Dissertation
BIOELECTROCHEMICAL SYSTEMS FOR WASTEWATER TREATMENT
Doctor of Philosophy (PhD), Washington State University
01/2018
Handle:
https://hdl.handle.net/2376/116907
Abstract
Bioelectrochemical systems (BESs) are capable of converting the chemical energy of organic matter using electrochemically-active microorganisms as a catalyst into electrical energy, hydrogen or other value-added products through oxidation/reduction reactions. The findings reported here addressed several different limitations and solutions of BESs operation and performance for wastewater treatment.
The first part of the dissertation was focused on the scaling up of anodic biofilms for higher the current generation. We tested the effect of the electrode size and electron donor concentrations, represented as Chemical Oxygen Demand (COD), by enriching anodic biofilms on multiple electrode sizes and quantifying the anodic current densities while changing the electron donor concentrations. It was found that current generated using anodic biofilms was linearly scaled up at high COD loading (1500 mg/L), while current density decreased with increasing electrode size at lower COD loadings (150 mg/L). Further, microbial community analysis showed that the microbial community on the anode was independent of the electrode size but dependent on the medium composition during the enrichment phase.
The second part of the dissertation was focused on developing a flow through 3-electrode bioelectrochemical reactor to evaluate how increased surface area could affect COD and total nitrogen (TN) removal rates and studying the mechanisms of nitrogen removal. It was found that increased surface area did not significantly increase COD removal rate. Compared to COD removal rate, TN removal rate increased proportionally to the surface area of the electrode in the BESs. Unexpectedly, outlet nitrite (NO2--N) and nitrate (NO3--N) concentrations increased. Our results indicated that it is possible to anaerobically remove COD while removing TN. Some future works such as integrated BESs with conventional systems to increase nitrogen removal efficiency, cost-benefit analysis, and life cycle analysis have been suggested.
Overall, it was concluded that BESs with appropriately designed conditions such as electrode material, electrode size, and electron donor concentrations can be used for current generation and wastewater treatment.
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Details
- Title
- BIOELECTROCHEMICAL SYSTEMS FOR WASTEWATER TREATMENT
- Creators
- SECIL TUTAR
- Contributors
- HALUK BEYENAL (Advisor)STEVEN R. SAUNDERS (Committee Member)ARDA GOZEN (Committee Member)ERIK R. COATS (Committee Member)ANITA VASAVADA (Committee Member)
- Awarding Institution
- Washington State University
- Academic Unit
- Voiland College of Engineering and Architecture
- Theses and Dissertations
- Doctor of Philosophy (PhD), Washington State University
- Number of pages
- 173
- Identifiers
- 99900581818601842
- Language
- English
- Resource Type
- Dissertation