1. Introduction:
Since the mid 19th century, societies have dramatically increased the level of
public health by the appropriate separation and treatment of human wastes and
unbalanced energy management due to increasing energy consumption. The world
today is undoubtedly facing a serious energy crisis, and energy demand in the whole
world continues to increase at an unsustainable pace. Possible options are carbonbased alternatives to oil, such as methane hydrates and conversion of coal into
methane gas, and the use of less readily available oil reservoirs and oil shale even if
the usage of these is critical. Climate change is being driven by the atmospheric
release of greenhouse gases like CO2 (1), and an impending global energy crisis is
coming at a time when we can least afford to release additional stored carbon. Nuclear
power offers a carbon-free approach to energy generation, but no good solutions for
nuclear waste exist. We must develop energy-saving technologies that can stretch oil
reserves while we modify our energy-use patterns and infrastructure to become more
sustainable over the next few decades and perhaps even centuries. The India, as a
matter of fact, has very few means for generating electricity. Alternative sources of
electricity such as hydroelectric power plants are still few in the country. In other
states, including developing countries, methane digester systems are being used to
harvest energy from biomass. However, using these systems is very expensive and is
subject to Several processes including combustion that releases harmful gases (Bilcan
et al, 2003). To provide a solution for the demand for energy, scientists have been
studying diverse organisms that may take part in the search for an alternative source
for electrical energy. In addition to these technologies an attractive and novel
alternative for the conservation of chemical energy into electrical energy is the
development of microbial fuel cells (MFCs) (Katz et al. 2003; lovely 2006). A
microbial fuel cell is a device that converts chemical energy to electrical energy by
the catalytic reaction of microorganisms (Allen and Bennetto 1993; Wingard et al.
1982., Reimers et al. 2001., Kim H.j. et al. 2002.). In addition, the MFCs offer an
environmentally friendly alternative to fossil fuels (Lovely 2006; Katz et al. 2003).
Initially, the concept of the electricity generation is given by M.C. Potter (Potter 1910,
1911). He stated that “the disintegration of organic compounds by microorganisms is
accompanied by the liberation of electrical energy (Potter 1911). These fuel cells
based on metabolic activity of microorganisms on the organic substrates which
contains sugars as the main component. Fuel cells, if used for wastewater treatment,
can provide clean energy for people, apart from effective treatment of wastewater.
The benefits of using fuel cells include clean, safe, quiet performance; high energy
efficiency; and easy to operating. Various research groups are keenly interested to
improve the current density by more facile and efficient methods (Palmore and
Whitesides 1994; Bond et al. 2002; Angenent et al. 2004; Pham et al. 2004).
Generation of electrical energy is based on the principles of fermentation in which
organic substrate undergo the biochemical reaction in the presence of microorganisms
which result in the formation of the hydrogen fuel. The fuel so formed is finally into
electrical energy and water through redox reaction. (Abdul majeed Khan.2009).
Presently, research on MFCs Using wastewater as substrate is in the initial stages of
laboratory evaluation around the world. The reported work so far is mainly based on
using the monoculture at laboratory level (Rabaey et al. 2003, Park et al. 2003,
Larminie et al. 2003.) The use of energy increasing day by day. Thus there is a need
to search for alternatives to fossil
fuel, utilizing renewable energy from waste organic source is the present trend of
active research and in view of this bioelectricity generation through microbial fuel cell
using variety of substrate is being studied extensively. It is well known that
microorganisms can produce fuels from organic matters. In present study we have
tried to generate electricity from wastewater using lactobacillus. The basic aim of the
present study is to design microbial fuel cells employing low-cost materials without
using toxic mediators, which will have the possibility to be implemented in the
wastewater treatment plants in the economical perspective. In present study we have
tried to generate electricity from wastewater using lactobacillus.
Objectives
Generally, this study aimed to:
Waste water can be a possible alternative source of electricity.
construct a MFC using inexpensive and local materials
Specifically, this study sought to:
Assess electricity generation from Sewage water in an MFC, employing lowcost materials without using toxic mediators, which will have the possibility to
be implemented in the wastewater treatment plants in the economical
perspective.
Hypotheses
Sewage water can be an efficient and cost-effective source of electricity.
Advantages of MFC over current energy generating technologies from organics
(Rabaey and Verstraete, 2005)
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High conversion efficiency
Ambient temperature
No gas treatment
No energy input for aeration
Application for wide locations and diverse fuels
Generation of energy out of wastewater.
So far, max. 30 mA, 3600 mW/m2, 216 W/m3, 0.5 volts
Direct conversion of substrate energy to electricity. Simple process chain.
Less sludge production.
Omission of gas treatment due to undesirable anaerobic off-gases not
produced.
Minimal Aeration necessary.
Scope and Limitations
This research project is specific to the feasibility of microorganisms as
biocatalysts in a MFC.Also, the study also aimed to construct a MFC.using
inexpensive and readily-available materials. The electricity produced will be on a
small scale hence, further studies have to be done to explore the possibility of using
Sewage water to produce electricity for home or industrial uses. Since the MFC
technology is not yet well-understood, we are aware of our many limitations in a lot
of things, specifically in methodology which we hope further studies could improve
on. In addition, this study aims to open doors to interested scientists and companies to
enhance the possibility of using microorganisms as alternative power sources to the
ones being used today.