Microbial Fuel Cell

[deleted-54839]

I need help on the project you have on your site, reguarding the microbial fuel cell experiment. I am conducting the experiment, and have been for the past two weeks, but I am not getting any readings. I have done everything according to the directions. In the beginning there were readings, then round three days later they stopped. During those three days, the readings were all over the place from .006 to .216. Why is this? and What can I do to make it stop doing that? Also, why is it necessary to use the benthic mud sample in 24 hours? I mean, I have used it within that period, but I am just curious. Thanks.

[deleted-71487]

This might be better answered in the life sciences category (if you don't get a better answer soon I'll move it), but from what I can tell from the experiment description, the reason you need the benthic mud is as a source of anerobic bacteria for the cell.

As for why you stopped getting results, the most reasonable guess I have (as a non-biologist is that the bacteria died. This is a very complex project and there are a lot of places it could go wrong. Did you use water from the stream, or tap water? If the latter, the chlorine could killed your bacteria. It's also possible that the mud might not have contained many bacteria in the first place for some reason, or that the stream is in some way contaminated, such as with antibiotics. Maybe try culturing the mud, stream water, and/or your experiment water in a petri dish with agar and see if it grows? Take the precautions in the experiment description, even though it's pretty unlikely you'll generate dangerous bacteria.

Sorry not to be much help directly.

[deleted-71588]

Try looking here for somebody who tried this before https://www.sciencebuddies.org/science- ... =26&t=6133 This is one of those cross discipline projects that requires electrical engineering, micro-biology, and chemistry backgrounds and a LOT of careful observations and descriptions of what the investigator tried.

[deleted-61597]

Hi everyone,

So I think they say to use the mud within one hour because the electricity-generating microbes that make the MFC run are anaerobic (meaning they don't like oxygen). When you disturb the mud, you are introducing oxygen (there is even oxygen in the overlaying water) into the mud which could kill these so-called "electrogenic" microbes over the course of an hour.

Also, there is a website that now sells MFC kits (www.keegotech.com) that you can fill up with dirt, mud, or sediment. Check them out!

[deleted-71588]

Hi everyone,

So I think they say to use the mud within one hour because the electricity-generating microbes that make the MFC run are anaerobic (meaning they don't like oxygen). When you disturb the mud, you are introducing oxygen (there is even oxygen in the overlaying water) into the mud which could kill these so-called "electrogenic" microbes over the course of an hour.

Also, there is a website that now sells MFC kits (http://www.keegotech.com) that you can fill up with dirt, mud, or sediment. Check them out!

The care and feeding of micro-organisms falls into the biology / life sciences area of expertise. What temperature do they like to grow and multiply in? What temperatures can they survive in a dormant state in? What do they eat? What bi-products do they produce that must be removed from their environment to allow them to survive? What pH do they like to grow and multiply in? There are LOTS of factors required to keep these things living, growing, multiplying, feeding, etc. so that the chemical environment of a MFC is causing an external electron flow.