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michka:research:microbial_fuel_cells:bruxelles2 [2014-09-26 10:01] michkamichka:research:microbial_fuel_cells:bruxelles2 [2014-10-09 16:09] michka
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 ====Experiment "Bruxelles2"==== ====Experiment "Bruxelles2"====
 +
 +{{ :michka:research:microbial_fuel_cells:dscf6353.jpg?300 |}}
  
 ===Salt Bridges=== ===Salt Bridges===
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 I failed a three batches of [[http://www.treehugger.com/slideshows/gadgets/make-microbial-fuel-cell/page/3/#slide-top|salt bridges]] before managing to have one stable made. I failed a three batches of [[http://www.treehugger.com/slideshows/gadgets/make-microbial-fuel-cell/page/3/#slide-top|salt bridges]] before managing to have one stable made.
  
-===The right protocol=== +The right protocol:
    * Mix 200 ml water, 5 g of agar and 75g of salt in a cooking pan.    * Mix 200 ml water, 5 g of agar and 75g of salt in a cooking pan.
    * Bring it to a boil while mixing regularly.    * Bring it to a boil while mixing regularly.
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    * Place them in the fridge for a few hours    * Place them in the fridge for a few hours
  
-===What not to do=== +What not to do:
    * Use hot water from a kettle and mix everything in a cold pot    * Use hot water from a kettle and mix everything in a cold pot
      * This induces a very uneven mix, where salt and agar are not well dissolved      * This induces a very uneven mix, where salt and agar are not well dissolved
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 ===Mud, Tall=== ===Mud, Tall===
 +
 +{{ :michka:research:microbial_fuel_cells:dscf6283.jpg?300 |}}
 +//Mud samping location - Sint-Jans-Molenbeek, Belgium//
 +
  
 Design details: Design details:
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    * Current is in the 1-2mA range.    * Current is in the 1-2mA range.
    * Power is therefore in the mW range.    * Power is therefore in the mW range.
 +
 +Longer-term results (12 days & more):
 +   * Tension is stable at 110  mV, but drops when measuring current (and rises up afterwards).
 +   * Current is stable at 107 microA, but drops after measuring tension (and rises up afterwards).
 +   * Overall power is therefore around 11 mW.
  
 ===Mud, Small=== ===Mud, Small===
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    * Current is sensitive to oxygen presence, and is very low - about 0.3 mV when activated, dropping to 0.1 mV at rest.    * Current is sensitive to oxygen presence, and is very low - about 0.3 mV when activated, dropping to 0.1 mV at rest.
    * Power is therefore in the microW range.    * Power is therefore in the microW range.
 +
 +Longer-term results (12 days & more):
 +   * Tension is stable at 20 mV.
 +   * Current is stable at 1 microA.
 +   * Overall power is therefore around 20 microW.
  
 ===Vegetable Waste & Compost Tea=== ===Vegetable Waste & Compost Tea===
 +
 +{{ :michka:research:microbial_fuel_cells:dscf6352.jpg?300 |}}
  
 Design details: Design details:
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    * Current is sensitive to oxygen presence, and is very low - about 0.4 mV when activated, dropping to 0.1 mV at rest.    * Current is sensitive to oxygen presence, and is very low - about 0.4 mV when activated, dropping to 0.1 mV at rest.
    * Power is therefore in the microW range.    * Power is therefore in the microW range.
 +
 +Longer-term results (12 days & more):
 +   * Tension is stable at 120 mV.
 +   * Current is stable at 135 microA.
 +   * Overall power is therefore around 16 mW.
 +
 +===Conclusion===
 +
 +   * Electrode surface area seems an important feature.
 +   * Most of the mud in the Tall-Mud design has been sitting here for a week, which may have an influence on community development.
 +   * Considering electrode area and overall volume, the compost tea design seems very productive.
 +
 +===Further Designs===
 +   * Scale-up the vegetable+compost tea design.
 +   * Look for carbon electrodes, which seem more appropriate
 +   * Replace salt bridge with paper
 +
 +{{ :michka:research:microbial_fuel_cells:dscf6357.jpg?300 |}}
  • michka/research/microbial_fuel_cells/bruxelles2.txt
  • Last modified: 2014-10-09 22:02
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