Treatment of domestic wastewater by a simulated canal using various aquatic plants : a case study in Vientiane, Laos | |
| Author | Athitaya Changduang |
| Call Number | AIT Thesis no.EV-13-02 |
| Subject(s) | Sewage--Purification--Laos--Vientiane Aquatic plants--Environmental aspects--Laos--Vientiane |
| 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-13-02 |
| 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 constructed wetland units were set up with different aquatic plant types, Pistia stratiotes Eichhornia crassipes, Hydrilla verticillata, Canna indica and constructed wetland unit was set up with combination plant (Canna indica, Ipomoea aquatic, Hydrilla verticillata) 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 units. Pistia stratiotes has the highest COD and BOD removal of approximately 5.6g/m².d (73%) and 1.45 g/m².d (78%). For TKN, Hydrilla verticillata has the highest removal of approximately 0.89 g/m2.d(79%). Canna indica has the highest removal of NH3-N approximately 0.75 g/m2.d. For TP and Ortho-P, Canna indica has the highest removal of approximately 0.04 g/m2.d (63%) and 0.04 g/m².d (62.5%), respectively. Specific removal rates for COD, BOD, TKN, NH4-N, TP and ortho-P for combination plant (Canna indica, Ipomoea aquatic, Hydrilla verticillata) were as follows: 5.13 g/m².d (67%), 1.18 g/m².d (64%), 0.82 g/m².d (72%), 0.73 g/m².d (72%), 0.03 g/m².d (43%), respectively. For study of growth rate of aquatic plants, Pistia stratiotes has the highest biomass growth rate of 3.9 kg/m².month Eichhornia crassipes, Canna indica were about 3.5, 2.3 kg/m², respectively while the Hydilla verticillata has the less growth rate compared to other plants. 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 and Management (EV) |
| Chairperson(s) | Shipin, Oleg V.; |
| Examination Committee(s) | Chongrak Polprasert;Annachhatre, Ajit P.;Lacoursiere, Jean; |
| Scholarship Donor(s) | Royal Thai Government;Asian Institute of Technology Fellowship |
| Degree | Thesis (M.Sc.) - Asian Institute of Technology, 2013 |