Sustainability of constructed wetlands in the treatment of domestic wastewater | |
| Author | Mugambi, Judith Kiende |
| Call Number | AIT Thesis no.ET-SUD-17-02 |
| Subject(s) | Water--Waste--Management Wetlands |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Environmental Engineering and Management with specialization in Environmental Technology and Sustainable Development Jointly offered by the Asian Institute of Technology, Thailand and UNESCO–IHE, Netherlands |
| Publisher | Asian Institute of Technology |
| Abstract | Natural waterways pollution by untreated wastewater is a rising issue especially in developing countries. Large portions of the populations in these countries are not connected to the main sewer lines and the conventional wastewater treatment systems don’t meet the demand or are too costly. Alternative means of efficiently treating wastewater in an environmentally friendly and economical way have been sort over the years. Constructed wetlands (CWs) have been found to be suitable alternatives for wastewater treatment. Questions have been raised however over their sustainability. This research looked into assessing sustainability of a small scale Free Water Constructed Wetland(FWCW) treating domestic wastewater based on treatment efficiency and Green House Gases (GHGs) emissions. The wastewater treatment efficiency in the FWCWs was found to be low contrary to expected, in Total Solids (TS) and Chemical Oxygen Demand (COD) removal. It was however found to be fairly efficient in Total Kjeldahl Nitrogen (TKN) and Total Phosphorus (TP) removal. The results further emphasized the relationship between maintenance of Constructed Wetlands (CWs) and treatment efficiency. The GHGs of focus were CH4& CO2 which were measured using 6 floating gas chambers. The results showed that the CO2 was the dominant gas captured; with only one recording of CH4at a concentration of 228mg/L. Out of the 6 gas chambers installed 2 of them recorded negative CO2-C flux while 1 recorded zero CO2 emissions. The highest CO2 flux emissions recorded was 267 CO2-C mg/m2/h. Treatment process of wastewater by CWs leads to the emission of GHGs however the CO2-C emissions from this Constructed wetland are not significant enough to be a cause of worry, therefore sustainable in this aspect. |
| Year | 2017 |
| 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 | Energy Technology (ET) |
| Chairperson(s) | Annachatre, Ajit P.;Bruggen, Johan J.A. van; |
| Examination Committee(s) | Shrestha, Rajendra Prasad;Nguyen, Kim Thi Oanh; |
| Scholarship Donor(s) | Netherlands Fellowships Programmes (NFP);UNESCO-IHE;Asian Institute of Technology; |
| Degree | Thesis (M.Sc.) - Asian Institute of Technology, 2017 |