Microbial Fuel Cells Book

Preface     xi
Introduction     1
Energy needs     1
Energy and the challenge of global climate change     2
Bioelectricity generation using a microbial fuel cell-the process of electrogenesis     4
MFCs and energy sustainability of the water infrastructure     6
MFC technologies for wastewater treatment     7
Renewable energy generation using MFCs     9
Other applications of MFC technologies     11
Exoelectrogens     12
Introduction     12
Mechanisms of electron transfer     13
MFC studies using known exoelectrogenic strains     18
Community analysis     22
MFCs as tools for studying exoelectrogens     27
Voltage Generation     29
Voltage and current     29
Maximum voltages based on thermodynamic relationships     30
Anode potentials and enzyme potentials     36
Role of communities versus enzymes in setting anode potentials     40
Voltage generation by fermentative bacteria?     41
Power Generation     44
Calculating power     44
Coulombic and energy efficiency     48
Polarization and power density curves     50
Measuring internal resistance     54
Chemical and electrochemical analysis of reactors     57
Materials     61
Finding low-cost, highly efficient materials     61
Anode materials     62
Membranes and separators (and chemical transport through them)     68
Cathode materials     76
Long-term stability of different materials     83
Architecture     85
General requirements     85
Air-cathode MFCs     86
Aqueous cathodes using dissolved oxygen     95
Two-chamber reactors with soluble catholytes or poised potentials     97
Tubular packed bed reactors     102
Stacked MFCs     104
Metal catholytes     105
Biohydrogen MFCs     108
Towards a scalable MFC architecture     110
Kinetics and Mass Transfer     111
Kinetic- or mass transfer-based models?     111
Boundaries on rate constants and bacterial characteristics     112
Maximum power from a monolayer of bacteria     116
Maximum rate of mass transfer to a biofilm     118
Mass transfer per reactor volume     122
MECS for Hydrogen Production     125
Principle of operation     125
MEC systems     127
Hydrogen yield     131
Hydrogen recovery     132
Energy recovery     134
Hydrogen losses     142
Differences between the MEC and MFC systems     145
MFCs for Wastewater Treatment     146
Process trains for WWTPs     146
Replacement of the biological treatment reactor with an MFC     149
Energy balances for WWTPs     154
Implications for reduced sludge generation     157
Nutrient removal     158
Electrogenesis versus methanogenesis     159
Other MFC Technologies     162
Different applications for MFC-based technologies     162
Sediment MFCs     162
Enhanced sediment MFCs     166
Bioremediation using MFC technologies     168
Fun!     171
MFCs for new scientists and inventors     171
Choosing your inoculum and media     174
MFC materials: electrodes and membranes     175
MFC architectures that are easy to build     176
MEC reactors     180
Operation and assessment of MFCs     181
Outlook     182
MFCs yesterday and today     182
Challenges for bringing MFCs to commercialization     183
Accomplishments and outlook     184
Notation     186
References     189
Index     199