| Author | Cerino, Grace F. |
| Call Number | AIT Thesis no. EV-90-19 |
| Subject(s) | Sewage--Purification--Activated sludge process
|
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Abstract | Filamentous bulking is one of the problems in wastewater
treatment that hinders the activated sludge to produce
high quality of eff1uent and thus creating a threat to our
environment. Such phenomenon is due to proliferation of
certain types of filamentous bacteria which are enhanced by
certain set of conditions. To cure this problem is to identify the filamentous bacteria that cause bulking and to
know the condition s t h at has caused their excessive growth.
Th is will give us a n idea on how to control them and inhibit
their growth . Substrate composition a nd feeding pat tern
are two major factors that affect their proliferation and
they are dealt with in this research .
Twelve experiments were undertaken in t his study. In
every experiment, a combination of one carbon source - either
glucose or acetic acid - a nd one nitrogen source - (NH4 ) 2S04 ,
NaN0 3 or peptone, together with other nutrients was used.
Each kind of substrate composition was subjected to two
feeding patterns , namely Continuously Stirred (Fed ) Tank
Reactor (CSTR) system and Sequential Batch Reactor ( SBR )
system.
Sphaerotilus natans has excessively grown in all
substrate composition and has caused filamentous bulking in
CSTR system. It h as appeared in all experiments (both CSTR
a nd SBR ) with NaN03 as the nitrogen source and has caused
bulking more rapidly in acetic acid than in glucose .
Haliscomenobacter hydrossis has appeared in a l l
experiments with (NH4 ) 2 S04 as nitrogen source. I t grew more
in SBR system where growth of Sphaerotilus natans was
suppressed and it was almost absent in CSTR sytem.
Haliscomenobacter h ydrossis did not grow in acetic acid
except only when nitrogen source was ( NH4 ) 2 S011.
Haliscomenobacter hydrossis grew most in glucose-peptone
medium than in any other substrate composition regardless of
the feeding pattern. Its growth was better than Sphaerotilus
natansin this medium.
I n CSTR system, excessive proliferation of filamentous
bacteria was observed. Al t ho ugh Haliscomenobacter hydrossis
was moderate in n umbers and slowly growing , there was no
filamentous bulking in SBR systems. Sphaerotilus natans was
also slowly growing in glucose - NaN03 and glucose - peptone
medium in SBR system.
Th ese two types of filaments were t h e most common
filament in t h e activated sludge that were investigated from
t h e three wastewater treatment p l ants in Thailand . In
addition Type 1702, Noscodia limicola, Type 1701 a nd Type II |
| Year | 1990 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Other Field of Studies (No Department) |
| Academic Program/FoS | Environmental Engineering (EV) |
| Chairperson(s) | Mino, Takashi |
| Examination Committee(s) | Chongrak Polprasert ;Suselo, Tri Binarko ;Harada, Hideki
|
| Scholarship Donor(s) | Canadian International
Development Agency
(CIDA) |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1990 |