Future Earth

Water Purification

Using Soil Microorganisms to Purify Water


The new technology has been tested in a fishing village in Brazil. Purifying water without electricity.

Microbial activity in soil could start to be used for water purification without the need for electricity. In the UK, researchers from the University of Bath have been working on harnessing the power of microbes to generate electricity to power water purification systems. In very unconventional ways, soil microbe fuel cells (SMFCs) create renewable energy sources to produce power.

Microorganisms in soil generate electricity as the first step. In order to perform metabolic processes, these organisms release electrons through the cell membranes. These organisms are known as electrogenic. 

Microorganisms in soil

Scientists from the University of Bristol have developed a carbon electrode system that uses two electrodes separated by four centimetres. The anode will be buried, whereas the cathode will be exposed. 

As electrons move from the cathode to the anode, a circuit is formed, generating electricity. Possibly, it is a weak electric current of only 0.4mW. Still, by installing multiple rows of electrodes, the energy can be multiplied for use in a variety of different ways. 

Finally, this renewable energy is stored in a battery connected to the electrode array. Electrodes cost no more than $6.5 AUD each. With mass production, they could be made even cheaper.

Purifying water in remote areas

Located in a semi-arid region, northeast Brazil is still underdeveloped. Water and electricity are difficult to access in many of the villages. 

In the fishing village of Icapui, in Brazil, both electricity and drinking water are scarce commodities. Electricigens, living microbes in the soil creating electricity. The current is then harnessed using electrodes, some placed in the soil and others above.

The power from this process is used to power an electrochemical reactor to help communities such as these purify water for drinking. Students in the areas are being taught on how to operate this sustainable technology so that it may be used for inhabitants of the community.

Pure Water

In tests conducted locally with elementary school students, it was possible to produce up to three liters of drinking water every day. With a single, easily installed device, an entire family’s daily necessities can be met. 

Electrochemical reactors have proven effective in laboratory conditions, but this project demonstrates they can be used on a daily basis as well. A prototype has been operating uninterruptibly for 140 days. 

As part of its mission to educate the Icapui school students on environmental values and sustainability, one of the initiative’s priorities has been to produce safe drinking water.

Be sure to check out the short clip below to better understand the process

A brilliant example of how communities that are lacking in infrastructure are able to build better, healthier communities through accessible innovation.