Affordable Wastewater Treatment Using Microbial Fuel Cells

Pollution has been a persistent threat to our water supply for many years and despite our best efforts in cleaning wastewater, more innovations need to be developed for more pervasive and affordable wastewater treatment methods to have a positive impact on the environment.

One source of pollution comes from agricultural farms that can dump vast amounts of wastewater that contain organic contaminants, foul gases, and other toxic substances that damage our water supply. Although conventional treatments exist to address these issues, some situations make it difficult to institute these measures.

A case in point can be found in Okinawa, Japan, where they have limited land resources and a lot of pig farms. The wastewater they produce outweighs the land available for treatment and recycling. The Biological Systems Unit at the Okinawa Institute of Science and Technology Graduate University (OIST), are conducting research on finding better, faster, and more affordable wastewater treatment. The team plans on using a promising yet affordable wastewater treatment technology called a microbial fuel cell (MFC) to help the island reduce its wastewater burden and if successful, apply it to other locations with similar wastewater issues.

An MFC is an anaerobic container of concentrated bacteria that feed on biodegradable material and bacteria found in wastewater. It operates via bio-electrochemistry, meaning that the energy used to run the cell is generated from electron transfer from the bacteria to electrodes within the device, removing the need for outside energy. When wastewater passes through an MFC, the “feeding” bacteria digest the organic compounds in the wastewater and cleaner water comes out the other side. In addition, the digesting process produces energy which is converted into usable electricity. The MFC therefore is a device that can not only clean wastewater but generate electricity as well.

MFCs are low maintenance, low cost, and don’t have a lot of moving parts, according to David Simpson, a technician in the OIST Biological Systems Unit. “Ideally what we’re working toward is to put the fuel cell [where you need it] and forget about it,” says Professor Igor Goryanin, who leads the Unit at OIST. “It will monitor and treat the wastewater by itself.”

The OIST researchers are already improving the MFCs with the ability to function for long periods of time without breaking down or “gunking” up. They have even identified a way to strengthen the devices’ performance too. Before running an MFC, it must first be cultured, or inoculated, with the “digesting” bacteria. To do this, one shovels sludge containing bacteria into a part of the MFC called the anode.

Here, the desired bacteria are propagated for later use in wastewater treatment. The team also theorized that MFC will be better at treating wastewater if the anode is prepared with sludge that has been in prior contact with that particular waste stream.

“The idea of affordable wastewater treatment is to eventually help those countries without access to clean drinking water,” Professor Goryanin explains, “perhaps by cleaning water to be used in potable wells.”

If you are a municipality in Ontario and in need of a biosolids management solution, please feel free to contact us at 1 (877) 479-1388.

Sources:
https://www.technologynetworks.com
https://www.sciencedaily.com

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