Modelling of free-water-surface constructed wetlands for the removal of biodegradable organic matter | |
| Author | Bhurtel, Jugal |
| Call Number | AIT Thesis no. EV-97-10 |
| Subject(s) | Constructed wetlands Water--Purification--Biological treatment |
| Note | A thesis submitted m 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-97-10 |
| Abstract | This study was conducted to determine the performance of free-water-surface (FWS) constructed wetlands located in the tropics in removing the organic matter and to assess the importance of biofilm bacteria in the overall kinetics of organic matter (or chemical oxygen demand, COD) removal. An integrated kinetic model incorporating the activities of the biofilm bacteria, dispersion number, and hydraulic retention time was employed. The model parameters essential for the calculation of COD removal in FWS constructed wetlands were obtained partly from the laboratory experiments and partly from the literature. Batch experiments were conducted to determine the kinetic rate constants for suspended and biofilm biomass, .separately. It was revealed that in a low bulk liquid condition with extensive surface area available through stems, roots, and litter for the biofilm formation, the environment in FWS constructed wetland is more favorable to the attached than to suspended biomass. A study was conducted to determine the dispersion characteristics of the FWS constructed wetlands. The response curves at the wetland outflow were intermediate between well mixed and plug flow, showing large dispersion and asymmetry. The dispersion numbers determined were within the range of0.15 to 0.20 . . The model was validated with the observed data obtained from a pilot-scale constructed wetland unit treating domestic wastewater. The predicted effluent COD values were found in close agreement with the observed effluent values, indicating the applicability of the proposed model in FWS constructed wetland design. |
| Year | 1997 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. EV-97-10 |
| 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) | Chongrak Polprasert; |
| Examination Committee(s) | Annachhatre, Ajit P. ;Nguyen Thi Kim Oanh; |
| Scholarship Donor(s) | The Royal Netherlands Government; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1997 |