The energy created by natural reactions of microorganisms in the soil can be captured and used, say engineers at the University of Bath. A team of electrical and chemical engineers demonstrated the potential of inexpensive, simple soil microbial fuel cells; the one that are buried in the Earth to provide energy to an electrochemical reactor used for water purification.
Meanwhile, the proof-of-concept (PoC) design of soil microbial fuel cells demonstrated at the time of field testing in North-East Brazil in 2019. The PoC demonstrated that soil microbial fuel cells can purify approx. three liters of water each day to fulfill an individual’s every day water needs.
The testing of soil microbial fuel cells carried out at a fishing village located in a semi-arid location. At this location, the main source of drinking water is rainwater and access to a reliable power source is scarce. In fact, to make it drinkable, rain water needs to be chlorinated; chlorination not only causes bad taste and odor, and uncontrolled chlorination is dangerous to human health.
Metabolic activity of Soil microorganisms produces energy
Soil microbial fuel cells produce energy from the metabolic action of specific microorganisms that are naturally present in soil. These microorganisms are able to transfer electrons outside the cells.
Structurally, the system comprises two carbon-based electrodes positioned apart at a fixed distance and connected to an external circuit. The anode, one electrode are buried inside the soil, on the other hand, the cathode is exposed on the soil surface.
In the apparatus, microorganisms of the soil populate the surface of the anode. And, as these microorganism feed on organic compound present in the soil, they generate electrons. The electrons are transferred to the anode and traverse to the cathode via the external circuit, producing electricity.