Science Buddies: "Ask an Expert"

My daughter has selected this project to try for her science fair project. She is trying to "make it her own" and want to try using animal waste, waste water, green waste and tap water (as control). We do not live close to a stream to collect mud. What do you think about using these as fuel? What are the potential issues? And do you think these will have a bacterial that will fuel the cell? There is also water that is needed for the cathedo, the procedure suggested using stream water. Since she is not using stream water she thought about using tap water or distilled water be used? If not what else might be suggested?
Thank you very much. I don't have the answers to these questions that she is asking, and would love to give her some advice.

Hi

Welcome to Science Buddies! A microbial fuel cell is a great project idea, but can be challenging. . It sounds like you may be doing this project, but please let me know if you are looking at a different project:

https://www.sciencebuddies.org/science- ... #materials

For a microbial fuel cell, you need a source of anaerobic bacteria that do not use oxygen to transfer electrons in their respiration and you need to source of energy for bacterial metabolism. . The animal waste, green waste, and waste water are good independent variables to use as these are materials that are available for recycling. There is a safety hazard in working with samples with unknown chemicals and unknown microorganisms so you will need to take safety precautions in working with these samples, or perhaps pick different samples. Do have your daughter check with her teacher on this topic.

The bottom of a stream is a very good source of anaerobic bacteria, but the project guide also mentions two brands of potting soil that will work, or you could use garden soil if it is available. The samples you are thinking about using will also contain some microorganisms.

Your daughter should do some additional background research at this point and try to find out what may be in the test samples that would supply suitable nutrients for the microbes. What is in the test samples that will support the bacterial growth? The production of electricity will be proportional to the growth of the microorganisms. The project guide in this website is very helpful; please refer to the background research section to get more ideas for planning the details of the experiment:

https://www.sciencebuddies.org/science- ... ndex.shtml

Please let us know if there are any additional questions.


Donna Hardy