Microbial Fuel Cells

[deleted-600080]

Hi, I am building a microbial fuel cell for my science project and there are no local streams near me, so I was wondering the following:
Is it possible to use topsoil in the anode container instead of using benthic mud.
If So, what water would I use for the liquid solution in the cathode chamber.

[norman40]

Hi SohanRasul,

Yes, you can use almost any type of soil in a microbial fuel cell. Take a look at the project described here:

https://www.sciencebuddies.org/science- ... ud#summary

The procedure section has a video with suggestions on soil sources and how to set up a cell. Distilled water is recommended for the cell preparation.

I hope this helps. Please post again if you have more questions.

A. Norman

[deleted-600080]

Thank you for taking the time to answer my question. However, I have one more question. In a two chambered mfc, the cathode is filled with a water and salt solution.

Question: What is the concentration of salt that I need to add to the water in that cathode chamber?

[norman40]

Hi SohanRasul,

The project at the following link describes how to build a two-chambered cell:

https://www.sciencebuddies.org/science- ... from-waste

The Procedure section calls for 6 Tbsp of salt dissolved in 12 cups of water to make the conductive solution for the cathode chamber (see Assembling the Microbial Fuel Cells).

I hope this helps. Please post again if you have more questions.

A. Norman

[deleted-600080]

Thank you for answering my question with the information that I needed. However, I have one more question.

In that project, in order to make the electrode, it says to nickel epoxy the wire to the carbon cloth. Due to the fact that nickel epoxy and other similar conductive epoxies are expensive and hard to obtain, would it be possible for me to solder the wire to that carbon cloth instead.

Thanks,
Sohan

[norman40]

Hi SohanRasul,

Soldering carbon cloth may not be possible. You might try soldering a wire to a small test piece of cloth to see if the solder will bond. But my suggestion is to use the conductive epoxy specified in the project procedure.

I hope this helps. Please post again if you have more questions.

A. Norman

[deleted-600080]

Thanks for answering my question. However the reason that I am asking about soldering is because the nickel epoxy is very hard to find. Can you recommend any online websites that ship to Canada that would sell this product or any other conductive epoxy. Also, in order to make the conductive solution in the cathode chamber of a microbial fuel cell, it requires stream water mixed with salt. However, due to my school timeline, the testing of my project will be done in january. This means that I will not be able to use stream water for the conductive solution in the cathode. Is it possible to simply use tap water and salt to make this conductive solution instead.

Thanks,
Sohan

[norman40]

Hi SohanRasul,

Amazon.ca sells several conductive adhesives online and I presume that these products ship to Canada.

My suggestion is to use distilled water to prepare your cathode chamber solution. That way you won't have any contaminants from tap water that might interfere with your experiments.

The procedure for the two-chambered cell project that I posted earlier calls for stream water from the same source as the mud sample. You might mimic this by soaking your soil sample in distilled water for a few days to allow some of the soil bacteria to migrate to the water. Filter the water then add salt to make the conductive solution as described in the project procedure (and in my previous post).

I hope this helps. Please post again if you have more questions.

A. Norman

[deleted-600080]

Thanks for answering my question. It was a big help. I do not have any more questions for now, but I will let you know if I have any more.