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The company is also working on a microbial fuel cell under a Department of Defense contract, which is part of US $8 million Cambrian Innovation has secured in DoD and National Science Foundation grants. The plan is to make a self-powered wastewater treatment facility for operating bases or for off-grid applications in the developing world.

CEO Silver has confidence that it can make an economic microbial fuel cell, but decided to target its first commercial product on the wastewater industry. By taking advantages of advances in other fields of engineering, the company was able to design a product that has compelling economics, he says. "We realized we needed to combine the advantages of biological systems with electrochemistry and information technology and really create a package," says Silver. It's now targeting companies in the food and beverage industry and seeking applications in other industries.

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One of the advantages of the EcoVolt over traditional anaerobic processes is that it can be remotely monitored in real time. By viewing the rate and the health of reactions on the electrodes, Cambrian Innovation engineers can adjust flow rates and other bioreactor parameters. That’s much quicker control than a typical anaerobic reactor, which requires taking a sample and doing tests, says company chief technology officer Justin Buck. Company engineers have also developed techniques to adjust the reactor’s biology, which allows the EcoVolt to be robust and work with different types of waste streams, he adds. “We make sure that the proper community of microbes gets established on these electrodes,” he says. “If we don’t do that, incoming water will bring in new microbes, which is essentially a source of contamination.”

There are several researchers and companies trying to take advantage of microbes to make electricity from wastewater. A group at Penn State, for example, combined a microbial fuel cell with reverse electrodialysis, a way to capture energy from a difference in water salinity, in an effort to increase electricity output.

Israeli company Emefcy (a play on the acronym for microbial fuel cell) has engineered a microbial fuel cell optimized for municipal wastewater. Another wastewater-to-energy startup is Arizona State University spin-off, Arbsource, an Arizona State University spin-off, uses anode-respiring bacteria to produce electricity, as Cambrian Innovation does, as well as hydrogen, ammonia, and other chemicals. And a number of municipalities produce biogas with digesters and use it to generate electricity and heat through fuel cells.

By contrast, the EcoVolt system is designed specifically for wastewater reuse. Cambrian Innovation hopes to appeal to businesses with high energy costs from wastewater treatment and, in general, bring more innovation to the slow-moving and conservative world of water treatment. "Up until now, compliance (with water treatment regulations) was viewed as a cost of doing business and a big part of the industry is designed around avoiding liability,” he says. “Now wastewater can be a source of revenue.”

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