How ‘pee bacteria’ could change electricity production as we know it

The world population is estimated to reach 9.5 billion by 2050. Given that the majority of our current energy is generated from fossil fuels, it poses significant challenges when it comes to providing sufficient sustainable electricity while mitigating climate change.

An idea that has gained traction in recent years is called electricity being generated using bacteria in devices Microbial fuel cell (MFC). These fuel cells rely on the ability of some naturally occurring microorganisms to exchange electrons to create electricity, the ability to “breathe” metals. This process can be fueled using substances called substrates, which include organic materials found in waste materials.

At this time microbial fuel cells are capable of generating electrical devices, such as calculators, small fans, and LEDs – in our lab we operated lights on a mini Christmas tree using “simulated wastewater”. But if technology is to be enhanced, it is a huge promise.

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how do they work

MFCs use a system of anode and cathode – electrodes that pass one on or off. Common MFC systems have an anode chamber and a cathode chamber separated by a membrane. Bacteria grow at the anode and transform the substrates into carbon dioxide, protons and electrons.

The electrons that are generated are then transferred to the cathode chamber via an external circuit, while protons pass through the membrane. In the cathode chamber, a reaction between protons and electrons uses oxygen and forms water. And as long as the substrates are continuously converted, electrons will flow – which is electric.

Generating electricity through MFC has several advantages: systems can be installed anywhere; They make less “mud” than traditional methods of wastewater treatment Activated sludge system; They can be small-scale, yet a modular design can be used to construct large systems; They have a high tolerance to salinity, and can function at room temperature.

MFC has the potential to revolutionize power generation in the future by the availability of a wide range of renewable substrates that can be used to generate electricity. Such substrates include urine, organic matter in the waste material, substances contained in the soil (released from the root) by living plants, inorganic wastes such as sulfides, and even Gaseous pollutants.

1. The power of urine

Biodegradable substances in waste materials such as feces and urine can be converted into electricity. It was demonstrated in a microbial fuel cell latrine in Ghana, which suggested Toilets could be a potential powerhouse in the future. The latrine, which had been in operation for two years, was able to generate 268 NW / m² of electricity, enough to power an LED light inside the latrine, while removing nitrogen from the urine and composting the feces.