Effects of membrane relaxation rate on performance of pilot-scale membrane aerated biofilm reactors | |
| Author | Nguyen Anh Vu |
| Call Number | AIT Thesis no.EV-21-10 |
| Subject(s) | Water--Purification--Membrane filtration Membrane reactors |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Environmental Engineering and Management |
| Publisher | Asian Institute of Technology |
| Abstract | The membrane aerated biofilm reactor (MABR) is a recently developed biofilm-based wastewater treatment technology that has been reported to provide effective heterotrophic oxidation and simultaneous nitrification and denitrification in a single reactor. Since it works as a bubble-less air diffuser and bio-carrier, the shape of membranes in an MABR plays an important role in influencing the efficiency of oxygen supplement and utilization. This study experimented with two pilot-scale MABRs using multi-layer hollow fiber membranes with the relaxation rates of 0.1-1.8% (MABR 1) and 1.0-2.8% (MABR 2) for the treatment of organics and nitrogen in actual medium-strength domestic wastewater, before and after adding the polyvinyl alcohol (PVA) gel beads carrying denitrifying bacteria. Higher relaxation-rate membranes have looser and more curved fiber bunch that may allow biofilm to grow more easily and air to diffuse more efficiently. During the operation without PVA gel beads, MABR 2 provided better performance than MABR 1 at 12- and 6-h hydraulic retention time (HRT), with respectively 0.7-4.3%, 17.7- 18.1%, and 5.5-9.0% higher removal efficiencies for COD, NH4 + -N, and TN. However, at the HRT of 3h, the difference between the nitrogen removal performance of two MABR systems was not significant. The highest COD, NH4 + -N, and TN removal efficiencies during this period were respectively 94.7%, 81.1%, and 57.1% at 12h HRT in MABR 2. The addition of the PVA gel beads had resulted in higher denitrification efficiencies in both reactors while not much affecting the COD removal and nitrification processes. The increments of 5.0-9.0% and 6.6-12.3% were reported for TN removal efficiencies of MABR 1 and 2, sequentially, in comparison with the previous period. Besides, the MABR 2 still showed 5.5-10.7% higher removal efficiencies than MABR 1, at HRT of 12 and 6h. On the other side, no significant difference was found when comparing the energy consumption and sludge production between the two systems. |
| Year | 2021 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Energy and Climate Change (Former title: Department of Energy, Environment, and Climate Change (DEECC)) |
| Academic Program/FoS | Environmental Engineering and Management (EV) |
| Chairperson(s) | Visvanathan, Chettiyappan; |
| Examination Committee(s) | Loc Thai Nguyen;Xue, Wenchao; |
| Scholarship Donor(s) | Kurita Water and Environment Foundation, Japan; |
| Degree | Thesis (M. Eng.) - Asian Institute of Technology, 2021 |