Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Engineer designs system to put wastewater to work

09.08.2006
Sparing the drain to power the neighborhood

In the midst of the worldwide energy crisis, researchers at Washington University in St. Louis have been continuing their work on a microbial fuel cell that generates electricity from wastewater. Advances in the design of this fuel cell in the last year have increased the power output by a factor of 10 and future designs, already in the minds of the researchers, hope to multiply that power output by 10 times again. If that goal can be achieved, the fuel cell could be scaled up for use in food and agricultural industries to generate electrical power - all with the wastewater that today goes right down the drain.

Lars Angenent, Ph.D., assistant professor of chemical engineering, and a member of the University's Environmental Engineering Science Program, has devised a continually fed upflow microbial fuel cell (UMFC). In a paper published online in the Environmental Science Technology, Angenent describes how wastewater enters from the bottom of a system and is continuously pumped up through a cylinder filled with granules of activated carbon. Many previous microbial experiments used closed systems with a single batch of nutrient solution, but because this system is continuously fed from a fresh supply of wastewater, Angenent's UMFC has more applications for industry since wastewater is continually outputted during industrial production.

The organic matter in the wastewater provides food for a diverse community of bacteria that have developed a biofilm (a thick-layered colony of bacteria) on a simple electrode in the anode chamber. An inexpensive U-shaped proton exchange membrane inside the anode chamber separates the anode from the cathode.

As the bacteria feed on the organic material in the wastewater they release electrons to the anodic electrode. These electrons then move to the cathodic electrode via a copper wire. The formed protons are transferred through the membrane towards the cathode where they react with electrons and oxygen to form water.

This is the second design of the UMFC. Last year, Angenent's design used a cathode on top of the anode. This time, with the U-shaped design, the surface area was increased and he reduced the distance between the anode and cathode, which helped reduce power loss due to resistance. These two changes are largely responsible for the boost in power by a magnitude of 10 times from a maximum of 3 watts per cubic meter of solution last year to a maximum of 29 w/m3 today. Sustained power in the system can average 20 watts per cubic meter - enough to run a small light bulb.

Angenent and his doctoral student Jason He are exploring other anode-cathode shapes, surface areas, and distances to both increase power and reduce the resistance in the system so that less power is lost as it runs. Angenent says that for the UMFC to be economical he needs "two more breakthroughs, but [he doesn't] know what they are yet."

The economic viability level for this microbial fuel cell is around 160 watts per cubic meter of solution and the goal of increasing the power output by 10 times would double that level to around 300. If that can happen, this microbial fuel cell system would be a proof of concept with far-reaching applications in the food and agricultural industries. Since this experiment uses common and inexpensive materials and wastewater is plentiful in industry, a scaleable version of this system at one food industry could one day generate enough power for 900 American single-family households. A clean and renewable energy source, all with what's already just going down the drain.

Tony Fitzpatrick | EurekAlert!
Further information:
http://www.wustl.edu

More articles from Ecology, The Environment and Conservation:

nachricht Successful calculation of human and natural influence on cloud formation
04.11.2016 | Goethe-Universität Frankfurt am Main

nachricht Invasive Insects Cost the World Billions Per Year
04.10.2016 | University of Adelaide

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

Im Focus: Fraunhofer ISE Develops Highly Compact, High Frequency DC/DC Converter for Aviation

The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.

Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

UTSA study describes new minimally invasive device to treat cancer and other illnesses

02.12.2016 | Medical Engineering

Plasma-zapping process could yield trans fat-free soybean oil product

02.12.2016 | Agricultural and Forestry Science

What do Netflix, Google and planetary systems have in common?

02.12.2016 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>