Evaluation of factors affecting phosphorus removal in constructed wetlands | |
| Author | Theingi Maw |
| Call Number | AIT Thesis no.EV-96-37 |
| Subject(s) | Sewage--Purification--Phosphate removal Wetland ecology |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering |
| Publisher | Asian Institute of Technology |
| Abstract | This study was conducted to evaluate the performance of free water surface (FWS) constructed wetlands (CW) on phosphorus (P) removal. The experiment employed three lab-scale and one pilot scale CW units which were fed with a weak domestic wastewater. The effects of hydraulic retention time (HRT), influent pH and plant harvesting on the extent of P removal were investigated. It was found that because of adequate P sedimentation and chemical precipitation, about 97 % of P were removed at the 9-d HRT; while at the HRT of 5, 3 and 1 days, the corresponding P removal were 92 %, 80 % and 68 %, respectively. The range of influent pH of about 4 to 9.5 did not produce any significant effect on P removal probably because of the buffering capacity of the wetland bed. The frequency of plant harvesting once in every two weeks did not show significant effect on P removal as compared with the units without plant harvesting; this phenomena was probably due to the short period employed in this study in which the long-term effect of plant uptake of P could not be studied. Based on mass balance analysis in the wetland beds, P was removed 90 % by plant uptake, 0.3 % by accumulation in sand, 3 % by accumulation in gravel, 3 % by accumulation in sludge and 3 % as overflow, when operating at the 9-d HRT. |
| Year | 1996 |
| 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) | Ishibashi, Yoshinobu;Eckhardt, Heinz; |
| Scholarship Donor(s) | Government of Switzerland; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1996 |