Treatment of municipal wastewater in a surface flow wetland using selected aquatic plant species : a case study in Vientiane, Laos | |
| Author | Siwat Somboondamrongkul |
| Call Number | AIT Thesis no.EV-13-26 |
| Subject(s) | Sewage disposal plants--Laos--Vientiane Surface impoundments--Laos--Vientiane Aquatic plants--Laos--Vientiane |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering Environmental Engineering and Management |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. EV-13-26 |
| Abstract | This study was conducted to investigate efficiency of the treatment of simulated urban canal wastewater by a free water surface flow wetland based on free floating, submerged and emergent plant species with a view to using plant biomass for biogas-energy conversion and for evaluation of public perception and acceptance of the canal-based wastewater treatment system in Vientiane, Laos. Four pilot-scale constructed wetland units were set up with different aquatic plant types, namely, morning glory, or water spinach (Ipomoea aquatic), pennywort (Hydrocotyle umbellata), cabomba (Cabomba caroliniana), cattail (Typha latifolia) and constructed wetland unit was set up with combination plant (Hydrocotyle umbellate and Typha latifolia). The constructed wetland units at AIT were operated with HRT of 5 days. The maximum COD, BOD5, TKN and NH3-N removal occurred in the constructed wetland unit with pennywort at 5.4 g/m².d (removal of 58%), 1.4 g/m².d (59%), 0.68 g/m².d (45%) and 0.62 g/m².d (47%), respectively. Cabomba has shown the highest removal of TP and ortho-P of approximately 0.071 g/m².d (61%) and 0.064 g/m².d (61%), respectively. In addition, specific removal rates for COD, BOD, TKN, NH4-N, TP and ortho-P for combination plants (cattail and pennywort) were found to be4.75 g/m².d (removal of 50%), 1.15 g/m².d (52%), 0.58 g/m².d (39%), 0.50g/m².d (40%), 0.06 g/m².d (53%), 0.06g/m².d (52%), respectively. Study of growth rate of aquatic plants has shown that pennywort had the highest biomass growth rate of 39.2 g/m².d, while cattail, cabomba, and morning glory were some what lower 34.7, 23.3 and 21.4 g/m²*d respectively. Study of public perception and local acceptance of the canal wastewater treatment by using aquatic plants treating wastewater has shown that people of local community around the canal discharged wastewater into the canal causing problems such as malodor and breeding mosquitos. These two were cited by respondents as the main problems in the canal treatment. The main purposes for using the wetland canals as judged by local respondents were found to be agriculture and household. The best aquatic plants were selected by respondents to be used in wetland canal for improvement of water quality, landscaping and edibility, these were morning glory, pennywort and canna. Aquatic plants were chosen to be promoted for the use in canals for CITYBLUES++ concept in Vientiane were Ipomoea aquatic, Hydrocotyle umbellate, Canna indica and Hydrilla verticillata. |
| Year | 2013 |
| 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 (EV) |
| Chairperson(s) | Shipin, Oleg V.; |
| Examination Committee(s) | Nguyen, Thi Kim Oanh;Thammarat Koottatep;Lacoursiere, Jean; |
| Scholarship Donor(s) | Royal Thai Government;Asian Institute of Technology Fellowship; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 2013 |