Removal kinetics of Bisphenol-A and mass balance analysis in subsurface flow constructed wetlands | |
| Author | Cao Thi Van Hau |
| Call Number | AIT Thesis no.EV-08-5 |
| Subject(s) | Constructed wetlands Bisphenol A |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Environmental Engineering and Management |
| Publisher | Asian Institute of Technology |
| Abstract | Bisphenol A (BPA) has been widely used as a chemical to produce plastics, paints or lacquers, binding and filling-in materials. However, this compound has suspected adverse impacts to the environment and human beings as an endocrine disrupting chemical. In this study, four lab-scale subsurface flow constructed wetlands (SFs) planted with cattails (Typha angustifolia L.) were investigated for their efficiencies to remove BPA in contaminated wastewater with the respect to hydraulic retention times (HRTs) and mechanisms of BPA removal. Under ambient conditions, the optimal HRT for BPA removal by SFs was 5 days with the removal efficiency of about 75%. The SFs also exhibited high removal efficiencies of COD, BOD5 and TKN. The first-order decay constant (k) of BPA at operation temperature and 20°C were 0.38 per day and 0.27 per day, respectively, which were lower than the k value of domestic wastewater of 1.104 per day probably because of some BPA toxic effects. Mass balance analysis revealed BPA degradation to be the major mechanism responsible for 55-70% of removed BPA by the SF units. The remaining BPA was removed by adsorption (1-5%) and plant uptake (1-5%) and the rest overflowed with the SF effluents. The bacteria growing in SF beds, which were quantified by fluorescence in situ hybridization (FISH), were found to play a significant role in BPA degradation, especially in the units operating at HRTs of 5 and 10 days. Bacillus was identified to exist in the unit under HRT of 10 days with the density of 18%. This bacterial strain suggests the favorable environmental conditions in the SF bed treating BPA-contaminated wastewater. |
| Year | 2008 |
| 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) | Annachhatre, Ajit P.;Preeda Pakpian; |
| Scholarship Donor(s) | France;Asian Institute of Technology fellowship; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 2008 |