BIOTECHNOLOGY FORWASTE MANAGEMENT

--- ARUNKUMAR S. YADAV

What is Biotechnology ?

‘Biotechnology is the application of science and technology to living organisms, as well as parts, products and models thereof, to alter living or non-living materials for the production of knowledge, goods and services.’

Biotechnology has various application fields ranging from waste treatment to medical treatment of cancer. A cleaner environment, advanced methods of diagnosis and medical treatment, better products and alternative energy resources can be considered among the benefit of biotechnology.

Importance of Biotechnology in Waste Management

Environmental pollution is today, one of the most important problems in all world countries.Biotechnology offers many treatment methods to overcome this pollution problem.

Biotechnology finds application fields in the treatment of wastewaters by biological methods and disposal of solid wastes by composting technique in waste management. Biological methods are also applied to treatment of air emissions. The methods based on biotechnology in wastewater treatment are activated sludge,trickling filters, oxidation ponds, biofilters and anaerobic treatment. Furthermore, solid waste composting techniques, biotrickling filters and biosorption are the examples of biotechnology applications in waste management.

In all these methods, it is essential to find suitable microorganisms that will degrade organic substances and to complete the treatment process in favorable conditions.

Biotechnology for Waste Management using Microbial Fuel Cell

We know how Biotechnology has various applications in Waste Management and it is widely used everywhere in the world.

One such application of Biotechnology is in Microbial Fuel Cell which not only helps in waste water management but also produces energy simultaneously. The energy generated in form of electricity can be utilised somewhere in operations of Effluent treatment Plant .

What is Microbial Fuel Cell?

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.

First demonstration of current and voltage generation via microorganisms was shown by a botany Prof. Michael Cresse Potter, in 1911.

Dependency on energy derived from fossil fuels and environmental concerns led researches on MFC accelerate for the last two decades.

Components of Microbial Fuel Cell(two chamber MFC type)

•Anode chamber•Cathode chamber

•Electrodes1. For Anode Materials used are: (carbon felt, graphite felt etc.)2. For Cathode Materials used are: ( activated carbon , graphite etc.)

•Ion exchange membrane or salt bridge

Microbes oxidise organic matter in anode chamber due to which electrons and protons are released. Electrons flow to the cathode through external circuit producing electric current. Protons flow through the membrane to the cathode. O2 or any other electron acceptor reacts with electrons and protons forming water. Anode chamber is in anaerobic condition while cathode chamber is in aerobic condition with oxygen or an elecctron acceptor. Reactions:(for acetate as a substrate)Anode: CH3 COO-- + 2H2O 2CO2 + 7H+ + 8e—

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

Overall Mechanism of Microbial Fuel Cell

My apparatus

Our Experimented Readings for Effluent water from LUPIN LTD.

DAY 1 DAY 2 DAY 3 DAY 4 DAY 50

20

40

60

80

100

120

VOLTAGE GENERATION (mV)

mV

Operating Conditions for my setup

1. Room Temperature2. Microbes already present in Effluent water3. Carbon Electrodes4. Salt Bridge with KCl electrolyte instead of Proton Exchange Membrane.5. pH 6-86. Oxygen used as electron acceptor7. Later used Curd in Anode compartment containing lactobacillus

plantarum bacteria.

Conclusion

Microbial fuel cell is a good step towards waste management and renewable source of energy useful to meet some demands of energy in future. Though it has some limitations it will be improved in forthcoming years and by use of MFC’s alongwith other Renewable sources like Solar, Tidal, Hydro etc. we can make our energy sources cleaner and greener and treat waste water at low cost.

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