Algae Culturing Methods:
Algae Culturing primarily consisted of the systematic maintenance of the
chambers and the bioreactor system (the entire MFC system with its
containment). Nearly 3.78 g/L of Miracle Gro (a generic nutrient media)
was mixtured into the bioreactor system- or 0.003 g/mL. The bioreactor
system primarily had two air pumps per microbial fuel cell system. This
system also included close contact fluorescent lights to further
maintain optimal growth conditions. Once the culture reduced towards 100
mL, it was replenished with 3.78 g/L of distilled water to replenish the
bioreactor. Constant agitation was balanced through a laboratory shaker
table at a setting of 2/10.
Essential Materials:
Spectrophotometer: This will measure the absorptive frequencies of
light, ensuring the growth rate of algae (this is a crucial part of the
experimental procedure).
Electrical output (mW) will be assessed and recorded by using a
multimeter.
Potassium Hydroxide is used for lipid extraction, with nearly 1 ml of
potassium hydroxide.
Quantification of Variables: Electrical Output, Lipid Yields, and Cell
Concentration
The variety of parameters and dependent variables obtained during
experimentation included the resulting oil production, electrical
output, and culture concentrations. Several instruments were utilized to
precisely analyze each variable in relation to algae development. Cell
concentration was primarily sampled to understand media and culture
densities. In other words, algal density and absorption rates were
recorded. A spectrophotometer was used to compare and acquire cell
concentration. Higher algal culture absorption rates in (A) defined as
highly dense cultures. Most importantly, electrical output was, simply,
analyzed through a multimeter in mW electrical-energy. The multimeter
was attached to a low-resistance copper wire which was coiled around a
graphite stick submerged into the cathodic and anodic chambers of the
MFC. Additionally, lipid yields were assessed to better understand the
capabilities of oil production (in mL).
Independent Variables Tested:
An Algae-based microbial fuel cell will be compared in different culture
species. More specifically, Nannochloropsis, Chlorella Vulgaris, and
Spirulina will be investigated as an alternative biological energy
source.
Controlled Variables: The results obtained will than be compared with a
generic bacterial-MFC system. The results, in terms of large scale
energy production, will be analyzed, in relation to traditional fossil
fuels and oil production.
Constant Parameters:
Throughout experimentation, parameters such as pH, salinity, lux levels
(light intensity), temperature, and cell concentration were maintained.
The containment was maintained by replenishing and releveling water
levels to maintain constant cell concentrations. In addition,
stabilizing pH, salinity, light intensity, and temperature was
significant to ensure genuine results.