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.