Hybrid constructed wetlands for phosphorus removal and purifications of eutrophic pond water | |
| Author | Sakkarin Meephon |
| Call Number | AIT Thesis no.EV-17-19 |
| Subject(s) | Constructed wetlands Sewage--Purification--Phosphate removal |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Environmental Engineering and Management |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. EV-17-19 |
| Abstract | In this study examined the material substrates for making newly-invented media in the constructed wetland for removal of P compounds and other micronutrients from eutrophic pond water. This study selected the best media from the chemical compositions and sorption of P capacity by four type of media as well as using Freundlich and Langmuir isotherm in batch experiment. The four type of media were used in research including natural clay, laterite soil, marl and peat to mixing ratio with charcoal and bentonite powder and modified to different four media which were CC, LC, MC and PC media, each type of media made two main sizes were Ø 3 and Ø 1 cm. The results found that P sorption was increased with concentration of P in all media types. The highest sorption of P capacity in the media after studied following order: PC (13,247 mg/kg) > LC (3,013 mg/kg) > MC (2,952 mg/kg) > CC (1,554mg/kg). The removal of P showed PC released P and LC removed P is the best. Therefore, LC was selected to use as media in Hybrid CW. VSSF CW was used in this study and used LC as a media, the present of vegetation was cattail plants (Typha latifolia). The performance of a Hybrid CW for treating eutrophic water was studied in two month experiment under different operational conditions including: Hybrid CW, Unplanted and general CW. This experiment used continuous feeding at different HRT namely, 0.5, 1, and3 day. The average removal efficiencies of TP, BOD, COD, TKN, NO-2-N and NO-3-N were 43.74%, 66.96%, 65.49%, 68.75%, 46.56%, and 49.14%, respectively, for the Hybrid CW compared to 24.50%, 52.44%, 61.63%, 72.50%, 37.15%,and 48.73%, respectively, for the unplanted beds as well as 84.40%, 68.42%, 65.67%, 80.86%, 52.22%, and 59.58%, respectively, for the general CW. The effect of media in Hybrid CW, unplanted and soil in CW were significant for removal of P and other pollutants (p < 0.05). General CWs was the highest pollution removal efficiency than Hybrid CWs and unplanted. The main P removal mechanisms in each system was adsorption from LC media and soil. Furthermore, plant uptake P was low. The other mechanism might be precipitation of P by Fe, Ca, Al and Mg content in LC media and soil. Most of selected parameters from effluent of each operation units and HRT can be reduced to meet the national standard. The first-order complete mix model was used for determination of the first-order rate constant of P removal (k) at the ambient temperature 20 °C. The results were measured k value of each unit operation to be 0.2, 0.1 and 11.0 d-1 of hybrid CW, unplanted and general CW, respectively. |
| Year | 2017 |
| Type | Thesis |
| School | School of Environment, Resources, and Development |
| 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) | Shipin, Oleg V.;Kim, Sohee Minsun; |
| Scholarship Donor(s) | Royal Thai Government;Asian Institute of Technology Fellowship; |
| Degree | Thesis (M.Sc.) - Asian Institute of Technology, 2017 |