2024-03-28T15:27:02Zhttps://keep.lib.asu.edu/oai/requestoai:keep.lib.asu.edu:node-1365912021-08-11T21:09:57Zoai_pmh:all136591
https://hdl.handle.net/2286/R.I.28604
http://rightsstatements.org/vocab/InC/1.0/
2015-05
33 pages
eng
Stadie, Mikaela Johanna
Torres, Cesar
Popat, Sudeep
Barrett, The Honors College
Chemical Engineering Program
Text
Microbial fuel cells (MFCs) promote the sustainable conversion of organic matter in black water to electrical current, enabling the production of hydrogen peroxide (H2O2) while making waste water treatment energy neutral or positive. H2O2 is useful in remote locations such as U.S. military forward operating bases (FOBs) for on-site tertiary water treatment or as a medical disinfectant, among many other uses. Various carbon-based catalysts and binders for use at the cathode of a an MFC for H2O2 production are explored using linear sweep voltammetry (LSV) and rotating ring-disk electrode (RRDE) techniques. The oxygen reduction reaction (ORR) at the cathode has slow kinetics at conditions present in the MFC, making it important to find a catalyst type and loading which promote a 2e- (rather than 4e-) reaction to maximize H2O2 formation. Using LSV methods, I compared the cathodic overpotentials associated with graphite and Vulcan carbon catalysts as well as Nafion and AS-4 binders. Vulcan carbon catalyst with Nafion binder produced the lowest overpotentials of any binder/catalyst combinations. Additionally, I determined that pH control may be required at the cathode due to large potential losses caused by hydroxide (OH-) concentration gradients. Furthermore, RRDE tests indicate that Vulcan carbon catalyst with a Nafion binder has a higher H2O2 production efficiency at lower catalyst loadings, but the trade-off is a greater potential loss due to higher activation energy. Therefore, an intermediate catalyst loading of 0.5 mg/cm2 Vulcan carbon with Nafion binder is recommended for the final MFC design. The chosen catalyst, binder, and loading will maximize H2O2 production, optimize MFC performance, and minimize the need for additional energy input into the system.
Linear Sweep Voltammetry
Hydrogen Peroxide
Gray Water
Activation Energy
RRDE
Nernst Equation
Environmental Biotechnology
MFC
Rotating Ring-disk Electrodes
SERDP
ORR
Polarization Curve
Peroxide
Concentration Gradients
Nafion
Loading
Forward Operating Base
Air-cathode
Wastewater treatment
Theoretical Potential
Microbial Fuel Cells
Collection Efficiency
Blackwater
pH Control
Cathodes
Vulcan
Chemical Engineering Program
Oxygen Reduction Reactions
Disinfection
Overpotential
wastewater
Carbon
LSV
Sustainable Energy
electrochemistry
U.S. Department of Defense
Mass Transport
Sustainable
Catalysts
A Sustainable Approach to Wastewater Treatment Using Microbial Fuel Cells with Peroxide Production