Experts estimate that about 3% of all the energy in developed countries is used to treat sewage. That's a lot, and much of that energy is the result of burning fossil fuels. That may all change, however, as researchers claim to have devised an efficient process that will convert wastewater into clean energy.
The new method would not only allow treatment plants to power themselves, but would enable them to sell excess energy at a profit. If proven feasible outside the lab, this breakthrough would represent a radical shift for this oft-unmentioned, but sizable segment of the global economy.
The research team based at Oregon State University claims they have demonstrated a giant leap in the performance of microbial fuel cells, which use wastewater and bacteria to create a huge waste-powered battery.
The team is certainly not the first to look into creating fuel cells from waste, but by utilizing a number of new concepts such as reduced anode-cathode spacing, evolved microbes, and new separator materials, the team can create 10 to 50 times more energy per volume than other leading approaches.
The new system is able to create more than two kilowatts per cubic meter of liquid reactor volume, an output that "far exceeds anything else done with microbial fuel cells" according to a statement released by OSU.
If the method holds true, then the technology would represent not just some governmental green initiative, but a practical business model that could be readily replicated around the world.
"If this technology works on a commercial scale the way we believe it will, the treatment of wastewater could be a huge energy producer, not a huge energy cost," said Hong Liu, an associate professor in the OSU Department of Biological and Ecological Engineering. "This could have an impact around the world, save a great deal of money, provide better water treatment and promote energy sustainability." (You can see video of Professor Liu below talking about an earlier incarnation of microbial fuel cells in 2009.)
The initial costs of these new microbial fuel plants would be about the same as today's conventional Activated Sludge treatment plants, but would actually be cheaper in the long run when factored for all the energy savings. But before all that, the team is seeking funding to set-up a real-world case study at a treatment plant to demonstrate its use in the field. If all goes well, we could see an all-green sewage treatment industry by the end of the decade.
Who would have thought. In the end, poo may save us all.