.5 Initial parameters of anaerobic sludge


1 PH 7

2 Colour Greyish



5 COD (g/L)16.7 ± 7



56

4.3 Evaluation on Treatability of Sewage Sludge

1. Characteristics of sludge on day-1

Table 4.6: Characteristics of sewage sludge on day 1


1 PH 7

2 Colour Greyish



5 COD (g/L) 14.2 ± 7

On day one a small amount of COD removal is seen which prove that the

system is working and removal of volatile and total suspended solids show that

mixed culture of microbes is capable of removing substrates like cadmium,

Sulphur, ammonia in wastewater. And on day-1 about 8% COD is removedthough not much power is achieved on day-1 shows microbial activity is

sometimes act on specific organic removal.


Table 4.7: Characteristics of sewage sludge on day-2

SI .No Characteristics MFC-2

1 PH 7

2 Colour Greyish



5 COD (g/L) 12.78 ± 7



57

On the second day of operation there seen a similar characteristics as found

on day-1 with same 7% removal efficiency. Thus though there is not much

power generated through microbial fuel cell there is steady and continuous

efficiency in removal of organic compounds.


Table 4.8: Characteristics of sewage sludge on day 3


1 PH 8

2 Colour Greyish



5 COD (g/L) 11.2 ± 7

On the third day of operation the parameters show that volatile solids were

removed to about only 1% which shows that there is certain bacteria for certain

removal of compounds which were higher at initial stages and later found to be

decreasing. One of most important change in day-3 was there is an increase in

PH level from 7 to 8 was determined.


Table 4.9: Characteristics of sewage sludge on day-4


1 PH 8

2 Colour Greyish



5 COD (g/L) 10.3 ± 7



58

On fourth day of operation the COD removal is attained to 12% and TSS of

10% which once again proves that there is a steady removal of biological

compounds. But VSS removal is limited as there are more complex volatile

substances that are not easily degradable.


Fig 4.10: Characteristics of sewage sludge on day 5


1 PH 8.5

2 Colour Greyish



5 COD (g/L) 9.9 ± 7

On the fifth day of operation the ph level increase from 8 to 8.5 which shows

that the waste becomes more alkaline that on initial stages and COD removal

is removed as on previous days with similar efficiency thus its evident that

COD removal in Microbial Fuel Cell is more efficient that conventional

anaerobic digestion.


Fig 4.11: Characteristics of sewage sludge on day-6


1 PH 9

2 Colour Greyish



5 COD (g/L) 9.2 ± 7





60

Power generated by anaerobic sludge using double chamber MFC was

recorded at an interval of 1&1/2 hr per day for the entire time period of 6 days

as shown in Fig 17-22. The maximum generated current in each of the six days

is depicted in Table 5. It is observed that there was a definitive increase in the

generated voltage from day 1 to day 5 and then a decline in trend is observed

on day 6. The maximum generated current at day 5 was 0.008442µW and the

minimum generated voltage of 0.003853 µW was observed on day 1. The

power measured was open circuit power since the external resistance is not

used.

4. Analysis of COD Removal in MFC.

A Short -term investigation was conducted on the technical performance of

MFCs used to treat sewage sludge. The MFCs satisfactorily reduced of both

organics and suspend solids. About 45% of COD is removed in six days HRT

and TSS of 30% with VSS of 45%.

The total energy production from sewage sludge in the two-stage MFC system

was comparable to that of anaerobic digesters; however, direct electricity

generation had a minor contribution while energy from biogas still dominated

the overall energy production. It will be very challenging to apply MFC

technology to treat primary sludge; but MFCs may be used to polish the

digested effluent from anaerobic digesters, offering potential benefits in energy

savings compared with aerobic treatment.





62

5.2 Proposal for Anaerobic Digester coupled with MFC configuration

5.2.1 GENERAL

Although the MFCs achieved good sludge reduction that is important to sludgetreatment, energy production is a key parameter to evaluate whether MFC

technology is suitable for treating primary sludge, because primary sludge is

usually treated for energy recovery in anaerobic digesters. Energy production

in MFCs, including those treating sludge, has not been properly presented

before. Most prior studies only showed power production, which is not an

energy parameter. In addition, methane production has not been well monitored

in the sludge-fed MFCs. In this study, presented a better picture of energy

production in the sludge-fed MFCs. Although the total energy production in the

two-stage MFC system was comparable to that of anaerobic digesters, we do

not think MFCs are efficient energy producers from primary sludge at this

moment. Our results show that direct production of electric energy has a minor

contribution to the overall energy production, which is still dominated by

methane gas.

The low Electric Currents also confirm that the majority of organic removal

was not associated with direct electricity generation; therefore, the MFCs fed

with the primary sludge act mostly as the ‘‘modified’’ anaerobic digesters.

Thus a proposal for modification of anaerobic digester with MFC configuration

to enhance power and waste treatability in primary sludge or secondary sludge.

This will benefit in much more energy production compared to AD and even

more energy compared to MFC only. Thus a modification in Anaerobic

Digester coupled with MFC configuration can be definite solution for energy

and waste treatment. Fig 7.1 represents the modification of Anaerobic Digester.



63

Fig: 5.1 proposed models for the integration of anaerobic digestion and

Microbial Fuel Cells for the treatment of wastewaters.

A – for domestic wastewater, B- for Industrial and Municipal Wastewater

Note: AD- Anaerobic Digestion, MFC- Microbial Fuel Cell, WTP-

Wastewater Treatment Process

While conventional AD can be applied on an industrial scale to treat high

strength substrates at temperatures above 30°C, the niche applications of MFCs

are to be sought in low concentrated substrates and low temperature

conversions. A number of factors still limit the application spectrum of MFCs.

In order to overcome the limitations of MFCs, making the technology practical

and economically feasible as well as sustainable, the key research and

development features for the future are 1. New materials for better

configurations of MFCs, particularly dry cathodes that have a high affinity to

oxygen and use gaseous oxygen directly from the air; 2. Low capex, meaning

low material costs as well as low operational costs. 3. A reliable output of “non-

commodity” electricity produced by MFCs.



References.

1.

Abhilasha S. M and Sharma V. N., (2009). “Bioelectricity production

from various wastewaters through microbial fuel cell technology”,

Journal of Biochemical Technology, 2(1), pp133-137.

2. Abhilasha S. M and Sharma V.N., (2010). “Treatment of Brewery

Wastewater and production of electricity through Microbial Fuel Cell

Technology”, International Journal of Biotechnology and Biochemistry,

6(1), pp 71 – 80.

3. Aelterman, P. (2009) Microbial fuel cells for the treatment of waste

streams with energy recovery. PhD Thesis, Gent University, Belgium

4.

Ahn Y and Logan B. E., (2010). “Effectiveness of domestic wastewater

treatment using microbial fuel cells at ambient and mesophilic

temperatures”, Bioresource Technology, 101, pp 469– 475.

5.

Behera M., Jana P. S., More T. T., Ghangrekar M. M., (2010). “Rice mill

wastewater treatment in microbial fuel cells fabricated using proton

exchange membrane and earthen pot at different pH”,

Bioelectrochemistry, 79, pp 228 – 233.

6. Bruce E. Logan et al. (2008) “Microbial Fuel Cells: Methodology and

Technology” ENVIRON. SCI. & TECHNOL.

7.

Clauwaert P., Aelterman P., Pham T. H., Schamphelaire L.D., Carballa

M., Rabaey

8. D.Singh, D.Pratap, Y. Baranwal et al. (2010) “Microbial fuel cells: A

green technology for power generation” Annals of Biological Research,

2010, 1 (3):

9.

Deepak Pant *, Gilbert Van Bogaert, Ludo Diels, Karolien

Vanbroekhoven (2009) “A review of the substrates used in microbial



fuel cells (MFCs)for sustainable energy production” Bioresource

Technology

10.

Feng Y., Wang X., Logan B. E., Lee H., (2008). “Brewery wastewater

treatment using aircathode microbial fuel cells”, Applied Microbiology

and Biotechnology, 78, pp 873 – 880.

11.

Freguiac S., Verstraete W., Rabaey K., (2006). “Microbial fuel cells:

methodology and technology”, Environmental Science and Technology,

40(17), pp 5181-5192.

12. Hampannavar U.S , Anupama , Pradeep N.V., (2011) “Treatment of

distillery wastewater using single chamber and double chambered

MFC”, International Journal of Environmental Sciences, Volume 2,

13. Hampannavar U.S and Shivayogimath C.B., (2010). “Anaerobic

treatment of sugar industry wastewater by Upflow anaerobic sludge

blanket reactor at ambient temperature”, International Journal of

Environmental Sciences, 1(4), pp 631 – 639.

14.

http://www.engr.psu.edu/ce/ENVE/logan.htm.15. Huang L and Logan B. E., (2008). “Electricity generation and treatment

of paper recycling wastewater using a microbial fuel cell”, Applied

Microbiology and Biotechnology, 80, pp 349 – 355.

16.

K., Verstraete W., (2008). “Minimizing losses in bioelectrochemical

systems: the road to applications”, Applied Microbiology and

Biotechnology, 79, pp 901 – 913.

17. Kim J. E., Dec J., Bruns M. E., Logan B.E., (2008). “Reduction of Odors

from Swine

18.

Kim J. R., Min, B., Logan B. E., (2005). “Evaluation of procedures to

acclimate a microbial fuel cell for electricity production”, Applied

Microbiology and Biotechnology, 68, pp 23 – 30.

19.

Kubota K., Yoochatchaval W., Yamaguchi T., Syutsubo K., (2010).

“Application of a Single Chamber Microbial Fuel Cell (MFC) for



organic wastewater treatment: Influence of changes in wastewater

composition on the process performance”,

20.

Lefebvre O., AlMamun A., and Ng H. Y., (2008). “A microbial fuel cell

equipped with a biocathode for organic reduction and denitrification”,

Water Science & Technology, 58(4), pp 881885.

21.

Liu H and Logan B. E., (2004). “Electricity Generation Using an Air

Cathode Single Chamber Microbial Fuel Cell in the Presence and

Absence of a Proton Exchange

22. Liu H., Ramnarayanan R., Logan B. E., (2004). “Production of

electricity during wastewater treatment using a single chamber microbial

fuel cell”, Environmental Science and Technology, 38, pp 2281-2285.

23. Logan B. E and Regan J. M., (2006). “Microbial fuel cells challenges

and applications”, Environmental Science and Technology, 40, pp 5172-

5180.

24.

Logan B. E., (2009). “Exoelectrogenic bacteria that power microbial

fuel cells”, Nature Reviews Microbiology, 7, pp 375-381.25. Logan B. E., (2010). “Scaling up microbial fuel cells and other

bioelectrochemical systems”, Applied Microbiology and Biotechnology,

85, pp 1665 – 1671.

26.

Logan B. E., Aelterman P., Hamelers B., Rozendal R., Schroder U.,

Keller J.,

27. Logan B. E., Cheng S., Watson V., Estadt G., (2007). “Graphite Fiber

Brush Anodes for Increased Power Production in Air Cathode Microbial

Fuel Cells”, Environmental Science and Technology, 41, pp 3341-3346.

28.

Logan B.E., (2005). “Simultaneous wastewater treatment and biological

electricity generation”, Water Science & Technology, 52, pp 31– 37.

29.

Luoa H., Liua G., Zhanga R., Jin S., (2009). “Phenol degradation in

microbial fuel cells”, Chemical Engineering Journal, 147, pp 259– 264.

30.

Membrane”, Environmental Science and Technology, 38, pp 4040-

4046.



31. Min B and Logan B. E., (2004). “Continuous Electricity Generation

from Domestic Wastewater and Organic Substrates in a Flat Plate

Microbial Fuel Cell”, Environmental Science and Technology, 38, pp

5809-5814.

32. Mohana S., Bhavik K. A., Madamwar D., (2009). “Distillery spent

wash: Treatment technologies and potential applications”, Journal of

Hazardous Materials, 163, pp 12 – 25

33.

Mohanakrishna G., Venkata Mohan S., Sarma P. N., (2010).

“Bioelectrochemical treatment of distillery wastewater in microbial fuel

cell facilitating decolorization and desalination along with power

generation”, Journal of Hazardous Material, 177, pp 487– 494.

34. Momoh O. L and Naeyor B.A., (2010). “A novel electron acceptor for

microbial fuel cells: Nature of circuit connection on internal resistance”,

Journal of Biochemical Technology, 2(4), pp 216-220.

35.

Pham (2006) “comparison between aerobic and anaerobic”

36.

Rabaey K and Verstraete W., (2005). “Microbial fuel cells: novel biotechnology for energy generation”, Trends in Biotechnology, 23(6),

pp 291-298.

37.

S. Venkata Mohan et al. (2008) “Bioelectricity generation from

chemical wastewater treatment in mediatorless (anode) microbial fuel

cell (MFC) using selectively enriched hydrogen producing mixed culture

under acidophilic microenvironment” Biochemical Engineering Journal

39 (2008) 121 – 130

38.

Standard Methods for Examination of Water and Wastewater, (1995).

19 th Edition. Prepared and Published by American Public Health

Association, American Water Works Association, Water Pollution

Control Federation.

39.

Sustainable Environment Research, 20(6), pp 347351.

40.

Wastewater by Using Microbial Fuel Cells”, Applied and

Environmental Microbiology, 74(8), pp 2540 – 2543.



41. Zhuwei Du, Haoran Li , TingyueGu (2007) “A state of the art review on

microbial fuel cells: A promising technology for wastewater treatment

and bioenergy” Biotechnology Advances 25 (2007) 464– 482

Documents

Project report on Microbial Fuel Cell