| Author | Ravipim Maythanukhraw |
| Call Number | AIT Thesis no. EV-95-33 |
| Subject(s) | Sewage--Purification--Activated sludge process
|
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering. |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. EV-95-33 |
| Abstract | In this study the possibility of application of air backflushing technique through hollow
fiber microfiltration was investigated. The membrane module with a pore size of 0.1 μm was
immersed in the activated sludge aeration tank. This study was divided into short term and long
term experiments.
In the short terms experimental runs, the optimum air backflushing and filtration cycle was
investigated. 15 minutes filtration and 15 minutes air backflushing gave the best result both in
terms of stable flux and highest net cumulative permeate volume. Although this cyclic operation,
could not completely remove the clogging, this process could improve the flux by up to 371 %
compared to the continuous operation. Due to the membrane module stability limitations, the
applied compressed air pressure was not sufficient to make the membrane to function totally as an
aeration unit.
In the long term runs, three different hydraulic detention times (HR T) of 12, 6 and 3
hours, which corresponds to the permeate flux of0.16, 0.32 and 0.64 m3/m2.d were investigated.
Here, it was noted that the filtration pressure increases with the increase of bioreactor :rvILSS
concentration. Whereas the stable operation could be obtained at the HRT of 12 hours. Decrease
in HR T, lead to rapid formation of compact cake layer on the membrane surface, augmentation of
transmembrane pressure. All the experimental runs produced more than 90% removal of COD,
and TKN. With operation time, the :ML VSS/:MLSS values was found decrease, without effecting
significantly the process performance, indicating the constant accumulation of inorganic mass
within the bioreactor. In terms of physical, chemical, biological and bacteriological parameters,
the membrane bioreactor effluent was superior to the conventional activated sludge process. |
| Year | 1995 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. EV-95-33 |
| 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 (EV) |
| Chairperson(s) | Visvanathan, C. |
| Examination Committee(s) | Samorn Muttamara;Yang, Byung-Soo |
| Scholarship Donor(s) | P.P. Center Co., Ltd. |
| Degree | Thesis (M. Eng.) - Asian Institute of Technology, 1995 |