Monitoring and source apportionment by receptor modeling of particulate matters in Bangkok metropolitan region | |
| Author | Atitaya Sawnsud |
| Call Number | AIT Thesis no.EV-16-02 |
| Subject(s) | Dust control Environmental aspects Air pollution Air--Pollution--Thailand--Bangkok Air quality |
| 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-16-02 |
| Abstract | Particulate matter (PM) is one of the most important air pollutants which have high levels in many urban areas of developing countries including Thailand. This study conducted monitoring for PM at 2 sites in the Bangkok Metropolitan Region (BMR), the Pollution Control Department (PCD) in the city center and at the Asian Institute of Technology (AIT) in the suburban area. The overall the PM mass levels were comparable at both sites. The average concentrations of PM2.5 and PM>2.5 were higher during the dry period, i.e. 32 ± 10 μg/m³ and 56 ± 15 μg/mm³ at AIT, and 31 ± 11 μg/m³ and 53 ± 14 μg/m³ at PCD, than the wet period, i.e. 23 ± 7 μg/m³ and 56 ± 20 μg/m³ at AIT, and 24 ± 4 μg/m³ and 59 ± 21 μg/m³ at PCD. The average EC and OC concentrations, measured by TOR, at AIT in PM2.5 were 4.56 ± 1.60 μg/m³ and 6.70 ± 3.88 μg/m³, respectively, while those in concentration of PM>2.5 was 1.49 ± 0.33 μg/m³ and 2.45 ± 0.45 μg/m³, respectively. The EC and OC concentrations at PCD site were 3.49±1.24 μg/m³ and 5.17±3.04 μg/m³, respectively, and EC/OC in coarse particle at PCD were 1.31±0.34 μg/m³ and 2.23±0.59 μg/m³, respectively. The BC measured by optical method for quartz filters were comparable to EC by TOR. In PM2.5 at both sites, the most dominant anion specie was SO42, higher at PCD than AIT, while the most dominant cation was NH4+, also higher at PCD than AIT. In the coarse fraction, NO3- was the largest anion, higher at PCD than AIT, while Ca2+ was the largest cation but higher at AIT than PCD. The reconstructed mass results of PM2.5 show that the major mass groups at both sites were OM-biomass which accounted for 32% at PCD, and 33% at AIT, followed by the secondary inorganic aerosol and soot. The percentage of mass explained for PM2.5 was high, i.e. 71% (dry) and 64% (wet) at AIT and 77% (dry) and 81% (wet) at PCD. However, the percentage of mass explained for PM>2.5 at both sites was low, below 25% at both sites, which may be due to lack of the elemental data. The CMB receptor modeling results showed that in AIT, the most important contributor to PM2.5 in wet period was traffic (diesel) of 26%, secondary sulfate (22%) and biomass burning(19%). In the dry period the biomass had the highest contribution (41%) followed by traffic (38%), soil (18%) and (NH4)2SO4 (13%). Other sources had only minor contributions. At PCD, the most important contributor to PM2.5 in wet period was secondary sulfate (31%), traffic diesel (23%) and biomass burning (20%). In the dry period the biomass had the highest contribution (36%) followed by traffic (32%), (NH4)2SO4 (16%) and soil (13%). Lack of source profiles for the coarse fractions prevented from CMB analysis for PM>2.5. The HYSPLIT back trajectory was applied to assess the potential of long range transport of air pollutants to the sites. The results showed that on the weeks with high PM2.5 at both sites the air mass trajectories had a longer pathway over the continental areas and also with slow movement indicating stagnant conditions. On the weeks with lower PM2.5, the air mass mainly originated from the ocean and had a longer marine pathway. Further studies are required to cover longer sampling period and produce more samples for statistical receptor models such as Positive Matrix Factorization (PMF). The source contributions to PM pollution at BMR would be a useful input for policy making to reduce the levels of this important air pollutant. |
| 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 (EV) |
| Chairperson(s) | Nguyen, Thi Kim Oanh; |
| Examination Committee(s) | Visvanathan, C. ;Permadi, Didin Agustian;Sato, Keiichi; |
| Scholarship Donor(s) | Royal Thai Government;Asian Institute of Technology Fellowship; |
| Degree | Thesis (M.Sc.) - Asian Institute of Technology, 2016 |