Study of the packed-cage as an aerator for activated sludge | |
| Author | Sanchai Thiewprasertkul |
| Call Number | AIT Thesis no. 975 |
| Subject(s) | Sewage--Purification--Aeration Sewage--Purification--Activated sludge process |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science of the Asian Institute of Technology, Bangkok, Thailand. |
| Publisher | Asian Institute of Technology |
| Abstract | Performance studies of a packed-cage drum aerator and a surface aerator were carried out using the non-steady state reoxygenation of tapwater. The results indicated that the drum aerator supplied more oxygen than a surface aerator at a lower power consumption. Variation of oxygen transfer coefficient with speed of the drum aerator was found to follow a logarithmic relationship while a linear arithmetic relationship was observed in the case of the surface aerator. Addition of air entrainment buckets in the drum aerator resulted in a significant increase of oxygen transfer at low speeds. The effect was reversed at speeds in excess of 30 rpm. Utilizing the optimum conditions obtained from the study with tapwater, parallel operation of the two aerators in the activated sludge process was carried out using a soft drink bottling waste from the factory of Serm Suk Co., Ltd., Bangkok, Thailand. Comparative studies of aerator efficiency were conducted simultaneously with the evaluation of efficiency, performance and stability of the systems. The results of studies on oxygen transfer show that the drum aerator performed at better efficiency, as indicated by the higher quantity of oxygen transferred per unit of power consumed and higher value. The substrate removal efficiency and sludge production in both systems were found to be of the same magnitude. Settleability of sludge maintained in the drum aeration system was observed to be better than in the surface aeration system when compared in the same region of dissolved oxygen concentration in the reactors. At low and moderate organic loadings (24, 18, 12 and 8 hr detention time), the stability of the drum system against both quantitative and qualitative shockloads was better, while the same magnitude of responses were obtained at high loadings (6 and 4 hours detention time) . Response of the COD and BOD removal efficiency of the drum system to the changing hydraulic flow rate was observed to be less than in the surface aeration system. |
| Year | 1976 |
| Type | Thesis |
| School | Student Research Before 1980 |
| Department | Other Field of Studies (No Department) |
| Academic Program/FoS | Thesis (Year <=1979) |
| Chairperson(s) | Pescod, M.B. |
| Scholarship Donor(s) | The Government of Japan. |
| Degree | Thesis (M.Sc.) - Asian Institute of Technology, 1976 |