| Author | Praphon Kemmadamrong |
| Call Number | AIT Diss. no. EV-92-1 |
| Subject(s) | Sewage--Purification--Biological treatment
|
| Note | A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Engineering, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Abstract | Experiments on ABR were conducted to investigate its efficiency on organic
carbon removal. Laboratory scale ABR units, made of PVC with dimensions of 0.25 x 0.15
x 0.32 m3 (width x depth x length), were used to treat the dissolved air flotation pre-treated
slaughterhouse wastewater whose COD concentrations were 480 - 730 mg/L. The steadystate performance was evaluated under organic loading rates (OLR) from 0.67 to 4.73 g
COD/(L.d) and hydraulic retention time (HRT) of 2.5 to 26 h. The ABR was started up at
an OLR of 0.67 g COD/(L.d) and at HRT of 26 h at ambient temperature (30 to 35' C
during day time and 25 to 30' C during night time).
The ABR unit was found to perform satisfactorily when operating from low OLR
of 0.67 g COD/(L.d) up to 4.73 g COD/(L.d) at HRT of 2.5 h, in which the treatment
efficiency of 75% was reached on a total COD basis and of 84% on a filtered COD basis.
Based on COD mass balance in the ABR unit, sludge accumulation factor (Xacc) was in the
range of 0.16 to 0.39 g VSS/g CODrcmovcd• and the conversion of COD removed into
methane was in the range of 0.44 to 0.78 g CH4-COD/g CODrcmovcd· The sludge activities
varied in the range of 0.066 to 0.293 kg CH4-COD/(kg VSS.d). Biagas produced contained
20 to 27% nitrogen, 69 to 73% methane and 2 to 4% carbon dioxide.
Pilot-scale ABR experiments were conducted by using two or three upflow reactors
in series. The results showed that between the OLR of 0.10 - 0.86 g COD/(L.d), the
significant decrease of COD concentration within the first reactor was observed. The COD
removal rates were found to increase from 0.09 to 0.66 g COD/(L.d) with increasing OLR
from 0.10 to 0.86 g COD/(L.d); resulting in an average treatment efficiency of 77 -.86%.
The results obtained from batch tests were used in computer simulation to
determine the constant and reaction orders. The constant C of Compartments 1, 2, 3 and
4 were found to be 3.8x10-
7
, 1.9x10-
5
, 0.586 and 0.522, respectively and the reaction orders
of Compartments 1, 2, 3 and 4 were 3.9, 3.1, 1 and 1, respectively.
The finite difference method of the model coupling mass transfer into a biofloc
with the reaction was applied to simulate the ABR performance. The model simulation of
the laboratory-scale ABR process showed that the observed and predicted effluent dissolved
COD concentrations agreed well between the OLR of 1.82 - 2.14 g COD/(L.d).
(ii)
The overall results obtained from this study have shown that ABR process is
efficient for the treatment of slaughterhouse wastewater and compares favorably with other
anaerobic systems. |
| Year | 1992 |
| Type | Dissertation |
| 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) | Chongrak Polprasert ;Tran, F. T.
|
| Examination Committee(s) | Verink, J. ;Mora, Jean-Claude ;Tyagi, R. D.
|
| Scholarship Donor(s) | Royal Norwegian Government ; |
| Degree | Thesis (Ph.D.) - Asian Institute of Technology, 1992 |