Microorganisms May Save Power In Chemical Waste Treatment

Japanese researchers may soon commercialize a treatment method for chemical plant waste that cuts the need for electricity by 80 percent compared to conventional processes.

Government-funded research is underway by University of Tokyo researchers with support from private companies including Sekisui Chemical, Panasonic, and the Tokyo University of Pharmacy.

The technique draws on the use of microorganisms. “The Geobacter species, which can produce power by itself, is touted as ‘a microbial fuel cell.’ It promises to significantly save energy in wastewater treatment,” Nikkei Asian Review reported.

“Geobacterspecies are of interest because of their novel electron transfer capabilities, the ability to transfer electrons outside the cell and transport these electrons over long distances via conductive filaments known as microbial nanowires,” according to the University of Massachusetts.

The new waste treatment technique attempts to address problems inherent in wastewater treatment at chemical plants, where activated sludge strategies are normally employed, according to the article. Activated sludge involves microbes decomposing organic substances in the waste. Aeration must be applied to the wastewater, along with churning, the article said.

The challenge is that aeration and churning processes require significant amounts of power. Drawing on "microbial fuel cell" technology and using Geobacter microbes decomposing organic substances attempts to reduce this problem.

“These proteobacteria are dubbed ‘electricity generating microbes’ because of their ability to do electrode respiration, which means transferring electrons to the electrode, instead of needing aerobic respiration,” the report said. “The electrons then move to the cathode, reacting with hydrogen ions and oxygen to generate water and creating an electrical current.”

The benefits of this approach, per the article:

Wastewater treatment equipment can use this electricity as a power source. This means Geobacter microbes use less energy for themselves. As a result, they do not multiply as much, leaving less sludge to clean up and creating even more energy savings in the disposal process. And since Geobacter microbes do not need oxygen, aeration and churning are no longer necessary.

Geobacterspecies is of particular interest because of its ability to survive in radioactive environments. “Radioactive elements are toxic to every organism on the planet—almost. Remarkably, microorganisms such as the soil-dwelling Geobacter bacteria don’t just survive contaminated environments—they actively thrive alongside radioactive material,” Asian Scientist Magazine reported.

For similar stories, visit Water Online’s Contaminant Removal Solutions Center.