Microbial 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 following statements given above is/are correct?

1. 1 only
2. 2 and 3 only
3. 1 and 3 only
4. 1, 2 and 3

Explanation

Statement 1 is correct

• A fuel cell is a device that converts chemical energy into electrical energy. It uses hydrogen and oxygen gas as fuel to generate electricity. However, there is no combustion involved. Fuel cells can vary from tiny devices producing only a few watts of electricity, right up to large power plants producing megawatts.
• A microbial fuel cell (MFC) is a bio-electrochemical system that converts chemical energy to electrical energy through reactions catalysed by microorganisms under anaerobic conditions.
• MFCs harness the power of microorganisms (such as bacteria) to break down organic matter, releasing electrons that generate electricity.

Statement 2 is incorrect

• MFCs primarily use organic materials (e.g., wastewater, agricultural waste, and other biodegradable matter) as substrates. While some inorganic compounds can be involved, they are not the main energy source for MFCs.

Statement 3 is correct

• They can be installed in wastewater treatment plants to cleanse water and produce electricity (Correct) MFCs help in bioremediation by breaking down organic pollutants in wastewater while simultaneously generating electricity. This makes them highly useful for sustainable wastewater treatment and energy generation.

Answer: (c) 1 and 3 only | Difficulty Level: Easy