A study of the optimal conditions for biological nitrogen removal in activated sludge processes by theoretical analysis and numerical calculation | |
| Author | Lee, Byoung-dea |
| Call Number | AIT Thesis no. EV-94-16 |
| Subject(s) | Sewage--Purification--Nitrogen removal Sewage--Purification--Activated sludge process |
| Note | A thesis submitted in partial fulfillment of the requirement for the degree of Master of Engineering, School of Environment, Resources & Development |
| Publisher | Asian Institute of Technology |
| Abstract | Two activated s ludge methods of Anoxic-oxic and step-feed system were analyzed theoretically and numerically for the optimal operation and design condition in this research, and the results were compared with several reports from these WWTPs. The key water quality items for this theoretical analysis are ammonium nitrogen, nitrate nitrogen, alkalinity, substrate and dissolved oxygen . The return ratio including mixed liquor recycling ratio is considered as an operation parameter in the anoxic-oxic system , while the internal recycling ratio and influent allocation ratio to the second anoxic tank are considered additionally as operation parameters in the step-feed system. In case of optimal operation conditions, minimum R value for the anoxic-oxic system and n value for the step-feed system to acquire the maximum TN and NH/-N removal efficiency were identified by theoretical analysis. Accordingly, theoretical maximum TN and NH4+- N removal efficiency were obtained. For further analysis, volume ratios of reactor compartments in both systems were illustrated through theoretical analysis to get the optimal design condition (optimal reactor volume ratio for maximum TN removal) . In some of WWTPs, the performance was simulated by model for the comparison with the theoretical and reported result. Finally, reported, theoretical and simulated TN effluent were compared with each other. The reported volume ratio of reactor compared favorably with theoretical volume ratio. |
| Year | 1994 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Other Field of Studies (No Department) |
| Academic Program/FoS | Environmental Engineering and Management (EV) |
| Chairperson(s) | Wise, Donald L. |
| Examination Committee(s) | Fujii, Shigeo ;Umita, Teruyuki |
| Scholarship Donor(s) | The Federal Republic of Germany(DAAD) |
| Degree | Thesis (M.Eng.) - Asian Institute of technology, 1994 |