Determination of optimum operating conditions of baffled septic tank systems treating blackwater | |
| Author | Rung Khumkhom |
| Call Number | AIT Thesis no.EV-04-19 |
| Subject(s) | Septic tanks Sewage disposal |
| 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 |
| Series Statement | Thesis ; no. EV-04-19 |
| Abstract | This study was conducted to determine the optimum organic loading rate (OLR) and effects of linear alkyl sulfonate (LAS) in the baffled septic tank systems treating blackwater. For determination of the optimum OLR, four laboratory-scale baffled septic tank units, made of acrylic plastic with dimensions of 0.25x0.4x0.64 m3 (width x height x length), were operated at the OLR of 0.5-1.25 g COD/(L.d). The wastewater was a mixture of septage and domestic wastewater. It was found that the removal efficiencies of baffled septic tank systems in terms of COD, BOD, and TS would increase with the increase of OLR at the magnitudes of greater than 80%, 70%, and 60%, respectively. Because clogging problems have been found in the laboratory-scale units operating at the highest OLR of 1.25 g COD/(L.d), the optimum OLR should be 1 g COD/(L.d). In addition, the investigations of treatment performance indicated that a septic tank with tlu·ee baffles (R.2) was the best as compared to other units. For investigations of the LAS effects, the laboratory-scale units were operated at the OLR of 1 g COD/(L.d) and fed with LAS of 0.5-1.0 g. It was found that the removal efficiencies of septic tank with three baffles (R.2) and septic tank with two baffles and anaerobic media (R.4) in terms of COD, TS, and TSS would have no effect with the increase of LAS loading. A conventional septic tank (R.1) or a septic tank with two baffles (R.3), the removal efficiencies in term of COD, TS, and TSS would increase with the increase of LAS loading, and be greater than 85%, 70%, and 85%, respectively. Based on fluorescence in situ hybridization (FISH) analysis, it was found that the percent of bacterial and archaeal communities of baffled septic tank systems were equal to 22.5% and 5%, respectively, at OLR of 0.5 - 1.25 g COD/(L.d). Both percent of bacterial and archaeal communities would likely increase with the increase of LAS loading. |
| Year | 2004 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. EV-04-19 |
| 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) | Thammarat Koottatep |
| Examination Committee(s) | Satoh, Hiroyasu; Shipin, Oleg V. |
| Scholarship Donor(s) | Royal Thai Government Fellowship |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 2004 |