| Author | Tran Thi Hong Nhien |
| Call Number | AIT Thesis no.EV-93-31 |
| Subject(s) | Sewage--Purification--Biological treatment
|
| Note | A thesis submitted in partial fulfillment of the requirement for the degree of Master of
Engineering |
| Publisher | Asian Institute of Technology |
| Abstract | A biological aerated filter combines bacterial degradation of pollutant by fixed biomass
with physical filtration in a single reactor. An organic removal process has been operated on
an experimental basis at a pilot plant over five months at the AIT - Environmental
Engineering Division Laboratory.
The wastewater feed was modified AIT domestic wastewater. The process consists of
a granular media bed, particularly of polystyrene (thus, named biostyr process) with a specific
gravity of approximately 0.06. The cylindial reactor was 4 m high and 0.2 m diameter.
Headloss measurement was studied as a function of wastewater temperature, velocity
and time. Experiments were conducted at 30°C, 38°C, 45°C and 55°C with velocities of 2
m/h, 4 m/h, 6 m/h and 8 m/h respectively. At 38°C, filtration time range was 5.5-10 hours
and over 84% of the soluble COD was removed at all velocities investigated. At 30°C, 75.8-
89.4% COD removal was noticed, 89.4% COD removal with the exception of 6 m/h velocity
and 8.5 hour filtration time. At 45 °C, 77.1-87.9% of soluble COD was removed, in which
87.9% COD removal could be obtained at 2 m/h velocity with a filtration time of 40 hours.
A decreasing gradient of biomass from bottom to top of the reactor was observed. 2-
5.8% of purified water was consumed for backwashing operation. The optimal suspended
solids removal occurred at 30°C with 6 m/h velocity. At lower temperature, maximum
suspended solid removal could be obtained. The results indicated that effluent SS could be less
than 30 mg/L, that is secondary treatment effluent standard in Thailand. |
| 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 (EV) |
| Chairperson(s) | Visvanathan, C.; |
| Examination Committee(s) | Chongrak Polprasert;Fujii, Shigeo; |
| Scholarship Donor(s) | Swedish International Development Agency (SIDA); |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1993 |