| Author | Ganguly, Sudip K. |
| Call Number | AIT Thesis no.EV-93-36 |
| 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 |
| Abstract | This research was done in three separate phases followed by statistical analysis.
In the first phase, WAS was thermochemically pretreated to determine conditions for
optimum solubilization and biodegradability. The optimal dosage of Na OH turned out
to be in the range of 0.4 to 0.5 gNaOH /gVSS and 0.2 to 0.4 gNaOH /gVSS for
solubilization and methanogenesis respectively.
In the second phase of the experiments, investigations related to the inhibitory effects
were carried out using thermal and thermochemical pretreatment at 115°C, l hr. contact
time, and 0.24 gNaOH /gVSS alkali dosage. Reduced methane conversion (20 to 35%)
was observed at and beyond FCOD/MVSSseed = 0.4 both in the case of thermal and
thermochemically pretreated WAS.
Finally, in the third phase Hen Egg Albumin was used to see if, the observed effects of
WAS could be explained from the behaviour of its simpler constituents under identical
pretreatment conditions. Results indicated very high biodegradability (85 % ) of the protein
used. Inhibitory effects on methane conversion were observed both in the case of thermal
(12 to 33%) and thermochemical (18 to 33%) with respect to the control possibly, due
to formation of nonbiodegradable substances at a high pretreatment temperature (115°C)
and also due to the presence of alkali dosage (0.24gNaOH /gVSS) leading to effects
observed in the case of WAS. Statistical analysis confirmed the experimental findings.
Contributory effects due to. FCOD/MVSSseed, Pretreatment Conditions and Time (days)
on methanogenic activity were evaluated using The Three way ANOV A Technique at
three levels of Significance (0.01, 0.04, and 0.001). Analysis revealed appreciably high
reliability of data obtained especially in the case of WAS. The quantitative trends
evaluated using the concept of pure effects due to each of the above explanatory variable
supported the experimental findings. |
| 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) | Fujii, Shigeo; |
| Examination Committee(s) | Samorn Muttamara;Umita, Teruyuki;Tanaka, Shuzo; |
| Scholarship Donor(s) | Government of Japan; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1993 |