| Author | Tanyarut Katekinta |
| Call Number | AIT Thesis no. EV-94-15 |
| Subject(s) | Constructed wetlands
|
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of
Engineering, School of Environment, Resources & Development |
| Publisher | Asian Institute of Technology |
| Abstract | Investigation of free water surface (FWS) constructed wetland performance for
polishing facultative pond effluent was conducted at the Environment Research Station,
AIT. Three laboratory-scale and one pilot-scale FWS constructed wetland units were set
up and cattails (Typha spp.) were planted in their beds. Effluent of a pilot-scale facultative
pond treating AIT wastewater was used as feed. Optimum hydraulic retention time (HRT)
and nitrogen loading rate (NLR) of the wetland units were determined from the
laboratory-scale experiments. In order to validate laboratory-scale data, the pilot-scale
wetland unit was operated at the optimum HRT obtained from the laboratory-scale
experiment.
The experimental results revealed that the FWS wetland systems polishing the pond
effluent operated at the HRT of 3-4 d could achieve more than 90 % removal efficiencies
of COD, SS, TKN, NHrN, N03--N, P, chlorophyll-a, and fecal coliforms. The maximum
TKN and NH3-N removal efficiencies were 95 % at the NLR of 40 kg/(ha-d); the N03--N
removal efficiencies were found to be effective under this operating condition, but
decreased when the NLR were higher than 40 kg/(ha-d).
Mass balance ofN removal in the wetland units was found to be: cattail uptake-46%,
soil accumulation-5%, volatilization-17%, and others (e.g. sedimentation and filtration)-
32%. Mass balance of P removal was: cattail plant uptake-65%, soil accumulation-24%,
and others (e.g. precipitation)-11 %. |
| Year | 1994 |
| 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) | Chongrak Polprasert; |
| Examination Committee(s) | Umita, Teruyuki ;Visvanathan, C.
|
| Scholarship Donor(s) | The Royal Thai Government; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1994 |