| Author | Aziz, Salman |
| Call Number | AIT Thesis no.EV-93-09 |
| Subject(s) | Sewage--Purification--Activated sludge process
|
| Note | A thesis submitted in partial fulfillment of the requirement for the Degree of Master of
Engineering |
| Publisher | Asian Institute of Technology |
| Abstract | Aerobic treatment of synthetic (polyester) fiber production wastewater was carried
out to solve the problem of sludge bulking in activated sludge process of the treatment plant
at a local factory in Bangkok. The causes of sludge bulking in three activated sludge process
units were found out to be non-filamentous or pin point floe and filamentous in nature. To
eradicate these two types of bulking, optimum loading and intermittent feeding pattern were
found out to be the solutions. Three laboratory scale activated sludge process units were
operated with continuous feeding at a loading of 1.88, 1.24 and 1.03 kg COD/m3 .d and F/M
ratio of 0.36, 0.3 and 0.23 kg COD/kg MLSS.d, respectively. Similarly, two pilot scale
reactors with intermittent feeding were operated at loading of 0.81 and 1.2 kg COD/m3.d
and F/M ratio of 0.16 and 0.26 kg COD/kg MLSS.d. Intermittent loading was found out to
be an effective method for the removal of filamentous bacteria. The optimum loading was
found out to be 1.2 kg COD/m3.d with F/M ratio of 0.26 kg COD/kg MLSS.d.
A pilot scale sequencing batch reactor was operated at a loading of 1.5kg COD/m3.d
with F/M ratio of 0.36 kg COD/kg MLSS.d and was found out to be very suitable for the
treatment of this wastewater in terms of sludge settleability and substrate removal.
Domestic wastewater produced in the factory compound was mixed with the synthetic
fiber wastewater for foint treatment by activated sludge process. Initially, the effect on sludge
settleability was found to be good but was later on it was effected by the proliferation of
filamentous bacteria, whereas the substrate removal was satisfactory.
Two laboratory scale activated sludge process reactors were operated to treat the
effluent from pilot scale anaerobic fixed bed reactor operating on synthetic fiber wastewater.
Anaerobic fixed bed reactor was operated at loadings of 2.5 and 4.0 kg COD/m3 .d, during
this period. A loading of 1.0 kg COD/m3.d and F/M ratio of 0.34 kg COD/kg MLSS.d for
aerobic treatment by activated sludge process was found to be the most suitable to achieve
the effluent standards required by the factory. |
| Year | 1993 |
| 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) | Reutergardh, Lars Baetz; |
| Examination Committee(s) | Fujii, Shigeo;Visvanathan, C.; |
| Scholarship Donor(s) | Government of France; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1993 |