Simultaneous measurements of ionic composition of rain water and ambient concentration of acid gases to assess acid deposition in Bangkok metropolitan region | |
| Author | Malulee Leamlaem |
| Call Number | AIT Thesis no.EV-16-09 |
| Subject(s) | Ionic equilibrium Environmental aspects. Environmental--Pollution. Air--Pollution--Thailand--Bangkok Acid deposition--Thailand--Bangkok |
| 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-16-09 |
| Abstract | This study characterized the ionic components of rainwater and ambient concentrations of acid gases to assess acid deposition at two sites in the Bangkok Metropolitan Region (BMR), AIT (Pathumthani) and PCD (Bangkok). The weekly samples of rainwater was done using automatic wet-only collectors while acid gases by filter pack method overt the period from September 2015 to February 2016 (26 weeks). The pH value of rainwater at AIT and PCD were 5.80±0.42 and 5.66±0.50, respectively. The average electrical conductivity of rainwater at AIT and PCD were 1.57±0.82 and 1.99±1.19 mS/m, respectively. The ionic species concentration (μeq/L) in rain water at both sites was ranked in the following order: NH4+> Ca2+> NO3-> SO42-> Cl-> Na+> Mg2+> K+. The total wet deposition fluxes for the species were followed the concentration rank. The deposition fluxes over 6 months for the listed species at AIT were 16.8, 19.2, 9.06, 8.75, 5.51, 2.77, 3.24 and 1.50 mEq/m²-month, respectively. The corresponding wet deposition at PCD over the six months was 24.1, 16.9, 12.1, 21.1, 3.85, 3.50, 0.93, 1.85 and 0.78 mEq/m²-month, respectively. The levels of the acidic gases (SO₂, HNO3, NH3, HCl) were found higher at PCD than AIT site. In general, higher levels were found in the dry sampling period than the wet period. However, SO₂ at AIT was slightly higher during the wet period which may be due to some local activity around the site. The average deposition velocity of the acidic gases was calculated using the resistance model. The highest velocity was obtained for the tree covered area (which was categorized as forest in the model output) than other surface types at both sites. The dry deposition velocity over tree cover for SO₂ was 0.80±0.30 m/s at AIT and 1.79±0.38 m/s at PCD, that of HNO3 was 2.54±0.45 at m/s AIT and 7.59±1.92 m/s at PCD. However, the dry velocity for NH3over the water surface at PCD (0.55±0.14 m/s) was slightly higher than that over the tree covered area (0.53±0.09m/s) but the large variation ranges indicate that the values overlap. The dry deposition flux of the acidic gases at both sites was different due to difference in the concentrations and also the surface. The total dry deposition flux of NH3was the largest among considered species at AIT (23.5 mmol/m²-month)while at PCD the flux for HNO3 was the highest of 71.0 mmol/m²-month. The total deposition of S (dry and wet deposition) over the six months was estimated at 222 kg/km² at AIT and 294kg/km² at PCD. The total deposition of N species in this study (sum of N in NO3-and N in NH4+) at AIT and PCD was estimated at 863 and 1,555 kg/km², respectively. Further studies should quantify the deposition associated NO₂. The deposition fluxes can be used to assess the potential effects on the environment and ecosystem in BMR. |
| Year | 2016 |
| 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) | Nguyen, Thi Kim Oanh; |
| Examination Committee(s) | Thammarat Koottatep;Permadi, Didin A.;Huo, Mingqun; |
| Scholarship Donor(s) | Royal Thai Government;Asian Institute of Technology Fellowship; |
| Degree | Thesis (M.Sc.) - Asian Institute of Technology, 2016 |