With fresh water scarcity becoming more and more of a problem as we speak, any industry that pollutes the “liquid gold” or wastes it in any way, is the first to be pointed at, and rightfully so. However, with oil and gas industry continuing to contaminate water with hydrocarbons, and number of fracking sites growing exponentially around the world as we speak, wasting the already limited fresh water resources, the pressure is put back on scientists and engineers to find an intermediate, green solution.
A team from University of Colorado Boulder took on the task and came up with a technique that not only removes pollutants, but also generates energy along the way. The scientists used microbes that feed on the hydrocarbons present in the wastewater. During the feeding process, the tiny organisms release energy, which is captured and used to create a microbial battery with positively and negatively charged electrodes. The electrical current is then used to remove salts from the wastewater, in a process referred to by the inventors as ‘microbial capacitive desalination’.
What makes the microbial battery technology even more interesting, is that the amount of energy produced during the desalination is much higher than what is needed for the process, resulting in generation of excess amounts. This, according to the scientists, could be used to power equipment on the site, turning the process of desalination from energy-wasting to energy-generating one.
The team also believes that the technique could also benefit fracking, as the water used to extract the gas from depth can be treated and reused on site, minimizing the waste of huge amounts of fresh water resources. More details can be found in their paper published in the journal Environmental Science Water Research & Technology.
Currently the team is working on scaling up the process and proving that it is far more cost-effective than currently used techniques. Once this is done they will proceed to commercializing the microbial battery tech via the spin-off company BioElectric Inc., which was established by the lead scientists.
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