Removal of linear alkylbenzene sulfonate (LAS) from greywater by using constructed wetlands | |
| Author | Huynh Thi Cam Hong |
| Call Number | AIT Thesis no.EV-08-12 |
| Subject(s) | Constructed wetlands Alkyl benzene sulphonates |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Environmental Engineering and Management |
| Publisher | Asian Institute of Technology |
| Abstract | Constructed wetland (CW) is an attractive wastewater treatment system which capable of treating greywater containing Linear Alkylbenzene Sulfonate (LAS), but, its removal mechanisms are complicated and not well understood. The aim of this study was to determine the influence of water level (WL), hydraulic loading rate (HLR) and N variation on LAS removal in laboratory scale vertical flow CW units, treating on synthetic greywater. Four laboratory-scale vertical-flow CW units were setup with different layer thickness of sand (0.13 m), small gravel (0.15 m), large grave (0.3 m) and hollow concrete (0.05 m) from top to bottom. Two of them were planted with Cattails (Typha Angustifolia) (CW-C1 and CW-C2) and others were planted with Umbrella plants (Cyperus Alternifolius) (CW-U3 and CW-U4). Each two lab-scale which are different the plants (Cattails and Umbrella plants) were operated with the same conditions. There were 5 operating conditions in which variable of HLR (10-30cm/d), WL (0.3-0.5m) and N concentration (5-20mg/L) were changed. In this study, LAS removal efficiencies were found highest (97.1% in CW-C2 and 96.8% in CW-U4) at lower HLR of 10 cm/d with lower water level of 0.64 m (0.5m from top). In average, the CW system could reach LAS and COD treatment efficiencies of 82–98% and 78–93% respectively. Furthermore, at influent nitrogen concentration of 10 mg/L was obtained suitable for achieving the high removal efficiency. LAS removal is also harnessed with the SO42- concentrations and the maximum SO42- concentration was obtained with HLR of 10 cm/d as a result of high degradation of LAS. With regard to the wetland plants, the research demonstrated that both plants (cattails and Umbrella) are suitable as CW vegetation in treating greywater. No significant difference was observed on treatment performances between the two plants, but cattails showed signs of stress at low nitrogen concentrations. |
| Year | 2008 |
| 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) | Thammarat Koottatep; |
| Examination Committee(s) | Annachhatre, Ajit P.;Shipin, Oleg V.;Morel, Antoine |
| Scholarship Donor(s) | Ministry of Education Training (MOET),Vietnam; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 2008 |