Prelims 2011 · archive
MediumMicrobial fuel cells are considered a source of sustainable energy. Why?
- 1.They use living organisms as catalysts to generate electricity from certain substrates.
- 2.They use a variety of inorganic materials as substrates.
- 3.They can be installed in wastewater treatment plants to cleanse water and produce electricity.
Which of the statements given above is/are correct?
Answer & explanation
Answer: (c) 1 and 3 only
A microbial fuel cell uses living microbes as biocatalysts to turn the chemical energy of organic matter into electricity. It can run on wastewater and clean it at the same time. Its fuel is organic matter, not a variety of inorganic materials, so statement 2 fails. The answer is (c).
- ✓ 1. Microorganisms act as biocatalysts. At the anode they oxidise the substrate and release electrons, which flow through an external circuit to the cathode as electric current.
- ✗ 2. An MFC converts the chemical energy of organics, such as the organic matter in wastewater, into electricity. Its sustainability rests on using organic waste as fuel, not on a variety of inorganic materials.
- ✓ 3. MFCs can be used in wastewater treatment plants. There they convert the organic matter in wastewater into electricity while also removing pollutants.
Remember · Microbial fuel cell: microbes act as biocatalysts on an organic substrate (e.g. wastewater) to give electricity. Waste treatment and power generation happen together.
Sources
- Microbial Fuel Cell Construction Features and Application for Sustainable Wastewater Treatment (NCBI/PMC, PMC10223362) ↗ “MFCs can be used in wastewater treatment plants since they can convert the organic matter in wastewater into electricity while also removing pollutants. … MFCs can be termed as a fuel cell that converts the chemical energy of organics to electrical energy where microorganisms act as the biocatalysts”
Question: UPSC Civil Services (Preliminary) 2011, General Studies paper. Explanation: Minimalist IAS, checked 25 Oct 2026 (how we verify). ·