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Hi
Initially,We have tried the above experiment with garden soil.before adding the soil,The maximum power attained was .094microwatt. we added salt after 2 weeks when power started decreasing.After adding 1g salt the maximum power was .69 microwatt.After adding 5g salt the max power was 0.094 microwatt .
Basically LED did not glow.
can you please explain what power stabilization means in this experiment?
We thought of showing like using different soils. we are assuming that the power output of garden soil is low as there are less bacteria in this type soil. We gather topsoil from an unplanted garden.Its very moist soil like clay soil.How can we sift this type soil ?
Are we in right direction?
What is the best place to get too soil ,as it's not available in any store?
if we go for soil near the river ,it's going to be moist.
should we get dry soils? my question is which one is preferable moist or clay soil?
Is it possible to complete the experiment without LED glowing?
What should I do if LED still doesn't not glow.
Please let me know.
Thanks

Hi,

Thanks for posting the link to your project and for the details about your results. You did observe very low power output, so something was not optimum, but your values are reasonable and consistent.

Here is some information that might help solve the problem with the LED not turning on::

An MFC depends on bacteria growing under anaerobic conditions and allowing enough time for the microbes to form a biofilm on the anode electrodes. The biofilm is like the slimy coating that forms on the surface of pet water dishes and consists of millions of bacteria. The current is generated when the bacteria transfer electrons from metabolism to the anode electrode and these are passed through the wires to the cathode electrode.

It takes a few days for the bacteria to deplete the oxygen and form the biofilm and start the process of transferring electrons at the maximum possible rate (power stabilization).

You should be able to get results with any type of rich garden soil, although the traditional soil used is a sample from the bottom of a pond of stream that has been covered with water for a while. A sample like this would contain a high concentration of anaerobic bacteria. Also, a soil sample that has some organic matter in it would contain plenty of food for the bacteria to grow well. From your description, I don’t think that the soil sample itself was the problem, since you tried more than one source.

How long did you let the MFC develop the biofilm? It can take up to a week to form the biofilm and achieve maximum power generation.

What temperature did you use? 20 to 30 degrees Celsius (68 to 86 degrees F) should work, although most researchers report the best results in the higher range. Bacteria metabolism would be slow at lower temperatures.

Were conditions anaerobic? You should have just enough water to completely exclude any air from the soil, so the soil should be mud (not loose soil).

Did you check the wire connections? If you use the multimeter to check the resistance of the MFC, the resistance should be close to zero. If there is any resistance, then perhaps one or more of the wire connections was not secure.
Was the cathode electrode exposed to air? The anode electrode must be kept anaerobic and the cathode electrode must have oxygen.

Did you use gloves to set up the MFC? If you used your bare hands to touch the electrodes, you may have coated them with oil from your skin. This could inhibit the flow of electrons. This problem could be solved by cleaning with 70% isopropanol or other solvent. Experiments that depend on electron flow require very clean surfaces.

If you are out of time to repeat your experiment, you should write up your results as they are, reporting the voltage values that you observed. You did the experiment and you did obtain results, so your experiment was successful. You should not conclude that your experiment did not work. In your conclusion, you should explain what you might do to increase the power output if you had time to do the experiment again.

I hope this helps. Let me know if you have any questions.

Donna Hardy

Hi
Thank you so much for your reply.
We were using 2 MFCs to compare the power output after adding the salt.For the first trial we used store bought potting soil(Nature's Care Organic Potting Soil Water Conserve).
Below are the power output measurements
https://docs.google.com/spreadsheets/d/ ... sp=sharing
Below are voltage current measurements at the first day
https://docs.google.com/spreadsheets/d/ ... sp=sharing
Voltage and current after adding the salt on day 13 are
Distilled water-0.3microA
soil
1g soil-8.66mA
5g soil-36.8mA

As you can see that the power out is low,so the LEDs for both MFCs did not blink.The internal resistance was high.The temperature was not constant .It was 68-72F.
The output of 1g salt is more than 5g salt(as expected).
During the second trial we soil we used the top soil from some one's backyard.We checked with them that there was no pesticides used.
Below is the link of the power output.
https://docs.google.com/spreadsheets/d/ ... sp=sharing
Below is the voltage and current of MFCs measure each day
https://docs.google.com/spreadsheets/d/ ... sp=sharing
Below is the current and voltage measure on the first day
https://docs.google.com/spreadsheets/d/ ... sp=sharing
Voltage and current after adding salt on day 13
Distilled water-o.1mA
1g soil-3.38mA,3.21mA,3.5mA
5g soil-14.46mA,14.55mA,14.79mA
We used heat wrap to keep the temperature constant at 72F at the time of taking reading.Throughout the day, temperature was 68-72F.The LED of 1g blinked.
On the day we added salt LED blinks are as follows
Temperature- Time between blinks
71F -30
73 -18
74.5 -15
74 -12
75 -10
78 -8
The temperature was recorded each day .The second MFC's LED(5g soil) never blinked.We tried switching LEDs and chip.It worked fine for 1g,but did not work for 2nd MFC.
As you can see that the power output of 5g salt is more than 1 g soil(which is opposite to first trial).The internal resitance of 1g salt is 4700ohms.Internal resistance of 5g soil decresed to 470 then went back to 1000ohms.

Our Hypothesis was the power output of 1g is more than 5g.
We also tried using using mud watt app for our second trial,but the results were not compatible with power output readings.

2nd day-8W,4W,3W
6 day-3W
13 day-3W
12 day 8w
The point is LEDs blinks were not uniform.How do we epresent the LEDs blinks output?
Which output was expected to be more ,1g salt or 5 g salt?
What do we explain for the opposite output of 2 trials.
Why is the output of topping soil so low?
Why did the internal resistance of 2nd MFC change?

We have 3 weeks left for Science fair and almost 2months for regional Science fair?Should we do one more trial with top soil and 10g salt ?
We were thinking about using soil under river for another trial .Is it a good idea?What do we show as 3 types of soil.First was potting soil,2nd consists of clay.Does it make sense to do do third trial with river soil as it may again consists of clay with bacteria rich soil.What explanation we should give for LED of 2nd MFC not blinking .
Thankyou so much.
Waiting for your reply before the next step.
Thanks
Maliha

Hi
Thank you so much for your reply.
We were using 2 MFCs to compare the power output after adding the salt.For the first trial we used store bought potting soil(Nature's Care Organic Potting Soil Water Conserve).
Below are the power output measurements
https://docs.google.com/spreadsheets/d/ ... sp=sharing
Below are voltage current measurements at the first day
https://docs.google.com/spreadsheets/d/ ... sp=sharing
Voltage and current after adding the salt on day 13 are
Distilled water-0.3microA
soil
1g soil-8.66mA
5g soil-36.8mA

As you can see that the power out is low,so the LEDs for both MFCs did not blink.The internal resistance was high.The temperature was not constant .It was 68-72F.
The output of 1g salt is more than 5g salt(as expected).
During the second trial we soil we used the top soil from some one's backyard.We checked with them that there was no pesticides used.
Below is the link of the power output.
https://docs.google.com/spreadsheets/d/ ... sp=sharing
Below is the voltage and current of MFCs measure each day
https://docs.google.com/spreadsheets/d/ ... sp=sharing
Below is the current and voltage measure on the first day
https://docs.google.com/spreadsheets/d/ ... sp=sharing
Voltage and current after adding salt on day 13
Distilled water-o.1mA
1g soil-3.38mA,3.21mA,3.5mA
5g soil-14.46mA,14.55mA,14.79mA
We used heat wrap to keep the temperature constant at 72F at the time of taking reading.Throughout the day, temperature was 68-72F.The LED of 1g blinked.
On the day we added salt LED blinks are as follows
Temperature- Time between blinks
71F -30
73 -18
74.5 -15
74 -12
75 -10
78 -8
The temperature was recorded each day .The second MFC's LED(5g soil) never blinked.We tried switching LEDs and chip.It worked fine for 1g,but did not work for 2nd MFC.
As you can see that the power output of 5g salt is more than 1 g soil(which is opposite to first trial).The internal resitance of 1g salt is 4700ohms.Internal resistance of 5g soil decresed to 470 then went back to 1000ohms.

Our Hypothesis was the power output of 1g is more than 5g.
We also tried using using mud watt app for our second trial,but the results were not compatible with power output readings.

2nd day-8W,4W,3W
6 day-3W
13 day-3W
12 day 8w
The point is LEDs blinks were not uniform.How do we epresent the LEDs blinks output?
Which output was expected to be more ,1g salt or 5 g salt?
What do we explain for the opposite output of 2 trials.
Why is the output of topping soil so low?
Why did the internal resistance of 2nd MFC change?

We have 3 weeks left for Science fair and almost 2months for regional Science fair?Should we do one more trial with top soil and 10g salt ?
We were thinking about using soil under river for another trial .Is it a good idea?What do we show as 3 types of soil.First was potting soil,2nd consists of clay.Does it make sense to do do third trial with river soil as it may again consists of clay with bacteria rich soil.What explanation we should give for LED of 2nd MFC not blinking .
Also I tried connecting MFCs is series and parallel ,but could not get any result.Can you please tell me in detail on how to do and where exactly to measure the output?
Also we tried the digital thermometer,but there was no display.Does it require additional capacitor or the capacitor with the kit can work?
Thankyou so much.
Waiting for your reply before the next step.
Thanks
Maliha

Hi
Thank you so much for your reply.
We were using 2 MFCs to compare the power output after adding the salt.For the first trial we used store bought potting soil(Nature's Care Organic Potting Soil Water Conserve).
Below are the power output measurements
https://docs.google.com/spreadsheets/d/ ... sp=sharing
Below are voltage current measurements at the first day
https://docs.google.com/spreadsheets/d/ ... sp=sharing
Voltage and current after adding the salt on day 13 are
Distilled water-0.3microA
soil
1g soil-8.66mA
5g soil-36.8mA

As you can see that the power out is low,so the LEDs for both MFCs did not blink.The internal resistance was high.The temperature was not constant .It was 68-72F.
The output of 1g salt is more than 5g salt).
During the second trial we soil we used the top soil from some one's backyard.We checked with them that there was no pesticides used.
Below is the link of the power output.
https://docs.google.com/spreadsheets/d/ ... sp=sharing
Below is the voltage and current of MFCs measure each day
https://docs.google.com/spreadsheets/d/ ... sp=sharing
Below is the current and voltage measure on the first day
https://docs.google.com/spreadsheets/d/ ... sp=sharing
Voltage and current after adding salt on day 13
Distilled water-o.1mA
1g soil-3.38mA,3.21mA,3.5mA
5g soil-14.46mA,14.55mA,14.79mA
We used heat wrap to keep the temperature constant at 72F at the time of taking reading.Throughout the day, temperature was 68-72F.The LED of 1g blinked.
On the day we added salt LED blinks are as follows
Temperature- Time between blinks
71F -30
73 -18
74.5 -15
74 -12
75 -10
78 -8
The temperature was recorded each day .
As you can see that the power output of 5g salt is more than 1 g soil(which is opposite to first trial).The internal resitance of 1g salt is 4700ohms.Internal resistance of 5g soil decresed.
After adding the in 5g soil,the LED blinked .Time between the blinks reduced from 8 sec to 1 sec,then LEd completely stopped blinking after 3 weeks of addition of salt.
The1 g LED stopping blinking after 1 week of addition of salt.
We also tried using using mud watt app for our second trial,but the results were not compatible with power output readings.

2nd day-8W,4W,3W
6 day-3W
13 day-3W
12 day 8w
The point is LEDs blinks were not uniform.How do we epresent the LEDs blinks output?
Which output was expected to be more ,1g salt or 5 g salt?
What do we explain for the opposite output of 2 trials.
Why is the output of topping soil so low?
Why did the internal resistance of 2nd MFC change?

We have 3 weeks left for Science fair and almost 2months for regional Science fair?Should we add 5g more salt to second MFC or start from fresh soil?
We were thinking about using soil under river for another trial .Is it a good idea?What do we show as 3 types of soil.First was potting soil,2nd consists of clay.Does it make sense to do do third trial with river soil as it may again consists of clay with bacteria rich soil.
Also I tried connecting MFCs is series and parallel ,but could not get any result.Can you please tell me in detail on how to do and where exactly to measure the output?
Also we tried the digital clock but there was no display with 10 micro farad capacitor.
Thankyou so much.
Waiting for your reply before the next step.
Thanks

Hi
I have been trying to get help from long time.I would really appreciate if I can get some guidance.
Details about the experiment in the last post below.
.At this stage we added 5g more salt in 2nd MFC with 5g salt on day 30 .
With the top soil,We are getting highest output power with 5g. The power decreased when we added more salt . Is it reasonable?For some reason the LED did not blink with 10 g salt. How do explain that.
According to us power out from maximum to minimum is from 5g,10g,1g.
Few questions at this stage.
Why is the power output of 1g is more than 5 g in potting soil?
What exactly is the relation between the LED blinking and power output?
The kit has only one capacitor.The digital clock does not work with it?What could be the problem?
Do we need additional capacitor for the digital clock or thermometer?
We have lot of trouble connecting MFC in series and parallel.Please show us exact connections and were to take the output.For some reason we get 0 output?



Hi
Thank you so much for your reply.
We were using 2 MFCs to compare the power output after adding the salt.For the first trial we used store bought potting soil(Nature's Care Organic Potting Soil Water Conserve).
Below are the power output measurements
https://docs.google.com/spreadsheets/d/ ... sp=sharing
Below are voltage current measurements at the first day
https://docs.google.com/spreadsheets/d/ ... sp=sharing
Voltage and current after adding the salt on day 13 are
Distilled water-0.3microA
soil
1g soil-8.66mA
5g soil-36.8mA

As you can see that the power out is low,so the LEDs for both MFCs did not blink.The internal resistance was high.The temperature was not constant .It was 68-72F.
The output of 1g salt is more than 5g salt).
During the second trial we soil we used the top soil from some one's backyard.We checked with them that there was no pesticides used.
Below is the link of the power output.
https://docs.google.com/spreadsheets/d/ ... sp=sharing
Below is the voltage and current of MFCs measure each day
https://docs.google.com/spreadsheets/d/ ... sp=sharing
Below is the current and voltage measure on the first day
https://docs.google.com/spreadsheets/d/ ... sp=sharing
Voltage and current after adding salt on day 13
Distilled water-o.1mA
1g soil-3.38mA,3.21mA,3.5mA
5g soil-14.46mA,14.55mA,14.79mA
We used heat wrap to keep the temperature constant at 72F at the time of taking reading.Throughout the day, temperature was 68-72F.The LED of 1g blinked.
On the day we added salt LED blinks are as follows
Temperature- Time between blinks
71F -30
73 -18
74.5 -15
74 -12
75 -10
78 -8
The temperature was recorded each day .
As you can see that the power output of 5g salt is more than 1 g soil(which is opposite to first trial).The internal resitance of 1g salt is 4700ohms.Internal resistance of 5g soil decresed.
After adding the in 5g soil,the LED blinked .Time between the blinks reduced from 8 sec to 1 sec,then LEd completely stopped blinking after 3 weeks of addition of salt.
The1 g LED stopping blinking after 1 week of addition of salt.
We also tried using using mud watt app for our second trial,but the results were not compatible with power output readings.

2nd day-8W,4W,3W
6 day-3W
13 day-3W
12 day 8w
The point is LEDs blinks were not uniform.How do we epresent the LEDs blinks output?
Which output was expected to be more ,1g salt or 5 g salt?
What do we explain for the opposite output of 2 trials.
Why is the output of topping soil so low?
Why did the internal resistance of 2nd MFC change?

Hi
I have been trying to get help from long time.I would really appreciate if I can get some guidance.
Details about the experiment in the last post below.
.At this stage we added 5g more salt in 2nd MFC with 5g salt on day 30 .
With the top soil,We are getting highest output power with 5g. The power decreased when we added more salt . Is it reasonable?For some reason the LED did not blink with 10 g salt. How do explain that.
According to us power out from maximum to minimum is from 5g,10g,1g.
Few questions at this stage.
Why is the power output of 1g is more than 5 g in potting soil?
What exactly is the relation between the LED blinking and power output?
The kit has only one capacitor.The digital clock does not work with it?What could be the problem?
Do we need additional capacitor for the digital clock or thermometer?
We have lot of trouble connecting MFC in series and parallel.Please show us exact connections and were to take the output.For some reason we get 0 output?



Hi
Thank you so much for your reply.
We were using 2 MFCs to compare the power output after adding the salt.For the first trial we used store bought potting soil(Nature's Care Organic Potting Soil Water Conserve).
Below are the power output measurements
https://docs.google.com/spreadsheets/d/ ... sp=sharing
Below are voltage current measurements at the first day
https://docs.google.com/spreadsheets/d/ ... sp=sharing
Voltage and current after adding the salt on day 13 are
Distilled water-0.3microA
soil
1g soil-8.66mA
5g soil-36.8mA

As you can see that the power out is low,so the LEDs for both MFCs did not blink.The internal resistance was high.The temperature was not constant .It was 68-72F.
The output of 1g salt is more than 5g salt).
During the second trial we soil we used the top soil from some one's backyard.We checked with them that there was no pesticides used.
Below is the link of the power output.
https://docs.google.com/spreadsheets/d/ ... sp=sharing
Below is the voltage and current of MFCs measure each day
https://docs.google.com/spreadsheets/d/ ... sp=sharing
Below is the current and voltage measure on the first day
https://docs.google.com/spreadsheets/d/ ... sp=sharing
Voltage and current after adding salt on day 13
Distilled water-o.1mA
1g soil-3.38mA,3.21mA,3.5mA
5g soil-14.46mA,14.55mA,14.79mA
We used heat wrap to keep the temperature constant at 72F at the time of taking reading.Throughout the day, temperature was 68-72F.The LED of 1g blinked.
On the day we added salt LED blinks are as follows
Temperature- Time between blinks
71F -30
73 -18
74.5 -15
74 -12
75 -10
78 -8
The temperature was recorded each day .
As you can see that the power output of 5g salt is more than 1 g soil(which is opposite to first trial).The internal resitance of 1g salt is 4700ohms.Internal resistance of 5g soil decresed.
After adding the in 5g soil,the LED blinked .Time between the blinks reduced from 8 sec to 1 sec,then LEd completely stopped blinking after 3 weeks of addition of salt.
The1 g LED stopping blinking after 1 week of addition of salt.
We also tried using using mud watt app for our second trial,but the results were not compatible with power output readings.

2nd day-8W,4W,3W
6 day-3W
13 day-3W
12 day 8w
The point is LEDs blinks were not uniform.How do we epresent the LEDs blinks output?
Which output was expected to be more ,1g salt or 5 g salt?
What do we explain for the opposite output of 2 trials.
Why is the output of topping soil so low?
Why did the internal resistance of 2nd MFC change?

Please help me.Details in the previous post.

My Science Fair is next week.Please answers my questions in the previous posts.

My Science Fair is next week.Please answers my questions in the previous posts.