Microbial Energy from Wastewater - An interdisciplinary team has created a new “microbial battery” that avails itself of common bacteria in nature, to which evolution has endowed with a striking capacity: the produce electricity when they “Digest” organic matter.
A long time ago, that it knew of the existence of such microbes, which evolve in suitable environments developed the features needed to create chemical reactions with minerals containing oxide, in order to obtain the “fuel” they need to live.
Over the past decade, some research groups have been tested several ways of using these microbes such as generators of electricity, but with due efficiency exploit this potential source of energy has been a challenge.
The microbial electric battery that Yi Cui, Craig Criddle, Xing Xie, Meng Ye, Po-Chun Hsu and Nian Liu, of Stanford University in California, have developed has novelty, with respect to the previous models, that its design is simple yet efficient.
This unique electric battery maker’s hope that it is used in places such as plants for wastewater treatment, or work as decompose organic contaminants in ” dead zones ” of many lakes and coastal marine sectors.
For the moment, however, the prototype, which is working at the laboratory scale, is little more than a bottle with two electrodes, one positive and another negative, placed in the Bowl containing wastewater.
Inside the jar, stuck to the negative electrode like limpets to the hull of a boat, a rare type of bacteria is given a feast with the particles of organic waste in the water and produces electricity that is then captured by the battery positive electrode.
In fact, the microbes projected a few tendrils, by way of electrical cables, which are ejected electrons that would otherwise accrue them dangerously.
As these microbes feed on organic matter and convert it into bio-fuel, their surplus electrons flow toward special filaments of the system, and continue their journey toward the electrode positive, made of a material that attracts the electrons.
Stanford University engineer’s estimate that microbial battery can be removed 30 percent of the potential energy contained in the wastewater. Approximately of the same order is the efficiency with which the best available solar cells commercially convert sunlight into electricity.