| Author | Lee, Heng Keng |
| Call Number | AIT Thesis no.EV-90-5 |
| 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 | Textile wastewater is generally highly alkaline , high in
BOD!! , COD and color. Conventional biological treatment methods
can reduce the biodegradable organics efficiently but poorly for
refractory organics and particularly for color. Tertiary
treatment would normally be required. However the addition of
powdered activated carbon in the aeration basin of the activated
s ludge system proved effective in the removal of refractory
organics and color.
A study on the powdered activated carbon- activated sludge
system revealed that a high l oading rate of 0.92 kg COD/m3 -d can
be applied to the powdered activated carbon unit without
affecting its stability. COD and color removal was better than
that of the control unit. COD removal was 95% and color
reduction was 76% at a carbon dosage of 3 g/L as compared to the
control unit achieving 84% COD removal and 16% color reduction.
The average influent COD was 919 mg/L and color was 44.6 percent
transmittance at 330 nm. BOD!! however showed slight improvement
at 99.4% and 98.6% for the carbon unit and control unit
respectively implying that adsorption was the main mechanism in
increased COD and color reduction. Average influent BODo was 539
mg/L. Variation of sludge age had little effect on COD removal
but color reduction was highest at a sludge age of 10 days.
At the face value cost could be a deterrant in the
utilization of PAC. However taking into account the other
benefits s uch as increased l oad ing rate, better sludge
settleability and reduced aeration foaming, it could be a viable
alternative.
The color of the wastewater after gamma radiation treatment
changed from brown to amber. COD values remain almost the same
as before irradiation. The effluent COD removal of the unit fed
with irradiated wastewater deteriorated but BOD!! removal was
unaffected. |
| Year | 1990 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Other Field of Studies (No Department) |
| Academic Program/FoS | Environmental Engineering and Management (EV) |
| Chairperson(s) | Samorn Muttamara |
| Examination Committee(s) | Verink, Johan ;Mino, Takashi
|
| Scholarship Donor(s) | ASEAN - USAID |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1990 |