IIT Guwahati researchers develop tech to generate green energy from waste water

PTI, Jun 2, 2022, 9:03 AM IST

Researchers at the Indian Institute of Technology (IIT), Guwahati have developed a bio-electrochemical device called Microbial Fuel Cell (MFC) which can generate green energy by treating waste water.

According to officials, the use of organic material such as waste water in MFC makes it an eco-friendly device that offers a dual benefit of bioelectricity generation and waste management.

”Rapid population growth has led to rising energy demands and environmental concerns, necessitating the development of renewable and sustainable energy production techniques. Along with several renewable energy sources (solar energy, wind energy, tidal energy, and geothermal energy, among others), the sustainable energy sources also include the ‘Blue Energy’ sources of energy harvesting,” said T G Sitharam, Director, IIT Guwahati.

”These are those sources of energy generation that have no negative impact on the environment, and energy is generated from various wastes, such as sewage waste and food industries wastes. This development by IIT team has provided an excellent sustainable energy source along with treating several waste waters. After scaling the process, it can be used as a source of clean energy using municipal waste water and other such areas economically,” he added.

Explaining the long-term impact of the research, Mihir Kumar Purkait, Professor at the Department of Chemical Engineering, IIT Guwahati, said further implementation of this process may provide an excellent alternative to several costlier renewable energy extraction processes.

”This study reveals that the prepared Cation Exchange Membranes (CEMs) are cheaper and perform better as compared to the several reported membranes, assisting in the separation of charges and potential development,” he said.

‘MFC’ is a bio-electrochemical reactor system that utilizes electrons liberated in the biochemical oxidation of organic substrates catalysed by anaerobic microbes. A conventional MFC reactor comprises an anaerobic biotic anode chamber, an aerobic biotic or abiotic cathode chamber, and a separator such as a Proton Exchange Membrane (PEM).

The active biocatalyst in the anodic chamber anaerobically oxidizes organic matter present in waste water to produce electrons and protons. Protons are transported to the cathodic chamber through the PEM. The external circuit conducts the electrons to the cathode, completing the electrical circuit. At the cathode, electrons and protons react in the presence of oxygen (or another electron acceptor), which gets reduced to water.

”The present research focuses on the development of cost-effective and high-performance CEMs for application in MFCs. CEMs being the heart of the energy extraction process using MFCs need to be highly cost-effective along with being able to perform magnificently in order to make the process feasible and scalable.

”The waste sugarcane bagasse has also been used in the study to improve the membrane performance, thereby preparing a valuable product from the agricultural waste. The investigation approves the applicability of prepared CEMs as a suitable PEM for application in MFC,” said Purkait.