to determine which wastewater sample creates the most millivolts using a microbial fuel cell
(MFC). I believe that the simulated ground food wastewater sample will produce the most millivolts using
an MFC.
Methods/Materials
Three microbial fuel cells with identical cathode and anode chambers, electrodes, and salt bridges were
built. The secondary (biological) treatment sample was collected from the wastewater plant, and the
ground food household wastewater sample was mixed. The wastewater samples and control were poured
into individual anode bottles, and sealed airtight. Each cathode bottle was filled with a saltwater
conductive solution. The external circuit was connected to the resistor (multi-meter) and the millivolt
readings were recorded twice daily, for seven days.
Results
The secondary (biological) treatment wastewater sample from the Sunnyvale, CA Water Pollution Control
Plant produced the highest reading, 152.45 millivolts. Simulated ground food wastewater sample
generated a 78.75 millivolt reading.
Conclusions/Discussion
My conclusion does not support my hypothesis that the simulated ground food wastewater sample will
produce the most millivolts using an MFC. Microorganisms added to the secondary (biological) treatment
wastewater at the treatment plant, generated the highest reading of 152.45 millivolts. This is only 10.16
percent of a 1.5 volt AA battery output. Ground food naturally produced nearly half the secondary
treatment millivolt level. The data demonstrates that a microbial fuel cell can be used to harvest electricity
from ground food and secondary (biological) treatment wastewater.
The purpose of my project is to present experimental data comparing the amount of electricity, measured
in millivolts, generated from wastewater samples using a microbial fuel cell.
My parents drove me to purchase supplies, collect wastewater plant samples, and borrow the multi-meter.
My parents paid for all materials and lent me tools. My parents answered questions about grammar and
word choice, took pictures, and made sure I thought safety first.