Chapter1INTRODUCTIONEnergy consumption is increasing day by day wihin theworld. These energy sources include fossil fuel ,renewable sources and nuclearsources in which non-renewable sources of energy,which include enormous portionof energy consumption, could be categorized into major classification; nuclearand fossil.
These energy soures are causing global warming and climate change. Fossil fuel have been formed from the organic remains oflong-dead plants and animals. They contain a high percentage of carbon andhydrocarbons. Primary sources of energy used around the world includepetroleum, coal, and natural gas, all fossil fuels. With energy needsincreasing, the production and use of these fossil fuels create seriousenvironmental concerns. Until a global movement for renewable energy issuccessful, the negative effects of fossil fuel will continue.
1.1 . ENERGY NEEDS AND MFCS:As we know that weurgently need a alternaive source of energy.we are currently using fossil fuelwhich is unsustainable for us and for our environment that is why many searchesare being conducted for replacement of energy source. And it does not appearthat one replacement will fullfil the whole energy necessity. Some countriesaround the world have made remarkableefforts to find a piece of cognen solution like Renewable souces , solar energyand energy produced by wind and water. These efforts proposed a new discoveryof Microbial Fuel cell in which bacteria can be used to produced electricityfrom waste water and renewable biomass . This discovery has gain much attention due to its uniqueness.
It is the oneof the 50 top most inventions of 2009 in Time magazine. This lead to increase interest in MFC and raise number of publications. These systems are veryadaptable and provide much energy in sustainable way but the major improvementwas widespread of this application.
MFCs uses active microorganisms as acatalyst in anaerobic mode for theproduction of bioelectricity. Electrical current produced by bacteria was firstobserved by Potter in 1911 and its research domain became wider in 1999s The microbial fuel cell is a bio-electrical systemin which bacteria is used to convert organic material into electricity. Thefuel cell itself is made up of four parts; the anode, the cathode, the protonexchange membrane and the external circuit.
The electrons are pulled out asreleased energy during the oxidation process and into the electron acceptor viaan external circuit. The protons pass through the ion/ proton exchange membraneand react with the electrons during the reduction process in the cathode thuscompleting the circuit. This simple process which is common and found in mostfuel cells i.e. battery cells, hydrogen fuel cells can be optimized for anefficient current generation. The exploration of various materials used inelectrodes that balances efficiency and cost-effectiveness is the key to thepotential large scale use of MFC particularly in wastewater treatment plantswhich is hoped to be a power generating plant as opposed to a power consumingplant1.2 .
ENERGY AND THE CHALLENGE OF GLOBAL CLIMATE CHANGE:There is no ‘MagicBullet’ for meeting our current andfuture energy needs. There is no question that the release of stored carbon infossil fuel is increasing the concentration of carbon dioxide in atmosphere,with increase from 316 ppmv in 1959 to 337 ppmv in 2004. Addressing the effectsof climate change is a top priority of the Energy Department. As globaltemperatures rise, wildfires, drought, and high electricity demandput stress on the nation’s energy infrastructure. And severe weather the leading cause of power outages and fuelsupply disruption in the United States is projected to worsen,with eight of the 10 most destructive hurricanes of all time having happened inthe last 10 years. To fight climate change, the Energy Department supportsresearch and innovation that makes fossil energy technologiescleaner and less harmful to the people and the environment. We’re takingresponsible steps to cut carbon pollution, develop domestic renewable energy productionand win the global race for clean energy innovation.
We’re also working todramatically increase the efficiency of appliances, homes, businesses and vehicles. 1.3. MFCs AND ENERGY SUSTAINABILITY OF THE WATERINFRASTURCTURE:Energyand water are intricately connected. Energy is itself required to make waterresources available for human use and consumption (including irrigation)through pumping, transportation, treatment, and desalination. Over two billion people on the planet lackadequate sanitation and one billion do not have access to portable water.
Energy demands for conventional water and waste water processes as a large partof the problem. We serve our most part of produced electricity in thetreatments of water. So greatly need a new sustainable source of energyproduction in the form of MFCs. And also MFCsare used in water treatment to harvest energy utilizing anaerobic digestion. The process can also reduce pathogens.