Bacteria Learn to Generate Electricity from the Bottom of Water Bodies

Polluted bottom sediments of rivers, lakes, and coastal areas can become not only a cleanup target but also a source of electrical energy. An international group of scientists summarized the results of developing sediment microbial fuel cell (SMFC) technology. This bioelectrochemical method allows turning polluted mud at the bottom of water bodies into an energy source. Analyses show that such systems have already moved beyond the laboratory, capable of treating wastewater with over 97% efficiency and powering autonomous sensors for years. Reported by Ixbt.com report .

The technology is based on a natural process that has been occurring for millions of years at the bottom of rivers and seas. Microorganisms that decompose plant and animal residues live in the oxygen-free layer of mud. During this process, bacteria release electrons. Usually, this energy dissipates into the environment, but in a microbial fuel cell, it can be collected and used to generate electric current. The system structure is simple: the anode is placed directly in the mud where bacteria are active, and the cathode is placed in the oxygen-rich water above it.

One of the key discoveries of the last decade was the identification of exoelectrogenic bacteria. Microorganisms such as Geobacter sulfurreducens and Shewanella oneidensis have the ability to transfer electrons directly to electrodes. They form unique "biological nanowires" that allow them to export electrical charge outside the cell. This makes it possible to transform polluted sediments from an environmental problem into an energy source.

In addition to generating electricity, SMFC systems show high results in removing heavy metals and excess phosphorus from water. Combining these elements with artificial wetlands is considered a promising direction. In this setup, plant roots provide additional nutrients for bacteria, while microbial communities purify the water and maintain ecosystem health. New electrode materials, particularly "biochar" derived from wood waste, are further increasing system efficiency.

Currently, while the power of such systems in natural conditions amounts to tens of milliwatts per square meter, this figure has exceeded 3 watts in optimized laboratory devices. This indicates that the technology may become an important tool for reducing CO2 emissions and protecting the environment in the future. With its expanding scope of practical application, this method is expected to play a significant role in solving global environmental problems in the coming years.