Waste not, want not…even when it comes to electricity.
Waste treatment plants may soon have a new way to treat wastewater that will also generate electricity. Oregon State University has developed a method using microbial fuel cells that can generate 10 to 50 times more electricity from waste treatment plants than methods that use similar cells.
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Currently, waste treatment plants use a process called "activated sludge" to speed up the decomposition process of solids in waste water. This uses microbes to break down organic material. During this process, anaerobic organisms (that don't require oxygen) convert organic materials to methane.
It's effective but has environmental drawbacks because methane is a greenhouse gas.
OSU's microbial fuel cell uses microorganisms to break down the particles directly on an anode, which generates electrons and protons. These transfer from the anode to a cathode (terminals where electricity flows in and out) inside of the fuel cell which creates an electric current.
Engineers on the project say the method was improved by reducing the space between the anode and cathode and using advanced microbes. This made it possible to produce more than two kilowatts per cubic meter of waste.
So, why is this important? According to a press release from OSU, 3 percent of electrical energy in the United States and other countries is used to treat waste water. Most of that electricity comes from coal, oil or gas.
A fuel cell process could make it so that waste treatment plants can create their own electricity to power their facilities.
If this process is put into place, treatment plants could even sell the excess electricity. Now we can't just focus on the wonders of sewage, this process can also be used for breweries, animal waste, dairy byproducts and water treatment plants.
A full pilot study will be underway soon in the hopes of moving the concept towards commercial use.
Credit: Oregon State University