Industrial and municipal waste doesn’t go away when we flush it down the drain. It takes an enormous amount of energy for treatment plants to process it, while massive environmental and financial costs go into disposing of the leftover sludge.
Now, two Israelis are about to change the way we look at wastewater, by turning its constituents into a valuable source of power.
Emefcy (M.F.C Microbial Fuel Cell) was founded in 2007 by Eytan Levy and his partner Ronen Shechter. It aims to harness a bacteria found in nature that produces electricity as it decomposes organic matter.
Electric bacteria known to science
“The idea was found about 100 years ago, that certain bacteria under certain conditions have the ability to generate electricity,” Levy tells ISRAEL21c. “The reactor has to be structured in a certain way, and generate it while consuming organic matter.”
Over the years teams of scientists tried to harness the power of the bacteria. “But it was never turned into a product, possibly due to the natural barrier between academia and industry,” explains Levy, Emefcy’s CEO.
Levy and his partner revived the idea, and are now working with a leader on microbial fuel cells, Bruce E. Logan from Pennsylvania State University. To optimize electricity production, the eight-man Caesarea-based company has created a network of tubes made from a special polymer – the cathodes – and a network of carbon brush anodes that together promote bioelectrochemical reactions.
The net result is that bacteria form an electrical conductive biofilm over the surface of the anodes and cathodes, decompose organic matter, and produce electricity at the same time.
This bioelectrochemical reaction is performed by three main bacteria, Geobacter sulfurreducens, Shewanella oneidensisand Rhodoferax ferrireducens, already present naturally in wastewater effluent. The company’s main goal, however, is to give the “electrifying” bacteria optimal conditions to digest the human and organic industrial waste in sewage treatment plants.
While the charge from each bacterium is tiny, about half a volt, the company can step it up to 220V, while each kilogram of organic contamination can produce 1-kilowatt hour of electricity, says Levy. In large industrial wastewater plants, Emefcy’s solution can produce megawatts of electricity. A real power plant, Levy says.
Tiny volts that add up
He believes the enormous cost savings of about 30-50 percent per year on various practices, can allow a power plant to achieve a return on investment (ROI) within two to three years. The solution has a number of financial benefits, he points out: the sale of generated electricity, treatment plants save money on aerating the sewage, the process reduces the amount of raw sludge for disposal by up to 90 percent; and working with this system can generate carbon credits.
The Emefcy solution can be an add-on to existing plants, and is expected to be on the market by 2010.
Levy and Shechter are specialists at inventing solutions for making the wastewater treatment market more efficient, and environmentally sound.
Before Emefcy, they founded AqWise, a company which specializes in creating tiny plastic beads to house and aerate bacteria, in order to increase the breakdown of biological waste in treatment plants. Today AqWise has 30 installations around the world.
With Emefcy, Levy and Shechter plan “to reinvent the wheel in the wastewater world,” says Levy. “We realized we were incorrect,” he explains. “Treatment plants are spending energy to purify wastewater and there is something wrong with that. Wastewater has energetic value.”
This article is reprinted courtesy of ISRAEL21c.