Biological nitrogen removal as nitrous oxide for energy recovery : process control and modeling
Abstract/Contents
- Abstract
- Recently, a new biological nitrogen removal process, Coupled Aerobic-anoxic Nitrous Decomposition Operation (CANDO), was developed for wastewater treatment. The process converts ammonia in wastewater into nitrous oxide (N2O), which can be used for energy recovery. CANDO is a two-step process, first oxidizing ammonia into nitrite, and then reducing to N2O. This thesis investigates both biological reaction steps for their microbial ecology, operation control and performance optimization. The approach to the research questions is reactor-based studies at both pilot-scale and bench-scale. Heterotrophic nitrifiers were found to be the major contributor to stable nitritation (first step) in the pilot-scale system, stimulated by the addition of dewatering polymer and particulate organics in the upstream process. The second step, namely nitrous denitritation, was found to be carried out by heterotrophic denitrifiers capable of accumulating polyhydroxyalkanoates. Optimal carbon to nitrogen input ratio was found to ensure sufficient reducing power for PHA synthesis and subsequent N2O production, and fast enrichment. Moreover, shortening both anaerobic and anoxic phases of an operational cycle was found to improve carbon utilization efficiency and recoverable N2O yield. From follow-up bench-scale studies, key microbial storage compounds were identified based on a better understanding of the mechanisms of nitrous denitritation pathways. A mathematical model was also developed for prediction and optimization of the CANDO process. The findings presented in this thesis showed the scalability and efficiency of implementing CANDO for resource and energy recovery from municipal wastewater
Description
| Type of resource | text |
|---|---|
| Form | electronic resource; remote; computer; online resource |
| Extent | 1 online resource |
| Place | California |
| Place | [Stanford, California] |
| Publisher | [Stanford University] |
| Copyright date | 2019; ©2019 |
| Publication date | 2019; 2019 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Author | Wang, Zhiyue (Philip) |
|---|---|
| Degree supervisor | Criddle, Craig |
| Thesis advisor | Criddle, Craig |
| Thesis advisor | Casciotti, Karen Lynn, 1974- |
| Thesis advisor | McCarty, Perry L |
| Degree committee member | Casciotti, Karen Lynn, 1974- |
| Degree committee member | McCarty, Perry L |
| Associated with | Stanford University, Civil & Environmental Engineering Department. |
Subjects
| Genre | Theses |
|---|---|
| Genre | Text |
Bibliographic information
| Statement of responsibility | Zhiyue Wang |
|---|---|
| Note | Submitted to the Civil & Environmental Engineering Department |
| Thesis | Thesis Ph.D. Stanford University 2019 |
| Location | electronic resource |
Access conditions
- Copyright
- © 2019 by Zhiyue Wang
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
Also listed in
Loading usage metrics...